Clinical effectiveness of implantable cardioverter-defibrillators among medicare beneficiaries with heart failure

Abstract

Background: The clinical effectiveness of implantable cardioverter-defibrillators (ICDs) in older patients with heart failure has not been established, and older patients have been underrepresented in previous studies.

Methods and results: We identified patients with heart failure who were aged 65 years or older and were eligible for an ICD, had left ventricular ejection fraction of 35% or less, and were discharged alive from hospitals participating in the Organized Program to Initiate Lifesaving Treatment in Hospitalized Patients With Heart Failure and the Get With the Guidelines-Heart Failure quality-improvement programs during the period January 1, 2003, through December 31, 2006. We matched the patients to Medicare claims to examine long-term outcomes. The main outcome measure was all-cause mortality over 3 years. The study population included 4685 patients who were discharged alive and were eligible for an ICD. Mean age was 75.2 years, 60% of the patients were women, mean ejection fraction was 25%, and 376 (8.0%) patients received an ICD before discharge. Mortality was significantly lower among patients who received an ICD compared with those who did not (19.8% versus 27.6% at 1 year, 30.9% versus 41.9% at 2 years, and 38.1% versus 52.3% at 3 years; P<0.001 for all comparisons). The inverse probability-weighted adjusted hazard of mortality at 3 years for patients receiving an ICD was 0.71 (95% CI, 0.56 to 0.91).

Conclusions: Medicare beneficiaries hospitalized with heart failure and left ventricular ejection fraction of 35% or less who were selected for ICD therapy had lower risk-adjusted long-term mortality compared with those who did not receive an ICD. Clinical Trial Registration- clinicaltrials.gov. Identifier: NCT00344513.