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Patients with heart failure and preserved ejection fraction (HFpEF) have a high burden of symptoms and functional limitations, and have a poor quality of life. By targeting cardiometabolic abmormalities, sodium glucose cotransporter 2 (SGLT2) inhibitors may improve these impairments. In this multicenter, randomized trial of patients with HFpEF (NCT03030235), we evaluated whether the SGLT2 inhibitor dapagliflozin improves the primary endpoint of Kansas City Cardiomyopathy Questionnaire Clinical Summary Score (KCCQ-CS), a measure of heart failure-related health status, at 12 weeks after treatment initiation. Secondary endpoints included the 6-minute walk test (6MWT), KCCQ Overall Summary Score (KCCQ-OS), clinically meaningful changes in KCCQ-CS and -OS, and changes in weight, natriuretic peptides, glycated hemoglobin and systolic blood pressure. In total, 324 patients were randomized to dapagliflozin or placebo. Dapagliflozin improved KCCQ-CS (effect size, 5.8 points (95% confidence interval (CI) 2.3–9.2, P = 0.001), meeting the predefined primary endpoint, due to improvements in both KCCQ total symptom score (KCCQ-TS) (5.8 points (95% CI 2.0–9.6, P = 0.003)) and physical limitations scores (5.3 points (95% CI 0.7–10.0, P = 0.026)). Dapagliflozin also improved 6MWT (mean effect size of 20.1 m (95% CI 5.6–34.7, P = 0.007)), KCCQ-OS (4.5 points (95% CI 1.1–7.8, P = 0.009)), proportion of participants with 5-point or greater improvements in KCCQ-OS (odds ratio (OR) = 1.73 (95% CI 1.05–2.85, P = 0.03)) and reduced weight (mean effect size, 0.72 kg (95% CI 0.01–1.42, P = 0.046)). There were no significant differences in other secondary endpoints. Adverse events were similar between dapagliflozin and placebo (44 (27.2%) versus 38 (23.5%) patients, respectively). These results indicate that 12 weeks of dapagliflozin treatment significantly improved patient-reported symptoms, physical limitations and exercise function and was well tolerated in chronic HFpEF., In a multicenter, randomized trial, the SGLT2 inhibitor dapagliflozin improved the health status and exercise function of patients with heart failure with preserved ejection fraction (HFpEF), a condition for which effective treatments are lacking.

Exercise intolerance (EI) is the primary manifestation of chronic heart failure with preserved ejection fraction (HFpEF), the most common form of heart failure among older individuals. The recent recognition that HFpEF is likely a systemic, multiorgan disorder that shares characteristics with other common, difficult-to-treat, aging-related disorders suggests that novel insights may be gained from combining knowledge and concepts from aging and cardiovascular disease disciplines. This state-of-the-art review is based on the outcomes of a National Institute of Aging-sponsored working group meeting on aging and EI in HFpEF. We discuss aging-related and extracardiac contributors to EI in HFpEF and provide the rationale for a transdisciplinary, "gero-centric" approach to advance our understanding of EI in HFpEF and identify promising new therapeutic targets. We also provide a framework for prioritizing future research, including developing a uniform, comprehensive approach to phenotypic characterization of HFpEF, elucidating key geroscience targets for treatment, and conducting proof-of-concept trials to modify these targets.

Aims While greater physical activity (PA) is associated with improved health outcomes, the direct links between distinct components of PA, their changes over time, and cardiorespiratory fitness are incompletely understood. Methods and results Maximum effort cardiopulmonary exercise testing (CPET) and objective PA measures [sedentary time (SED), steps/day, and moderate-vigorous PA (MVPA)] via accelerometers worn for 1 week concurrent with CPET and 7.8 years prior were obtained in 2070 Framingham Heart Study participants [age 54 ± 9 years, 51% women, SED 810 ± 83 min/day, steps/day 7737 ± 3520, MVPA 22.3 ± 20.3 min/day, peak oxygen uptake (VO2) 23.6 ± 6.9 mL/kg/min]. Adjusted for clinical risk factors, increases in steps/day and MVPA and reduced SED between the two assessments were associated with distinct aspects of cardiorespiratory fitness (measured by VO2) during initiation, early-moderate level, peak exercise, and recovery, with the highest effect estimates for MVPA (false discovery rate Conclusions Our findings provide a detailed assessment of relations of different types of PA with multidimensional cardiorespiratory fitness measures and suggest favourable longitudinal changes in PA (and MVPA in particular) are associated with greater objective fitness.

Objectives The purpose of this study was to evaluate the effects of intravenous levosimendan on hemodynamics and 6-min walk distance (6MWD) in patients with pulmonary hypertension and heart failure with preserved ejection fraction (PH-HFpEF). Background There are no proven effective treatments for patients with PH-HFpEF. Methods Patients with mean pulmonary artery pressure (mPAP) ≥35 mm Hg, pulmonary capillary wedge pressure (PCWP) ≥20 mm Hg, and LVEF ≥40% underwent 6MWD and hemodynamic measurements at rest, during passive leg raise, and supine cycle exercise at baseline and after an open-label 24-h levosimendan infusion (0.1 μg/kg/min). Hemodynamic responders (those with ≥4 mm Hg reduction of exercise-PCWP) were randomized (double blind) to weekly levosimendan infusion (0.075 to 0.1ug/kg/min for 24 h) or placebo for 5 additional weeks. The primary end point was exercise-PCWP, and key secondary end points included 6MWD and PCWP measured across all exercise stages. Results Thirty-seven of 44 patients (84%) met responder criteria and were randomized to levosimendan (n = 18) or placebo (n = 19). Participants were 69 ± 9 years of age, 61% female, and with resting mPAP 41.0 ± 9.3 mm Hg and exercise-PCWP 36.8 ± 11.3 mm Hg. Compared with placebo, levosimendan did not significantly reduce the primary end point of exercise-PCWP at 6 weeks (−1.4 mm Hg; 95% confidence interval [CI]: −7.8 to 4.8; p = 0.65). However, levosimendan reduced PCWP measured across all exercise stages (−3.9 ± 2.0 mm Hg; p = 0.047). Levosimendan treatment resulted in a 29.3 m (95% CI: 2.5 to 56.1; p = 0.033) improvement in 6MWD compared with placebo. Conclusions Six weeks of once-weekly levosimendan infusion did not affect exercise-PCWP but did reduce PCWP incorporating data from rest and exercise, in tandem with increased 6MWD. Further study of levosimendan is warranted as a therapeutic option for PH-HFpEF. (Hemodynamic Evaluation of Levosimendan in Patients With PH-HFpEF [HELP]; NCT03541603 )

AIMS CONCERT-HF is an NHLBI-sponsored, double-blind, placebo-controlled, Phase II trial designed to determine whether treatment with autologous bone marrow-derived mesenchymal stromal cells (MSCs) and c-kit positive cardiac cells (CPCs), given alone or in combination, is feasible, safe, and beneficial in patients with heart failure (HF) caused by ischaemic cardiomyopathy. METHODS AND RESULTS Patients were randomized (1:1:1:1) to transendocardial injection of MSCs combined with CPCs, MSCs alone, CPCs alone, or placebo, and followed for 12 months. Seven centres enrolled 125 participants with left ventricular ejection fraction of 28.6 ± 6.1% and scar size 19.4 ± 5.8%, in New York Heart Association class II or III. The proportion of major adverse cardiac events (MACE) was significantly decreased by CPCs alone (-22% vs. placebo, P = 0.043). Quality of life (Minnesota Living with Heart Failure Questionnaire score) was significantly improved by MSCs alone (P = 0.050) and MSCs + CPCs (P = 0.023) vs. placebo. Left ventricular ejection fraction, left ventricular volumes, scar size, 6-min walking distance, and peak oxygen consumption did not differ significantly among groups. CONCLUSIONS This is the first multicentre trial assessing CPCs and a combination of two cell types from different tissues in HF patients. The results show that treatment is safe and feasible. Even with maximal guideline-directed therapy, both CPCs and MSCs were associated with improved clinical outcomes (MACE and quality of life, respectively) in ischaemic HF without affecting left ventricular function or structure, suggesting possible systemic or paracrine cellular mechanisms. Combining MSCs with CPCs was associated with improvement in both these outcomes. These results suggest potential important beneficial effects of CPCs and MSCs and support further investigation in HF patients.

