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Background: In patients with hypertrophic cardiomyopathy (HCM), impaired augmentation of stroke volume and diastolic dysfunction contribute to exercise intolerance. Systolic–diastolic (S‐D) coupling characterizes how systolic contraction of the left ventricle (LV) primes efficient elastic recoil during early diastole. Impaired S‐D coupling may contribute to the impaired cardiac response to exercise in patients with HCM. Methods: Patients with HCM (n = 25, age = 47 ± 9 years) and healthy adults (n = 115, age = 49 ± 10 years) underwent a cardiopulmonary exercise testing (CPET) and echocardiogram. S‐D coupling was defined as the ratio of LV longitudinal excursion of the mitral annulus during early diastole (EDexc) and systole (Sexc) and compared between groups. Peak oxygen uptake (peak V̇O2) (Douglas bags), cardiac index (C2H2 rebreathe), and stroke volume index (SVi) were assessed during CPET. Linear regression was performed between S‐D coupling and peak V̇O2, peak cardiac index, and peak SVi. Results: S‐D coupling was lower in HCM (Controls: 0.63 ± 0.08, HCM: 0.56 ± 0.10, p < 0.001). Peak V̇O2 and stroke volume reserve were lower in patients with HCM (Peak VO2 Controls: 28.5 ± 5.5, HCM: 23.7 ± 7.2 mL/kg/min, p < 0.001, SV reserve: Controls 39 ± 16, HCM 30 ± 18 mL, p = 0.008). In patients with HCM, S‐D coupling was associated with peak V̇O2 (r = 0.47, p = 0.018), peak cardiac index (r = 0.60, p = 0.002), and peak SVi (r = 0.63, p < 0.001). Conclusion: Systolic–diastolic coupling was impaired in patients with HCM and was associated with fitness and the cardiac response to exercise. Inefficient S‐D coupling may link insufficient stroke volume generation, diastolic dysfunction, and exercise intolerance in HCM. [ABSTRACT FROM AUTHOR]

• Aficamten is a next-generation cardiac myosin inhibitor (CMI). • CMIs are a novel treatment for obstructive hypertrophic cardiomyopathy (oHCM). • We report the efficacy and safety of aficamten with disopyramide for refractory oHCM. • In cohort 3 of REDWOOD-HCM, aficamten plus disopyramide was well tolerated. • Patients showed improved left ventricular outflow-tract gradient and NYHA class. [ABSTRACT FROM AUTHOR]

Patients with hypertrophic cardiomyopathy (HCM) often have reduced exercise capacity, and it is unclear whether cardiovascular regulation during exercise is intact in these patients. We aimed to determine the relationship between cardiac output (Q̇c) and oxygen uptake (V̇o2), and stroke volume (SV) reserve in HCM compared with healthy participants and participants with left ventricular hypertrophy (LVH) but not HCM. Sixteen patients with HCM (48 ± 7 yr, 44% female), 16 participants with LVH (49 ± 5 yr, 44% female), and 61 healthy controls (CON: 52 ± 5 yr, 52% female) completed submaximal steady-state treadmill exercise followed by a maximal exercise test. V̇o2, Q̇c, SV, and arteriovenous oxygen difference were measured during rest and exercise, and Q̇c/V̇o2 slopes were constructed, The Q̇c/V̇o2 slope was blunted in HCM compared with CON and LVH [HCM 4.9 ± 0.7 vs. CON 5.5 ± 1.0 (P = 0.027) vs. LVH 6.0 ± 1.0 AU (P = 0.002)] and participants with HCM had a lower SV reserve (HCM 53 ± 33%, controls 83 ± 33%, LVH 82 ± 22%; HCM vs. controls P = 0.002; HCM vs. LVH P = 0.015). Despite a blunted Q̇c/V̇o2 slope, 75% of patients with HCM achieved ≥80% predicted V̇o2max by augmenting a-vo2 difference at maximal exercise (16.0 ± 0.8 mL/100 mL vs. 13.8 ± 2.7 mL/100 mL, P = 0.021). Patients with HCM do not appropriately match Q̇c to metabolic demand, primarily due to inadequate stroke volume augmentation. Despite this central limitation, many patients achieve normal exercise capacities by significantly increasing peripheral oxygen extraction. NEW & NOTEWORTHY Through state-of-the-art hemodynamic and oxygen uptake methodologies, this study found the cardiac output response to increasing metabolic demand is blunted among patients with hypertrophic cardiomyopathy (HCM), primarily due to a reduced stroke volume reserve. Many patients with HCM augment their peripheral oxygen extraction during maximal exercise to achieve normal exercise capacity and overcome ineffective matching of cardiac output. Peripheral adaptations that compensate for cardiac limitations may contribute to the heterogeneity of functional limitations observed within this patient population. [ABSTRACT FROM AUTHOR]

