Additional mineralocorticoid receptor antagonists in heart failure underdosed with guideline-directed medication

Objective Renin-angiotensin-aldosterone system inhibitors (RAASi) and beta-blockers decrease cardiovascular (CV) mortality in patients with heart failure and reduced left ventricular ejection fraction (HFrEF) as the dose increases. Mineralocorticoid receptor antagonists (MRA) can also minimize CV mortality. This study aimed to investigate the potential of early administration of additional MRA to insufficient doses of RAASi and beta-blockers. Methods Among 609 hospitalized patients with HFrEF, we analyzed 401 patients who received either or both <50% target dose of RAASi and beta-blockers at discharge. They were divided into two groups based on the prescription of MRA: MRA (n = 287) and non-MRA (n = 114). We performed propensity score (PS) matching using diverse parameters at discharge.CV death was the primary endpoint. Results Among 401 unmatched patients with HFrEF, Kaplan–Meier analysis for the unmatched population did not show a statistical difference between the MRA and non-MRA groups (log-rank, p = 0.34). However, in the 160 PS-matched population, patients in the MRA group had a significantly lower CV mortality rate than those in the non-MRA group (hazard ratio: 0.29 [95% confidence interval: 0.10–0.79]). Conclusions Early administration of additional MRA in patients with HFrEF, even those who received insufficient target doses of RAASi and beta-blockers, may be a therapeutic option.