Background Heart failure with preserved ejection fraction (HFpEF) is characterized by left ventricular hypertrophy and decreased exercise capacity. Fibroblast growth factor 23 (FGF23), a hormone involved in phosphate, vitamin D, and iron homeostasis, is linked to left ventricular hypertrophy and HF. We measured c-terminal FGF23 (cFGF23) and intact FGF23 (iFGF23) levels and examined their associations with exercise capacity in patients with HFpEF. Methods and Results Using multivariable linear regression and linear mixed models, we studied the associations of cFGF23 and iFGF23 with baseline and mean weekly change over 24 weeks in peak oxygen consumption and 6-minute walk distance in individuals enrolled in the Phosphodiesterase-5 Inhibition to Improve Clinical Status and Exercise Capacity in HFpEF trial. Our study population included 172 individuals with available plasma for cFGF23 and iFGF23 measurements. Median (25th–75th percentile) baseline cFGF23 and iFGF23 levels were 208.7 RU/mL (132.1–379.5 RU/mL) and 90.3 pg/mL (68.6–128.5 pg/mL), respectively. After adjustment for cardiovascular disease and hematologic and kidney parameters, higher cFGF23 was independently associated with a lower peak oxygen consumption at baseline. Higher iFGF23 was independently associated with shorter 6-minute walk distance at baseline. No significant associations were appreciated with the longitudinal outcomes. Conclusions In patients with HFpEF, higher FGF23 levels are independently associated with decreased exercise capacity at baseline.

There have been nearly 70 million cases of COVID‐19 worldwide, with over 1.5 million deaths at the time of this publication. This global pandemic has mandated dramatic changes in healthcare delivery with a particular focus on social distancing in order to reduce viral transmission. Heart failure patients are among the highest utilizers of health care and are at increased risk for COVID‐related vulnerabilities. Effectively managing this complex and resource‐intensive patient population from a distance presents new and unique challenges. Here, we review relevant data on telemedicine and remote monitoring strategies for heart failure patients and provide a framework to help providers treat this population during the COVID‐19 pandemic. This includes (i) dedicated pre‐visit contact and planning (i.e. confirm clinical appropriateness, presence of compatible technology, and patient comfort); (ii) utilization of virtual clinic visits (use of telehealth platforms, a video‐assisted exam, self‐reported vital signs, and weights); and (iii) use of existing remote heart failure monitoring sensors when applicable (CardioMEMS, Optivol, and HeartLogic). While telemedicine and remote monitoring strategies are not new, these technologies are emerging as an important tool for the effective management of heart failure patients during the COVID‐19 pandemic. In general, these strategies appear to be safe; however, additional data will be needed to determine their effectiveness with respect to both process and outcomes measures.

Background: Whereas cardiovascular disease (CVD) metrics define risk in individuals >40 years of age, the earliest lesions of CVD appear well before this age. Despite the role of metabolism in CVD antecedents, studies in younger, biracial populations to define precise metabolic risk phenotypes are lacking. Methods: We studied 2330 White and Black young adults (mean age, 32 years; 45% Black) in the CARDIA study (Coronary Artery Risk Development in Young Adults) to identify metabolite profiles associated with an adverse CVD phenome (myocardial structure/function, fitness, vascular calcification), mechanisms, and outcomes over 2 decades. Statistical learning methods (elastic nets/principal components analysis) and Cox regression generated parsimonious, metabolite-based risk scores validated in >1800 individuals in the Framingham Heart Study. Results: In the CARDIA study, metabolite profiles quantified in early adulthood were associated with subclinical CVD development over 20 years, specifying known and novel pathways of CVD (eg, transcriptional regulation, brain-derived neurotrophic factor, nitric oxide, renin–angiotensin). We found 2 multiparametric, metabolite-based scores linked independently to vascular and myocardial health, with metabolites included in each score specifying microbial metabolism, hepatic steatosis, oxidative stress, nitric oxide modulation, and collagen metabolism. The metabolite-based vascular scores were lower in men, and myocardial scores were lower in Black participants. Over a nearly 25-year median follow-up in CARDIA, the metabolite-based vascular score (hazard ratio, 0.68 per SD [95% CI, 0.50–0.92]; P =0.01) and myocardial score (hazard ratio, 0.60 per SD [95% CI, 0.45–0.80]; P =0.0005) in the third and fourth decades of life were associated with clinical CVD with a synergistic association with outcome ( P interaction =0.009). We replicated these findings in 1898 individuals in the Framingham Heart Study over 2 decades, with a similar association with outcome (including interaction), reclassification, and discrimination. In the Framingham Heart Study, the metabolite scores exhibited an age interaction ( P =0.0004 for a combined myocardial–vascular score with incident CVD), such that young adults with poorer metabolite-based health scores had highest hazard of future CVD. Conclusions: Metabolic signatures of myocardial and vascular health in young adulthood specify known/novel pathways of metabolic dysfunction relevant to CVD, associated with outcome in 2 independent cohorts. Efforts to include precision measures of metabolic health in risk stratification to interrupt CVD at its earliest stage are warranted.

Consistent survival of life-supporting pig heart xenograft recipients beyond 90 days was recently reported using genetically modified pigs and a clinically applicable drug treatment regimen. If this remarkable achievement proves reproducible, published benchmarks for clinical translation of cardiac xenografts appear to be within reach. Key mechanistic insights are summarized here that informed recent pig design and therapeutic choices, which together appear likely to enable early clinical translation.

The PARADIGM-HF (Prospective Comparison of Angiotensin II Receptor Blocker Neprilysin Inhibitor With Angiotensin-Converting Enzyme Inhibitor to Determine Impact on Global Mortality and Mor...

Exercise intolerance is a principal feature of heart failure with preserved ejection fraction (HFpEF), whether or not there is evidence of congestion at rest. The degree of functional limitation observed in HFpEF is comparable to patients with advanced heart failure and reduced ejection fraction. Exercise intolerance in HFpEF is characterized by impairments in the physiological reserve capacity of multiple organ systems, but the relative cardiac and extracardiac deficits vary among individuals. Detailed measurements made during exercise are necessary to identify and rank-order the multiorgan system limitations in reserve capacity that culminate in exertional intolerance in a given person. We use a case-based approach to comprehensively review mechanisms of exercise intolerance and optimal approaches to evaluate exercise capacity in HFpEF. We also summarize recent and ongoing trials of novel devices, drugs, and behavioral interventions that aim to improve specific exercise measures such as peak oxygen uptake, 6-min walk distance, heart rate, and hemodynamic profiles in HFpEF. Evaluation during the clinically relevant physiological perturbation of exercise holds promise to improve the precision with which HFpEF is defined and therapeutically targeted.

Background The United Network of Organ Sharing (UNOS) heart allocation policy designates patients on ECMO or with nondischargeable, surgically implanted, nonendovascular support devices (TCS-VAD) to higher listing statuses. Objectives This study aimed to explore whether temporary circulatory support-ventricular assist devices (TCS-VAD) have a survival advantage over extracorporeal membrane oxygenation (ECMO) as a bridge to transplant. Methods The UNOS database was used to conduct a retrospective analysis of adult heart transplants performed in the United States between 2005 and 2017. Survival analysis was performed to compare patients bridged to transplant with different modalities. Results Of the 24,905 adult transplants performed, 7,904 (32%) were bridged with durable left ventricular assist devices (LVADs), 177 (0.7%) with ECMO, 203 (0.8%) with TCS-VAD, 44 (0.2%) with percutaneous endovascular devices, and 8 (0.03%) with TandemHeart (LivaNova, London, United Kingdom). Unadjusted survival at 1 and 5 years post-transplant was 90 ± 0.4% and 77 ± 0.7% for durable LVAD, 84 ± 3% and 71 ± 4% for all TCS-VAD types, 79 ± 9% and 73 ± 14% for biventricular TCS-VAD, and 68 ± 3% and 61 ± 8% for ECMO. After propensity-matched pairwise comparisons were made, survival after all TCS-VAD types continued to be superior to ECMO (p = 0.019) and similar to LVAD (p = 0.380). ECMO was a predictor of post-transplant mortality in the Cox analysis compared with TCS-VAD (hazard ratio 2.40; 95% confidence interval: 1.44 to 4.01; p = 0.001). Conclusions Post-transplant survival with TCS-VAD is superior to ECMO and similar to LVAD in a national database.