To link to full-text access for this article, visit this link: http://dx.doi.org/10.1016/j.ahj.2007.01.005 Byline: Aslan T. Turer (a), Kenneth W. Mahaffey (a), Kate L. Compton (c)(d), Robert M. Califf (a)(d), Kevin A. Schulman (b)(c) Abstract: Nonpublication of research results threatens the integrity of clinical research, but the extent of nonpublication and factors associated with publication remain poorly documented. We sought to examine rates of publication or presentation of research findings from multicenter clinical trials and determine what factors are associated with dissemination of results. Author Affiliation: (a) Division of Cardiology, Department of Medicine, Duke University Medical Center, Durham, NC (b) Division of General Internal Medicine, Duke University Medical Center, Durham, NC (c) Center for Clinical and Genetic Economics, Duke University Medical Center, Durham, NC (d) Duke Clinical Research Institute, Duke University Medical Center, Durham, NC Article History: Received 3 October 2006; Accepted 9 January 2007

Abstract Background Cardiac biomarkers are routinely obtained in the setting of suspected myocardial ischemia and infarction. Evidence suggests these markers may correlate with functional and clinical outcomes, but the strength of this correlation is unclear. The relationship between enzyme measures of myocardial necrosis and left ventricular performance and adverse clinical outcomes were explored. Methods Creatine kinase (CK) and CK-MB data were analyzed, as were left ventricular ejection fraction (LVEF) by angiogram, and infarct size by single-photon emission computed tomography (SPECT) imaging in patients in 2 trials: Prompt Reperfusion In Myocardial-infarction Evolution (PRIME), and Efegatran and Streptokinase to Canalize Arteries Like Accelerated Tissue plasminogen activator (ESCALAT). Both trials evaluated efegatran combined with thrombolysis for treating acute ST-segment elevation myocardial infarction (STEMI). Results Peak CK and CK area-under-the-curve (AUC) correlated significantly with SPECT-determined infarct size 5 to 10 days after enrollment. Peak CK had a statistically significant correlation with LVEF, but CK-AUC and LVEF correlation were less robust. Statistically significant correlations exist between SPECT-determined infarct size and peak CK-MB and CK-MB AUC. However, there was no correlation with LVEF for peak CK-MB and CK-MB AUC. The combined outcome of congestive heart failure and death were significantly associated with CK AUC, CK-MB AUC, peak CK, and peak CK-MB measurements. Conclusion Peak CK and CK-MB values and AUC calculations have significant correlation with functional outcomes (LVEF- and SPECT-determined infarct size) and death or CHF outcomes in the setting of STEMI. Cardiac biomarkers provide prognostic information and may serve as valid endpoint measurements for phase II clinical trials.

