Sex Differences in Mineralocorticoid Receptor Antagonist Trials: A Pooled Analysis of Three Large Clinical Trials

AIMS: Women with heart failure (HF) are under-represented in individual randomized clinical trials (RCTs). Little is known about sex-specific treatment effects in HF medications. We evaluated sex differences in the response to mineralocorticoid receptor antagonists (MRAs) in major HF MRA trials, including a broad spectrum of left ventricular ejection fraction (LVEF). METHODS AND RESULTS: Individual patient data fixed-effect meta-analysis was performed using 6167 patients (31.4% were women) recruited in three placebo-controlled RCTs: Randomized Aldactone Evaluation Study (RALES), Eplerenone in Mild Patients Hospitalization and Survival Study in Heart Failure (EMPHASIS-HF) and Spironolactone for Heart Failure with Preserved Ejection Fraction (TOPCAT)-Americas. Compared to men, women were older, had higher body mass index and lower glomerular filtration rate. They also had higher LVEF and poorer New York Heart Association functional class and were less likely to be taking angiotensin-converting enzyme inhibitors/angiotensin II receptor blockers. Placebo-arm event rates were lower for women compared with men (15.4 vs. 22.1 per 100 person-year; P = 0.002). MRAs reduced consistently, in men and women, the relative risk for cardiovascular death or HF hospitalization (P for interaction = 0.83), cardiovascular death (P for interaction = 0.44) and all-cause death (P for interaction = 0.19). These findings remained consistent after adjustment for potential confounders, regardless of LVEF. There was no sex-specific impact of MRA on the rate of hyperkalaemia and worsening renal function during the median 22 months of follow-up. CONCLUSION: In three large MRA RCTs, women were substantially different from men with regard to their clinical features and event rates. Nonetheless, this meta-analysis supports a consistent and beneficial MRA effect regardless of sex.