Routine use of spironolactone after myocardial infarction may not significantly reduce cardiovascular mortality or adverse events, according to a recent study.

In the CLEAR trial, published in The New England Journal of Medicine, researchers assessed the routine use of spironolactone in patients with myocardial infarction (MI) to evaluate its effect on cardiovascular outcomes. Presented at the American Heart Association's Scientific Sessions 2024, the study implemented a multicenter, randomized, placebo-controlled design with a 2-by-2 factorial approach, focusing on spironolactone and colchicine separately. The new report focused on the spironolactone arm.

The researchers enrolled 7,062 patients from 104 centers across 14 countries, who were randomly assigned to receive spironolactone (n = 3,537) or placebo (n = 3,525) after undergoing percutaneous coronary intervention. The patients were followed for a median duration of 3 years, with two primary outcomes assessed. The first was a composite of death from cardiovascular causes or new or worsening heart failure, analyzed as total events. The second was a composite of MI, stroke, cardiovascular death, or new or worsening heart failure, analyzed as time to the first event.

For the first outcome, the spironolactone group experienced 183 events (1.7 per 100 patient-years) compared with 220 events (2.1 per 100 patient-years) in the placebo group (hazard ratio [HR] = 0.91, 95% confidence interval [CI] = 0.69–1.21, P = .51). For the second outcome, events occurred in 7.9% of the patients in the spironolactone group and 8.3% of those in the placebo group (HR = 0.96, 95% CI = 0.81–1.13, P = .60).

Safety analyses highlighted increased adverse events in the spironolactone group, including hyperkalemia (1.1% vs 0.6% in placebo) and gynecomastia (2.3% vs 0.5%, P < .001). Cardiovascular mortality rates were similar between groups (3.2% spironolactone vs 3.3% placebo).

The researchers concluded that spironolactone showed no substantial impact on reducing cardiovascular mortality or adverse outcomes in patients who experienced MI without heart failure, whereas adverse events such as hyperkalemia were more frequent in the spironolactone group.

Full disclosures can be found in the published study.