Mineralocorticoid receptor antagonist initiation during admission is associated with improved outcomes irrespective of ejection fraction in patients with acute heart failure

Aims: Heart failure (HF) guidelines recommend initiation and optimization of guideline-directed medical therapy, including mineralocorticoid receptor antagonists (MRAs), before hospital discharge. However, scientific evidence for this recommendation is lacking. Our objective was to determine whether initiation of MRA prior to hospital discharge is associated with improved outcomes. Methods and results: We performed a secondary analysis of 6197 patients enrolled in the RELAX-AHF-2 study. Patients were divided into four groups according to MRA therapy at baseline and discharge. At baseline 30% of patients received MRA therapy, which increased to 50% of patients at discharge. In-hospital initiation of an MRA was observed in 1690 (27%) patients, 1438 (23%) patients remained on MRA therapy, 418 (7%) patients discontinued MRA treatment, and 2651 (43%) patients did not receive an MRA during hospital stay. Compared with patients who did not receive MRA therapy, in-hospital initiation of an MRA was independently associated with lower risks of mortality (multivariable hazard ratio [HR] 0.76, 95% confidence interval [CI] 0.60–0.96; p = 0.02), cardiovascular death (HR 0.77, 95% CI 0.59–1.01; p = 0.06), hospitalization for HF or renal failure (HR 0.72, 95% CI 0.60–0.86; p = 0.0003) and the composite endpoint of cardiovascular death and/or rehospitalization for HF or renal failure (HR 0.71, 95% CI 0.61–0.83; p < 0.0001) at 180 days. These results were independent of baseline left ventricular ejection fraction. Conclusion: In patients hospitalized for acute HF, in-hospital initiation of an MRA was associated with improved post-discharge outcomes, independent of left ventricular ejection fraction and other potential confounders.