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.