Gender differences in advanced heart failure: insights from the BEST study

OBJECTIVES: The goal of this study was to determine the influence of gender on baseline characteristics, response to treatment, and prognosis in patients with heart failure (HF) and impaired left ventricular ejection fraction (LVEF). BACKGROUND: Under-representation of women in HF clinical trials has limited our understanding of gender-related differences in patients with HF. METHODS: The impact of gender was assessed in the Beta-Blocker Evaluation of Survival Trial (BEST) which randomized 2,708 patients with New York Heart Association class III/IV and LVEF < or =0.35 to bucindolol versus placebo. Women (n = 593) were compared with men (n = 2,115). Mean follow-up period was two years. RESULTS: Significant differences in baseline clinical and laboratory characteristics were found. Women were younger, more likely to be black, had a higher prevalence of nonischemic etiology, higher right and left ventricular ejection fraction, higher heart rate, greater cardiothoracic ratio, higher prevalence of left bundle branch block, lower prevalence of atrial fibrillation, and lower plasma norepinephrine level. Ischemic etiology and measures of severity of HF were found to be predictors of prognosis in women and men. However, differences in the predictive values of various variables were noted; most notably, coronary artery disease and LVEF appear to be stronger predictors of prognosis in women. In the nonischemic patients, women had a significantly better survival rate compared with men. CONCLUSIONS: In HF patients with impaired LVEF, significant gender differences are present, and the prognostic predictive values of some variables vary in magnitude between women and men. The survival advantage of women is confined to patients with nonischemic etiology.