Background: Excess adipose tissue has been implicated in the pathogenesis of insulin resistance and atherosclerosis and is a key risk factor for blood pressure (BP) elevation. However, circulating levels of adiponectin, a protein produced by adipose tissue and widely implicated in the pathogenesis of insulin resistance and atherosclerosis, are inversely proportional to adiposity. The relationship between adiponectin and incident hypertension has not been determined in the general US population.Methods: Normotensive participants (n = 1233) enrolled in the Dallas Heart Study, a multiethnic, probability-based population sample of Dallas County adults were followed for median of 7 years. Retroperitoneal, intraperitoneal, visceral, and subcutaneous adipose tissue were measured at baseline by magnetic resonance imaging. Liver fat content was measured by 1 H-magnetic resonance spectroscopy. Relative risk regression was used to determine the association of adiponectin with incident hypertension after adjustment for age, race, sex, BMI, smoking, diabetes, baseline systolic BP, total cholesterol, and regional fat depot.Results: Of the 1233 study participants (median age 40 years, 40% black, and 56% women), 391 (32%) had developed hypertension over a median follow-up of 7 years. Adiponectin levels were associated with reduced risk of incident hypertension (RR 0.81, 95% CI [0.68-0.96]) in the fully adjusted model, which included liver fat. Similar results were observed after adjustment for subcutaneous or visceral fat depots when tested individually or simultaneously in the model.Conclusion: Our study suggested a protective role of adiponectin against incident hypertension independent of body fat distribution. [ABSTRACT FROM AUTHOR]

More than 1 in 10 US adolescents have prediabetes or diabetes, and elevated glycosylated haemoglobin (HbA1C) in youth is associated with increased risk of death before the age of 55 years. We conducted a prospective, cross-sectional study of 31,546 consecutive volunteer blood donors, 16–19 years of age, who donated blood during school blood drives between 1 September 2011 and 21 December 2012 in Texas. In the overall cohort, the prevalence of elevated HbA1C was 11.5%, including 11.0% in the prediabetes range (HbA1C 5.7%–6.4%) and 0.5% in the diabetes range (HbA1C ⩾ 6.5%). The prevalence of elevated HbA1C was higher in boys compared with girls (15.7% vs 7.9%, p < 0.001) and was especially high in racial/ethnic minorities (Blacks 32.7%, Asians 19.7%, Hispanics 13.1%) compared with Whites (8.0%, p < 0.001). There was a significant increase in total cholesterol and blood pressure across categories of increasing HbA1C in the overall cohort and stratified by sex and race/ethnicity. Blood donation programmes can serve as unique portals for health screening with potential for intervention in adolescents. [ABSTRACT FROM AUTHOR]

Objective: To determine whether increases in cardiac work lead to alterations in the plasma metabolome and whether such changes arise from the heart or peripheral organs. Background: There is growing evidence that the heart influences systemic metabolism through endocrine effects and affecting pathways involved in energy homeostasis. Methods: Nineteen patients referred for cardiac catheterization were enrolled. Peripheral and selective coronary sinus (CS) blood sampling was performed at serial timepoints following the initiation of pacing, and metabolite profiling was performed by liquid chromatography-mass spectrometry (LC-MS). Results: Pacing-stress resulted in a 225% increase in the median rate·pressure product from baseline. Increased myocardial work induced significant changes in the peripheral concentration of 43 of 125 metabolites assayed, including large changes in purine [adenosine (+99%, p = 0.006), ADP (+42%, p = 0.01), AMP (+79%, p = 0.004), GDP (+69%, p = 0.003), GMP (+58%, p = 0.01), IMP (+50%, p = 0.03), xanthine (+61%, p = 0.0006)], and several bile acid metabolites. The CS changes in metabolites qualitatively mirrored those in the peripheral blood in both timing and magnitude, suggesting the heart was not the major source of the metabolite release. Conclusions: Isolated increases in myocardial work can induce changes in the plasma metabolome, but these changes do not appear to be directly cardiac in origin. A number of these dynamic metabolites have known signaling functions. Our study provides additional evidence to a growing body of literature on metabolic ‘cross-talk’ between the heart and other organs. [ABSTRACT FROM AUTHOR]

