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BACKGROUND: The ratio of ucGMP (urinary cyclic guanosine monophosphate) to BNP (B-type natriuretic peptide) is thought to reflect the responsiveness of tissues to natriuretic peptides. METHODS: We examined the relationship between ucGMP/BNP ratio and clinical outcomes, the effect of sacubitril/valsartan, compared with enalapril, on the ucGMP/BNP ratio, and the efficacy of sacubitril/valsartan on clinical outcomes according to baseline ucGMP/BNP ratio in PARADIGM-HF trial (Prospective Comparison of ARNI With ACEI to Determine Impact on Global Mortality and Morbidity in Heart Failure). ucGMP/BNP ratio was available at baseline (N=2031), 1 month (N=1959), and 8 months after randomization (N=1746). The primary outcome was a composite of heart failure hospitalization or cardiovascular death. RESULTS: Compared with the lowest tertile of baseline ucGMP/BNP ratio, patients in the higher tertiles had a lower risk of the primary outcome (tertile 1, reference; tertile 2, hazard ratio 0.57 [95% CI, 0.45–0.71]; tertile 3, hazard ratio, 0.54 [0.43–0.67]). Compared with baseline, the ucGMP/BNP ratio at 1 month and 8 months after randomization was higher with sacubitril/valsartan than with enalapril: ratio of geometric mean ratios at 1 month, 1.38 (95% CI, 1.27–1.51) and 8 months, 1.32 (95% CI, 1.20–1.45), and this difference was consistent across tertiles of ucGMP/BNP ratio at baseline ( P interaction =0.19 and 0.91, respectively). The effect of sacubitril/valsartan, compared with enalapril, was consistent across tertiles of ucGMP/BNP ratio at baseline for all outcomes ( P interaction ≥0.31). CONCLUSIONS: In patients with heart failure and reduced ejection fraction, higher ucGMP/BNP ratio was associated with better outcomes. Sacubitril/valsartan increased the ucGMP/BNP ratio, compared with enalapril, and the effect of sacubitril/valsartan on clinical outcomes was not modified by baseline ucGMP/BNP ratio. REGISTRATION: URL: https://www.clinicaltrials.gov ; Unique Identifier: NCT01035255.

Background: Left ventricular pressure overload (LVPO) can develop from antecedent conditions, like aortic stenosis, and is associated with increased myocardial collagen content that can lead to increases in myocardial stiffness. Alleviation of LVPO in patients undergoing surgical aortic valve replacement (SAVR) resulted in reduced but persistent fibrosis evident in biopsies taken 5-yrs following SAVR. Little is known regarding cellular mechanisms that contribute to ECM turnover following hemodynamic unloading. Objective: Determine the time course of ECM remodeling after alleviation of LVPO. Methods: Transverse aortic constriction (TAC) was used to induce LVPO. Following 4wks of TAC, alleviation of LVPO was performed by removing the TAC band (unTAC). Five time points were assessed: Control no TAC, 4wk TAC, 4wk TAC+2wk unTAC, 4wk TAC+4wk unTAC, and 4wk TAC+6wk unTAC for cardiomyocyte cross-sectional area (CSA), collagen volume fraction (CVF), collagen degradation, and myocardial stiffness. Results: CSA increased by 47% at 4wk TAC vs control. Compared to 4wk TAC, CSA decreased by 20% at 2wk unTAC, but returned to control levels by 6wk unTAC. CVF increased by 204% at 4wk TAC vs control. Although CVF was similar between 4wk TAC and 2wk unTAC, 2wk unTAC demonstrated robust increases in markers of collagen degradation (cathepsin K, pro-matrix metalloproteinase 2 (pro-MMP2), MMP3, and MMP8). CVF significantly decreased at 4wk unTAC compared to 2wk unTAC. However, the markers of collagen degradation were reduced by 4wk- and 6wk unTAC likely contributing to persistent fibrosis. Furthermore, passive stiffness remained elevated at 6wk unTAC. Conclusion: In LVPO hearts, hypertrophy and fibrosis were present. Although cardiomyocyte hypertrophy fully regressed with normalization of hemodynamic load, increased myocardial stiffness and elevated interstitial fibrosis were persistent.

Background: While disease-modifying therapies exist for heart failure (HF) with reduced left ventricular ejection fraction (LVEF), few options are available for patients in the higher range of LVEF (>40%). Sacubitril/valsartan has been compared with a renin-angiotensin-aldosterone–system inhibitor alone in 2 similarly designed clinical trials of patients with reduced and preserved LVEF, permitting examination of its effects across the full spectrum of LVEF. Methods: We combined data from PARADIGM-HF (LVEF eligibility≤40%; n=8399) and PARAGON-HF (LVEF eligibility≥45%; n=4796) in a prespecified pooled analysis. We divided randomized patients into LVEF categories: ≤22.5% (n=1269), >22.5% to 32.5% (n=3987), >32.5% to 42.5% (n=3143), > 42.5% to 52.5% (n=1427), > 52.5% to 62.5% (n=2166), and >62.5% (n=1202). We assessed time to first cardiovascular death and HF hospitalization, its components, and total heart failure hospitlizations, all-cause mortality, and noncardiovascular mortality. Incidence rates and treatment effects were examined across categories of LVEF. Results: Among 13 195 randomized patients, we observed lower rates of cardiovascular death and HF hospitalization, but similar rates of noncardiovascular death, among patients in the highest versus the lowest groups. Overall sacubitril/valsartan was superior to renin-angiotensin-aldosterone–system inhibition for first cardiovascular death or heart failure hospitalization (Hazard Ratio [HR] 0.84 [95% CI, 0.78–0.90]), cardiovascular death (HR 0.84 [95% CI, 0.76–0.92]), heart failure hospitalization (HR 0.84 [95% CI, 0.77–0.91]), and all-cause mortality (HR 0.88 [95% CI, 0.81–0.96]). The effect of sacubitril/valsartan was modified by LVEF (treatment-by-continuous LVEF interaction P =0.02), and benefit appeared to be present for individuals with EF primarily below the normal range, although the treatment benefit for cardiovascular death diminished at a lower ejection fraction. We observed effect modification by LVEF on the efficacy of sacubitril/valsartan in both men and women with respect to composite total HF hospitalizations and cardiovascular death, although women derived benefit to higher ejection fractions. Conclusions: The therapeutic effects of sacubitril/valsartan, compared with a renin-angiotensin-aldosterone–system inhibitor alone, vary by LVEF with treatment benefits, particularly for heart failure hospitalization, that appear to extend to patients with heart failure and mildly reduced ejection fraction. These therapeutic benefits appeared to extend to a higher LVEF range in women compared with men. Clinical Trial Registration: https://www.clinicaltrials.gov . Unique identifiers: NCT01920711 (PARAGON-HF), NCT01035255 (PARADIGM-HF).

Background Heart failure phenotyping in single‐ventricle Fontan patients is challenging, particularly in patients with normal ejection fraction (EF). The objective of this study was to identify Fontan patients with abnormal diastolic function, who are high risk for heart failure with preserved ejection fraction (HFpEF), and characterize their cardiac mechanics, exercise function, and functional health status. Methods and Results Data were obtained from the Pediatric Heart Network Fontan Cross‐sectional Study database. EF was considered abnormal if 90th percentile (≥0.26 mL ‐1 ). Patients were divided into: controls=normal EF and diastolic function; systolic dysfunction (SD) = abnormal EF with normal diastolic function; diastolic dysfunction (DD) = normal EF with abnormal diastolic pressure:volume quotient. Exercise function was quantified as percent predicted peak VO 2 . Physical Functioning Summary Score (FSS) was reported from the Child Health Questionnaire. A total of 239 patients were included, 177 (74%) control, 36 (15%) SD, and 26 (11%) DD. Median age was 12.2 (5.4) years. Arterial elastance, a measure of arterial stiffness, was higher in DD (3.6±1.1 mm Hg/mL) compared with controls (2.5±0.8 mm Hg/mL), P 2 compared with controls (52% [20] versus 67% [23], P P Conclusions Fontan patients with abnormal diastolic function and normal EF have decreased exercise tolerance, decreased functional health status, and elevated arterial stiffness. Identification of patients at high risk for HFpEF is feasible and should be considered when evaluating Fontan patients.

Background: Antecedent conditions, like aortic stenosis, can induce left ventricular pressure overload (LVPO), that can lead to Heart Failure with Preserved Ejection Fraction (HFpEF). Myocardial fibrosis and stiffness are key characteristics of HFpEF. Cardiac fibroblasts are the primary cell type regulating ECM production and deposition. In previous studies, biopsies isolated at the time of SAVR surgery, to correct stenosis, and then at 1-year and 5-years post-SAVR showed reductions in hypertrophy and fibrosis demonstrating these processes can regress. However, cellular mechanisms, including fibroblast activity, are poorly defined. Objective: Define mechanisms that contribute to remodeling of ECM before and after LVPO. Methods: LVPO was induced using transverse aortic constriction (TAC). LVPO was relieved by removal of the band (unTAC) at 4 wks. Cardiomyocyte cross-sectional area (CSA), collagen volume fraction (CVF), and protein production was measured by histology and immunoblot for five time points: nonTAC, 2wk TAC, 4wk TAC, 4wk TAC+2wk unTAC, and 4wk TAC+4wk unTAC. Results: In response to LVPO, myocyte CSA increased by 23% at 2wk TAC and by 47% at 4wk. CVF increased by 64% and 204% at 2wk and 4wk TAC, respectively, versus nonTAC. In 2wk TAC hearts, SMA, a marker of fibroblast activation was increased as was production of two collagen cross-linking enzymes, lysyl oxidase (LOX) and LOXL2, in the absence of significant increases in markers of ECM degradation. After unloading, myocyte CSA decreased by 20% in 2wk unTAC versus 4wk TAC and CVF decreased by 38% in 4wk unTAC versus 4wk TAC. Coincident with decreases in CVF, levels of pro-MMP2 increased at 2wk unTAC as did levels of degraded collagen measured by collagen hybridizing peptide reactivity. Whereas markers of ECM deposition, LOX and LOXL2, were not increased in unTAC myocardium, a resurgence of SMA production occurred in 2wk unTAC. Conclusions: In LVPO hearts, hypertrophy was characterized by increases in myocyte CSA, greater CVF, and fibroblast activation with increased production of pro-fibrotic ECM. After unloading, hypertrophy and fibrosis significantly decreased accompanied by increases in ECM degrading activity and reductions in proteins that contribute to collagen assembly.