Background Abnormal pulmonary arterial pressure (PAP) responses to exercise have been described in select individuals; however, clinical and prognostic implications of exercise pulmonary hypertension (exPH) among broader samples remains unclear. Objectives This study sought to investigate the association of exPH with clinical determinants and outcomes. Methods The authors studied individuals with chronic exertional dyspnea and preserved ejection fraction who underwent cardiopulmonary exercise testing with invasive hemodynamic monitoring. Exercise pulmonary hypertension was ascertained using minute-by-minute PAP and cardiac output (CO) measurements to calculate a PAP/CO slope, and exPH defined as a PAP/CO slope >3 mm Hg/l/min. The primary outcome was cardiovascular (CV) hospitalization or all-cause mortality. Results Among 714 individuals (age 57 years, 59% women), 296 (41%) had abnormal PAP/CO slopes. Over a mean follow-up of 3.7 ± 2.9 years, there were 208 CV or death events. Individuals with abnormal PAP/CO slope had a 2-fold increased hazard of future CV or death event (multivariable-adjusted hazard ratio: 2.03; 95% confidence interval: 1.48 to 2.78; p Conclusions Exercise pulmonary hypertension is independently associated with CV event-free survival among individuals undergoing evaluation of chronic dyspnea. These findings suggest incremental value of exercise hemodynamic assessment to resting measurements alone in characterizing the burden of PH in individuals with dyspnea. Whether PH and PH subtypes unmasked by exercise can be used to guide targeted therapeutic interventions requires further investigation.

Objective: Arterial stiffness is a risk factor for cardiovascular disease, including heart failure with preserved ejection fraction (HFpEF). MGP (matrix Gla protein) is implicated in vascular calcification in animal models, and circulating levels of the uncarboxylated, inactive form of MGP (ucMGP) are associated with cardiovascular disease-related and all-cause mortality in human studies. However, the role of MGP in arterial stiffness is uncertain. Approach and Results: We examined the association of ucMGP levels with vascular calcification, arterial stiffness including carotid-femoral pulse wave velocity (PWV), and incident heart failure in community-dwelling adults from the Framingham Heart Study. To further investigate the link between MGP and arterial stiffness, we compared aortic PWV in age- and sex-matched young (4-month-old) and aged (10-month-old) wild-type and Mgp +/− mice. Among 7066 adults, we observed significant associations between higher levels of ucMGP and measures of arterial stiffness, including higher PWV and pulse pressure. Longitudinal analyses demonstrated an association between higher ucMGP levels and future increases in systolic blood pressure and incident HFpEF. Aortic PWV was increased in older, but not young, female Mgp +/− mice compared with wild-type mice, and this augmentation in PWV was associated with increased aortic elastin fiber fragmentation and collagen accumulation. Conclusions: This translational study demonstrates an association between ucMGP levels and arterial stiffness and future HFpEF in a large observational study, findings that are substantiated by experimental studies showing that mice with Mgp heterozygosity develop arterial stiffness. Taken together, these complementary study designs suggest a potential role of therapeutically targeting MGP in HFpEF.

Importance The use of sacubitril/valsartan is not endorsed by practice guidelines for use in patients with New York Heart Association class IV heart failure with a reduced ejection fraction because of limited clinical experience in this population. Objective To compare treatment with sacubitril/valsartan treatment with valsartan in patients with advanced heart failure and a reduced ejection fraction and recent New York Heart Association class IV symptoms. Design, Setting, and Participants A double-blind randomized clinical trial was conducted; a total of 335 patients with advanced heart failure were included. The trial began on March 2, 2017, and was stopped early on March 23, 2020, owing to COVID-19 risk. Intervention Patients were randomized to receive sacubitril/valsartan (target dose, 200 mg twice daily) or valsartan (target dose, 160 mg twice daily) in addition to recommended therapy. Main Outcomes and Measures The area under the curve (AUC) for the ratio of N-terminal pro–brain natriuretic peptide (NT-proBNP) compared with baseline measured through 24 weeks of therapy. Results Of the 335 patients included in the analysis, 245 were men (73%); mean (SD) age was 59.4 (13.5) years. Seventy-two eligible patients (18%) were not able to tolerate sacubitril/valsartan, 100 mg/d, during the short run-in period, and 49 patients (29%) discontinued sacubitril/valsartan during the 24 weeks of the trial. The median NT-proBNP AUC for the valsartan treatment arm (n = 168) was 1.19 (IQR, 0.91-1.64), whereas the AUC for the sacubitril/valsartan treatment arm (n = 167) was 1.08 (IQR, 0.75-1.60). The estimated ratio of change in the NT-proBNP AUC was 0.95 (95% CI 0.84-1.08;P = .45). Compared with valsartan, treatment with sacubitril/valsartan did not improve the clinical composite of number of days alive, out of hospital, and free from heart failure events. Aside from a statistically significant increase in non–life-threatening hyperkalemia in the sacubitril/valsartan arm (28 [17%] vs 15 [9%];P = .04), there were no observed safety concerns. Conclusions and Relevance The findings of this trial showed that, in patients with chronic advanced heart failure with a reduced ejection fraction, there was no statistically significant difference between sacubitril/valsartan and valsartan with respect to reducing NT-proBNP levels. Trial Registration ClinicalTrials.gov Identifier:NCT02816736

Fournier's gangrene (FG) is a perineal and abdominal necrotizing infection. It is most commonly found in middle-aged men with comorbidities such as diabetes mellitus. Initial symptoms are often indistinct and can rapidly progress to overwhelming infections with a relatively high mortality rate. It is crucial to make a prompt diagnosis so that the patient receives appropriate treatment. Given the importance of the identification of FG, we explored what were the most common signs and symptoms associated with FG, as well as distinguished the gold standard treatment. This systematic review utilized articles identified exclusively through PubMed using key terms such as Fournier's gangrene, signs, symptoms, and treatment. A total of 37 studies, including a total of 3,224 patients (3,093 males and 131 females), fit our inclusion parameters for relevance that included either the most identifiable presentation of FG or the most effective treatment. From our search, the most common clinical presentation was scrotal and labial pain, fever, abscesses, crepitus, erythema, and cellulitis. Diagnosis is made from clinical findings in conjunction with imaging. The gold standard for treatment was found to be a combination of surgical debridement, broad-spectrum antibiotics, and the administration of intravenous fluids. Further, patient survival was found to be directly related to the time from diagnosis to treatment when they underwent surgical debridement. The importance of early identification for improved outcomes or survival highlights the need for further studies or measures to enhance the identification of the signs and symptoms of FG.

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Background Dyspnea and exercise intolerance are commonly reported post-acute sequelae of SARS-CoV-2 infection (PASC), but routine diagnostic testing is often normal. Cardiopulmonary exercise testing (CPET) offers comprehensive assessment of dyspnea to characterize pulmonary PASC. Methods We performed a retrospective cohort study of CPET performed on patients reporting dyspnea and/or exercise intolerance following confirmed Covid-19 between August 1, 2020 and March 1, 2021, and compared them to age- and sex-matched patients with unexplained dyspnea referred for CPET at the same center in the pre-Covid-19 era. Findings Compared to matched unexplained dyspnea comparators, PASC patients shared similar medical comorbidities and subjective dyspnea at referral (mMRC score 1.6 ± 0.9 vs. 1.4 ± 0.9, P = 0.5). Fifteen (83.3%) PASC patients underwent high resolution computed tomography of the chest, of which half (46.7%) were normal, and 17 (94.4%) patients had pulmonary function testing, of which the majority (76.5%) were normal. All patients underwent CPET, and 12 (67%) had normal findings. Compared to matched comparators, PASC patients had similar peak oxygen consumption, oxygen consumption at ventilatory anaerobic threshold, and ventilatory efficiency measured by the minute ventilation to carbon dioxide production (VE/VCO2) slope. Interpretation Despite prominent dyspnea, physiological abnormalities on CPET were mild across a range of initial Covid-19 severity and similar to matched comparators referred for dyspnea without antecedent SARS-CoV-2. Funding The project was supported by the NHLBI (R01HL131029, R01HL151841, U10HL110337, T32HL116275) and a KL2 award (5KL2TR002542–02) from Harvard Catalyst.