Background: Aggregation of metabolic risk factors- i.e., elevated plasma triglyceride (TG), reduced high-density lipoprotein cholesterol (HDL-C), elevated blood pressure, and raised plasma glucose-convey increased risk for atherosclerotic cardiovascular disease and type 2 diabetes. Methods: This study was carried out to determine the association of waist girth, ethnicity, and gender with susceptibility for metabolic risk. Included were 1671 adult women (50.7% black) and 1339 men (46.5% black) enrolled in the Dallas Heart Study. Subjects were stratified into three categories by waist girth-low, intermediate, and high, corresponding to BMI ranges of <25 kg/m2, 25-29.9 kg/m2, and ≥30 kg/m2. Results: Risk factor prevalence rose progressively through each waist-girth category. However, even among those with high waist-girth, prevalence of three or more risk factors was less than 50%. Several differences among the ethnic groups were noted; for example, Hispanic men had a higher prevalence of elevated TG compared to whites; black men, on the other hand, had a lower frequency of high TG. There were also fewer black men with low HDL-C than in the other groups. Black and Hispanic men had a higher prevalence of elevated glucose and updated homeostasis model assessment of insulin resistance (HOMA2-IR) than whites. More black men had elevated blood pressure than other groups. These differences were less pronounced among ethnic groups of women. Conclusion: Although ethnic and gender differences in risk factor prevalence may exist, it is notable that the majority of subjects, even when obese, did not have elevated risk factors. This finding points to the need to focus largely on subjects with metabolic risk factors when implementing therapeutic interventions. [ABSTRACT FROM AUTHOR]

The relation of body fat distribution to left ventricular (LV) structure and function is poorly defined.A total of 2710 participants without heart failure or LV dysfunction in the Dallas Heart Study underwent dual energy x-ray absorptiometry and MRI assessment of fat distribution, LV morphology, and hemodynamics. Cross-sectional associations of fat distribution with LV structure and function were examined after adjustment for age, sex, race, comorbidities, and lean mass. Mean age was 44 years with 55% women; 48% blacks; and 44% obese. After multivariable adjustment, visceral adipose tissue was associated with concentric remodeling characterized by lower LV end-diastolic volume (β=-0.21), higher concentricity (β=0.20), and wall thickness (β=0.09; P<0.0001 for all). In contrast, lower body subcutaneous fat was associated with higher LV end-diastolic volume (β=0.48), reduced concentricity (β=-0.50), and wall thickness (β=-0.28, P<0.0001 for all). Visceral adipose tissue was also associated with lower cardiac output (β=-0.10, P<0.05) and higher systemic vascular resistance (β=0.08, P<0.05), whereas lower body subcutaneous fat associated with higher cardiac output (β=0.20, P<0.0001) and lower systemic vascular resistance (β=-0.18, P<0.0001). Abdominal subcutaneous fat showed weaker associations with concentric remodeling and was not associated with hemodynamics. Among the subset of obese participants, visceral adipose tissue, but not abdominal subcutaneous fat, was significantly associated with concentric remodeling.Visceral adipose tissue, a marker of central adiposity, was independently associated with concentric LV remodeling and adverse hemodynamics. In contrast, lower body subcutaneous fat was associated with eccentric remodeling. The impact of body fat distribution on heart failure risk requires prospective study. [ABSTRACT FROM AUTHOR]

