Patterns, Prognostic Implications, and Rural-Urban Disparities in Optimal GDMT Following HFrEF Diagnosis Among Medicare Beneficiaries

Abstract

BackgroundPatterns and disparities in guideline-directed medical therapy (GDMT) uptake for heart failure with reduced ejection fraction (HFrEF) across rural vs urban regions are not well described. ObjectivesThis study aims to evaluate patterns, prognostic implications, and rural-urban differences in GDMT use among Medicare beneficiaries following new-onset HFrEF. MethodsPatients with a diagnosis of new-onset HFrEF in a 5% Medicare sample with available data for Part D medication use were identified from January 2015 through December 2020. The primary exposure was residence in rural vs urban zip codes. Optimal triple GDMT was defined as ≥50% of the target daily dose of beta-blockers, ≥50% of the target daily dose of angiotensin-converting enzyme inhibitors/angiotensin receptor blocker or any dose of sacubitril/valsartan, and any dose of mineralocorticoid receptor antagonist. The association between the achievement of optimal GDMT over time following new-onset HFrEF diagnosis and risk of all-cause mortality and subsequent HF hospitalization was also evaluated using adjusted Cox models. The association between living in rural vs urban location and time to optimal GDMT achievement over a 12-month follow-up was assessed using cumulative incidence curves and adjusted Fine-Gray subdistribution hazard models. ResultsA total of 41,296 patients (age: 76.7 years; 15.0% Black; 27.6% rural) were included. Optimal GDMT use over the 12-month follow-up was low, with 22.5% initiated on any dose of triple GDMT and 9.1% on optimal GDMT doses. Optimal GDMT on follow-up was significantly associated with a lower risk of death (HR: 0.89 [95% CI: 0.85-0.94]; P < 0.001) and subsequent HF hospitalization (HR: 0.93 [95% CI: 0.87-0.98]; P = 0.02). Optimal GDMT use at 12 months was significantly lower among patients living in rural (vs urban) areas (8.4% vs 9.3%; P = 0.02). In adjusted analysis, living in rural (vs urban) locations was associated with a significantly lower probability of achieving optimal GDMT (HR: 0.92 [95% CI: 0.86-0.98]; P = 0.01 Differences in optimal GDMT use following HFrEF diagnosis accounted for 16% of excess mortality risk among patients living in rural (vs urban) areas. ConclusionsUse of optimal GDMT following new-onset HFrEF diagnosis is low, with substantially lower use noted among patients living in rural vs urban locations. Suboptimal GDMT use following new-onset HFrEF was associated with an increased risk of mortality and subsequent HF hospitalization.