The EMPHASIS-HF trial studied the effects of adding eplerenone to recommended medical therapy in patients with systolic heart failure and mild symptoms. The trial found that adding eplerenone reduced the primary composite outcome of cardiovascular death or heart failure hospitalization by 37% compared to placebo. Eplerenone also reduced mortality from any cause by 24% and hospitalization from any cause by 23%. The benefits were consistent across subgroups. Safety analysis found eplerenone increased serum potassium similarly to other trials. The study concluded that addition of eplerenone to recommended medical therapy reduces morbidity and mortality for patients with mild systolic heart failure.