Abstract Background Classification of chronic heart failure (HF) is on the basis of criteria that may not adequately capture disease heterogeneity. Improved phenotyping may help inform research and ...therapeutic strategies. Objectives This study used cluster analysis to explore clinical phenotypes in chronic HF patients. Methods A cluster analysis was performed on 45 baseline clinical variables from 1,619 participants in the HF-ACTION (Heart Failure: A Controlled Trial Investigating Outcomes of Exercise Training) study, which evaluated exercise training versus usual care in chronic systolic HF. An association between identified clusters and clinical outcomes was assessed using Cox proportional hazards modeling. Differential associations between clinical outcomes and exercise testing were examined using interaction testing. Results Four clusters were identified (ranging from 248 to 773 patients in each), in which patients varied considerably among measures of age, sex, race, symptoms, comorbidities, HF etiology, socioeconomic status, quality of life, cardiopulmonary exercise testing parameters, and biomarker levels. Differential associations were observed for hospitalization and mortality risks between and within clusters. Compared with cluster 1, risk of all-cause mortality and/or all-cause hospitalization ranged from 0.65 (95% confidence interval 95% CI: 0.54 to 0.78) for cluster 4 to 1.02 (95% CI: 0.87 to 1.19) for cluster 3. However, for all-cause mortality, cluster 3 had a disproportionately lower risk of 0.61 (95% CI: 0.44 to 0.86). Evidence suggested differential effects of exercise treatment on changes in peak oxygen consumption and clinical outcomes between clusters (p for interaction <0.04). Conclusions Cluster analysis of clinical variables identified 4 distinct phenotypes of chronic HF. Our findings underscore the high degree of disease heterogeneity that exists within chronic HF patients and the need for improved phenotyping of the syndrome. (Exercise Training Program to Improve Clinical Outcomes in Individuals With Congestive Heart Failure; NCT00047437 )
Objectives The aim of this study was to examine the relation of galectin-3 (Gal-3), a marker of cardiac fibrosis, with incident heart failure (HF) in the community. Background Gal-3 is an emerging ...prognostic biomarker in HF, and experimental studies suggest that Gal-3 is an important mediator of cardiac fibrosis. Whether elevated Gal-3 concentrations precede the development of HF is unknown. Methods Gal-3 concentrations were measured in 3,353 participants in the Framingham Offspring Cohort (mean age 59 years; 53% women). The relation of Gal-3 to incident HF was assessed using proportional hazards regression. Results Gal-3 was associated with increased left ventricular mass in age-adjusted and sex-adjusted analyses (p = 0.001); this association was attenuated in multivariate analyses (p = 0.06). A total of 166 participants developed incident HF and 468 died during a mean follow-up period of 11.2 years. Gal-3 was associated with risk for incident HF (hazard ratio HR: 1.28 per 1 SD increase in log Gal-3; 95% confidence interval CI: 1.14 to 1.43; p < 0.0001) and remained significant after adjustment for clinical variables and B-type natriuretic peptide (HR: 1.23; 95% CI: 1.04 to 1.47; p = 0.02). Gal-3 was also associated with risk for all-cause mortality (multivariable-adjusted HR: 1.15; 95% CI: 1.04 to 1.28; p = 0.01). The addition of Gal-3 to clinical factors resulted in negligible changes to the C-statistic and minor improvements in net reclassification improvement. Conclusions Higher concentration of Gal-3, a marker of cardiac fibrosis, is associated with increased risk for incident HF and mortality. Future studies evaluating the role of Gal-3 in cardiac remodeling may provide further insights into the role of Gal-3 in the pathophysiology of HF.
