Predictors of the Use of Mineralocorticoid Receptor Antagonists in Patients With Left Ventricular Dysfunction Post-ST-Segment-Elevation Myocardial Infarction

Background Guidelines recommend mineralocorticoid receptor antagonist (MRA) use in patients with left ventricular ejection fraction <= 40% following a myocardial infarction plus heart failure or diabetes mellitus, based on mortality benefit in the EPHESUS (Eplerenone Post-Acute Myocardial Infarction Heart Failure Efficacy and Survival Study) trial. The objective of this study was to evaluate the real-world utilization of MRAs for patients with ST-segment-elevation myocardial infarction (STEMI) with left ventricular dysfunction. Methods and Results The prospective, population-based, Vancouver Coastal Health Authority STEMI database was linked with local outpatient cardiology records from 2007 to 2018. EPHESUS criteria were used to define post-STEMI MRA eligibility (left ventricular ejection fraction <= 40% plus clinical heart failure or diabetes mellitus, and no dialysis-dependent renal dysfunction). The primary outcome was MRA prescription among eligible patients at discharge and the secondary outcome was MRA prescription within 3 months postdischarge. Of 2691 patients with STEMI, 317 (12%) were MRA eligible, and 70 (22%) eligible patients were prescribed an MRA at discharge. Among eligible patients with no MRA at discharge, 12/126 (9.5%) with documented postdischarge follow-up were prescribed an MRA within 3 months. In multivariable analysis, left ventricular ejection fraction (odds ratio [OR], 1.55 per 5% left ventricular ejection fraction decrease; 95% CI, 1.26-1.90) and calendar year (OR, 1.23 per year, 95% CI, 1.11-1.37) were associated with MRA prescription at discharge. Other prespecified variables were not associated with MRA prescription. Conclusions In this contemporary STEMI cohort, only 1 in 4 MRA-eligible patients were prescribed an MRA within 3 months following hospitalization despite high-quality evidence for use. Novel decision-support tools are required to optimize pharmacotherapy decisions during hospitalization and follow-up to target this gap in post-STEMI care.