Cardiorespiratory fitness (CRF) is intricately related to health status. The optimal approach for CRF quantification is through assessment of peak oxygen uptake (VO(2)), but such measurements have been largely confined to small referral populations. Here we describe protocols and methodological considerations for peak VO(2) assessment and determination of volitional effort in a large community-based sample. Maximum incremental ramp cycle ergometry cardiopulmonary exercise testing (CPET) was performed by Framingham Heart Study participants at a routine study visit (2016–2019). Of 3486 individuals presenting for a multi-component study visit, 3116 (89%) completed CPET. The sample was middle-aged (54±9 years), with 53% women, body mass index 28.3±5.6 kg/m(2), 48% with hypertension, 6% smokers, and 8% with diabetes. Exercise duration was 12.0±2.1 minutes (limits 3.7–20.5). No major cardiovascular events occurred. A total of 98%, 96%, 90%, 76%, and 57% of the sample reached peak respiratory exchange ratio (RER) values of ≥1.0, ≥1.05, ≥1.10, ≥1.15, and ≥1.20, respectively (mean peak RER=1.22±0.10). With rising peak RER values up to ≈1.10, steep changes were observed for percent predicted peak VO(2), VO(2) at the ventilatory threshold/peak VO(2), heart rate response, and Borg (subjective dyspnea) scores. More shallow changes for effort dependent CPET variables were observed with higher achieved RER values. In conclusion, measurement of peak VO(2) is feasible and safe in a large sample of middle-aged, community-dwelling individuals with heterogeneous cardiovascular risk profiles. Peak RER ≥1.10 was achievable by the majority of middle-aged adults and RER values beyond this threshold did not necessarily correspond to higher peak VO(2) values.

BackgroundTherapeutically immunosuppressed transplant recipients exhibit attenuated responses to COVID-19 vaccines. To better understand the immune alterations that determined poor vaccine response, we correlated quantities of circulating T and B cell subsets at baseline with longitudinal serologic responses to SARS-CoV-2 mRNA vaccination in heart and lung transplant recipients.MethodsSamples at baseline and at approximately 8 and 30 days after each vaccine dose for 22 heart and lung transplant recipients with no history of COVID-19, four heart and lung transplant recipients with prior COVID-19 infection, and 12 healthy controls undergoing vaccination were analyzed. Anti-spike protein receptor binding domain (RBD) IgG and pseudovirus neutralization activity were measured. Proportions of B and T cell subsets at baseline were comprehensively quantitated.ResultsAt 8-30 days post vaccination, healthy controls displayed robust anti-RBD IgG responses, whereas heart and lung transplant recipients showed minimally increased responses. A parallel absence of activity was observed in pseudovirus neutralization. In contrast, three of four (75%) transplant recipients with prior COVID-19 infection displayed robust responses at levels comparable to controls. Baseline levels of activated PD-1+ HLA-DR+ CXCR5- CD4+ T cells (also known as T peripheral helper [TPH] cells) and CD4+ T cells strongly predicted the ability to mount a response.ConclusionsImmunosuppressed patients have defective vaccine responses but can be induced to generate neutralizing antibodies after SARS-CoV-2 infection. Strong correlations of vaccine responsiveness with baseline TPH and CD4+ T cell numbers highlights a role for T helper activity in B cell differentiation into antibody secreting cells during vaccine response.

Although end-organ damage caused by AL amyloidosis historically portends a poor prognosis, advances in therapy in combination with solid organ transplantation can lead to significant improvements in survival. Immunomodulatory agents (IMiDs), such as lenalidomide and pomalidomide, are an effective class of drugs in the treatment of AL amyloidosis. However, there is growing concern that these agents may precipitate acute transplant rejection via upregulation of interleukin-2 and inhibition of immune tolerance. This case series describes three patients who underwent orthotopic heart transplantation for AL amyloidosis and later had progression of their underlying plasma cell dyscrasia, leading to treatment with IMiD therapy. Two patients subsequently developed acute allograft rejection, including the first reported case of pomalidomide-associated allograft rejection. The third patient tolerated long-term therapy without signs of rejection: the first reported case of IMiD tolerability after heart transplant. These cases, together with a review of the literature, demonstrate variable outcomes and elucidate the potential risk of organ rejection associated with the use of IMiDs. When treatment with IMiDs is necessary, close surveillance and modification of immunosuppression may mitigate risks of rejection and complications.

Hearts from older donors are increasingly utilized for transplantation due to unmet demand. Conflicting evidence exists regarding the prognosis of recipients of advanced age donor hearts, especially in young recipients. A retrospective analysis was performed on 11 433 patients aged 18 to 45 who received a cardiac transplant from 2000 to 2017. Overall, 10 279 patients received hearts from donors less than 45 and 1145 from donors greater than 45. Recipients of older donors were older (37 vs. 34 years, P < .01) and had higher rates of inotropic dependence (48% vs. 42%, P < .01). However, groups were similar in terms of comorbidities and dependence on mechanical circulatory support. Median survival for recipients of older donors was reduced by 2.6 years (12.6 vs. 15.2, P < .01). Multivariable analysis demonstrated donor age greater than 45 to be a predictor of mortality (HR 1.18 [1.05-1.33], P = .01). However, when restricting the analysis to patients who received a donor with a negative preprocurement angiogram, donor age only had a borderline association with mortality (HR 1.20 [0.98-1.46], P = .06). Older donor hearts in young recipients are associated with decreased long-term survival, however this risk is reduced in donors without atherosclerosis. The long-term hazard of this practice should be carefully weighed against the risk of waitlist mortality.

OBJECTIVES Outcomes of cardiac transplantation in patients undergoing reoperative sternotomy are often worse than primary transplants. However, the risks imposed by a prior sternotomy, left ventricular assist device (LVAD) or retransplantation have not been independently analysed. METHODS Using the United Network for Organ Sharing (UNOS) database, a retrospective propensity-matched cohort analysis was performed on 14 730 patients who received a heart transplant between 2005 and 2017. Of 7365 patients who underwent a reoperative sternotomy, 4526 (61%) patients had previous cardiac surgery, 2364 (32%) patients had an LVAD and 475 (6%) patients had a previous transplant. Baseline characteristics were compared, and survival was analysed using a Cox model. RESULTS Compared to patients who underwent a primary transplant, patients with a prior sternotomy had a worse long-term survival (P

Aims Accurate interpretation of cardiopulmonary exercise testing (CPET) relies on age, gender, and exercise modality-specific reference values. To date, clinically applicable CPET reference values derived from a source population of endurance athletes (EAs) have been lacking. The purpose of this study was to generate CPET reference values for use in the clinical assessment of EA. Methods and Results Prospective data accrued during the clinical care of healthy EA were used to derive CPET reference values and to develop novel equations for V˙O2peak. The performance of these equations was compared to the contemporary standard of care equations and assessed in a discrete EA validation cohort. A total of 272 EA (age = 42 ± 15 years, female = 31%, V˙O2peak = 3.6 ± 0.83 L/min) met inclusion criteria and comprised the derivation cohort. V˙O2peak prediction equations derived from general population cohorts described a modest amount of V˙O2peak variability [R2 = 0.58–0.70, root mean square error (RMSE) = 0.46–0.54 L/min] but were mis-calibrated (calibration-in-the-large = 0.45–1.18 L/min) among EA leading to significant V˙O2peak underestimation. Newly derived, externally validated V˙O2peak prediction equations for EA that included age, sex, and height for both treadmill (R2 = 0.74, RMSE = 0.42 L/min) and cycle ergometer CPET (Cycle: R2 = 0.69, RMSE = 0.42 L/min) demonstrated improved accuracy. Conclusion Commonly used V˙O2peak prediction equations derived from general population cohorts perform poorly among competitive EA. Newly derived CPET reference values including novel V˙O2peak prediction equations may improve the clinical utility of CPET in this rapidly growing patient population.

Background: Iron deficiency (ID) has a prevalence of ≈40% to 50% among patients in heart failure (HF) with reduced ejection fraction and is associated with worse prognosis. Several trials demonstrated that intravenous ferric carboxymaltose leads to early and sustained improvement in patient-reported outcomes and functional capacity in patients with HF with reduced ejection fraction with ID, yet morbidity and mortality data are limited. Methods: The objective of the HEART-FID trial (Ferric Carboxymaltose in Heart Failure With Iron Deficiency) is to assess efficacy and safety of ferric carboxymaltose compared with placebo as treatment for symptomatic HF with reduced ejection fraction with ID. HEART-FID is a multicenter, randomized, double-blind, placebo-controlled trial enrolling ≈3014 patients at ≈300 international centers. Eligible patients are aged ≥18 years in stable chronic HF with New York Heart Association functional class II to IV symptoms, ejection fraction ≤40%, ID (ferritin Conclusions: The HEART-FID trial will inform clinical practice by clarifying the role of long-term treatment with intravenous ferric carboxymaltose, added to usual care, in ambulatory patients with symptomatic HF with reduced ejection fraction with ID. Registration: URL: https://www.clinicaltrials.gov ; Unique identifier: NCT03037931.

