Association Between Beta-Blockers and Mortality and Readmission in Older Patients with Heart Failure: an Instrumental Variable Analysis.

Abstract

The demographics of heart failure are changing. The rate of growth of the "older" heart failure population, specifically those ≥ 75, has outpaced that of any other age group. These older patients were underrepresented in the early beta-blocker trials. There are several reasons, including a decreased potential for mortality benefit and increased risk of side effects, why the risk/benefit tradeoff may be different in this population. We aimed to determine the association between receipt of a beta-blocker after heart failure discharge and early mortality and readmission rates among patients with heart failure and reduced ejection fraction (HFrEF), specifically patients aged 75+. We used 100% Medicare Parts A and B and a random 40% sample of Part D to create a cohort of beneficiaries with ≥ 1 hospitalization for HFrEF between 2008 and 2016 to run an instrumental variable analysis. The primary measure was 90-day, all-cause mortality; the secondary measure was 90-day, all-cause readmission. Using the two-stage least squared methodology, among all HFrEF patients, receipt of a beta-blocker within 30-day of discharge was associated with a - 4.35% (95% CI - 6.27 to - 2.42%, p < 0.001) decrease in 90-day mortality and a - 4.66% (95% CI - 7.40 to - 1.91%, p = 0.001) decrease in 90-day readmission rates. Even among patients ≥ 75 years old, receipt of a beta-blocker at discharge was also associated with a significant decrease in 90-day mortality, - 4.78% (95% CI - 7.19 to - 2.40%, p < 0.001) and 90-day readmissions, - 4.67% (95% CI - 7.89 to - 1.45%, p < 0.001). Patients aged ≥ 75 years who receive a beta-blocker after HFrEF hospitalization have significantly lower 90-day mortality and readmission rates. The magnitude of benefit does not appear to wane with age. Absent a strong contraindication, all patients with HFrEF should attempt beta-blocker therapy at/after hospital discharge, regardless of age.