Effectiveness of Guideline-Recommended Cardiac Drugs for Reducing Mortality in the Elderly Medicare Heart Failure Population

Abstract

Heart failure (HF) management guidelines recommend that most patients with HF receive an ACE inhibitor or an angiotensin II type 1 receptor antagonist (angiotensin receptor blocker [ARB]) and a β-blocker (β-adrenoceptor antagonist), collectively referred to as 'cardiac drugs', based on results from randomized controlled trials showing that these drugs reduce mortality. However, the results of randomized controlled trials may not be generalizable to the population most likely (i.e. the elderly) to receive these drugs in clinical practice. To determine the effectiveness of cardiac drugs for reducing mortality in the elderly Medicare HF population. Retrospective, survey-weighted, cohort analysis of the 2002 Medicare Current Beneficiary Survey Cost and Use files. 12 697 beneficiaries, of whom 1062 had a diagnosis of HF and 577 were eligible to receive cardiac drugs. Association between mortality and cardiac drugs, adjusted for sociodemographics, co-morbidity and propensity to receive cardiac drugs. The mortality rate among the 577 eligible beneficiaries with HF was 9.7%. The mortality rate for those receiving an ACE inhibitor or ARB alone, a β-blocker alone, or both an ACE inhibitor or ARB and a β-blocker, was 6.1%, 5.9% and 5.3%, respectively; in the absence of any of the three cardiac drugs, the mortality rate was 20.0% (p < 0.0001). In multivariable analyses, mortality rates remained significantly lower for beneficiaries receiving an ACE inhibitor or ARB alone (odds ratio [OR] 0.24; 95% CI 0.11, 0.50), a β-blocker alone (OR 0.17; 95% CI 0.07, 0.41), or both an ACE inhibitor or ARB and a β-blocker (OR 0.24; 95% CI 0.10, 0.55) compared with patients who did not receive any of the three cardiac drugs. Use of guideline-recommended cardiac drugs is associated with reduced mortality in the elderly Medicare HF population. Providing evidence of the benefit of cardiac drugs among the elderly with HF will become increasingly important as the size of the Medicare population grows.