Background The hemodynamic effects of cardiac resynchronization therapy in patients with left ventricular assist devices (LVADs) are uncharacterized. We aimed to quantify the hemodynamic effects of different ventricular pacing configurations in patients with LVADs, focusing on short‐term changes in load‐independent right ventricular (RV) contractility. Methods and Results Patients with LVADs underwent right heart catheterization during spontaneous respiration without sedation and with pressures recorded at end expiration. Right heart catheterization was performed at different pacemaker configurations (biventricular pacing, left ventricular pacing, RV pacing, and unpaced conduction) in a randomly generated sequence with >3 minutes between configuration change and hemodynamic assessment. The right heart catheterization operator was blinded to the sequence. RV maximal change in pressure over time normalized to instantaneous pressure was calculated from digitized hemodynamic waveforms, consistent with a previously validated protocol. Fifteen patients with LVADs who were in sinus rhythm were included. Load‐independent RV contractility, as assessed by RV maximal change in pressure over time normalized to instantaneous pressure, was higher in biventricular pacing compared with unpaced conduction (15.7±7.6 versus 11.0±4.0 s −1 ; P =0.003). Thermodilution cardiac output was higher in biventricular pacing compared with unpaced conduction (4.48±0.7 versus 4.38±0.8 L/min; P =0.05). There were no significant differences in heart rate, ventricular filling pressures, or atrioventricular valvular regurgitation across all pacing configurations. Conclusions Biventricular pacing acutely improves load‐independent RV contractility in patients with LVADs. Even in these patients with mechanical left ventricular unloading via LVAD who were relative pacing nonresponders (required LVAD support despite cardiac resynchronization therapy), biventricular pacing was acutely beneficial to RV contractility.

Introduction: Patients with heart failure and a preserved ejection fraction (HFpEF) present heart function abnormalities that remain poorly understood. Defining proteomic signature of HF that is independent of left ventricular hypertrophy (LVH) should allow for stratification of its subtypes and potential mechanism that contributes to the disease. Hypothesis: We hypothesized that HFpEF proteomic signature would be comprised of the hypertrophy and contractile protein phenotype. Methods: Intraoperative left ventricular (LV) myocardial biopsies were obtained from patients (n=21) recruited to undergo coronary artery bypass grafting (CABG). Patients were categorized to: control non-hypertensive (n=9), LVH (n=5), and HFpEF (n=7). Myocardial tissue was subfractionated: cytoplasmic- (neutral pH), myofilament- (acidic pH), and membrane-enriched extract (SDS-soluble). All fractions were assessed for protein quantity and Lys/Arg modifications using liquid chromatography mass spectrometry (LC-MS). Results: In HFpEF, 13% of the cardiac LV proteome changed compared to control heart, with a substantial proportion (77%) decreasing in quantity across all three cardiac fractions, while with LVH, 61% of the proteomic LV changes were increased. Although glycolysis and gluconeogenesis increased in both cardiopathies with respect to control, in HFpEF more subtly than in LVH. Modified proteome of the HFpEF was dominated by decreases in protein succinylation (e.g. ATP5L, THIM, IDHP, APOB, GSH1, KNTC1) and to a lesser degree in methylation (ROA3, HSP7C) or acetylation compared to control. This general trend of down-regulation of succinylation can be attributed to depletion in the levels of succinyl-CoA, the cofactor of enzymatic Lys succinylation. Importantly, there was a striking discordant activation/inhibition of cell death and proliferation pathways between the HFpEF and LVH. Two major upstream regulator clusters linked the proteome changes in cell growth and proliferation to RICTOR and Myc that showed completely opposite trends in LVH and HFpEF groups. Conclusions: HFpEF has a unique proteome signature compared to LV hypertrophy profile which does not arise from sub-proteome involved in contraction but rather is involved in overall cell death.

Introduction: In patients with heart failure (HF), worsening of HF signs and symptoms is associated with increased cardiovascular (CV) risk. Differences in burden of HF signs and symptoms and their prognostic value in HF with preserved (HFpEF) versus reduced ejection fraction (HFrEF) are poorly understood. Hypothesis: High burden of HF signs and symptoms is associated with adverse CV events, and is of greater prognostic value in patients with HFrEF. Methods: Using combined data from PARADIGM-HF (LVEF eligibility ≤40%) and PARAGON-HF (LVEF eligibility ≥45%), Cox models were fit to assess the relationship between burden of HF signs and symptoms (≤2 or ≥3) and first HHF or CV death in patients with HFrEF (n=8385) and HFpEF (n=4709) with available signs and symptoms at screening (rest dyspnea, exertional dyspnea, paroxysmal nocturnal dyspnea, orthopnea, fatigue, edema, jugular venous distension, rales, third heart sound). Results: High burden of HF signs and symptoms (≥3) was more common among patients with HFpEF (48%) than HFrEF (42%, pinteraction = 0.03) (Figure). Conclusion: Patients with HFpEF have slightly higher burden of HF signs and symptoms than those with HFrEF. High burden of HF signs and symptoms identifies patients at high risk foradverse CV events, and may have greater prognostic importance in patients with HFrEF than HFpEF.

Background: Little is known about the prognostic significance of chronic obstructive pulmonary disease (COPD) in patients with heart failure and preserved ejection fraction (HFpEF). Purpose: To evaluate the association between COPD and outcomes in the Prospective Comparison of ARNI and ARB Global Outcomes in HFpEF trial (PARAGON-HF). Methods: We assessed the relationship between the presence of COPD and the composite of time to first heart failure hospitalization or CV death, components of that composite, and all-cause death in PARAGON-HF using Cox proportional hazard models. Outcomes were adjusted for other prognostic variables including age, sex, comorbidities, LVEF, NT-proBNP and NYHA class. Results: Among 4791 participants, 670 patients (14%) had COPD. Patients with COPD were older, less likely to be female, had a worse functional class, lower LVEF, higher creatinine and markers of systemic inflammation, including neutrophil count and neutrophil/lymphocyte ratio. Compared to patients without COPD, those with COPD had a lower baseline KCCQ-CSS and were more likely to experience a clinically significant decrease in KCCQ-CSS during follow-up. COPD was associated with higher adjusted risks of the composite outcome (hazard ratio 1.50, 95%CI 1.29-1.75), heart failure hospitalization (1.54, 1.30-1.83), CV death (1.42, 1.10-1.82) and all-cause death (1.52, 1.25-1.84), all p Conclusion: In HFpEF, patients with COPD have worse functional class, quality of life and outcomes than those without COPD, and COPD is associated with a higher risk of death than other comorbidities

Background: Obesity is associated with incident heart failure (HF), particularly HF with preserved ejection fraction (HFpEF). Weight loss is difficult to achieve in patients with limited physical capacity and the benefits remain uncertain in established HF. Methods: Patients with EF > 50% and at least 1 objective criteria for HFpEF (BNP 200 pg/ml, elevated resting or exercise wedge pressure (15 or 25 mmHg) or pulmonary edema on CXR) and BMI 30 kg/m2 were enrolled in a 15-week weight management program that entailed weekly counseling, weight checks, and meal replacement (twice daily weeks 1-8, once daily weeks 9-12). Primary endpoints were change from baseline to 15-weeks for weight, Minnesota Living With HF (MLWHF) score and 6 minute walk (6MW). Paired t-test was used to test for differences from baseline to the 15 week clinical endpoint, and one-way ANOVA was used to evaluate if these differences persisted at 26 week follow up. Results: 65 patients signed consent, 41 completed the 15-week program and 37 had 26-week follow up. Mean age was 67±9 years, BMI 41±6 kg/m 2 , 65% were female, and 43% black. Mean weight decreased by 8.1±6.6 kg at the 15-week endpoint (p Conclusions: Clinically relevant weight loss is possible in patients with established HFpEF and when it occurs, this is associated with significant improvements in quality of life and exercise capacity. There may be racial differences in the biochemical response to weight management in this population.

Background NT-proBNP (N-terminal pro-B-type natriuretic peptide) is useful in diagnosis and prognostication in heart failure (HF). We examined the relationship between NT-proBNP and outcomes in patients with HF and preserved ejection fraction, with and without atrial fibrillation (AF). Methods and Results Among 3835 HF with preserved ejection fraction patients enrolled in the I-Preserve (Irbesartan in Heart Failure With Preserved Systolic Function trial) or TOPCAT trial (Treatment of Preserved Cardiac Function in Heart Failure With an Aldosterone Antagonist), 719 (19%) patients had AF on their baseline ECG. Median (Q1–Q3) levels of NT-proBNP were 1286 pg/mL (778–2072) in those with AF and 288 pg/mL (122–704) in those without ( P Conclusions Event rates in HF with preserved ejection fraction patients without AF and with NT-proBNP Clinical Trial Registration URL: https://www.clinicaltrials.gov . Unique identifiers: NCT00094302 and NCT00095238.

Background— Many episodes of worsening of heart failure (HF) are treated by increasing oral therapy or temporary intravenous treatment in the community or emergency department (ED), without hospital admission. We studied the frequency and prognostic importance of these episodes of worsening in the Prospective Comparison of ARNI (angiotensin-receptor-neprilysin inhibitor) with ACEI (angiotensin-converting enzyme inhibitor) to Determine Impact on Global Mortality and Morbidity in Heart Failure Trial (PARADIGM-HF). Methods and Results— Outpatient intensification of HF therapy was added to an expanded composite outcome with ED visits, HF hospitalizations, and cardiovascular deaths. In an examination of first nonfatal events, 361 of 8399 patients (4.3%) had outpatient intensification of HF therapy without a subsequent event (ie, ED visit/HF hospitalizations) within 30 days; 78 of 8399 (1.0%) had an ED visit without previous outpatient intensification of HF therapy or a subsequent event within 30 days; and 1107 of 8399 (13.2%) had HF hospitalizations without a preceding event. The risk of death (in comparison with no-event patients) was similar after each manifestation of worsening: outpatient intensification of HF therapy (hazard ratio, 4.8; 95% confidence interval, 3.9–5.9); ED visit (hazard ratio, 4.5; 95% confidence interval, 3.0–6.7); HF hospitalizations (hazard ratio, 5.9; 95% confidence interval, 5.2–6.6). The expanded composite added 14% more events and shortened time to accrual of a fixed number of events. The benefit of sacubitril/valsartan over enalapril was similar to the primary outcome for the expanded composite (hazard ratio, 0.79; 95% confidence interval, 0.73–0.86) and was consistent across the components of the latter. Conclusions— Focusing only on HF hospitalizations underestimates the frequency of worsening and the serious implications of all manifestations of worsening. For clinical trials conducted in an era of heightened efforts to avoid HF hospitalizations, inclusion of episodes of outpatient treatment intensification (and ED visits) in a composite outcome adds an important number of events and shortens the time taken to accrue a target number of end points in an event-driven trial. Clinical Trial Registration— URL: http://www.clinicaltrials.gov . Unique identifier: NCT01035255.

