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Background: Detection of ≥50% diameter stenosis left main coronary artery disease (LMD) has prognostic and therapeutic implications. Noninvasive stress imaging or an exercise tolerance test (ETT) are the most common methods to detect obstructive coronary artery disease, though stress test markers of LMD remain ill-defined.Objectives: The authors sought to identify markers of LMD as detected on coronary computed tomography angiography (CTA), using clinical and stress testing parameters.Methods: This was a post hoc analysis of ISCHEMIA (International Study of Comparative Health Effectiveness With Medical and Invasive Approaches), including randomized and nonrandomized participants who had locally determined moderate or severe ischemia on nonimaging ETT, stress nuclear myocardial perfusion imaging, or stress echocardiography followed by CTA to exclude LMD. Stress tests were read by core laboratories. Prior coronary artery bypass grafting was an exclusion. In a stepped multivariate model, the authors identified predictors of LMD, first without and then with stress testing parameters.Results: Among 5,146 participants (mean age 63 years, 74% male), 414 (8%) had LMD. Predictors of LMD were older age (P < 0.001), male sex (P < 0.01), absence of prior myocardial infarction (P < 0.009), transient ischemic dilation of the left ventricle on stress echocardiography (P = 0.05), magnitude of ST-segment depression on ETT (P = 0.004), and peak metabolic equivalents achieved on ETT (P = 0.001). The models were weakly predictive of LMD (C-index 0.643 and 0.684).Conclusions: In patients with moderate or severe ischemia, clinical and stress testing parameters were weakly predictive of LMD on CTA. For most patients with moderate or severe ischemia, anatomical imaging is needed to rule out LMD. (International Study of Comparative Health Effectiveness With Medical and Invasive Approaches [ISCHEMIA]; NCT01471522). [ABSTRACT FROM AUTHOR]

Background: There is limited evidence that fractional flow reserve (FFR) is effective in guiding therapeutic strategy in multivessel coronary artery disease (CAD) beyond prespecified percutaneous coronary intervention or coronary graft surgery candidates.Objectives: The FUTURE (FUnctional Testing Underlying coronary REvascularization) trial aimed to evaluate whether a treatment strategy based on FFR was superior to a traditional strategy without FFR in the treatment of multivessel CAD.Methods: The FUTURE trial is a prospective, randomized, open-label superiority trial. Multivessel CAD candidates were randomly assigned (1:1) to treatment strategy based on FFR in all stenotic (≥50%) coronary arteries or to a traditional strategy without FFR. In the FFR group, revascularization (percutaneous coronary intervention or surgery) was indicated for FFR ≤0.80 lesions. The primary endpoint was a composite of major adverse cardiac or cerebrovascular events at 1 year.Results: The trial was stopped prematurely by the data safety and monitoring board after a safety analysis and 927 patients were enrolled. At 1-year follow-up, by intention to treat, there were no significant differences in major adverse cardiac or cerebrovascular events rates between groups (14.6% in the FFR group vs 14.4% in the control group; hazard ratio: 0.97; 95% confidence interval: 0.69-1.36; P = 0.85). The difference in all-cause mortality was nonsignificant, 3.7% in the FFR group versus 1.5% in the control group (hazard ratio: 2.34; 95% confidence interval: 0.97-5.18; P = 0.06), and this was confirmed with a 24 months' extended follow-up. FFR significantly reduced the proportion of revascularized patients, with more patients referred to exclusively medical treatment (P = 0.02).Conclusions: In patients with multivessel CAD, we did not find evidence that an FFR-guided treatment strategy reduced the risk of ischemic cardiovascular events or death at 1-year follow-up. (Functional Testing Underlying Coronary Revascularisation; NCT01881555). [ABSTRACT FROM AUTHOR]

