The effect of gender on outcome in digitalis-treated heart failure patients

Background: The use of digitalis is recommended for the treatment of heart failure to reduce hospitalization. Methods and Results: Recent data suggest that digitalis treatment may adversely affect survival in women but not in men. We studied patients with left ventricular dysfunction enrolled in the Studies of Left Ventricular Dysfunction (SOLVD) to determine whether there was a gender-based survival difference in patients treated with digitalis. Symptomatic (n = 2569) and asymptomatic (n = 4228) patients with left ventricular ejection fraction ≤0.35 were studied. Digitalis use was assessed at baseline and baseline demographic variables were catalogued and compared. A multivariate analysis, incorporating known covariates of risk for adverse cardiovascular events, was used to examine the association of digitalis with all-cause mortality, cardiovascular death, death from heart failure, and arrhythmic death, with, or without, worsening heart failure in women compared with men. Analysis for an interaction between digitalis and gender on mortality was also performed. No interaction between gender and digitalis treatment on survival was found, and there was no significant difference in the hazard ratios for men and women on digitalis either with respect to all-cause mortality, cardiovascular mortality, heart failure mortality, or arrhythmic death with worsening heart failure. When mortality for arrhythmic death without worsening heart failure was adjusted for the probability of being treated with digitalis (propensity analysis), women fared better than men. Conclusion: Data from the SOLVD trials suggest that digitalis treatment of heart failure does not result in a difference in survival between men and women. Because a randomized trial to definitively answer the question is unlikely, and perhaps inappropriate, examination of other heart failure populations for a gender-digitalis interaction is indicated.