Background: Soluble ST2 (sST2) is associated with cardiac remodeling and fibrosis. In chronic heart failure, the predictive value of sST2 has not been evaluated in a model that includes both NT-proBNP (N-terminal pro-B-type natriuretic peptide) and hs-TnT (high-sensitivity cardiac troponin T), in a trial in which treatment had a major impact. Therefore, the effects of treatment on sST2 levels in PARADIGM-HF trial (Prospective Comparison of ARNI With ACEI to Determine Impact on Global Mortality and Morbidity in Heart Failure), the relationships between sST2 and outcomes, and the prognostic utility of various sST2 partition values were examined. Methods and Results: Baseline (n=2002), 1-month (n=1936), and 8-month postrandomization (n=1758) sST2 levels were compared between treatment groups (sacubitril/valsartan versus enalapril). Relationships between baseline sST2 and (1) heart failure hospitalization, (2) cardiovascular death, and (3) combined heart failure hospitalization and cardiovascular death were assessed using restricted cubic spline models. Adjusted Cox proportional hazards models were used to examine the impact of sST2 change from baseline to 1 month on the hazard of experiencing each outcome. Sacubitril/valsartan led to more reductions and fewer increases in sST2 levels versus enalapril. After adjusting for other predictors, including NT-proBNP and hs-TnT, baseline sST2 remained an independent predictor of outcomes. Associations between baseline sST2 and outcomes were linear. sST2 increases at 1 month were associated with worse subsequent outcomes and decreased with better outcomes ( P =0.001, 0.012, and 0.009 for the 3 outcomes, respectively). Conclusions: Sacubitril/valsartan resulted in greater reductions and less increases in sST2 levels than enalapril. No specific threshold was associated with risk, as linear relationships between baseline sST2 and outcomes were observed. Changes in sST2 from baseline to 1 month were independently associated with the risk of outcomes. Clinical Trial Registration : URL: https://www.clinicaltrials.gov . Unique identifier: NCT01035255.

Background— MicroRNAs (miRNAs) and histone deacetylases (HDACs) serve a significant role in the pathogenesis of a variety of cardiovascular diseases. The transcriptional regulation of miRNAs is poorly understood in cardiac hypertrophy. We investigated whether the expression of miR-133a is epigenetically regulated by class I and IIb HDACs during hypertrophic remodeling. Methods and Results— Transverse aortic constriction (TAC) was performed in CD1 mice to induce pressure overload hypertrophy. Mice were treated with class I and IIb HDAC inhibitor (HDACi) via drinking water for 2 and 4 weeks post TAC. miRNA expression was determined by real-time polymerase chain reaction. Echocardiography was performed at baseline and post TAC end points for structural and functional assessment. Chromatin immunoprecipitation was used to identify HDACs and transcription factors associated with miR-133a promoter. miR-133a expression was downregulated by 0.7- and 0.5-fold at 2 and 4 weeks post TAC, respectively, when compared with vehicle control ( P Conclusions— The results reveal that HDACs play a role in the regulation of pressure overload–induced miR-133a downregulation. This work is the first to provide insight into an epigenetic-miRNA regulatory pathway in pressure overload–induced cardiac fibrosis.

Background— Heart failure (HF) is the leading cause for hospital readmission. Hospice care may help palliate HF symptoms but its association with 30-day all-cause readmission remains unknown. Methods and Results— Of the 8032 Medicare beneficiaries hospitalized for HF in 106 Alabama hospitals (1998–2001), 182 (2%) received discharge hospice referrals. Of the 7850 patients not receiving hospice referrals, 1608 (20%) died within 6 months post discharge (the hospice-eligible group). Propensity scores for hospice referral were estimated for each of the 1790 (182+1608) patients and were used to match 179 hospice-referral patients with 179 hospice-eligible patients who were balanced on 28 baseline characteristics (mean age, 79 years; 58% women; 18% non-white). Overall, 22% (1742/8032) died in 6 months, of whom 8% (134/1742) received hospice referrals. Among the 358 matched patients, 30-day all-cause readmission occurred in 5% and 41% of hospice-referral and hospice-eligible patients, respectively (hazard ratio associated with hospice referral, 0.12; 95% confidence interval, 0.06–0.24). Hazard ratios (95% confidence intervals) for 30-day all-cause readmission associated with hospice referral among the 126 patients who died and 232 patients who survived 30-day post discharge were 0.03 (0.04–0.21) and 0.17 (0.08–0.36), respectively. Although 30-day mortality was higher in the hospice referral group (43% versus 27%), it was similar at 90 days (64% versus 67% among hospice-eligible patients). Conclusions— A discharge hospice referral was associated with lower 30-day all-cause readmission among hospitalized patients with HF. However, most patients with HF who died within 6 months of hospital discharge did not receive a discharge hospice referral.

Background— The purpose of this study was to determine whether patients with heart failure and a preserved ejection fraction (HFpEF) have an increase in passive myocardial stiffness and the extent to which discovered changes depend on changes in extracellular matrix fibrillar collagen and cardiomyocyte titin. Methods and Results— Seventy patients undergoing coronary artery bypass grafting underwent an echocardiogram, plasma biomarker determination, and intraoperative left ventricular epicardial anterior wall biopsy. Patients were divided into 3 groups: referent control (n=17, no hypertension or diabetes mellitus), hypertension (HTN) without (–) HFpEF (n=31), and HTN with (+) HFpEF (n=22). One or more of the following studies were performed on the biopsies: passive stiffness measurements to determine total, collagen-dependent and titin-dependent stiffness (differential extraction assay), collagen assays (biochemistry or histology), or titin isoform and phosphorylation assays. In comparison with controls, patients with HTN(–)HFpEF had no change in left ventricular end-diastolic pressure, myocardial passive stiffness, collagen, or titin phosphorylation but had an increase in biomarkers of inflammation (C-reactive protein, soluble ST2, tissue inhibitor of metalloproteinase 1). In comparison with both control and HTN(–)HFpEF, patients with HTN(+)HFpEF had increased left ventricular end-diastolic pressure, left atrial volume, N-terminal propeptide of brain natriuretic peptide, total, collagen-dependent, and titin-dependent stiffness, insoluble collagen, increased titin phosphorylation on PEVK S11878(S26), reduced phosphorylation on N2B S4185(S469), and increased biomarkers of inflammation. Conclusions— Hypertension in the absence of HFpEF did not alter passive myocardial stiffness. Patients with HTN(+)HFpEF had a significant increase in passive myocardial stiffness; collagen-dependent and titin-dependent stiffness were increased. These data suggest that the development of HFpEF depends on changes in both collagen and titin homeostasis.

Background— International geographic differences in outcomes may exist for clinical trials of heart failure and reduced ejection fraction (HF-REF), but there are few data for those with preserved ejection fraction (HF-PEF). Methods and Results— We analyzed outcomes by international geographic region in the Irbesartan in Heart Failure with Preserved systolic function trial (I-Preserve), the Candesartan in Heart failure Assessment of Reduction in Mortality and morbidity (CHARM)-Preserved trial, the CHARM-Alternative and CHARM–Added HF-REF trials, and the Controlled Rosuvastatin Multinational Trial in HF-REF (CORONA). Crude rates of heart failure hospitalization varied by geographic region, and more so for HF-PEF than for HF-REF. Rates in patients with HF-PEF were highest in the United States/Canada (HF hospitalization rate 7.6 per 100 patient-years in I-Preserve; 8.8 in CHARM-Preserved), intermediate in Western Europe (4.8/100 and 4.7/100), and lowest in Eastern Europe/Russia (3.3/100 and 2.8/100). The difference between the United States/Canada versus Eastern Europe/Russia persisted after adjustment for key prognostic variables: adjusted hazard ratios 1.34 (95% confidence interval, 1.01–1.74; P =0.04) in I-Preserve and 1.85 (95% confidence interval, 1.17–2.91; P =0.01) in CHARM-Preserved. In HF-REF, rates of HF hospitalization were slightly lower in Western Europe compared with other regions. For both HF-REF and HF-PEF, there were few regional differences in rates of all-cause or cardiovascular mortality. Conclusions— The differences in event rates observed suggest there is international geographic variation in 1 or more of the definition and diagnosis of HF-PEF, the risk profile of patients enrolled, and the threshold for hospitalization, which has implications for the conduct of future global trials.