Background: Outcome data after extended long-term follow-up of patients with coronary artery disease treated with drug-eluting stents (DES) in randomized clinical trials are scant.Objectives: Performance differences among devices may be expected to emerge over time depending on whether stenting is done with polymer-free or durable polymer DES. This study assessed the 10-year outcomes of patients enrolled in the ISAR-TEST-5 (Test Efficacy of Sirolimus- and Probucol-Eluting Versus Zotarolimus-Eluting Stents) trial.Methods: A total of 3,002 patients were randomized to treatment with either polymer-free sirolimus- and probucol-eluting stents (n = 2,002) or durable polymer zotarolimus-eluting stents (n = 1,000). The primary endpoint was the composite of cardiac death, target vessel-related myocardial infarction, or target lesion revascularization (a device-oriented composite endpoint [DOCE]). Additional endpoints of interest were the patient-oriented composite endpoint (POCE), including all-cause death, any myocardial infarction, or any revascularization; individual components of the composite endpoints; and definite or probable stent thrombosis.Results: The median age of the patients at randomization was 67.8 years. At 10 years, 63.9% of patients were alive. The rates of DOCE and POCE were high in both groups with no difference in the incidence between polymer-free sirolimus- and probucol-eluting stents and durable polymer zotarolimus-eluting stents (DOCE: 43.8% vs. 43.0%, respectively; hazard ratio: 1.01; 95% confidence interval [CI]: 0.89 to 1.14; p = 0.90; POCE: 66.2% vs. 67.7%, respectively; hazard ratio: 0.94; 95% CI: 0.86 to 1.04; p = 0.22). The rates of the individual components of the composite endpoints were comparable in both groups. The incidence of definite/probable stent thrombosis over 10 years was low and comparable in both groups (1.6% vs. 1.9%; hazard ratio: 0.85; 95% CI: 0.46 to 1.54; p = 0.58).Conclusions: At 10 years, there were no measurable differences in outcomes between patients treated with polymer-free versus durable polymer DES. The incidence of stent thrombosis was low and comparable in both groups. High overall adverse clinical event rates were observed during extended follow-up. (Test Efficacy of Sirolimus- and Probucol-Eluting Versus Zotarolimus-Eluting Stents [ISAR-TEST-5]; NCT00598533). [ABSTRACT FROM AUTHOR]

Background: Coronary microvascular dysfunction (CMD) is defined by diminished flow reserve. Functional and structural CMD endotypes have recently been described, with normal and elevated minimal microvascular resistance, respectively.Objectives: This study determined the mechanism of altered resting and maximal flow in CMD endotypes.Methods: A total of 86 patients with angina but no obstructive coronary disease underwent coronary pressure and flow measurement during rest, exercise, and adenosine-mediated hyperemia and were classified as the reference group or as patients with CMD by a coronary flow reserve threshold of 2.5; functional or structural endotypes were distinguished by a hyperemic microvascular resistance threshold of 2.5 mm Hg/cm/s. Endothelial function was assessed by forearm blood flow (FBF) response to acetylcholine, and nitric oxide synthase (NOS) activity was defined as the inverse of FBF reserve to NG-monomethyl-L-arginine.Results: Of the 86 patients, 46 had CMD (28 functional, 18 structural), and 40 patients formed the reference group. Resting coronary blood flow (CBF) (24.6 ± 2.0 cm/s vs. 16.6 ± 3.9 cm/s vs. 15.1 ± 4.7 cm/s; p < 0.001) and NOS activity (2.27 ± 0.96 vs. 1.77 ± 0.59 vs. 1.30 ± 0.16; p < 0.001) were higher in the functional group compared with the structural CMD and reference groups, respectively. The structural group had lower acetylcholine FBF augmentation than the functional or reference group (2.1 ± 1.8 vs. 4.1 ± 1.7 vs. 4.5 ± 2.0; p < 0.001). On exercise, oxygen demand was highest (rate-pressure product: 22,157 ± 5,497 beats/min/mm Hg vs. 19,519 ± 4,653 beats/min/mm Hg vs. 17,530 ± 4,678 beats/min/mm Hg; p = 0.004), but peak CBF was lowest in patients with structural CMD compared with the functional and reference groups.Conclusions: Functional CMD is characterized by elevated resting flow that is linked to enhanced NOS activity. Patients with structural CMD have endothelial dysfunction, which leads to diminished peak CBF augmentation and increased demand during exercise. The value of pathophysiologically stratified therapy warrants investigation. [ABSTRACT FROM AUTHOR]

