Real world comparison of spironolactone and eplerenone in patients with heart failure

In the absence of previous direct comparative studies, we aimed to evaluate the effectiveness of spironolactone and eplerenone in patients with heart failure and reduced ejection fraction (HFrEF) in a real-world clinical setting.

Using Fine-Gray´s competing risk regression, we compared the clinical outcomes of 293 patients with chronic HF and left ventricular ejection fraction <40% treated with eplerenone and 293 propensity-score matched individuals treated with spironolactone. Study subjects were selected from a prospective cohort of 1404 ambulatory patients with HFrEF seen since 2010 to 2019 in a single specialized HF clinic, among which 992 received a mineralocorticoid receptor antagonist at baseline. Median follow-up was 3.95 years.

No statistically significant differences between patients treated with eplerenone versus spironolactone were observed with regard to the risk of the primary composite end-point cardiovascular death or HF hospitalization (HR 0.95; 95% CI 0.73-1.23; p= 0.677). However, eplerenone use was associated to lower cardiovascular mortality (HR 0.55; 95% CI 0.35-0.85; p= 0.008) and lower all-cause mortality (HR 0.67; 95% CI 0.47-0.95; p= 0.027). The incidence of drug suspension due to side effects (HR 0.58, 95% CI 0.40-0.85; p= 0.005) and drug suspension due to any reason (HR 0.70, 95% CI 0.51-0.97; p= 0.033) were lower among patients treated with eplerenone.

In this observational, real-world, propensity-score matched study of patients with HFrEF, eplerenone was associated to lower cardiovascular mortality and lower all-cause mortality than spironolactone.