Circulating levels of natriuretic peptides (NP) are inversely related to body mass index (BMI), and obese patients with heart failure (HF) have lower brain natriuretic peptide (BNP) and N-terminal pro-brain natriuretic peptide (NT-proBNP) concentrations than nonobese patients.1,2 These observations have raised concerns about the prognostic value of NP in patients with HF with an elevated BMI. Prior observational studies suggested that NP may retain their capacity to predict mortality across all BMI categories in HF with individuals with reduced ejection fraction.3,4 Nevertheless, these studies included a relatively small number of events and did not evaluate additional cardiovascular end points. Because it remains uncertain whether BMI may influence the prognostic utility of NP in patients with HF, we examined the influence of BMI on the predictive value of NT-proBNP and BNP in patients with reduced ejection fraction from the PARADIGM-HF trial (Prospective Comparison of ARNI with ACEI to Determine Impact on Global Mortality and Morbidity in Heart Failure; URL: http://www.clinicaltrials.gov. Unique identifier: NCT01035255). The design and primary results of the PARADIGM-HF trial have been previously described.5 The patients randomized in the trial (n=8399) were required to have a plasma BNP ≥150 pg/mL or an NT-proBNP ≥600 pg/mL or, if they were hospitalized for HF within the previous …

Background Patients with heart failure and reduced ejection fraction have impaired health-related quality of life (HRQL) with variable responses to therapies that target mortality and heart failure hospitalizations. In PARADIGM-HF trial (Prospective Comparison of ARNI [Angiotensin Receptor–Neprilysin Inhibitor] With ACEI [Angiotensin-Converting–Enzyme Inhibitor] to Determine Impact on Global Mortality and Morbidity in Heart Failure), sacubitril/valsartan reduced morbidity and mortality compared with enalapril. Another major treatment goal is to improve HRQL. Given improvements in mortality with sacubitril/valsartan, this analysis provides comprehensive assessment of impact of therapy on HRQL in survivors only. Methods and Results Patients (after run-in phase) completed disease-specific HRQL using Kansas City Cardiomyopathy Questionnaire (KCCQ) at randomization, 4 month, 8 month, and annual visits. Changes in KCCQ scores were calculated using repeated measures analysis of covariance model that adjusted for treatment and baseline values (principal efficacy prespecified at 8 months). Among the 8399 patients enrolled in PARADIGM-HF, 7623 (91%) completed KCCQ scores at randomization with complete data at 8 months for 6881 patients (90% of baseline). At 8 months, sacubitril/valsartan group noted improvements in both KCCQ clinical summary score (+0.64 versus −0.29; P =0.008) and KCCQ overall summary score (+1.13 versus −0.14; P P =0.01). Adjusted change scores demonstrated consistent improvements in sacubitril/valsartan compared with enalapril through 36 months. Conclusions Change scores in KCCQ clinical summary scores and KCCQ overall summary scores were better in patients treated with sacubitril/valsartan compared with those treated with enalapril, with consistency in most domains, and persist during follow-up beyond 8 months. These findings demonstrate that sacubitril/valsartan leads to better HRQL in surviving patients with heart failure. Clinical Trial Registration URL: http://www.c linicalt rials.gov . Unique identifier: NCT01035255.

Background— Stress cardiomyopathy (SCM) is a peculiar form of reversible left ventricular dysfunction seen predominantly in women and occurs in response to emotional or physical stress. Because dysfunction in SCM is reversible and that of acute myocardial infarction (MI) is not, we hypothesized that these fundamental mechanistic differences between SCM and MI would be associated with different systolic and diastolic properties. Methods and Results— We examined 3 groups, all women: patients with SCM (n=24; mean age, 63±12 years), those with left anterior (LAD) ST-segment–elevation MI (n=36; mean age, 63±10 years), and referent control subjects (n=30; mean age, 62±8 years). All underwent angiography, ventriculography, and pressure measurements within 48 hours of presentation. Left ventricular volumes, diastolic pressures, and diastolic stiffness were higher in SCM and LAD MI patients than in control subjects but no different from each other. Similarly, left ventricular diastolic pressures and diastolic stiffness were elevated in the SCM and LAD MI groups compared with the control group. Left ventricular ejection fraction in SCM and LAD MI were 40.8±12.3% and 49.6±5.6%, respectively, versus 70.4±9.4% in control subjects ( P Conclusions— SCM and LAD MI show severe diastolic dysfunction. At similar left ventricular volumes, their diastolic pressures are more than twice as high as in control subjects, and systolic dysfunction is equally reduced in SCM and LAD MI. Despite a completely different pathophysiology in terms of systolic and diastolic function, SCM is indistinguishable from acute LAD-territory MI.

Background— Although matrix metalloproteinases (MMPs) were initially thought to result primarily in extracellular matrix degradation, certain MMP types, such as membrane type-1 (MT1) MMP, may also be involved in profibrotic cascades through hydrolysis of latency-associated transforming growth factor–binding protein (LTBP-1) and activation of transforming growth factor–dependent profibrotic signaling. The present study tested the hypothesis that MT1-MMP plays a direct role in the matrix remodeling response to a left ventricular (LV) pressure overload (PO) stimulus. Methods and Results— Wild-type (WT) and transgenic mice with cardiac-restricted MT1-MMP overexpression or MT1-MMP reduced expression underwent PO for 4 weeks. PO resulted in a 57% increase in LV mass (no change in LV end diastolic volume, resulting in an increase in the LV mass/volume ratio consistent with concentric remodeling), a 60% increase in MT1-MMP–mediated LTBP-1 hydrolysis and a 190% increase in collagen content in WT mice. Although LV mass was similar among WT, MT1-MMP overexpression, and MT1-MMP reduced expression after PO, significant differences in LV function, MT1-MMP–mediated LTBP-1 hydrolysis, and collagen content occurred. PO in MT1-MMP overexpression increased LTBP-1 hydrolysis (18%), collagen content (60%), and left atrial dimension (19%; indicative of LV diastolic dysfunction) when compared with WT. PO in MT1-MMP reduced expression reduced left atrial dimension (19%), LTBP-1 hydrolysis (40%), and collagen content (32%) when compared with both WT. Conclusions— Despite an equivalent PO stimulus and magnitude of LV myocardial growth, altering MT1-MMP levels caused specific matrix-dependent changes in remodeling, thereby demonstrating a mechanistic role in the development of the maladaptive remodeling and myocardial fibrotic response to PO.

In contrast to public perception, the morbidity and mortality and the resultant healthcare costs associated with chronic heart failure (HF) are increasing and arguably reaching epidemic proportions. Although basic research efforts have provided unique insights into fundamental processes that govern myocardial extracellular matrix (ECM) growth and function, the translation of these findings to improved diagnostics and therapeutics for HF has not been as forthcoming. The factors that contribute to this relative paucity of new clinical tools for HF are multifactorial but likely include the need to recognize and differentiate HF phenotypes and to couple the use of biomarkers and multimodality imaging in early translational research studies. Recognizing the classification scheme of HF with a reduced ejection fraction (EF) to that of HF with a preserved EF and incorporating unique and differential measurements of ECM remodeling to these specific disease processes are warranted. For example, profiling pathways of ECM degradation such as the matrix metalloproteinases in patients with ischemic heart disease and HF with a reduced EF can provide prognostic information in terms of risk of progression to HF. In patients with chronic hypertensive disease and HF with a preserved EF, plasma profiling indexes of ECM synthesis and turnover, as well as advances in ECM imaging, have been shown to provide diagnostic and prognostic use. In terms of therapeutics, strategies to stabilize the ECM in HF with a reduced EF hold potential, whereas in contradistinction, selective antifibrotic agents may hold promise for HF with a preserved EF. Clinical Trial Registration— URL: http://www.clinicaltrials.gov . Unique identifier: NCT 00946231

Background— The purpose of the current study was to define exercise-induced changes in indices of left ventricular (LV) systolic and diastolic properties in patients with chronic heart failure (HF), compare these changes in patients with HF and a reduced ejection fraction (EF) versus HF and a preserved EF, and compare the hemodynamic responses to activities of daily living with symptom-limited upright exercise. Methods and Results— Subjects with HF and a preserved EF (n=8) and subjects with HF and a reduced EF (n=5) underwent symptom-limited Naughton protocol treadmill exercise tests. Implantable hemodynamic monitor data and echocardiographic data were obtained before exercise and at peak exercise. Implantable hemodynamic monitor data were obtained during activities of daily living during a 24-hour time period. In patients with HF and a reduced EF, limited exercise time (639±164 seconds) was associated with a marked rise in right ventricular systolic, diastolic, and estimated pulmonary artery diastolic (ePAD) pressures and an increase in LV end diastolic volume (EDV). LV systolic properties, namely EF, end systolic elastance, stroke work, and preload recruitable stroke work, all decreased. The ePAD/EDV ratio increased; to a large extent, this was dependent on an increase in EDV. By contrast, in HF and a preserved EF, limited exercise time (411±128 seconds) and the marked rise in right ventricular systolic, diastolic, and ePAD pressures were associated with no change in LV EDV. LV systolic properties increased or were unchanged; ePAD/EDV ratio increased during exercise, but the increase was independent of a change in EDV. The ranges of right ventricular systolic, diastolic, and ePAD pressures during activities of daily living were higher than the ranges of these values during the exercise stress test. Conclusions— Although exercise limitations were similar between HF and a reduced EF and HF and a preserved EF, there were significant differences in exercise-induced changes in LV systolic and diastolic properties. These differences likely reflect the different pathophysiologies of these clinical syndromes of HF.

Background— The 8442 patients randomized in the Prospective Comparison of Angiotensin Receptor-Neprilysin Inhibitor With an Angiotensin-Converting Enzyme Inhibitor to Determine Impact on Global Mortality and Morbidity in Heart Failure (PARADIGM-HF) trial, in which sacubitril/valsartan (LCZ696) reduced both death and HF hospitalization more than enalapril, were a subset of 10 521 patients entering sequential, single-blind run-in periods (enalapril 10 mg twice daily for 2 weeks followed by LCZ696 200 mg twice daily for 4 to 6 weeks) to ensure short-term tolerability of the 2 study medications. We identified the predictors of run-in noncompletion and estimated the implications of noncompletion for the overall study result. Methods and Results— Patient factors associated with run-in noncompletion were defined in multivariable logistic regression models. The effectiveness of LCZ696 in a broader cohort approximating the full run-in population was estimated by weighting randomized patients according to the inverse probability of run-in completion; 2079 (19.8%) subjects discontinued the study during the run-in period, including 1102 (10.5%) during the enalapril phase and 977 (9.3%) during the LCZ696 phase. In multivariable models, lower systolic blood pressure, lower estimated glomerular filtration rate, higher N-terminal pro–B-type natriuretic peptide, and ischemic cause of heart failure were associated with higher risk for run-in noncompletion. Repeat analysis of the effect of randomized treatment giving greater weight to randomized patients resembling those who did not complete the run-in did not alter the hazard ratio favoring LCZ696 over enalapril for the primary end point of cardiovascular death or heart failure hospitalization, or the additional key end points of cardiovascular death and all-cause mortality. Conclusions— Patients with lower blood pressure, lower glomerular filtration rate, and more severe heart failure were at higher risk for noncompletion during the run-in period of PARADIGM-HF. Weighted analysis of key study outcomes accounting for the effect of run-in noncompletion did not alter the benefit of LCZ696 over enalapril. Clinical Trial Registration— URL: http://www.clinicaltrials.gov . Unique identifier: NCT01035255.

