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

Background: Patterns 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. Objectives: This study aims to evaluate patterns, prognostic implications, and rural-urban differences in GDMT use among Medicare beneficiaries following new-onset HFrEF. Methods: Patients 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. Results: A 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. Conclusions: Use 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.