Background The cholesterol content of low-density lipoprotein (LDL) particles is variable, causing frequent discrepancies between concentrations of LDL cholesterol (LDL-C) and LDL particle number ...(LDL-P). In managing patients at risk for cardiovascular disease (CVD) to LDL target levels, it is unclear whether LDL-C provides the optimum measure of residual risk and adequacy of LDL-lowering treatment. Objective To compare the ability of alternative measures of LDL to provide CVD risk discrimination at relatively low levels consistent with current therapeutic targets. Methods Concentrations of LDL-C and non–HDL-C were measured chemically and LDL-P and VLDL-P were measured by nuclear magnetic resonance in 3066 middle-aged white participants (53% women) without CVD in the Framingham Offspring cohort. The main outcome measure was incidence of first CVD event. Results At baseline, the cholesterol content per LDL particle was negatively associated with triglycerides and positively associated with LDL-C. On follow-up (median 14.8 years), 265 men and 266 women experienced a CVD event. In multivariable models adjusting for nonlipid CVD risk factors, LDL-P was related more strongly to future CVD in both genders than LDL-C or non–HDL-C. Subjects with a low level of LDL-P (<25th percentile) had a lower CVD event rate (59 events per 1000 person-years) than those with an equivalently low level of LDL-C or non–HDL-C (81 and 74 events per 1000 person-years, respectively). Conclusions In a large community-based sample, LDL-P was a more sensitive indicator of low CVD risk than either LDL-C or non–HDL-C, suggesting a potential clinical role for LDL-P as a goal of LDL management.
Objectives This study sought to determine and compare the prognostic and incremental value of positron emission tomography (PET) in normal, overweight, and obese patients. Background Cardiac rubidium ...82 (Rb-82) PET is increasingly being used for myocardial perfusion imaging (MPI). A strength of PET is its accurate attenuation correction, thereby potentially improving its diagnostic accuracy in obese patients. The prognostic value of PET in obese patients has not been well studied. Methods A total of 7,061 patients who had undergone Rb-82 PET MPI were entered into a multicenter observational registry. All patients underwent pharmacologic Rb-82 PET and were followed for cardiac death and all-cause mortality. Based on body mass index (BMI), patients were categorized as normal (<25 kg/m2 ), overweight (25 to 29.9 kg/m2 ), or obese (≥30 kg/m2 ). Using a 17-segment model and 5-point scoring system, the percentage of abnormal myocardium was calculated for stress and rest patients categorized as normal (0%), mild (0.1% to 9.9%), moderate (10% to 19.9%), and severe (≥20%). Results A total of 6,037 patients were followed for cardiac death (median: 2.2 years) and the mean BMI was 30.5 ± 7.4 kg/m2 . A total of 169 cardiac deaths were observed. PET MPI demonstrated independent and incremental prognostic value over BMI. Normal PET MPI conferred an excellent prognosis with very low annual cardiac death rates in normal (0.38%), overweight (0.43%), and obese (0.15%) patients. As well, both moderately and severe obese patients with a normal PET MPI had excellent prognosis (0.20% and 0.10%, respectively). The net reclassification improvement of PET was 0.46 (95% confidence interval CI: 0.31 to 0.61), and appeared similar in the moderately and severe obese patients which were 0.44 (95% CI: 0.12 to 0.76) and 0.63 (95% CI: 0.27 to 0.98), respectively. Conclusions Rb-82 PET has incremental prognostic value in all patients irrespective of BMI. In the obese population, where other modalities may have reduced diagnostic accuracy, cardiac PET appears to be a promising noninvasive modality with prognostic value.
Summary Background Atrial fibrillation contributes to substantial increases in morbidity and mortality. We aimed to develop a risk score to predict individuals' absolute risk of developing the ...condition, and to provide a framework for researchers to assess new risk markers. Methods We assessed 4764 participants in the Framingham Heart Study from 8044 examinations (55% women, 45–95 years of age) undertaken between June, 1968, and September, 1987. Thereafter, participants were monitored for the first event of atrial fibrillation for a maximum of 10 years. Multivariable Cox regression identified clinical risk factors associated with development of atrial fibrillation in 10 years. Secondary analyses incorporated routine echocardiographic measurements (5152 participants, 7156 examinations) to reclassify the risk of atrial fibrillation and to assess whether these measurements improved risk prediction. Findings 457 (10%) of the 4764 participants developed atrial fibrillation. Age, sex, body-mass index, systolic blood pressure, treatment for hypertension, PR interval, clinically significant cardiac murmur, and heart failure were associated with atrial fibrillation and incorporated in a risk score (p<0·05, except body-mass index p=0·08), clinical model C statistic 0·78 (95% CI 0·76–0·80). Risk of atrial fibrillation in 10 years varied with age: more than 15% risk was recorded in 53 (1%) participants younger than 65 years, compared with 783 (27%) older than 65 years. Additional incorporation of echocardiographic measurements to enhance the risk prediction model only slightly improved the C statistic from 0·78 (95% CI 0·75–0·80) to 0·79 (0·77–0·82), p=0·005. Echocardiographic measurements did not improve risk reclassification (p=0·18). Interpretation From clinical factors readily accessible in primary care, our risk score could help to identify risk of atrial fibrillation for individuals in the community, assess technologies or markers for improvement of risk prediction, and target high-risk individuals for preventive measures. Funding US National Institutes of Health.