Background: The FREEDOM (Future Revascularization Evaluation in Patients with Diabetes Mellitus: Optimal Management of Multivessel Disease) trial demonstrated that for patients with diabetes mellitus (DM) and multivessel coronary disease (MVD), coronary artery bypass grafting (CABG) is superior to percutaneous coronary intervention with drug-eluting stents (PCI-DES) in reducing the rate of major adverse cardiovascular and cerebrovascular events after a median follow-up of 3.8 years. It is not known, however, whether CABG confers a survival benefit after an extended follow-up period.Objectives: The purpose of this study was to evaluate the long-term survival of DM patients with MVD undergoing coronary revascularization in the FREEDOM trial.Methods: The FREEDOM trial randomized 1,900 patients with DM and MVD to undergo either PCI with sirolimus-eluting or paclitaxel-eluting stents or CABG on a background of optimal medical therapy. After completion of the trial, enrolling centers and patients were invited to participate in the FREEDOM Follow-On study. Survival was evaluated using Kaplan-Meier analysis, and Cox proportional hazards models were used for subgroup and multivariate analyses.Results: A total of 25 centers (of 140 original centers) agreed to participate in the FREEDOM Follow-On study and contributed a total of 943 patients (49.6% of the original cohort) with a median follow-up of 7.5 years (range 0 to 13.2 years). Of the 1,900 patients, there were 314 deaths during the entire follow-up period (204 deaths in the original trial and 110 deaths in the FREEDOM Follow-On). The all-cause mortality rate was significantly higher in the PCI-DES group than in the CABG group (24.3% [159 deaths] vs. 18.3% [112 deaths]; hazard ratio: 1.36; 95% confidence interval: 1.07 to 1.74; p = 0.01). Of the 943 patients with extended follow-up, the all-cause mortality rate was 23.7% (99 deaths) in the PCI-DES group and 18.7% (72 deaths) in the CABG group (hazard ratio: 1.32; 95% confidence interval: 0.97 to 1.78; p = 0.076).Conclusions: In patients with DM and MVD, coronary revascularization with CABG leads to lower all-cause mortality than with PCI-DES in long-term follow-up. (Comparison of Two Treatments for Multivessel Coronary Artery Disease in Individuals With Diabetes [FREEDOM]; NCT00086450). [ABSTRACT FROM AUTHOR]

Background: Although previous observational studies have documented late luminal enlargement and expansive remodeling following implantation of a bioresorbable vascular scaffold (BVS), no comparison with metallic stents has been conducted in a randomized fashion.Objectives: This study sought to compare vessel remodeling patterns after either Absorb BVS or Xience metallic drug-eluting stent (DES) implantation (Abbott Vascular, Santa Clara, California) and determine the independent predictors of remodeling.Methods: In the ABSORB II randomized trial, 383 lesions (n = 359) were investigated by intravenous ultrasound both post-procedure and at 3-year follow-up. According to vessel and lumen area changes over 3 years, we categorized 9 patterns of vessel remodeling that were beyond the reproducibility of lumen and vessel area measurements.Results: The relative change in mean vessel area was significantly greater with the BVS compared to the DES (6.7 ± 12.6% vs. 2.9 ± 11.5%; p = 0.003); the relative change in mean lumen area was significantly different between the 2 arms (1.4 ± 19.1% vs. -1.9 ± 10.5%, respectively; p = 0.031). Multivariate analysis indicated that use of the BVS, female sex, balloon-artery ratio >1.25, expansion index ≥0.8, previous percutaneous coronary intervention, and higher level of low-density lipoprotein cholesterol were independent predictors of expansive remodeling. Furthermore, in the BVS arm, necrotic core pre-procedure was an independent determinant of expansive remodeling.Conclusions: Expansive vessel wall remodeling was more frequent and intense with the BVS than the metallic DES and could be determined by patient baseline characteristics and periprocedural factors. The clinical effect of the observed lumen and vessel remodeling must be investigated in further large clinical studies to optimize the clinical outcome of patients and lesions treated by bioresorbable scaffolds. (ABSORB II Randomized Controlled Trial; NCT01425281). [ABSTRACT FROM AUTHOR]