Objective: Visceral (VAT) and abdominal subcutaneous (SAT) adipose tissues contribute to obesity but may have different metabolic and atherosclerosis risk profiles. We sought to determine the associations of abdominal VAT and SAT mass with markers of cardiac and metabolic risk in a large, multiethnic, population-based cohort of obese adults. Design and Methods: Among obese participants in the Dallas Heart Study, we examined the cross-sectional associations of abdominal VAT and SAT mass, assessed by magnetic resonance imaging (MRI) and indexed to body surface area (BSA), with circulating biomarkers of insulin resistance, dyslipidemia, and inflammation ( n = 942); and with aortic plaque and liver fat by MRI and coronary calcium by computed tomography ( n = 1200). Associations of VAT/BSA and SAT/BSA were examined after adjustment for age, sex, race, menopause, and body mass index. Results: In multivariable models, VAT significantly associated with the homeostasis model assessment of insulin resistance (HOMA-IR), lower adiponectin, smaller LDL and HDL particle size, larger VLDL size, and increased LDL and VLDL particle number ( p < 0.001 for each). VAT also associated with prevalent diabetes, metabolic syndrome, hepatic steatosis, and aortic plaque ( p < 0.001 for each). VAT independently associated with C-reactive protein but not with any other inflammatory biomarkers tested. In contrast, SAT associated with leptin and inflammatory biomarkers, but not with dyslipidemia or atherosclerosis. Associations between SAT and HOMA-IR were significant in univariable analyses but attenuated after multivariable adjustment. Conclusion: VAT associated with an adverse metabolic, dyslipidemic, and atherogenic obesity phenotype. In contrast, SAT demonstrated a more benign phenotype, characterized by modest associations with inflammatory biomarkers and leptin, but no independent association with dyslipidemia, insulin resistance, or atherosclerosis in obese individuals. These findings suggest that abdominal fat distribution defines distinct obesity sub-phenotypes with heterogeneous metabolic and atherosclerosis risk. [ABSTRACT FROM AUTHOR]

Abstract: There is a long history of investigation into the metabolism of the failing heart. Congestive heart failure is marked both by severe disruptions in myocardial energy supply and an inability of the heart to efficiently uptake and oxidize fuels. Despite the many advancements in our understanding, there are still even more outstanding questions in the field. Metabolomics has the power to assist our understanding of the metabolic derangements which accompany myocardial dysfunction. Metabolomic investigations in animal models of heart failure have already highlighted several novel, potentially important pathways of substrate selection and toxicity. Metabolomic biomarker studies in humans, already successfully applied to other forms of cardiovascular disease, have the potential to improve diagnosis and patient care. This article is part of a Special Issue entitled "Focus on Cardiac Metabolism". [Copyright &y& Elsevier]

Left ventricular outflow tract (LVOT) obstruction is a major determinant of heart failure symptoms in obstructive hypertrophic cardiomyopathy (oHCM). Aficamten, a next-in-class cardiac myosin inhibitor, may lower gradients and improve symptoms in these patients. This study aims to evaluate the safety and efficacy of aficamten in patients with oHCM. Patients with oHCM and LVOT gradients ≥30 mm Hg at rest or ≥50 mm Hg with Valsalva were randomized 2:1 to receive aficamten (n = 28) or placebo (n = 13) in 2 dose-finding cohorts. Doses were titrated based on gradients and ejection fraction (EF). Safety and changes in gradient, EF, New York Heart Association functional class, and cardiac biomarkers were assessed over a 10-week treatment period and after a 2-week washout. From baseline to 10 weeks, aficamten reduced gradients at rest (mean difference: −40 ± 27 mm Hg, and −43 ± 37 mm Hg in Cohorts 1 and 2, P = 0.0003 and P = 0.0004 vs placebo, respectively) and with Valsalva (−36 ± 27 mm Hg and −53 ± 44 mm Hg, P = 0.001 and <0.0001 vs placebo, respectively). There were modest reductions in EF (−6% ± 7.5% and −12% ± 5.9%, P = 0.007 and P < 0.0001 vs placebo, respectively). Symptomatic improvement in ≥1 New York Heart Association functional class was observed in 31% on placebo, and 43% and 64% on aficamten in Cohorts 1 and 2, respectively (nonsignificant). With aficamten, N-terminal pro–B-type natriuretic peptide was reduced (62% relative to placebo, P = 0.0002). There were no treatment interruptions and adverse events were similar between treatment arms. Aficamten resulted in substantial reductions in LVOT gradients with most patients experiencing improvement in biomarkers and symptoms. These results highlight the potential of sarcomere-targeted therapy for treatment of oHCM. [Display omitted] [ABSTRACT FROM AUTHOR]