Background— Left atrial (LA) size is an established marker of risk for adverse outcomes in heart failure with preserved ejection fraction (HFpEF). However, the independent prognostic importance of LA function in HFpEF is not known. Methods and Results— We assessed LA function measured by speckle-tracking echocardiography in 357 patients with HFpEF enrolled in the Treatment Of Preserved Cardiac Function Heart Failure With an Aldosterone Antagonist (TOPCAT) trial who were in sinus rhythm at the time of echocardiography. Lower peak LA strain, indicating LA dysfunction, was associated with older age, higher prevalence of atrial fibrillation and left ventricular (LV) hypertrophy, worse LV and right ventricular systolic function, and worse LV diastolic function. At a mean follow-up of 31 months (interquartile range, 18–43months), 91 patients (25.5%) experienced the primary composite end point of cardiovascular death, HF hospitalization, and aborted sudden death. Lower peak LA strain was associated with a higher risk of the composite end point (hazard ratio, 0.96 per unit of reduction in strain; 95% confidence interval, 0.94–0.99; P =0.009) and of HF hospitalization alone (hazard ratio, 0.95 per unit of reduction in strain; 95% confidence interval, 0.92–0.98; P =0.003). The association of LA strain with incident HF hospitalization remained significant after adjustment for clinical confounders, but not after further adjustment for LV global longitudinal strain and the E/E′ ratio, parameters of LV systolic and diastolic function, respectively. Conclusions— LA dysfunction in HFpEF is associated with a higher risk of HF hospitalization independent of potential clinical confounders, but not independent of LV strain and filling pressure. Impairment in LV systolic and diastolic function largely explains the association between impaired LA function and higher risk of HF hospitalization in HFpEF. Clinical Trial Registration— URL: http://www.clinicaltrials.gov . Unique identifier: NCT00094302.

Background— Intrathoracic impedance-derived OptiVol fluid index calculated using implanted devices has been shown to predict mortality; direct measurements of impedance have not been examined. We hypothesized that baseline measured impedance predicts all-cause mortality; changes in measured impedance result in a change in the predicted mortality; and the prognostic value of measured impedance is additive to the calculated OptiVol fluid index. Methods and Results— A retrospective analysis of 146 238 patients within the Medtronic CareLink database with implanted devices was performed. Baseline measured impedance was determined using daily values averaged from month 6 to 9 after implant and were used to divide patients into tertiles: group L=low impedance, ≤65 ohms; group M=medium impedance, 66 to 72 ohms; group H=high impedance, ≥73 ohms. Change in measured impedance was determined from values averaged from month 9 to 12 post implant compared with the 6- to 9-month values. OptiVol fluid index was calculated using published methods. All-cause mortality was assessed beginning 9 months post implant; changes in mortality was assessed beginning 12 months post implant. Baseline measured impedance predicted all-cause mortality; 5-year mortality for group L was 41%, M was 29%, and H was 25%, P Conclusions— Direct measurements of intrathoracic impedance using an implanted device can be used to stratify patients at varying mortality risk.

Background— Hypertension (HTN) causes concentric left ventricular remodeling, defined as an increased relative wall thickness or overt left ventricular hypertrophy, and associated diastolic dysfunction. HTN and concentric remodeling are also common precursors to heart failure with a preserved ejection fraction. It is not known whether the myofilament contributes to diastolic dysfunction in patients with concentric remodeling. Methods and Results— Intraoperative myocardial biopsies were obtained in 15 male patients undergoing coronary bypass grafting, all with normal left ventricular ejection fraction and wall motion. Eight patients had a history of HTN and concentric remodeling. Seven without HTN or remodeling served as controls. Myocardial strips were dissected and demembranated with detergent. Isometric tension was measured and sinusoidal length perturbation analysis performed at sarcomere length 2.2 μm and pCa 8 to 4.5. Sinusoidal analysis provides estimates of cross-bridge dynamics, including rate constants of attachment and detachment and cross-bridge attachment time. The normalized isometric tension–pCa relation was similar in HTN and controls. However, cross-bridge attachment time was significantly prolonged at submaximal [Ca 2+ ] (pCa ≥6.5) in HTN patients. Analysis of protein phosphorylation revealed ≈25% reduction in phosphorylation of troponin I in HTN patients ( P Conclusions— Compared with controls, patients with HTN and concentric remodeling display prolonged cross-bridge attachment time at submaximal [Ca 2+ ] without a change in the tension–pCa relation. Prolonged cross-bridge attachment time implicates altered cross-bridge dynamics as a cause of slowed relaxation in these patients. This finding was associated with reduced phosphorylation of troponin I, suggesting decreased phosphorylation of protein kinase A/G sites as a mechanism.

Background— Obesity is a major risk factor for incident heart failure (HF). Paradoxically, in HF with reduced left ventricular ejection fraction (HFREF), a high body mass index (BMI) appears to be beneficial. Approximately 50% of HF patients have a preserved left ventricular ejection fraction (HFPEF). However, there are few data regarding the relationship between BMI and outcomes in HFPEF. Methods and Results— Baseline characteristics and cardiovascular outcomes were assessed in the 4109 patients (mean age, 72 years; mean follow-up, 49.5 months) in the Irbesartan in HF with Preserved Ejection Fraction (I-PRESERVE) trial. Based on the BMI distribution, 5 BMI categories were defined: 2 . Most patients (71%) had a BMI ≥26.5, 21% had a BMI between 23.5 and 26.4, and 8% had a BMI 2 . Patients with higher BMI were younger, more often women, and more likely to have hypertension and diabetes and higher left ventricular ejection fraction. Patients with BMI of 26.5 to 30.9 kg/m 2 had the lowest rate for the primary composite outcome (death or cardiovascular hospitalization) and were used as reference group. After adjustment for 21 risk variables including age, sex, and N-terminal pro-brain natriuretic peptide, the hazard ratio for the primary outcome was increased in patients with BMI P =0.019) and in those with BMI ≥35 kg/m 2 (hazard ratio, 1.27; 95% confidence interval, 1.06 to 1.52; P =0.011) compared with the referent group. A similar relationship was found for all-cause mortality and for HF hospitalization. Conclusions— Obesity is common in HFPEF patients and is accompanied by multiple differences in clinical characteristics. Independent of other key prognostic variables, there was a U-shaped relationship, with the greatest rate of adverse outcomes in the lowest and highest BMI categories. Clinical Trial Registration— URL: http://www.clinicaltrials.gov . Unique identifier: NCT000095238.

Background— Intracardiac pressures in heart failure (HF) have been measured in patients while supine in the hospital but change at home with posture and activity. The optimal level of chronic ambulatory pressure is unknown. This analysis compared chronic intracardiac pressures to later HF events and sought a threshold above which higher pressures conferred worse outcomes. Methods and Results— Median pressures were measured every 24 hours from continuous 8-minute segments for 6 months after implantation of hemodynamic monitors in 261 patients with New York Heart Association class III-IV HF in the Chronicle Offers Management to Patients with Advanced Signs and Symptoms of Heart Failure Study. Baseline and chronic daily medians of estimated pulmonary artery diastolic, right ventricular systolic, and right ventricular end-diastolic pressures were compared with HF event rate. The group median for chronic 24-hour estimated pulmonary artery diastolic pressure was 28 mm Hg (excluding 7 days before and after events). Despite weight-guided management, events occurred in 100 of 261 (38%) patients. Event risk increased progressively with higher chronic 24-hour estimated pulmonary artery diastolic pressure, from 20% at 18 mm Hg to 34% at 25 mm Hg and 56% at 30 mm Hg, with similar relations for right ventricular pressures. Among patients with baseline day median estimated pulmonary artery diastolic pressures of ≥25 mm Hg, event risk was 1.10/6 mo when they remained chronically ≥25 mm Hg, but risk fell to 0.47 when 24-hour pressures declined to Conclusions— Despite current management, many patients with advanced HF live on a plateau of high filling pressures from which later events occur. This risk is progressively higher with higher chronic ambulatory pressures. It is not known whether more targeted intervention could maintain lower chronic ambulatory pressures and better outcomes.

Background— Prior investigations suggest that superimposing continuous flow on aortic flow (continuous aortic flow augmentation) produces vasodilation, cardiac unloading, and improved cardiac performance. Methods and Results— We compared percutaneous continuous aortic flow augmentation (flow ≤1.5 L/min for up to 96 hours) plus medical therapy versus medical therapy alone by randomizing 168 patients (device, n=109; control, n=59) hospitalized with heart failure, reduced left ventricular ejection fraction and cardiac index, elevated pulmonary capillary wedge pressure, and renal impairment or substantial diuretic requirement despite intravenous inotropes/vasodilators. The primary composite efficacy end point included pulmonary capillary wedge pressure (72 to 96 hours) and days alive out of hospital off mechanical support over 35 days. The population’s illness severity posed unique challenges. Enrollment ended early because of an inability to demonstrate significant benefit on the primary composite end point (device, 17.4%; control, 13.6%; P =0.45) in the face of excess device group bleeding. Pulmonary capillary wedge pressure decreased from 28.8±6.3 mm Hg (mean±SD) to 24.9±7.2 mm Hg (average, 72 to 96 hours) and 28.9±7.1 to 26.5±6.2 mm Hg in the device and control groups, respectively (between-group P =0.074). Cardiac index progressively increased in the device (2.05±0.53 to 2.44±0.52 L · min −1 · m −2 ) but not the control (between-group P P =0.10). Through 65 days, device-to-control hazard ratios were as follows: all-cause mortality, 1.05 (95% confidence interval, 0.60 to 1.82); death or heart failure hospitalization, 0.87 (95% confidence interval, 0.57 to 1.33); and heart failure hospitalization, 0.66 (95% confidence interval, 0.38 to 1.13). Major bleeds occurred in 16.5% in the device (7.3% treatment related) and 5.1% in the control ( P =0.05) group. Conclusions— Continuous aortic flow augmentation improved cardiac performance, improving cardiac index and pulmonary capillary wedge pressure, but statistical significance for the primary efficacy end point was not attained. Hemodynamic and clinical observations provide direction toward additional studies to further investigate the clinical effects of this treatment.

