Race, Exercise Training, and Outcomes in Chronic HF
Race, Exercise Training, and Outcomes in Chronic HF
Background The strength of race as an independent predictor of long-term outcomes in a contemporary chronic heart failure (HF) population and its association with exercise training response have not been well established. We aimed to investigate the association between race and outcomes and to explore interactions with exercise training in patients with ambulatory HF.
Methods We performed an analysis of HF-ACTION, which randomized 2331 patients with HF having an ejection fraction ≤35% to usual care with or without exercise training. We examined characteristics and outcomes (mortality/hospitalization, mortality, and cardiovascular mortality/HF hospitalization) by race using adjusted Cox models and explored an interaction with exercise training.
Results There were 749 self-identified black patients (33%). Blacks were younger with significantly more hypertension and diabetes, less ischemic etiology, and lower socioeconomic status versus whites. Blacks had shorter 6-minute walk distance and lower peak VO2 at baseline. Over a median follow-up of 2.5 years, black race was associated with increased risk for all outcomes except mortality. After multivariable adjustment, black race was associated with increased mortality/hospitalization (hazard ratio [HR] 1.16, 95% CI 1.01–1.33) and cardiovascular mortality/HF hospitalization (HR 1.46, 95% CI 1.20–1.77). The hazard associated with black race was largely caused by increased HF hospitalization (HR 1.58, 95% CI 1.27–1.96), given similar cardiovascular mortality. There was no interaction between race and exercise training on outcomes (P > .5).
Conclusions Black race in patients with chronic HF was associated with increased prevalence of modifiable risk factors, lower exercise performance, and increased HF hospitalization, but not increased mortality or a differential response to exercise training.
African American or black populations are at an increased risk for developing heart failure (HF), which occurs at an earlier age and may be associated with increased morbidity and mortality compared with whites. Elderly black Medicare patients were recently shown to have increased 30-day readmission rates for HF compared with whites. However, several studies during the 1990s in the Veterans Affairs health care system and in Medicare patients demonstrated better survival in black patients with HF compared with white patients. Recent registry data from patients hospitalized with acute HF have also suggested that blacks may have comparatively lower inhospital mortality and similar short-term outcomes.
Importantly, none of these studies investigated the strength of race as an independent predictor of long-term outcomes in a diverse, contemporary chronic HF population, and the association between race and exercise training response has not been well established. Although there was no evidence of a significant race and treatment interaction for all-cause mortality/hospitalization in the HF-ACTION study, further investigation is warranted of the disease-specific outcomes of cardiovascular morbidity and mortality. We investigated the association between race and outcomes following multivariable adjustment and explored interactions with exercise training in patients with ambulatory HF enrolled in the HF-ACTION study.
Abstract and Introduction
Abstract
Background The strength of race as an independent predictor of long-term outcomes in a contemporary chronic heart failure (HF) population and its association with exercise training response have not been well established. We aimed to investigate the association between race and outcomes and to explore interactions with exercise training in patients with ambulatory HF.
Methods We performed an analysis of HF-ACTION, which randomized 2331 patients with HF having an ejection fraction ≤35% to usual care with or without exercise training. We examined characteristics and outcomes (mortality/hospitalization, mortality, and cardiovascular mortality/HF hospitalization) by race using adjusted Cox models and explored an interaction with exercise training.
Results There were 749 self-identified black patients (33%). Blacks were younger with significantly more hypertension and diabetes, less ischemic etiology, and lower socioeconomic status versus whites. Blacks had shorter 6-minute walk distance and lower peak VO2 at baseline. Over a median follow-up of 2.5 years, black race was associated with increased risk for all outcomes except mortality. After multivariable adjustment, black race was associated with increased mortality/hospitalization (hazard ratio [HR] 1.16, 95% CI 1.01–1.33) and cardiovascular mortality/HF hospitalization (HR 1.46, 95% CI 1.20–1.77). The hazard associated with black race was largely caused by increased HF hospitalization (HR 1.58, 95% CI 1.27–1.96), given similar cardiovascular mortality. There was no interaction between race and exercise training on outcomes (P > .5).
Conclusions Black race in patients with chronic HF was associated with increased prevalence of modifiable risk factors, lower exercise performance, and increased HF hospitalization, but not increased mortality or a differential response to exercise training.
Introduction
African American or black populations are at an increased risk for developing heart failure (HF), which occurs at an earlier age and may be associated with increased morbidity and mortality compared with whites. Elderly black Medicare patients were recently shown to have increased 30-day readmission rates for HF compared with whites. However, several studies during the 1990s in the Veterans Affairs health care system and in Medicare patients demonstrated better survival in black patients with HF compared with white patients. Recent registry data from patients hospitalized with acute HF have also suggested that blacks may have comparatively lower inhospital mortality and similar short-term outcomes.
Importantly, none of these studies investigated the strength of race as an independent predictor of long-term outcomes in a diverse, contemporary chronic HF population, and the association between race and exercise training response has not been well established. Although there was no evidence of a significant race and treatment interaction for all-cause mortality/hospitalization in the HF-ACTION study, further investigation is warranted of the disease-specific outcomes of cardiovascular morbidity and mortality. We investigated the association between race and outcomes following multivariable adjustment and explored interactions with exercise training in patients with ambulatory HF enrolled in the HF-ACTION study.
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