Abstract
BACKGROUND: Underprescribing of guideline-directed medical therapy (GDMT) for heart failure (HF) persists. OBJECTIVES: The purpose of this study was to assess polypharmacy as a barrier to GDMT. METHODS: We examined participants hospitalized for HF with reduced ejection fraction and HF with mildly reduced ejection fraction between 2003 and 2017 from the Reasons for Geographic and Racial Differences in Stroke study. Participants were stratified by admission medication count-0 to 4, 5 to 9, and ≥10 medications. We examined GDMT use at admission, GDMT contraindications, and initiation of eligible indicated GDMT by medication count. We conducted a multivariable Poisson regression with robust standard errors to examine the association between medication count and GDMT initiation. GDMT included agents for HF with reduced ejection fraction/HF with mildly reduced ejection fraction, antiplatelet agents and statins for coronary artery disease, and anticoagulants for atrial fibrillation. RESULTS: Among 545 participants with HF, 34% were not taking a beta-blocker, 39% were not taking an angiotensin-converting enzyme inhibitor/angiotensin receptor blocker/angiotensin receptor-neprilysin inhibitor, or hydralazine-isosorbide dinitrate, and 90% were not taking a mineralocorticoid receptor antagonist at admission; among participants with coronary artery disease, 36% were not taking an antiplatelet agent, and 38% were not taking a statin; and among participants with atrial fibrillation, 49% were not taking an anticoagulant. Polypharmacy was inversely associated with initiation of at least one indicated medication (5-9 medications: relative risk [RR]: 0.67; 95% CI: 0.56-0.82; P < 0.001; ≥10 medications: RR: 0.50; 95% CI: 0.39-0.64; P < 0.001) and initiation of at least half of indicated medications (5-9 medications: RR: 0.64; 95% CI: 0.51-0.81; P < 0.001; ≥10 medications: RR: 0.50; 95% CI: 0.38-0.67; P < 0.001). CONCLUSIONS: Polypharmacy is an important barrier to GDMT.