BACKGROUND: Obesity has multifactorial effects on lung function and exercise capacity. The contributions of obesity-related inflammatory pathways to alterations in lung function remain unclear. RESEARCH QUESTION: To examine the association of obesity-related inflammatory pathways with pulmonary function, exercise capacity, and pulmonary-specific contributors to exercise intolerance. METHOD: We examined 695 patients who underwent cardiopulmonary exercise testing (CPET) with invasive hemodynamic monitoring at Massachusetts General Hospital between December 2006–June 2017. We investigated the association of adiponectin, leptin, resistin, IL-6, CRP, and insulin resistance (HOMA-IR) with pulmonary function and exercise parameters using multivariable linear regression. RESULTS: Obesity-related inflammatory pathways were associated with worse lung function. Specifically, higher CRP, IL-6, and HOMA-IR were associated with lower percent predicted FEV(1) and FVC with a preserved FEV(1)/FVC ratio suggesting a restrictive physiology pattern (P≤0.001 for all). For example, a 1-SD higher natural-logged CRP level was associated with a nearly 5% lower percent predicted FEV(1) and FVC (beta −4.8, s.e. 0.9 for FEV1; beta −4.9, s.e. 0.8 for FVC; P

Aims: Viral-induced cardiac inflammation can induce heart failure with preserved ejection fraction (HFpEF)-like syndromes. COVID-19 can lead to myocardial damage and vascular injury. We hypothesised that COVID-19 patients frequently develop a HFpEF-like syndrome, and designed this study to explore this. Methods and results: Cardiac function was assessed in 64 consecutive, hospitalized, and clinically stable COVID-19 patients from April-November 2020 with left ventricular ejection fraction (LVEF) ≥50% (age 56 ± 19 years, females: 31%, severe COVID-19 disease: 69%). To investigate likelihood of HFpEF presence, we used the HFA-PEFF score. A low (0-1 points), intermediate (2-4 points), and high (5-6 points) HFA-PEFF score was observed in 42%, 33%, and 25% of patients, respectively. In comparison, 64 subjects of similar age, sex, and comorbidity status without COVID-19 showed these scores in 30%, 66%, and 4%, respectively (between groups: P = 0.0002). High HFA-PEFF scores were more frequent in COVID-19 patients than controls (25% vs. 4%, P = 0.001). In COVID-19 patients, the HFA-PEFF score significantly correlated with age, estimated glomerular filtration rate, high-sensitivity troponin T (hsTnT), haemoglobin, QTc interval, LVEF, mitral E/A ratio, and H2 FPEF score (all P < 0.05). In multivariate, ordinal regression analyses, higher age and hsTnT were significant predictors of increased HFA-PEFF scores. Patients with myocardial injury (hsTnT ≥14 ng/L: 31%) vs. patients without myocardial injury, showed higher HFA-PEFF scores [median 5 (interquartile range 3-6) vs. 1 (0-3), P < 0.001] and more often showed left ventricular diastolic dysfunction (75% vs. 27%, P < 0.001). Conclusion: Hospitalized COVID-19 patients frequently show high likelihood of presence of HFpEF that is associated with cardiac structural and functional alterations, and myocardial injury. Detailed cardiac assessments including echocardiographic determination of left ventricular diastolic function and biomarkers should become routine in the care of hospitalized COVID-19 patients.

Background Exercise testing plays an important role in evaluating heart failure prognosis and selecting patients for advanced therapeutic interventions. However, concern for severe acute respiratory syndrome novel coronavirus-2 transmission during exercise testing has markedly curtailed performance of exercise testing during the novel coronavirus disease-2019 pandemic. Methods and Results To examine the feasibility to conducting exercise testing with an in-line filter, 2 healthy volunteer subjects each completed 2 incremental exercise tests, one with discrete stages of increasing resistance and one with a continuous ramp. Each subject performed 1 test with an electrostatic filter in-line with the system measuring gas exchange and air flow, and 1 test without the filter in place. Oxygen uptake and minute ventilation were highly consistent when evaluated with and without use of an electrostatic filter with a >99.9% viral efficiency. Conclusions Deployment of a commercially available in-line electrostatic viral filter during cardiopulmonary exercise testing is feasible and provides consistent data compared with testing without a filter.

To assess the prevalence and clinical correlates of exercise oscillatory ventilation (EOV) in patients with hypertrophic cardiomyopathy (HCM). Retrospective single-center study. Thirty-six consecutive HCM patients who underwent cardiopulmonary exercise testing. Two patients (5.6%) had EOV. Both patients with peak oxygen consumption (VO2) less than or equal to 9.1 ml/kg/min had EOV. Left atrial size was greater in patients with EOV. Of the 2 patients in the study population with an abnormal blood pressure response to exercise, 1 had EOV. Both patients with New York Heart Association Class 3 heart failure had EOV. This is the first report of EOV in HCM. EOV is uncommon in patients with HCM. EOV appears to be a marker of disease severity as evidenced by overt heart failure, left atrial enlargement, and low peak VO2.

Objective To examine trends in utilization of hearts from hepatitis C virus (HCV) viremic donors for transplantation, a strategy to expand organ availability. Methods The United Network for Organ Sharing (UNOS) registry was queried for adult patients undergoing heart transplantation between 2015 and 2019. We excluded multiorgan transplants, incomplete data, and loss to follow-up. Nucleic acid testing (NAT) defined HCV status. Results Between 2015 and 2019, a total of 11,393 adults underwent heart transplantation: 326 from HCV NAT+ donors and 11,067 from NAT− donors. The use of NAT+ hearts increased from 1 in 2015 to 137 in 2018 against a static number of NAT− organs. The use of NAT+ hearts varied significantly across regions and individual centers. More than 75% of NAT+ hearts were transplanted in the Northeast region, leading to further travel (mean, 299 miles vs 173 miles for NAT− transplantations; P 20% of all transplantations from viremic donors. Survival in the 2 groups did not differ by Kaplan-Meier analysis (P = .240), and multivariable regression showed no differences in acute rejection (P = .455) or 30-day mortality (P = .490). Of the 326 recipients of NAT+ hearts, 38 seroconverted and 14 became viremic within 1 year. Survival was 100% in the viremic patients and 97.4% in seroconverted patients at 1 year. Conclusions Heart transplantation from HCV viremic donors continues to increase but varies significantly across UNOS regions and individual centers. Short-term outcomes are comparable, but effects of seroconversion and long-term outcomes remain unclear.

Introduction: The COVID-19 Pandemic has mandated limiting routine visit frequency for patients with chronic cardiovascular (CV) diseases. In patients with heart failure (HF) followed longitudinally, the period of clinical trial participation provides an opportunity to evaluate the influence of high-frequency per-protocol in-person visits compared to less frequent routine visits during longitudinal clinical care. Hypothesis: Patients enrolled in clinical trials will have a lower CV and HF event rates during periods of trial enrollment than during non-trial periods. Methods: We examined clinical characteristics, CV and HF hospitalization rates, and outcomes in patients with HF receiving longitudinal HF care at a single center. We evaluated hospitalization rates during the 1-year preceding trial enrollment and hospitalization and death rates during enrollment in clinical trials and for up to 1 year following trial completion. Results: Among the 121 patients enrolled in HF clinical trials, 72% were HFrEF (age 62±11, 19% females, BMI 30.4±6.0, LVEF 25±7, NYHA 2.7±0.6, NT-proBNP 2336±2671) and 28% were HFpEF (age 69±9, BMI 32.1±5.5, 29% females, LVEF 60±10, NYHA 2.4±0.5, NT-proBNP 957±997). Average clinical trial exposure was 8±6.6 months. Per-protocol visit frequency was 16±7 per year during clinical trial enrollment. In the one-year pre-trial period, compared to the within-trial period, CV hospitalizations were 0.88/patient-year vs. 0.32/patient-year (p Conclusion: In HF patients followed longitudinally at a single center, periods of clinical trial enrollment were associated with high visit frequency and lower CV and HF hospitalization rates. These findings highlight the potential benefits of trial enrollment and high-frequency visits for HF patients at a time when routine visit frequency is being carefully considered during the COVID-19 Pandemic.