Background: Lipid-rich plaque (LRP) is thought to be a precursor to cardiac events. However, its clinical significance in coronary arteries has never been systematically investigated.Objectives: This study investigated the prevalence and clinical significance of LRP in the nonculprit region of the target vessel in patients undergoing percutaneous coronary intervention (PCI).Methods: The study included 1,474 patients from 20 sites across 6 countries undergoing PCI, who had optical coherence tomography (OCT) imaging of the target vessel. Major adverse cardiac events (MACE) were defined as a composite of cardiac death, acute myocardial infarction, and ischemia-driven revascularization. Patients were followed for up to 4 years (median of 2 years).Results: Lipid-rich plaque was detected in nonculprit regions of the target vessel in 33.6% of patients. The cumulative rate of nonculprit lesion-related MACE (NC-MACE) over 48 months in patients with LRP was higher than in those without LRP (7.2% vs. 2.6%, respectively; p = 0.033). Acute coronary syndrome at index presentation (risk ratio: 2.538; 95% confidence interval [CI]: 1.246 to 5.173; p = 0.010), interruption of statin use ≥1 year (risk ratio: 4.517; 95% CI: 1.923 to 10.610; p = 0.001), and LRP in nonculprit regions (risk ratio: 2.061; 95% CI: 1.050 to 4.044; p = 0.036) were independently associated with increased NC-MACE. Optical coherence tomography findings revealed that LRP in patients with NC-MACE had longer lipid lengths (p < 0.001), wider maximal lipid arcs (p = 0.023), and smaller minimal lumen areas (p = 0.003) than LRPs in patients without MACE.Conclusions: Presence of LRP in the nonculprit regions of the target vessel by OCT predicts increased risk for future NC-MACE, which is primarily driven by revascularization for recurrent ischemia. Lipid-rich plaque with longer lipid length, wider lipid arc, and higher degree of stenosis identified patients at higher risk of future cardiac events. (The Massachusetts General Hospital Optical Coherence Tomography Registry; NCT01110538). [ABSTRACT FROM AUTHOR]

Background: Cangrelor, an intravenous, reversible P2Y12 antagonist, is approved for use in patients undergoing percutaneous coronary intervention (PCI).Objectives: This study sought to evaluate the efficacy and safety of cangrelor compared with clopidogrel in subgroups that did and did not receive glycoprotein IIb/IIIa inhibitors (GPIs).Methods: This pooled, patient-level analysis of the 3 CHAMPION (Cangrelor versus Standard Therapy to Achieve Optimal Management of Platelet Inhibition) trials analyzed all randomized patients who underwent PCI and received the study drug (n = 24,902). Only bailout/rescue GPI use was permitted, except in CHAMPION PCI, in which routine or bailout/rescue GPI use was at the site investigator's discretion. The primary efficacy endpoint was the composite of all-cause mortality, myocardial infarction, ischemia-driven revascularization, or stent thrombosis at 48 h after randomization.Results: Overall, 3,173 patients (12.7%) received a GPI, most commonly eptifibatide (69.4%). Despite variation in indications for GPIs, baseline characteristics were well balanced between the cangrelor and clopidogrel arms in subsets receiving and not receiving GPIs. Rates of the primary composite endpoint were lower with cangrelor compared with clopidogrel in patients who did (4.9% vs. 6.5%; odds ratio [OR]: 0.74; 95% confidence interval [CI]: 0.55 to 1.01) or did not receive a GPI (3.6% vs. 4.4%; OR: 0.82; 95% CI: 0.72 to 0.94; Pint = 0.55). Cangrelor did not increase the primary safety endpoint, GUSTO-defined severe/life-threatening bleeding, in patients who did (0.4% vs. 0.5%; OR: 0.71; 95% CI: 0.25 to 1.99) or did not receive GPIs (0.2% vs. 0.1%; OR: 1.56; 95% CI: 0.80 to 3.04; Pint = 0.21). GPI use was associated with increased risk of bleeding in both treatment arms.Conclusions: Cangrelor's efficacy in reducing ischemic complications in patients undergoing PCI was maintained irrespective of GPI administration. GPI use was associated with substantially higher bleeding rates, regardless of the randomization to cangrelor or clopidogrel. (A Clinical Trial to Demonstrate the Efficacy of Cangrelor [PCI]: NCT00305162; Cangrelor Versus Standard Therapy to Achieve Optimal Management of Platelet Inhibition [PLATFORM]: NCT00385138; A Clinical Trial Comparing Cangrelor to Clopidogrel Standard Therapy in Subjects Who Require Percutaneous Coronary Intervention [PCI] [CHAMPION PHOENIX] [CHAMPION]: NCT01156571). [ABSTRACT FROM AUTHOR]