Introduction: Heart failure with preserved ejection fraction (HFpEF) is associated with considerable morbidity and mortality. Insulin-like growth factor-binding protein 7 (IGFBP7) is a cell cycle arrest biomarker associated with abnormal diastology and prognosis in HF with reduced EF (HFrEF). Its role in patients with HFpEF is unknown. Hypothesis: IGFBP7 will be associated with adverse outcomes in HFpEF. Methods: Baseline (BL) IGFBP7 (n=302; placebo=154, irbesartan=148) and 6 month change (Δ; n=293; placebo=147, irbesartan=146) were measured and correlated with clinical data, biomarkers, estimated glomerular filtration rate (eGFR), and the primary outcome of all-cause mortality (ACM) or cardiovascular hospitalization (CVH) in patients from the Irbesartan in HFpEF (I-PRESERVE) Trial; secondary outcomes included HF events. Results: Median BL IGFBP7 concentration was 218 ng/mL, higher than previously seen in patients with HFrEF. BL IGFBP7 was correlated with age (R 2 =0.13; P2 =0.22; P2 =0.14; PFigure ) and remained significant for all outcomes after adjustment for NT-proBNP and eGFR. After 6 months, IGFBP7 did not change significantly in either treatment group. ΔIGFBP7 was not independently associated with outcomes but was associated with a decrease in eGFR in patients randomized to receive irbesartan (R 2 =0.09; P Conclusions: IGFBP7 is associated with adverse outcomes in HFpEF. Further studies are needed to identify the mechanistic link between IGFBP7, renal function, and outcomes in patients with HFpEF.

Introduction: Heart failure with reduced ejection fraction (HF) patients have impaired health-related quality of life (HRQL) with variable responses to therapies that target mortality and HF hospitalizations. In PARADIGM-HF, LCZ696 reduced morbidity and mortality compared with enalapril. Prior analysis demonstrated a significant difference in 8-month Kansas City Cardiomyopathy-Clinical Summary score (KCCQ-CSS) when imputing 0 for death (-2.99 vs. -4.63, p=0.0014). Given improvements in mortality with LCZ696, this analysis provides impact of therapy on all domains of HRQL in survivors only. Hypothesis: LCZ696 will improve HRQL Methods: Patients (after run-in phase) completed disease-specific KCCQ at randomization, 4 month, 8 month, and annual visits. Changes in KCCQ scores were calculated using repeated measures ANCOVA model adjusting for treatment, region, & baseline values (primary efficacy pre-specified at 8 months), and association of KCCQ with mortality was assessed. Results: Among 8442 patients enrolled in PARADIGM-HF, 7623 (90%) completed KCCQ scores at randomization with complete data at 8 months on 7281 (86%). Baseline KCCQ scores were similar in LCZ696 and enalapril groups (73.5±20 vs. 72.3±19). Death increased with every 10 point decrement of baseline KCCQ-CSS [HR 1.11 (1.09, 1.14)]. At 8 months, LCZ696 group noted improvements in both KCCQ-CSS (+0.61 vs. -0.28, p=0.010) and KCCQ-Overall summary score (+1.10 vs. -0.15, p Conclusions: Disease-specific HRQL is associated with survival. Changes in HRQL were better in patients treated with LCZ696 compared with enalapril with consistency in most domains. These findings suggest that LCZ696 leads to better HRQL in addition to morbidity & mortality in HF-reduced ejection fraction patients.

Introduction: The angiotensin receptor neprilysin inhibitor LCZ696 reduced cardiovascular death, heart failure hospitalization and all-cause mortality in patients with heart failure and reduced ejection fraction compared with enalapril. Hypothesis: We hypothesized that LCZ696 would reduce 30-day readmission after a heart failure hospitalization. Methods: PARADIGM-HF randomized 8399 patients with HF and reduced ejection fraction to either LCZ696 200mg bid or Enalapril 10mg bid. We assessed the risk of 30-day readmission for any cause following investigator reported and adjudicated hospitalization for heart failure. Admission and discharge dates were available for 2800 hospitalizations (95%) in 1638 patients. Results: Of 2800 HF hospitalizations, 1545 occurred in 871 patients in the enalapril group and 1255 occurred in 767 patients in the LCZ arm. Overall, 10.5% of these HF hospitalizations were followed by a repeat hospitalization for any cause within 30 days of discharge, and this occurred significantly less frequently in the LCZ arm (8.7%) relative to the enalapril arm (12.0%), in both unadjusted models and a random-effects logistic regression model accounting for the repeated HF hospitalizations experienced by some patients. We observed similar results in a sensitivity analysis restricted only to the first HF hospitalization for each patient. Further adjustment for baseline characteristics did not alter these findings. Similar effect sizes were observed for adjudicated heart failure hospitalizations. Conclusion: In patients admitted with heart failure in PARADIGM-HF, LCZ reduced 30-day readmissions for any-cause.

Background: The aim of this analysis was to examine the effect of the angiotensin receptor neprilysin inhibitor (ARNI) sacubitril/valsartan (LCZ696), compared with enalapril, on progressive worsening over time in patients with heart failure and reduced ejection fraction (HF-REF) enrolled in the Prospective comparison of ARNI with ACEI to Determine Impact on Global Mortality and Morbidly in Heart Failure trial (PARADIGM-HF). Methods: In PARADIGM-HF, 4212 patients were randomized to enalapril and 4187 to sacubitril/valsartan. The primary outcome was the composite of cardiovascular (CV) death or hospitalization for heart failure (HF). To make a more comprehensive evaluation of HF worsening over time, we analysed the broader composite of CV death, HF hospitalization, emergency department visit for HF or intensification of therapy for HF (as time-to-first event) using the Kaplan-Meier (KM) method. Results: At baseline, 71% of patients were in NYHA functional class II and 24% in class III. Their mean LVEF was 27% and 93% were treated with a beta-blocker and 56% with a mineralocorticoid receptor antagonist. The median duration of follow-up was 27 months. The 1, 2 and 3 year KM rates for the composite outcome in the enalapril group were 16.5 (95% CI 15.5, 17.7)%, 27.6 (26.2, 29.1) and 34.8 (33.1-36.6)%, respectively. The corresponding rates in the sacubitril/valsartan group were 13.4 (12.4, 14.5), 22.1 (20.8, 23.4) and 29.5 (27.9, 31.2)%, respectively. Overall 1275 enalapril treated and 1038 sacubitril/valsartan treated patients had an event, giving a hazard ratio 0.79 (95% CI 0.73, 0.86), p Conclusions: Even in patients with predominantly mild symptoms, well treated with evidence-based pharmacological therapy, worsening of HF over time was common, with more than a third of patients exhibiting progression within 3 years. The ARNI sacubitril/valsartan led to clinically important relative and absolute reductions in progressive worsening, compared with enalapril.

Background— Changes in matrix metalloproteinase (MMP) and tissue inhibitors of MMPs (TIMPs) contribute to left ventricular (LV) remodeling after myocardial infarction (MI). We tested the hypothesis that a specific plasma MMP/TIMP profile would emerge after MI and be associated with the degree of LV dilation. Methods and Results— LV end-diastolic volume and MMP/TIMP plasma profiles were determined in 53 age-matched control subjects and 32 post-MI patients from day 1 through 180 after MI. LV end-diastolic volume increased by >38% at day 90 after MI ( P 150% from control at day 1 after MI ( P 120% at day 3 after MI ( P 60% from control at day 1 after MI ( P P Conclusions— A specific temporal pattern of MMP/TIMPs occurred in post-MI patients that included an early and robust rise in MMP-9 and MMP-8 and a uniform fall in TIMP-4. These findings suggest that a specific MMP/TIMP plasma profile occurs after MI and holds both prognostic and diagnostic significance.

In contrast to systolic heart failure (SHF), for which knowledge of pathophysiology and therapy has advanced rapidly over the past decade, little is known about diastolic heart failure (DHF). The article by van Heerebeek et al1 in this issue of Circulation that describes an abnormal distribution of titin isoforms in DHF may herald a new approach to understanding the pathophysiology of this syndrome. Article p 1966 Recognition of 2 forms of heart failure is not new; almost 70 years ago, Fishberg2 described “those forms of cardiac insufficiency which are due to inadequate diastolic filling of the heart (hypodiastolic failure) [and] the far more common ones in which the heart fills adequately but does not empty to the normal extent (hyposystolic failure)” (p 23). This distinction has stood the test of time, because there is a growing consensus that these 2 clinical syndromes differ in epidemiology, demographics, and origin. Because DHF and SHF represent subgroups of patients with heart failure, they share many clinical features, notably the hemodynamic findings, but it is now clear that they are caused by different pathophysiological mechanisms. Hearts in SHF are characterized by eccentric hypertrophy, progressive left ventricular (LV) dilation, and abnormal LV systolic properties, whereas in DHF, the hearts generally exhibit concentric hypertrophy, normal or reduced LV volume, concentric remodeling, and abnormal diastolic function.3,4 In addition, cardiomyocyte size, shape, and molecular composition differ in these 2 syndromes. Diastolic dysfunction refers to mechanical and functional abnormalities present during relaxation and filling, whereas DHF refers to clinical syndromes in which patients with heart failure have little or no ventricular dilatation and significant, often dominant diastolic dysfunction. Diastolic dysfunction can be quantified with indices of LV pressure decline and filling. Abnormal pressure decline is characterized by decreased peak −dP/dt, prolonged isovolumic time constant (τ), and …

Received March 31, 2005; revision received July 15, 2005; accepted July 21, 2005. In diastolic heart failure, the left ventricular (LV) ejection fraction (EF) is normal and there is increased passive stiffness with impaired relaxation of the ventricle, resulting in disturbances in the pattern of filling and elevated diastolic pressure.1–3 The mechanism underlying such failure has been thought to be principally diastolic because LV diastolic function is universally abnormal and systolic performance, function, and contractility are normal.4 However, several reports suggest that abnormalities in regional shortening are present in diastolic heart failure.5–9 The significance of these findings, especially their relation to the syndrome of heart failure, remains uncertain. Accordingly, we will review some of the structural and functional differences between systolic and diastolic heart failure, and, emphasizing the systolic or contractile behavior of the left ventricle, we will attempt to reconcile what appear to be disparate conclusions about LV systolic function in patients with diastolic heart failure. The hearts of patients with systolic heart failure differ dramatically from those of patients with diastolic heart failure in regard to both gross and microscopic anatomic features. As will be seen, these anatomic differences tend to parallel physiological and functional differences in systolic and diastolic heart failure10,11 (Table 1). View this table: TABLE 1. LV Structure and Function in Chronic Heart Failure ### LV Chamber Remodeling Patients with diastolic heart failure generally exhibit a concentric pattern of LV remodeling and a hypertrophic process that is characterized by a normal or near-normal end-diastolic volume, increased wall thickness, and a high ratio of mass to volume with a high ratio of wall thickness to chamber radius.12 By contrast, patients with systolic heart failure exhibit a pattern of eccentric remodeling with an increase in end-diastolic volume, little increase in wall thickness, and a substantial decrease in the ratio …

Background— Patients with diastolic heart failure (DHF) have significant abnormalities in left ventricular (LV) diastolic function, including slow and delayed relaxation and increased chamber stiffness. Whether and to what extent these abnormalities in diastolic function occur in association with abnormalities in LV systolic performance, function, and contractility has not been investigated thoroughly. Methods and Results— The systolic properties of the LV were examined in 75 patients with heart failure and a normal ejection fraction (ie, DHF) and 75 normal control subjects with no evidence of cardiovascular disease. LV systolic properties were assessed with echocardiographic and cardiac catheterization data. Stroke work (an index of LV systolic performance), preload recruitable stroke work and ejection fraction (indices of LV systolic function), systolic stress-shortening relationship, end-systolic pressure-volume relationship, and peak (+)dP/dt (indices of LV contractility) were examined. The systolic properties of the LV were normal in patients with DHF. Stroke work was 8.4±2.3 in DHF versus 8.8±2.5 kg · cm in controls ( P =0.26). Preload recruitable stroke work was 99±22 in DHF versus 109±18 g/cm 2 in controls ( P =0.13). The relationship between stroke work and end-diastolic volume was similar in DHF and controls. Peak (+) dP/dt was 1596±362 in DHF versus 1664±305 mm Hg/s in controls ( P =0.54). The end-systolic pressure-volume relationship was increased in DHF. The systolic stress versus endocardial fractional shortening relationship was similar in DHF and controls. Conclusions— Patients with DHF had normal LV systolic performance, function, and contractility. The pathophysiology of DHF does not appear to be related to significant abnormalities in these systolic properties of the LV.