Introduction: Although preclinical studies of cell delivery in models of ischemic heart failure (HF) suggest a beneficial interaction between mesenchymal stromal cells (MSCs) and c-kit+ cardiac progenitor cells (CPCs) resulting in additive therapeutic effects, no clinical trial has examined a combination of different cell types in ischemic HF. Furthermore, comparative studies of different cell products in humans are rare. CONCERT-HF (NCT02501811) is an NHLBI-sponsored, randomized, double-blind, placebo-controlled, Phase II trial of the Cardiovascular Cell Therapy Research Network (CCTRN) investigating feasibility, safety, and efficacy of MSCs and CPCs, alone and in combination, in patients with chronic ischemic HF. Objectives: To address the following questions: Is combined treatment with MSCs and CPCs feasible and safe in patients with ischemic HF? Do MSCs and CPCs, given alone or in combination, alleviate LV dysfunction, reduce scar size, improve quality of life, and/or augment functional capacity? Is either cell type more effective than the other? Is the combination of MSCs and CPCs more efficacious than MSCs alone or CPCs alone? Methods: Patients were randomized (1:1:1:1) to receive i) the combination of autologous bone marrow-derived MSCs and autologous CPCs, ii) MSCs alone, iii) CPCs alone, or iv) placebo. Target doses were 150 x 10 6 MSCs and 5 x 10 6 CPCs. All patients underwent bone marrow aspiration and right heart catheterization. Endomyocardial biopsy was performed only in the MSC + CPC and CPC alone groups; a “sham biopsy” was performed in the MSC alone and placebo groups. All patients underwent study product injection using the NOGA ® XP Mapping System and were followed for 12 months. Results: A total of 125 patients (116 M, 9 F), 62.5 ± 8.9 years old, were enrolled at 7 CCTRN centers between Nov 2016 and Oct 2018. Baseline LVEF (cardiac MRI) was 28.6 ± 6.1% with a mean scar size of 31.8 ± 10.9 g and NYHA class II (80%) or class III (15.2%). Conclusions: CONCERT-HF is the first cell therapy trial to assess a combination of different cell types and to directly compare two different cell products in patients with HF. All patients will complete follow-up by the end of June and final primary (12-month) safety and outcomes data will be available in August 2020.

Introduction: During maximum incremental exercise expiratory flow rates increase > 10-fold and minute ventilation can exceed 100L/min, raising concern for possible spread of COVID-19 in asymptomatic patients undergoing exercise testing. Moreover, use of surgical or N95 masks that limit airflow are recognized to limit the ability to perform maximum exercise. Hypothesis: Use of an in-line filter during cardiopulmonary exercise testing is feasible and will not adversely impact measurements of exercise capacity. Methods: We conducted a proof-of-principle study in which a commercially available electrostat filter (Figure 1A), which has >99.9% viral efficiency without affecting spirometry measurements during pulmonary function testing, was placed in-line, upstream of the flow meter and gas analyzer sample line for use during cardiopulmonary exercise testing. A single healthy subject completed incremental exercise with a 3 min period of unloaded exercise followed by 4-min stages of exercise at 50, 100, 150, and 200W with and without the filter in place on the same day. Mechanical dead space was 53 ml with the filter and 45 ml without. Results: In comparison to no internal filter, use of an in-line filter resulted in VO 2 measurements of 99%, 97%, 98%, and 97% during 50W, 100W, 150W, and 200W, respectively (Figure 1A). VO 2 /work slope measurements and measurements of minute ventilation were also highly consistent throughout exercise with and without use of an in-line filter (Figure 1B). Conclusions: Exercise testing is an integral part of cardiovascular care delivery. Our findings require further validation but suggest that an in-line filtration system can be utilized in an effort to reduce droplet and viral dissemination without impacting measures of cardiopulmonary performance.

Introduction: The post-exercise recovery period poses advantages over the within-exercise period for acquisition of hemodynamic measurements because of attenuated respirophasic changes, ability to time measurements precisely relative to peak exercise, and increased feasibility of multi-modality data acquisition (i.e. echocardiographic imaging). While several studies have linked rest and exercise hemodynamic measurements to outcomes, the prognostic significance of recovery hemodynamics in patients with dyspnea on exertion remains unknown. Hypothesis: Impaired recovery of mean pulmonary arterial pressure (mPAP) following exercise predicts poor clinical outcomes. Methods: Upright incremental ramp cycle ergometry cardiopulmonary exercise testing with invasive hemodynamic monitoring was performed in patients referred for evaluation of exertional dyspnea. mPAP was obtained at rest, peak exercise, and at two-minutes following peak exercise. In addition, maximum workload was recorded for each patient. mPAP elevation at recovery versus baseline, indexed to peak workload, was determined. Cox regression was performed using the primary outcome of heart failure event-free survival. Results: Among 272 patients with dyspnea on exertion and preserved LVEF [age 61 (IQR 49 – 70), 47% male, BMI 29 kg/m 2 (25 – 34), exercise duration 8.1 minutes (6.9 – 9.2), peak workload 91 watts (71 – 121)] we observed an increase in mPAP from 17 (14– 20) to 33 (28 – 41) mmHg with a fall in mPAP to 22 (18 – 29) at 2 minutes of recovery. Median mPAP elevation at recovery versus baseline mPAP, indexed to peak workload, was 0.057 (0.031 – 0.101) mmHg/W. Persistently elevated mPAP, indexed to peak workload, was associated with future risk of HF hospitalization or death both in unadjusted analysis (Cox hazard ratio 1.53 for every standard deviation increase, p=0.003), and when adjusted for age, sex, and BMI (HR 1.40, p=0.025). Conclusions: Among patients with dyspnea on exertion undergoing invasive hemodynamic evaluation during exercise, persistently elevated mPAP following exercise predicts future heart failure event-free survival and may be more feasible to estimate non-invasively than measures obtained at peak exercise.

Introduction: Cardiopulmonary exercise testing (CPET) can help identify early stages of heart failure with preserved ejection fraction (HFpEF). We sought to determine if percent predicted peak oxygen pulse (%PredO 2 P, as defined by peak oxygen uptake/heart rate), a noninvasive measure combining stroke volume and peripheral oxygen extraction, could serve as a marker of the hemodynamic response to exercise in HFpEF patients. Methods: 154 consecutive patients who underwent maximal CPET (RER>1.05) and were diagnosed with HFpEF (defined as LVEF>50% and PCWP/CO >2 mmHg*min/L or supine resting PCWP >15 mmHg) were included. Exclusion criteria included patients who were taking AV nodal agents, were paced, or had atrial fibrillation. Peak O 2 P and percent predicted were calculated using the Wasserman equation for peak VO2 in conjunction with peak predicted heart rate (220-age). Results: Tertiles of %PredO 2 P were determined with first tertile at 42.1-76.2%, second tertile at 76.2-94.4%, and third tertile at 94.4-139.2%. Baseline parameters differed across %PredO 2 P tertiles ( Table 1 ) with BMI increasing (trend p=0.014). Peak cardiac output (1 st : 10.0±3.0 L/min, 2 nd : 11.1±2.4, 3 rd : 11.5±3.5; p=0.038) and peak stroke volume (1 st : 70.6±20.1 mL, 2 nd : 83.0±16.6, 3 rd : 92.7±20.1; pst : 143±23 bpm, 2 nd : 135±25, 3 rd : 123±26; pst : 959±304 dynes*s/cm 5 , 2 nd : 831±187, 3 rd : 810±321; p=0.009) were lower. Exercise PAP/CO slope (1 st : 4.5±2.1 mmHg*min/L, 2 nd : 3.6±1.6, 3 rd : 3.3±1.7; p=0.003) and PCWP/CO slope (1 st : 3.4±1.8 mmHg*min/L, 2 nd : 2.9±1.4, 3 rd : 2.8±2.0; p=0.015) were lower across tertiles of %PredO 2 P. Conclusions: %PredO 2 P is a noninvasive variable that associates with vascular responses to exercise in HFpEF patients. Higher %PredO 2 P was associated with improved vascular responses to exercise with lower SVR, PAP/CO and PCWP/CO slopes.

