Aldosterone blockade and left ventricular dysfunction: a systematic review of randomized clinical trials

Abstract

Context: Aldosterone blockade has been used to treat acute myocardial infarction (MI) and chronic heart failure.

Objective: The aim of this study is to summarize the evidence on the efficacy of spironolactone (SP), eplerenone (EP), or canrenoate (CAN) in patients with left ventricular dysfunction.

Data sources: A search of multiple electronic databases until June 2008 was supplemented by hand searches of reference lists of included studies and review articles, meeting abstracts, FDA reports, and contact with study authors and drug manufacturers.

Study selection and data extraction: Studies were eligible for inclusion if they included patients with left ventricular systolic or diastolic dysfunction, treatment with SP, EP, or CAN vs. control, and reported clinical outcomes. Nineteen randomized controlled trials (four in acute MI and 15 in heart failure, n = 10 807 patients) were included -- 14 of SP, three of EP, and three of CAN. Analysis was performed using relative risks (RRs) with 95% confidence intervals (CIs) and a random effects model with statistical heterogeneity assessed by I(2).

Data synthesis: Aldosterone blockade reduced all-cause mortality by 20% (RR 0.80, 95% CI 0.74-0.87). All-cause mortality was reduced in both heart failure (RR = 0.75, 95% CI 0.67-0.84) and post-MI (RR 0.85, 95% CI 0.76-0.95) patients. Only nine trials reported hospitalizations, and the RR reduction was 23% (RR 0.77, 95% CI 0.68-0.87), although 98% of the outcomes came from two trials. Ejection fraction (EF) improved in the seven heart failure trials, which assessed this outcome (weighted mean difference 3.1%, 95% CI 1.6-4.5).

Conclusion: We demonstrated a 20% reduction in all-cause mortality with the use of aldosterone blockade in a clinically heterogeneous group of clinical trial participants with heart failure and post-MI. In addition, we found a 3.1% improvement in EF. Further study in those with less severe symptoms or preserved systolic function is warranted.