Abstract Background Prediction models for cardiovascular events and cardiovascular death in patients with established cardiovascular disease are not generally available. Methods Participants from the ...prospective REduction of Atherothrombosis for Continued Health (REACH) Registry provided a global outpatient population with known cardiovascular disease at entry. Cardiovascular prediction models were estimated from the 2-year follow-up data of 49,689 participants from around the world. Results A developmental prediction model was estimated from 33,419 randomly selected participants (2394 cardiovascular events with 1029 cardiovascular deaths) from the pool of 49,689. The number of vascular beds with clinical disease, diabetes, smoking, low body mass index, history of atrial fibrillation, cardiac failure, and history of cardiovascular event(s) <1 year before baseline examination increased risk of a subsequent cardiovascular event. Statin (hazard ratio 0.75; 95% confidence interval, 0.69-0.82) and acetylsalicylic acid therapy (hazard ratio 0.90; 95% confidence interval, 0.83-0.99) also were significantly associated with reduced risk of cardiovascular events. The prediction model was validated in the remaining 16,270 REACH subjects (1172 cardiovascular events, 494 cardiovascular deaths). Risk of cardiovascular death was similarly estimated with the same set of risk factors. Simple algorithms were developed for prediction of overall cardiovascular events and for cardiovascular death. Conclusions This study establishes and validates a risk model to predict secondary cardiovascular events and cardiovascular death in outpatients with established atherothrombotic disease. Traditional risk factors, burden of disease, lack of treatment, and geographic location all are related to an increased risk of subsequent cardiovascular morbidity and cardiovascular mortality.
Abstract Exenatide once-weekly is an extended release formulation of exenatide, a glucagon-like peptide (GLP)-1 receptor agonist, which can improve glycemic control, body weight, blood pressure, and ...lipid levels in patients with type 2 diabetes mellitus (T2DM). The EXenatide Study of Cardiovascular Event Lowering (EXSCEL) will compare the impact of adding exenatide once-weekly to usual care with usual care alone on major cardiovascular outcomes. EXSCEL is an academically-led, phase III/IV, double-blind, pragmatic placebo-controlled, global trial conducted in 35 countries aiming to enrol 14,000 patients with T2DM and a broad range of cardiovascular risk over approximately 5 years. Participants will be randomized (1:1) to receive exenatide once-weekly 2 mg or matching placebo by subcutaneous injections. The trial will continue until 1360 confirmed primary composite cardiovascular endpoints, defined as cardiovascular death, non-fatal myocardial infarction, or non-fatal stroke, have occurred. The primary efficacy hypothesis is that exenatide once-weekly is superior to usual care with respect to the primary composite cardiovascular endpoint. EXSCEL is powered to detect a 15% relative risk reduction in the exenatide once weekly group, with 85% power and a 2-sided 5% alpha. The primary safety hypothesis is that exenatide once-weekly is noninferior to usual care with respect to the primary cardiovascular composite endpoint. Noninferiority will be concluded if the upper limit of the confidence interval is <1.30. EXSCEL will assess whether exenatide once-weekly can reduce cardiovascular events in patients with T2DM with a broad range of cardiovascular risk. It will also provide long-term safety information on exenatide once-weekly in people with T2DM. ClinicalTrials.gov Identifier: NCT01144338
Background Atrial fibrillation (AF) is associated with increased morbidity. P-wave indices (PWIs) measure atrial electrical function and are associated with AF. Study of PWI has been limited to ...single-cohort investigations, and their contributions to risk enhancement are unknown. Methods We examined PWI from the FHS and ARIC study. We calculated 10-year AF risk using adjusted Cox models. We conducted cross-cohort meta-analyses for the PWI estimates and assessed their contributions to risk discrimination ( c statistic), net reclassification index, and integrated discrimination improvement. Results After exclusions, the analysis included 3,110 FHS (62.6 ± 9.8 years, 56.9% women) and 8,254 ARIC participants (62.3 ± 5.6 years, 57.3% women, 20.3% black race). Over 10 years, 217 FHS and 458 ARIC participants developed AF. In meta-analysis, P-wave duration >120 milliseconds was significantly associated with AF (hazard ratio 1.55, 95% CI 1.29-1.85) compared with ≤120 milliseconds. P-wave area was marginally but not significantly related to AF (hazard ratio 1.31, 95% CI 0.95-1.80). P-wave terminal force was strongly associated with AF in ARIC but not FHS. P-wave indices had a limited contribution toward predictive risk beyond traditional risk factors and markers. Conclusions P-wave indices are intermediate phenotypes for AF. They are associated with AF in cross-cohort meta-analyses but contribute minimally toward enhancing risk prediction.