The matrix metalloproteinases (MMPs) are an endogenous family of proteolytic enzymes implicated to contribute to LV remodeling. However, broad-spectrum MMP inhibition (MMPi), particularly inhibition of interstitial collagenase (MMP-1), may not be clinically applicable. This study examined the effects of selective MMPi (sparing MMP-1) in a model of developing congestive heart failure. Pigs were randomly assigned to 3 groups: (1) rapid pacing for 3 weeks (240 bpm, n=10); (2) selective MMPi (20 mg/kg per day-PO;PGE7113313) and rapid pacing (n=12); and (3) controls (n=10). LV peak wall stress increased from controls with rapid pacing (140±6 versus 319±18 g/cm 2 ; P 2 ; P P P P P

Secreted protein acidic and rich in cysteine (SPARC) is a collagen-binding matricellular protein that facilitates the formation and assembly of mature cross-linked collagen fibrils. We previously reported that aged mice exhibit increased SPARC levels in the heart, and SPARC deletion inhibits age-related collagen deposition. The present study investigated whether SPARC deletion could suppress age-related cardiac inflammation. Six groups of mice were studied: young (3-5 month old), middle-aged (10-12 m.o.) and old (18-29 m.o.) C57BL/6J wild type (WT) and SPARC-null (Null) mice (n=5-10 per group). Echocardiography and histology revealed that LV wall thickness and myocyte size were 15% and 43% increased with age in WT, respectively (both p

Background The diagnosis of diastolic heart failure is generally made in patients who have the signs and symptoms of heart failure and a normal left ventricular (LV) ejection fraction. Whether the diagnosis also requires an objective measurement of parameters that reflect the diastolic properties of the ventricle has not been established. Methods and Results We hypothesized that the vast majority of patients with heart failure and a normal ejection fraction exhibit abnormal LV diastolic function. We tested this hypothesis by prospectively identifying 63 patients with a history of heart failure and an echocardiogram suggesting LV hypertrophy and a normal ejection fraction; we then assessed LV diastolic function during cardiac catheterization. All 63 patients had standard hemodynamic measurements; 47 underwent detailed micromanometer and echocardiographic-Doppler studies. The LV end-diastolic pressure was >16 mm Hg in 58 of the 63 patients; thus, 92% had elevated end-diastolic pressure (average, 24±8 mm Hg). The time constant of LV relaxation (average, 51±15 ms) was abnormal in 79% of the patients. The E/A ratio was abnormal in 48% of the patients. The E-wave deceleration time (average, 349±140 ms) was abnormal in 64% of the patients. One or more of the indexes of diastolic function were abnormal in every patient. Conclusions Objective measurement of LV diastolic function serves to confirm rather than establish the diagnosis of diastolic heart failure. The diagnosis of diastolic heart failure can be made without the measurement of parameters that reflect LV diastolic function.

Background —The purpose of this study was to determine whether changes in the constitutive properties of the cardiac muscle cell play a causative role in the development of diastolic dysfunction. Methods and Results —Cardiocytes from normal and pressure-hypertrophied cats were embedded in an agarose gel, placed on a stretching device, and subjected to a change in stress (σ), and resultant changes in cell strain (ε) were measured. These measurements were used to examine the passive elastic spring, viscous damping, and myofilament activation. The passive elastic spring was assessed in protocol A by increasing the σ on the agarose gel at a constant rate to define the cardiocyte σ-versus-ε relationship. Viscous damping was assessed in protocol B from the loop area between the cardiocyte σ-versus-ε relationship during an increase and then a decrease in σ. In both protocols, myofilament activation was minimized by a reduction in [Ca 2+ ] i . Myofilament activation effects were assessed in protocol C by defining cardiocyte σ versus ε during an increase in σ with physiological [Ca 2+ ] i . In protocol A, the cardiocyte σ-versus-ε relationship was similar in normal and hypertrophied cells. In protocol B, the loop area was greater in hypertrophied than normal cardiocytes. In protocol C, the σ-versus-ε relation in hypertrophied cardiocytes was shifted to the left compared with normal cells. Conclusions —Changes in viscous damping and myofilament activation in combination may cause pressure-hypertrophied cardiocytes to resist changes in shape during diastole and contribute to diastolic dysfunction.

Abstract —Increased microtubule density causes cardiocyte contractile dysfunction in right ventricular (RV) pressure-overload hypertrophy, and these linked phenotypic and contractile abnormalities persist and progress during the transition to failure. Although more severe in cells from failing than hypertrophied RVs, the mechanical defects are normalized in each case by microtubule depolymerization. To define the role of increased microtubule density in left ventricular (LV) pressure-overload hypertrophy and failure, in a given LV we examined ventricular mechanics, sarcomere mechanics, and free tubulin and microtubule levels in control dogs and in dogs with aortic stenosis both with LV hypertrophy alone and with initially compensated hypertrophy that had progressed to LV muscle failure. In comparing initial values with those at study 8 weeks later, dogs with hypertrophy alone had a very substantial increase in LV mass but preservation of a normal ejection fraction and mean systolic wall stress. Dogs with hypertrophy and associated failure had a substantial but lesser increase in LV mass and a reduction in ejection fraction, as well as a marked increase in mean systolic wall stress. Cardiocyte contractile function was equivalent, and unaffected by microtubule depolymerization, in cells from control LVs and those with compensated hypertrophy. In contrast, cardiocyte contractile function in cells from failing LVs was quite depressed but was normalized by microtubule depolymerization. Microtubules were increased only in failing LVs. These contractile and cytoskeletal changes, when assayed longitudinally in a given dog by biopsy, appeared in failing ventricles only when wall stress began to increase and function began to decrease. Thus, the microtubule-based cardiocyte contractile dysfunction characteristic of pressure-hypertrophied myocardium, originally described in the RV, obtains equally in the LV but is shown here to have a specific association with increased wall stress.

Background When a pressure overload is placed on the left ventricle, some patients develop relatively modest hypertrophy whereas others develop extensive hypertrophy. Likewise, the occurrence of contractile dysfunction also is variable. The cause of this heterogeneity is not well understood. Methods and Results We recently developed a model of gradual proximal aortic constriction in the adult canine that mimicked the heterogeneity of the hypertrophic response seen in humans. We hypothesized that differences in outcome were related to differences present before banding. Fifteen animals were studied initially. Ten developed left ventricular dysfunction (dys group). Five dogs maintained normal function (nl group). At baseline, the nl group had a lower mean systolic wall stress (96±9 kdyne/cm 2 ; dys group, 156±7 kdyne/cm 2 ; P P 2 . Eighteen of 20 dogs with baseline mean systolic stress >115 kdyne/cm 2 developed dysfunction whereas 6 of 8 dogs with resting stress ≤115 kdyne/cm 2 maintained normal function. Conclusions We conclude that this canine model mimicked the heterogeneous hypertrophic response seen in humans. In the group that eventually developed dysfunction there was less cardiac mass despite 60% higher wall stress at baseline, suggesting a different set point for regulating myocardial growth in the two groups.

We thank the authors of the letters to the editor for their commendation for our work and the validation of our published conclusions.1 We agree with Moody et al that defining the molecular, cellular, and ventricular causes of heart failure with a preserved ejection fraction (HF-pEF) is an important goal that should lead to the development of novel management strategies. We further agree that abnormalities of the renin-angiotensin-aldosterone system as well as abnormalities in the autonomic nervous system may represent such mechanisms. It is for this reason that randomized clinical trials such as the National Heart, Lung, and Blood Institute–sponsored “Aldosterone Antagonist Therapy for Adults with Heart Failure and Preserved Systolic Function” study (TOPCAT; this trial is registered at http://www.clinicaltrials.gov; unique identifier NCT00094302) is being performed. TOPCAT has completed patient enrollment and the results are anticipated to be released in 2013–2014. In addition, several randomized clinical trials examining the efficacy of autonomic modulation in HF-pEF are also underway and were reviewed in a recent editorial.2 Although molecular and cellular mechanisms that underlie structural remodeling and changes in ventricular function are difficult to define in a randomized clinical trial, a number of recent studies in relevant murine models have demonstrated that molecular determinants of collagen synthesis, processing, posttranslational modification, and degradation that result in changes in fibroblast phenotype …

BACKGROUND It is generally accepted that the adrenergic nervous system provides inotropic support for the failing heart. However, the magnitude of this support has never been studied extensively. The present study was performed to test the hypothesis that the adrenergic nervous system is capable of maintaining indexes of pump and contractile function in the normal range despite significant innate myocardial depression. METHODS AND RESULTS We used our model of experimental canine mitral regurgitation, which produces left ventricular dysfunction after 3 months of volume overload. We studied indexes of contractile function on and off beta-blockade at baseline and again on and off beta-blockade 3 months after chronic mitral regurgitation had induced significant contractile dysfunction. At baseline, acute beta-blockade caused insignificant reductions in the mass-corrected slope of the end-ejection stress-volume relation (EESVR), the end-systolic stiffness constant, and the ejection fraction-end-systolic stress and the mean velocity of circumferential fiber shortening (VCF)-end-systolic stress relations. After 3 months of chronic mitral regurgitation, all indexes of contractile function were normal in the unblocked state except for the VCF-stress relation, which was mildly reduced. However, after acute beta-blockade after 3 months of chronic mitral regurgitation, the EESVR fell to 303 +/- 27 versus 443 +/- 24 during acute beta-blockade before mitral regurgitation was created (P < .05), and the end-systolic stiffness constant was reduced to 2.54 +/- 0.15 versus 3.27 +/- 0.11 (P < .05). Only after beta-blockade was the ejection fraction-stress relation significantly reduced for dogs with chronic mitral regurgitation. The VCF-stress relation became markedly more abnormal. The viscosity-velocity relation of myocytes isolated from the ventricles of the dogs with mitral regurgitation confirmed that substantial innate contractile depression was present. CONCLUSIONS After 3 months of chronic mitral regurgitation, the adrenergic nervous system was able to maintain most indexes of contractile function in the normal range despite significant depression in innate contractile function. Thus, in the absence of beta-blockade, significant innate contractile depression may be obscured by adrenergic support.