Background: The prognostic impact of microvascular status in patients with high fractional flow reserve (FFR) is not clear.Objectives: The goal of this study was to investigate the implications of coronary flow reserve (CFR) and the index of microcirculatory resistance (IMR) in patients who underwent FFR measurement.Methods: Patients with high FFR (>0.80) were grouped according to CFR (≤2) and IMR (≥23 U) levels: group A, high CFR with low IMR; group B, high CFR with high IMR; group C, low CFR with low IMR; and group D, low CFR with high IMR. Patient-oriented composite outcome (POCO) of any death, myocardial infarction, and revascularization was assessed. The median follow-up was 658 days (interquartile range: 503.8 to 1,139.3 days).Results: A total of 313 patients (663 vessels) were assessed with FFR, CFR, and IMR. Correlation (r = 0.201; p < 0.001) and categorical agreement (kappa value = 0.178; p < 0.001) between FFR and CFR were modest. Low CFR was associated with higher POCO than high CFR (p = 0.034). There were no significant differences in clinical and angiographic characteristics among groups. Patients with high IMR with low CFR had the highest POCO (p = 0.002). Overt microvascular disease (p = 0.008), multivessel disease (p = 0.033), and diabetes mellitus (p = 0.033) were independent predictors of POCO. Inclusion of a physiological index significantly improved the discriminant function of a predictive model (relative integrated discrimination improvement 0.467 [p = 0.037]; category-free net reclassification index 0.648 [p = 0.007]).Conclusions: CFR and IMR improved the risk stratification of patients with high FFR. Low CFR with high IMR was associated with poor prognosis. (Clinical, Physiological and Prognostic Implication of Microvascular Status; NCT02186093). [ABSTRACT FROM AUTHOR]

Background: Long-term benefits of coronary stenosis treatment with an everolimus-eluting bioresorbable scaffold are unknown.Objectives: This study sought to evaluate clinical and imaging outcomes 5 years after bioresorbable scaffold implantation.Methods: In the ABSORB multicenter, single-arm trial, 45 (B1) and 56 patients (B2) underwent coronary angiography, intravascular ultrasound (IVUS), and optical coherence tomography (OCT) at different times. At 5 years, 53 patients without target lesion revascularization underwent final imaging.Results: Between 6 months/1 year and 5 years, angiographic luminal late loss remained unchanged (B1: 0.14 ± 19 mm vs. 0.13 ± 0.33 mm; p = 0.7953; B2: 0.23 ± 0.28 mm vs. 0.18 ± 0.32 mm; p = 0.5685). When patients with a target lesion revascularization were included, luminal late loss was 0.15 ± 0.20 mm versus 0.15 ± 0.24 mm (p = 0.8275) for B1 and 0.30 ± 0.37 mm versus 0.32 ± 0.48 mm (p = 0.8204) for B2. At 5 years, in-scaffold and -segment binary restenosis was 7.8% (5 of 64) and 12.5% (8 of 64). On IVUS, the minimum lumen area of B1 decreased from 5.23 ± 0.97 mm(2) at 6 months to 4.89 ± 1.81 mm(2) at 5 years (p = 0.04), but remained unchanged in B2 (4.95 ± 0.91 mm(2) at 1 year to 4.84 ± 1.28 mm(2) at 5 years; p = 0.5). At 5 years, struts were no longer discernable by OCT and IVUS. On OCT, the minimum lumen area in B1 decreased from 4.51 ± 1.28 mm(2) at 6 months to 3.65 ± 1.39 mm(2) at 5 years (p = 0.01), but remained unchanged in B2, 4.35 ± 1.09 mm(2) at 1 year and 4.12 ± 1.38 mm(2) at 5 years (p = 0.24). Overall, the 5-year major adverse cardiac event rate was 11.0%, without any scaffold thrombosis.Conclusions: At 5 years, bioresorbable scaffold implantation in a simple stenotic lesion resulted in stable lumen dimensions and low restenosis and major adverse cardiac event rates. (ABSORB Clinical Investigation, Cohort B [ABSORB B]; NCT00856856). [ABSTRACT FROM AUTHOR]