Background Coronary computed tomographic angiography (CCTA) of 64-detector rows or greater represents a novel noninvasive anatomic method for evaluation of patients with suspected coronary artery ...disease (CAD). Early studies suggest a potential for prognostic risk assessment by CCTA findings but were limited by small patient cohorts or single centers. The CONFIRM ( CO ronary CT Angiography Evaluatio N F or Clinical Outcomes: An I nte R national M ulticenter) registry is a large, prospective, multinational dynamic observational study of patients undergoing CCTA. The primary aim of CONFIRM is to determine the prognostic value of CCTA findings for the prediction of future adverse CAD events. Methods The CONFIRM registry currently represents 27,125 consecutive patients at 12 cluster sites in 6 countries in North America, Europe, and Asia. CONFIRM sites were chosen on the basis of adequate CCTA volume, site CCTA proficiency, and local demographic characteristics and medical facilities to ensure a broad-based sample of patients. Patients comprising the present CONFIRM cohort include those with suspected but without known CAD, with known CAD, or asymptomatic persons undergoing CAD evaluation. A data dictionary comprising a wide array of demographic, clinical, and CCTA findings was developed by the CONFIRM investigators and is uniformly used for all patients. Patients are followed up after CCTA performance to identify adverse CAD events, including death, myocardial infarction, unstable angina, target vessel revascularization, and CAD-related hospitalization. Conclusions From a number of countries worldwide, the information collected from the CONFIRM registry will add incremental and important insights into CCTA findings that confer prognostic value beyond demographic and clinical characteristics. The results of the CONFIRM registry will provide valuable information about the optimal methods for using CCTA findings.
Higher left ventricular (LV) mass, wall thickness, and internal dimension are associated with increased heart failure (HF) risk. Whether different LV hypertrophy patterns vary with respect to rates ...and types of HF incidence is unclear. In this study, 4,768 Framingham Heart Study participants (mean age 50 years, 56% women) were classified into 4 mutually exclusive LV hypertrophy pattern groups (normal, concentric remodeling, concentric hypertrophy, and eccentric hypertrophy) using American Society of Echocardiography–recommended thresholds of echocardiographic LV mass indexed to body surface area and relative wall thickness, and these groups were related to HF incidence. Whether risk for HF types (HF with reduced ejection fraction <45% vs preserved ejection fraction ≥45%) varied by hypertrophy pattern was then evaluated. On follow-up (mean 21 years), 458 participants (9.6%, 250 women) developed new-onset HF. The age- and gender-adjusted 20-year HF incidence increased from 6.96% in the normal left ventricle group to 8.67%, 13.38%, and 15.27% in the concentric remodeling, concentric hypertrophy, and eccentric hypertrophy groups, respectively. After adjustment for co-morbidities and incident myocardial infarction, LV hypertrophy patterns were associated with higher HF incidence relative to the normal left ventricle group (p = 0.0002); eccentric hypertrophy carried the greatest risk (hazard ratio HR 1.89, 95% confidence interval CI 1.41 to 2.54), followed by concentric hypertrophy (HR 1.40, 95% CI 1.04 to 1.87). Participants with eccentric hypertrophy had a higher propensity for HF with reduced ejection fraction (HR 2.23, 95% CI 1.48 to 3.37), whereas those with concentric hypertrophy were more prone to HF with preserved ejection fraction (HR 1.66, 95% CI 1.09 to 2.51). In conclusion, in this large community-based sample, HF risk varied by LV hypertrophy pattern, with eccentric and concentric hypertrophy predisposing to HF with reduced and preserved ejection fraction, respectively.
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