Introduction: Exercise intolerance is common in cardiovascular disease and is a cardinal manifestation of heart failure with preserved ejection fraction (HFpEF). Decreased exercise capacity is often attributed to cardiac limitations, though HFpEF is increasingly recognized to be both a metabolic and a cardiovascular disorder. Hypothesis: Patients with HFpEF will have exaggerated metabolic cost of exercise initiation with associated high expenditure of hemodynamic reserve capacity. Methods: We quantified the workload-equivalent cost of initiating exercise using cardiopulmonary exercise testing in patients with HFpEF (N=184, age 62±13, 47% women, peak VO2 13.8±3.3 ml/kg/min). Individualized VO2-work rate relationships during loaded exercise were used to derive the work-equivalents required to move extremities with zero external resistance (0 watts)—termed “internal work” (IW). Standard linear regression techniques were used for comparisons. Results: In individuals with HFpEF, the internal work (42±28 W) was often a large portion of the total workload achieved. BMI accounted for the greatest variance in IW (23%), suggesting a metabolic basis for IW. Resting measures of myocardial function and biventricular filling pressures did not measurably contribute to explanatory variance in IW, suggesting a non-cardiac origin. Individuals with HFpEF in the fourth quartile of IW (76±28W) had a dramatic hemodynamic response to exercise in pulmonary capillary wedge and mean pulmonary arterial pressures. Changes in hemodynamic measurements were more modest between quartiles of IW in the submaximal ramp period following unloaded exercise. Conclusions: Internal work is a new measure that captures the metabolic cost of initiating movement. Internal work is associated with limitations in achievable external workload as well as steep early increases in cardiac filling pressures in HFpEF. Further investigation into the pathophysiology of elevated IW is needed.

In this chapter, we will discuss several different key aspects of pericardial physiology and pathology, including acute and chronic inflammatory states of the pericardium, cardiac tamponade, and chronic constrictive pericarditis. In addition, we will provide an overview of pressure-volume loops.

IMPORTANCE: Heart failure with preserved ejection fraction (HFpEF) is often characterized by nitric oxide deficiency. OBJECTIVE: To evaluate the efficacy and adverse effects of praliciguat, an oral soluble guanylate cyclase stimulator, in patients with HFpEF. DESIGN, SETTING, AND PARTICIPANTS: CAPACITY HFpEF was a randomized, double-blind, placebo-controlled, phase 2 trial. Fifty-nine sites enrolled 196 patients with heart failure and an ejection fraction of at least 40%, impaired peak rate of oxygen consumption (peak V̇o(2)), and at least 2 conditions associated with nitric oxide deficiency (diabetes, hypertension, obesity, or advanced age). The trial randomized patients to 1 of 3 praliciguat dose groups or a placebo group, but was refocused early to a comparison of the 40-mg praliciguat dose vs placebo. Participants were enrolled from November 15, 2017, to April 30, 2019, with final follow-up on August 19, 2019. INTERVENTIONS: Patients were randomized to receive 12 weeks of treatment with 40 mg of praliciguat daily (n = 91) or placebo (n = 90). MAIN OUTCOMES AND MEASURES: The primary efficacy end point was the change from baseline in peak V̇o(2) in patients who completed at least 8 weeks of assigned dosing. Secondary end points included the change from baseline in 6-minute walk test distance and in ventilatory efficiency (ventilation/carbon dioxide production slope). The primary adverse event end point was the incidence of treatment-emergent adverse events (TEAEs). RESULTS: Among 181 patients (mean [SD] age, 70 [9] years; 75 [41%] women), 155 (86%) completed the trial. In the placebo (n = 78) and praliciguat (n = 65) groups, changes in peak V̇o(2) were 0.04 mL/kg/min (95% CI, –0.49 to 0.56) and −0.26 mL/kg/min (95% CI, −0.83 to 0.31), respectively; the placebo-adjusted least-squares between-group difference in mean change from baseline was −0.30 mL/kg/min ([95% CI, −0.95 to 0.35]; P = .37). None of the 3 prespecified secondary end points were statistically significant. In the placebo and praliciguat groups, changes in 6-minute walk test distance were 58.1 m (95% CI, 26.1-90.1) and 41.4 m (95% CI, 8.2-74.5), respectively; the placebo-adjusted least-squares between-group difference in mean change from baseline was –16.7 m (95% CI, −47.4 to 13.9). In the placebo and praliciguat groups, the placebo-adjusted least-squares between-group difference in mean change in ventilation/carbon dioxide production slope was −0.3 (95% CI, −1.6 to 1.0). There were more dizziness (9.9% vs 1.1%), hypotension (8.8% vs 0%), and headache (11% vs 6.7%) TEAEs with praliciguat compared with placebo. The frequency of serious TEAEs was similar between the groups (10% in the praliciguat group and 11% in the placebo group). CONCLUSIONS AND RELEVANCE: Among patients with HFpEF, the soluble guanylate cyclase stimulator praliciguat, compared with placebo, did not significantly improve peak V̇o(2) from baseline to week 12. These findings do not support the use of praliciguat in patients with HFpEF. TRIAL REGISTRATION: ClinicalTrials.gov Identifier: NCT03254485

Background: Whereas regular exercise is associated with lower risk of cardiovascular disease and mortality, mechanisms of exercise-mediated health benefits remain less clear. We used metabolite profiling before and after acute exercise to delineate the metabolic architecture of exercise response patterns in humans. Methods: Cardiopulmonary exercise testing and metabolite profiling was performed on Framingham Heart Study participants (age 53±8 years, 63% women) with blood drawn at rest (n=471) and at peak exercise (n=411). Results: We observed changes in circulating levels for 502 of 588 measured metabolites from rest to peak exercise (exercise duration 11.9±2.1 minutes) at a 5% false discovery rate. Changes included reductions in metabolites implicated in insulin resistance (glutamate, −29%; P =1.5×10 −55 ; dimethylguanidino valeric acid [DMGV], −18%; P =5.8×10 −18 ) and increases in metabolites associated with lipolysis (1-methylnicotinamide, +33%; P =6.1×10 −67 ), nitric oxide bioavailability (arginine/ornithine + citrulline, +29%; P =2.8×10 −169 ), and adipose browning (12,13-dihydroxy-9Z-octadecenoic acid +26%; P =7.4×10 −38 ), among other pathways relevant to cardiometabolic risk. We assayed 177 metabolites in a separate Framingham Heart Study replication sample (n=783, age 54±8 years, 51% women) and observed concordant changes in 164 metabolites (92.6%) at 5% false discovery rate. Exercise-induced metabolite changes were variably related to the amount of exercise performed (peak workload), sex, and body mass index. There was attenuation of favorable excursions in some metabolites in individuals with higher body mass index and greater excursions in select cardioprotective metabolites in women despite less exercise performed. Distinct preexercise metabolite levels were associated with different physiologic dimensions of fitness (eg, ventilatory efficiency, exercise blood pressure, peak V o 2 ). We identified 4 metabolite signatures of exercise response patterns that were then analyzed in a separate cohort (Framingham Offspring Study; n=2045, age 55±10 years, 51% women), 2 of which were associated with overall mortality over median follow-up of 23.1 years ( P ≤0.003 for both). Conclusions: In a large sample of community-dwelling individuals, acute exercise elicits widespread changes in the circulating metabolome. Metabolic changes identify pathways central to cardiometabolic health, cardiovascular disease, and long-term outcome. These findings provide a detailed map of the metabolic response to acute exercise in humans and identify potential mechanisms responsible for the beneficial cardiometabolic effects of exercise for future study.

The development of cardiovascular disease during renal impairment involves striking multi-tiered, multi-dimensional complex alterations encompassing the entire oxygen transport system. Complex interactions between target organ systems involving alterations of the heart, vascular, musculoskeletal and respiratory systems occur in Chronic Kidney Disease (CKD) and collectively contribute to impairment of cardiovascular function. These systemic changes have challenged our diagnostic and therapeutic efforts, particularly given that imaging cardiac structure at rest, rather than ascertainment under the stress of exercise, may not accurately reflect the risk of premature death in CKD. The multi-systemic nature of cardiovascular disease in CKD patients provides strong rationale for an integrated approach to the assessment of cardiovascular alterations in this population. State-of-the-art cardiopulmonary exercise testing (CPET) is a powerful, dynamic technology that enables the global assessment of cardiovascular functional alterations and reflects the integrative exercise response and complex machinery that form the oxygen transport system. CPET provides a wealth of data from a single assessment with mechanistic, physiological and prognostic utility. It is an underutilized technology in the care of patients with kidney disease with the potential to help advance the field of cardio-nephrology. This article reviews the integrative physiology and pathophysiology of cardio-renal impairment, critical new insights derived from CPET technology, and contemporary evidence for potential applications of CPET technology in patients with kidney disease.