: ObjectivesWe evaluated the effect of therapy with folic acid and cobalamin on coronary endothelial function, expressed as a change in volumetric coronary blood flow (CBF), in hyperhomocysteinemic patients with coronary artery disease (CAD).: BackgroundHyperhomocysteinemia is an independent risk factor for CAD. The mechanism responsible for this increased risk is unclear, but it is generally assumed that hyperhomocysteinemia causes endothelial dysfunction. It is unknown whether lowering plasma homocysteine levels with folic acid and cobalamin improves coronary endothelial function in patients with hyperhomocysteinemia and symptomatic CAD.: MethodsFifteen patients scheduled for elective percutaneous transluminal coronary angioplasty (PTCA) with plasma homocysteine levels of ≥16 μmol/l were randomized for six months of treatment with folic acid 5 mg and cobalamin 400 μg daily or placebo. Coronary endothelial function was evaluated in a non-PTCA vessel using acetylcholine infusion in dosages of 10−8 M, 10−7 M, and 10−6 M. Endothelium- dependent CBF is determined using intracoronary Doppler velocity and quantitative coronary angiography at baseline and after six months.: ResultsIn the folic acid/cobalamin treated group, CBF increased after acetylcholine infusion with 96% (standard deviation 54; 95% confidence interval [CI]: 44% to 154%) compared with a decrease of 16% (standard deviation 35; 95% CI: −20% to +30%) of the CBF in the placebo-treated group (p < 0.005).: ConclusionsThis is the first prospective randomized placebo-controlled intervention study evaluating coronary endothelial function in hyperhomocysteinemic patients with CAD. Our results suggest that coronary endothelial function improves after treatment with folic acid and cobalamin. [Copyright &y& Elsevier]

: ObjectivesThe study was done to evaluate whether ethnic differences exist in the prevalence of coronary artery calcification (CAC), and to determine whether differences in calcification correlate with the degree of coronary obstruction.: BackgroundElectron beam tomography (EBT) can be used to quantitate the amount of CAC and assist in prognostication of future cardiac events. It is unclear whether ethnic differences in coronary mortality are related to differences in the prevalence of coronary obstruction and CAC.: MethodsA total of 782 symptomatic subjects underwent both EBT and angiography. A 50% luminal narrowing defined an angiographic obstruction.: ResultsWe observed substantial ethnic differences in prevalence of both CAC and angiographic stenosis. In whites (n = 453), prevalence of CAC (score >0) was 84%, and significant obstruction on angiogram was 71%. Compared with whites, blacks (n = 108) had a significantly lower prevalence of CAC (62%, p < 0.001) and angiographic disease (49%, p < 0.01). Hispanics (n = 177) also had a lower prevalence of CAC (71%, p < 0.001) and angiographic obstruction (58%, p < 0.01). Asians (n = 44) were not significantly different in regard to CAC (73%, p = 0.06) or angiographic stenosis (64%, p = 0.30). These ethnic differences remained after simultaneously controlling (by use of multiple logistic regression) for age, gender and cardiac risk factors.: ConclusionsAs compared with whites, blacks and Hispanics had significantly lower prevalence of CAC and obstructive coronary disease. Ethnic differences in risk-factor profiles do not explain these differences. This study demonstrated that whites have a higher atherosclerotic burden than blacks and Hispanics, independent of risk-factor differences among symptomatic patients referred for angiography. [Copyright &y& Elsevier]