BACKGROUND Standard mitral valve replacement (MVR) in patients with chronic mitral regurgitation consistently results in a decrease in postoperative left ventricular (LV) ejection performance. This fall in ejection performance has been attributed, at least in part, to unfavorable loading conditions imposed by the elimination of the low-impedance pathway for LV emptying into the left atrium. In contrast to standard MVR in which the chordae tendineae are severed, however, MVR with chordal preservation (MVR-CP) does not usually decrease LV ejection performance despite similar removal of the low-impedance pathway. The purpose of the present study was to define the mechanisms responsible for this discordance in postoperative ejection performance between MVR with and without chordal preservation. METHODS AND RESULTS Echocardiography and sphygmomanometer blood pressures were obtained in 15 patients with pure chronic mitral regurgitation before and 7-10 days after mitral valve surgery. These measurements were used to calculate ventricular volume, wall stress, and ejection fraction. Seven patients underwent MVR with chordal transection (MVR-CT), and eight patients underwent MVR-CP. MVR-CT resulted in no postoperative change in LV end-diastolic volume, a significant increase in LV end-systolic volume, a significant increase in end-systolic stress, from 89 +/- 9 to 111 +/- 12 g/cm2 (p < 0.05), and a significant decrease in ejection fraction, from 0.60 +/- 0.02 to 36 +/- 0.02 (p < 0.05). In contrast, patients who underwent MVR-CP had a significant decrease in LV end-diastolic and end-systolic volumes. End-systolic wall stress actually fell from 95 +/- 6 to 66 +/- 6 g/cm2 (p < 0.05), and ejection fraction was unchanged (0.63 +/- 0.01 before and 0.61 +/- 0.02 after mitral valve surgery) instead of reduced. CONCLUSIONS MVR-CT resulted in a decrease in ejection performance caused in part by an increase in end-systolic stress, which in turn increased end-systolic volume. Conversely, MVR-CP resulted in a smaller LV size, allowing a reduced end-systolic stress and preservation of ejection performance despite closure of the low-impedance left atrial ejection pathway.

BACKGROUND Chronic supraventricular tachycardia (SVT) causes a dilated cardiomyopathy and myocyte injury. Termination of SVT improves left ventricular (LV) function but is associated with LV hypertrophy. Changes in myocardial blood flow (MBF) that may accompany the development of and recovery from SVT cardiomyopathy might have a significant effect on LV function and myocyte structure. The goal of this study was to relate changes in LV function, myocyte composition, and coronary vascular structure to changes in MBF with the development and recovery of SVT cardiomyopathy. METHODS AND RESULTS LV function and MBF were measured in three groups of conscious pigs: sham control (control; n = 8), after 3 weeks of atrial pacing (SVT, 240 beats per minute; n = 8), and after a 4-week recovery from SVT (post-SVT; n = 8) by echocardiography catheterization and microspheres. Measurements were made under three states: 1) at rest with a basal heart rate, 2) rapid atrial pacing (240 beats per minute), and 3) during adenosine infusion (1.5 mumol/l.kg-1.min-1) without pacing. LV myocyte, capillary, and arteriole morphometric studies were performed in five additional pigs from each group using histochemistry and electron microscopy. LV fractional shortening was lower and left atrial pressure was significantly higher in the SVT group compared with control at rest, during pacing, and with adenosine (p less than 0.05). In the post-SVT group, fractional shortening returned to control values at rest and with adenosine, but fell from control values with pacing (p less than 0.05). Left atrial pressure fell in the post-SVT but remained significantly higher than control (p less than 0.05). LV/body weight ratio was significantly increased in the post-SVT group (p less than 0.05). In all states, SVT LVMBF was significantly reduced from control values (rest, 0.8 +/- 0.3 versus 1.6 +/- 0.3 ml-min-1.g-1; pacing, 1.2 +/- 0.2 versus 3.1 +/- 0.3 ml.min-1.g-1; adenosine, 1.4 +/- 0.3 versus 4.4 +/- 0.4 ml.min-1.g-1, respectively, p less than 0.05). In the post-SVT group, LVMBF was similar to control at rest (1.3 +/- 0.2 ml.min-1.g-1) but was significantly lower than control with pacing and adenosine (2.0 +/- 0.4 and 2.5 +/- 0.5 ml.min-1.g-1, respectively, p less than 0.05). Myofibrillar content fell significantly with SVT compared with control (42 +/- 5 versus 61 +/- 3%, p less than 0.05) and returned to control values in the post-SVT group (64 +/- 3%). Capillary density remained unchanged in the SVT and post-SVT groups, but capillary luminal diameter decreased and arteriole diameter increased in the SVT group (p less than 0.05). CONCLUSIONS The LV dysfunction and myocyte injury with SVT cardiomyopathy were associated with reduced MBF. Early recovery from SVT cardiomyopathy resulted in hypertrophy with normal MBF at rest, but significantly reduced coronary reserve.

Chronic supraventricular tachycardia (SVT) causes left ventricular (LV) dilatation and dysfunction. Termination of SVT appears to reduce LV size and improve function. However, changes in myocyte structure and morphology that accompany the development and regression of SVT-induced cardiomyopathy have not been studied. Accordingly, we measured LV function using echocardiography and catheterization in three groups of six pigs each: 3 weeks of atrial pacing (SVT; 240 beats/min), 4-week recovery from SVT (PST), and sham-operated controls. At each of these three end points, isolated myocyte dimensions and nuclear number were measured using fluorescence, and the volume percent of myocytes and myofibrils was computed from tissue sections using stereological techniques. SVT resulted in reduced LV fractional shortening (15 +/- 3% versus 31 +/- 2%, p less than 0.05), increased end-diastolic dimension (5.6 +/- 0.8 versus 3.8 +/- 0.2 cm, p less than 0.05), and no change in mass (2.6 +/- 0.1 versus 2.6 +/- 0.2 g/kg, p = NS) compared with controls. Myocyte length significantly increased with SVT (171 +/- 9 versus 109 +/- 11 microns, p less than 0.05), without significant changes in cell width (28 +/- 2 versus 26 +/- 2 microns). Nuclear number did not change with SVT; however, nuclear area/myocyte area significantly increased compared with controls (9.5 +/- 0.8 versus 8.7 +/- 0.8 x 10(-2), p less than 0.05). The volume percent of myocytes within the ventricular wall and the volume percent of myofibrils within myocytes decreased with SVT compared with controls (72 +/- 3% versus 80 +/- 3% and 45 +/- 5% versus 63 +/- 4%, respectively, p less than 0.05), with no change in total myocyte volume (54.2 +/- 2.7 versus 54.3 +/- 1.8 microns3 x 10(12)). In the PST group, LV fractional shortening returned to control values; however, there was persistent dilatation (end-diastolic dimension: 4.2 +/- 0.1 cm, p less than 0.05), and LV hypertrophy developed (3.3 +/- 0.3 g/kg, p less than 0.05). Increased myocyte length (158 +/- 5 microns, p less than 0.05) and width (33 +/- 2 microns, p less than 0.05) were observed in the PST group. The volume percent of myocytes and myofibrils returned to control values, with total myocyte volume significantly increased in the PST group compared with the control and SVT groups (74.5 +/- 2.6 microns3 x 10(12), p less than 0.05). In addition, the number of nuclei per myocyte in the PST group significantly increased from control values (5.1 +/- 0.1 versus 4.0 +/- 0.1, p less than 0.05).(ABSTRACT TRUNCATED AT 400 WORDS)

We tested the hypothesis that maximum systolic elastance (Emax) fails to detect a decline in left ventricular (LV) contractile function when diastolic dysfunction is present. Canine hearts were studied in an isolated blood-perfused heart apparatus (isovolumic LV); contractile dysfunction was produced by 60 or 90 minutes of global ischemia, followed by 90 minutes of reperfusion. Nine normal hearts underwent 60 minutes of ischemia, and five underwent 90 minutes of ischemia. After the ischemia-reperfusion sequence, developed pressure, pressure-volume area, and myocardial ATP level were significantly less than those at baseline in all 14 hearts. In the group undergoing 60 minutes of ischemia, LV diastolic pressure did not increase, whereas Emax decreased from 5.2 +/- 2.5 to 2.9 +/- 1.4 mm Hg/ml (p less than 0.05). In the group undergoing 90 minutes of ischemia, diastolic pressure increased (from 10 +/- 2 to 37 +/- 20 mm Hg, p less than 0.05), and Emax did not change significantly (from 5.1 +/- 4.3 to 4.3 +/- 2.5 mm Hg/ml). A second series of experiments was performed in 13 hearts with pressure-overload hypertrophy (aortic-band model with echocardiography and catheterization studies before the ischemia-reperfusion protocol). Five had evidence for pump failure, whereas eight remained compensated. After 60 minutes of ischemia and 90 minutes of reperfusion, developed pressure, pressure-volume area, and myocardial ATP level were significantly less than those at baseline in all 13 hearts. In the group with compensated LV hypertrophy, LV diastolic pressure did not change, whereas Emax decreased from 6.9 +/- 3.0 to 3.1 +/- 2.3 mm Hg/ml (p less than 0.05).(ABSTRACT TRUNCATED AT 250 WORDS)