Background: Proteomics have already provided novel insights into the pathophysiology of heart failure (HF) with reduced ejection fraction. Previous studies have evaluated cross-sectional protein signatures of HF, but few have characterized proteomic changes following HF with reduced ejection fraction treatment with ARNI (angiotensin receptor/neprilysin inhibitor) therapy or left ventricular assist devices. Methods: In this retrospective omics study, we performed targeted proteomics (N=625) of whole blood sera from patients with American College of Cardiology/American Heart Association stage D (N=29) and stage C (N=12) HF using proximity extension assays. Samples were obtained before and after (median=82 days) left ventricular assist device implantation (stage D; primary analysis) and ARNI therapy initiation (stage C; matched reference). Oblique principal component analysis and point biserial correlations were used for feature extraction and selection; standardized mean differences were used to assess within and between-group differences; and enrichment analysis was used to generate and cluster Gene Ontology terms. Results: Core sets of proteins were identified for stage C (N=9 proteins) and stage D (N=18) HF; additionally, a core set of 5 shared HF proteins (NT-proBNP [N-terminal pro-B type natriuretic peptide], ESM [endothelial cell-specific molecule]-1, cathepsin L1, osteopontin, and MCSF-1) was also identified. For patients with stage D HF, moderate (δ, 0.40–0.60) and moderate-to-large (δ, 0.60–0.80) sized differences were observed in 8 of their 18 core proteins after left ventricular assist devices implantation. Additionally, specific protein groups reached concentration levels equivalent ( g Conclusions: HF with reduced ejection fraction severity associates with distinct proteomic signatures that reflect underlying disease attributes; these core signatures may be useful for monitoring changes in cardiac function following initiation on ARNI or left ventricular assist device implantation.

Arterial stiffness is thought to contribute to the pathophysiology of heart failure with preserved ejection fraction (HFpEF). We sought to examine arterial stiffness in HFpEF and hypertension and investigate associations of arterial and left ventricular hemodynamic responses to exercise.A total of 385 symptomatic individuals with an EF of ≥50% underwent upright cardiopulmonary exercise testing with invasive hemodynamic assessment of arterial stiffness and load (aortic augmentation pressure, augmentation index, systemic vascular resistance index, total arterial compliance index, effective arterial elastance index, and pulse pressure amplification) at rest and during incremental exercise. An abnormal hemodynamic response to exercise was defined as a steep increase in pulmonary capillary wedge pressure relative to cardiac output (∆PCWP/∆CO2 mm Hg/L/min). We compared rest and exercise measures between HFpEF and hypertension in multivariable analyses. Among 188 participants with HFpEF (mean age 61 ± 13 years, 56% women), resting arterial stiffness parameters were worse compared with 94 hypertensive participants (mean age 55 ± 15 years, 52% women); these differences were accentuated during exercise in HFpEF (all P ≤ .0001). Among all participants, exercise measures of arterial stiffness correlated with worse ∆PCWP/∆CO. Specifically, a 1 standard deviation higher exercise augmentation pressure was associated with 2.15-fold greater odds of abnormal LV hemodynamic response (95% confidence interval 1.52-3.05; P.001). Further, exercise measures of systemic vascular resistance index, elastance index, and pulse pressure amplification correlated with a lower peak oxygen consumption.Exercise accentuates the increased arterial stiffness found in HFpEF, which in turn correlates with left ventricular hemodynamic responses. Unfavorable ventricular-vascular interactions during exercise in HFpEF may contribute to exertional intolerance and inform future therapeutic interventions.

Purpose We aimed to develop a novel free-breathing cardiac diffusion tensor MRI (DT-MRI) approach, M2-MT-MOCO, capable of whole left ventricular coverage that leverages second-order motion compensation (M2) diffusion encoding and multitasking (MT) framework to efficiently correct for respiratory motion (MOCO). Methods Imaging was performed in 16 healthy volunteers and 3 heart failure patients with symptomatic dyspnea. The healthy volunteers were scanned to compare the accuracy of interleaved multislice coverage of the entire left ventricle with a single-slice acquisition and the accuracy of the free-breathing conventional MOCO and MT-MOCO approaches with reference breath-hold DT-MRI. Mean diffusivity (MD), fractional anisotropy (FA), helix angle transmurality (HAT), and intrascan repeatability were quantified and compared. Results In all subjects, free-breathing M2-MT-MOCO DT-MRI yielded DWI of the entire left ventricle without bulk motion-induced signal loss. No significant differences were seen in the global values of MD, FA, and HAT in the multislice and single-slice acquisitions. Furthermore, global quantification of MD, FA, and HAT were also not significantly different between the MT-MOCO and breath-hold, whereas conventional MOCO yielded significant differences in MD, FA, and HAT with MT-MOCO and FA with breath-hold. In heart failure patients, M2-MT-MOCO DT-MRI was feasible yielding higher MD, lower FA, and lower HAT compared with healthy volunteers. Substantial agreement was found between repeated scans across all subjects for MT-MOCO. Conclusion M2-MT-MOCO enables free-breathing DT-MRI of the entire left ventricle in 10 min, while preserving quantification of myocardial microstructure compared to breath-held and single-slice acquisitions and is feasible in heart failure patients.

BACKGROUND: Heart failure (HF) with preserved ejection fraction (HFpEF) is a heterogeneous syndrome. Some patients develop elevated filling pressures exclusively during exercise and never require hospitalization, whereas others periodically develop congestion that requires inpatient treatment. The features differentiating these cohorts are unclear. METHODS: We performed a secondary analysis of 7 NIH sponsored multicenter trials of HFpEF (EF≥50%, n=727). Patients were stratified by history of HF hospitalization, comparing patients never hospitalized (HFpEF(NH)) to those with a prior hospitalization (HFpEF(PH)). Currently hospitalized (HFpEF(CH)) patients were included to fill the spectrum. Clinical characteristics, cardiac structure, biomarkers, quality of life (QOL), functional capacity, activity levels, and outcomes were compared. RESULTS: As expected, HFpEF(CH) (n=338) displayed the greatest severity of congestion, as assessed by NTproBNP levels, edema, and orthopnea. As compared to HFpEF(NH) (n=109), HFpEF(PH) (n=280) displayed greater comorbidity burden with more lung disease, renal dysfunction and anemia, along with lower activity levels (accelerometry), poorer exercise capacity (6 minute walk distance and peak exercise capacity), and more orthopnea. Patients with current or prior hospitalization displayed higher rates of future HF hospitalization, but QOL was similarly impaired in all HFpEF patients, regardless of hospitalization history. CONCLUSIONS: A greater burden of non-cardiac organ dysfunction, sedentariness, functional impairment, and higher event rates distinguish patients with HFpEF and prior HF hospitalization from those never hospitalized. Despite lower event rates, quality of life is severely and similarly in patients with no history of hospitalization. These data suggest that the two clinical profiles of HFpEF may require different treatment strategies. TRIAL REGISTRATION: RELAX trial clinicaltrials.gov Identifier: NCT00763867; NEAT trial clinicaltrials.gov Identifier: NCT02053493; INDIE trial clinicaltrials.gov Identifier: NCT02742129; DOSE trial clinicaltrials.gov Identifier: NCT00577135; CARRESS trial clinicaltrials.gov Identifier: NCT00608491; ROSE trial clinicaltrials.gov Identifier: NCT01132846; ATHENA trial clinicaltrials.gov Identifier: NCT02235077.

IMPORTANCE: Aortic dilatation is frequently encountered in clinical practice among aging endurance athletes, but the distribution of aortic sizes in this population is unknown. It is additionally uncertain whether this may represent aortic adaptation to long-term exercise, similar to the well-established process of ventricular remodeling. OBJECTIVE: To assess the prevalence of aortic dilatation among long-term masters-level male and female athletes with about 2 decades of exercise exposure. DESIGN, SETTING, AND PARTICIPANTS: This cross-sectional study evaluated aortic size in veteran endurance athletes. Masters-level rowers and runners aged 50 to 75 years were enrolled from competitive athletic events across the United States from February to October 2018. Analysis began January 2019. EXPOSURES: Long-term endurance exercise. MAIN OUTCOMES AND MEASURES: The primary outcome was aortic size at the sinuses of Valsalva and the ascending aorta, measured using transthoracic echocardiography in accordance with contemporary guidelines. Aortic dimensions were compared with age, sex, and body size–adjusted predictions from published nomograms, and z scores were calculated where applicable. RESULTS: Among 442 athletes (mean [SD] age, 61 [6] years; 267 men [60%]; 228 rowers [52%]; 214 runners [48%]), clinically relevant aortic dilatation, defined by a diameter at sinuses of Valsalva or ascending aorta of 40 mm or larger, was found in 21% (n = 94) of all participants (83 men [31%] and 11 women [6%]). When compared with published nomograms, the distribution of measured aortic size displayed a rightward shift with a rightward tail (all P