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

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.