Clinical Effectiveness of Implantable Cardioverter-DefibrillatorsAmong Medicare Beneficiaries With Heart Failure

Adrian F. Hernandez, MD, MHS; Gregg C. Fonarow, MD; Bradley G. Hammill, MS; Sana M. Al-Khatib, MD, MHS; Clyde W. Yancy, MD; Christopher M.

O’Connor, MD; Kevin A. Schulman, MD; Eric D. Peterson, MD, MPH; Lesley H. Curtis, PhD

BackgroundBackground Previous reports have demonstrated that

participation in Get With The Guidelines- Heart Failure (GWTG-HF), a national quality initiative of the American Heart Association, is associated with improved guideline adherence for patients hospitalized with HF. We sought to establish whether these benefits from participation in GWTG-HF were sustained over time.

IntroductionIntroduction

The American Heart Association (AHA) and the American The American Heart Association (AHA) and the American College of Cardiology (ACC) have developed treatment College of Cardiology (ACC) have developed treatment guidelines for patients with heart failure (HF).guidelines for patients with heart failure (HF).

Despite widely available evidence-based therapies that Despite widely available evidence-based therapies that have been shown to improve clinical outcomes for have been shown to improve clinical outcomes for patients with heart failure (HF), a treatment gap exists patients with heart failure (HF), a treatment gap exists between clinical practice and use of guideline between clinical practice and use of guideline recommended therapies.recommended therapies.

GWTG-HF quality improvement program has shown GWTG-HF quality improvement program has shown significant improvements in guideline adherence for significant improvements in guideline adherence for patients hospitalized with HF.patients hospitalized with HF.

ObjectiveObjective

The clinical effectiveness of implantable The clinical effectiveness of implantable cardioverter-defibrillators (ICDs) in older cardioverter-defibrillators (ICDs) in older patients with HF has not been patients with HF has not been established, and older patients have established, and older patients have been underrepresented in previous been underrepresented in previous studies. The purpose of the paper was to studies. The purpose of the paper was to evaluate the clinical effectiveness of ICD evaluate the clinical effectiveness of ICD therapy in older patients and women to therapy in older patients and women to address the potential risks and benefits.address the potential risks and benefits.

MethodsMethods• Patient population included 4685 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 program

• Study period of January 1, 2003, through December 31, 2006.

• Patients matched to Medicare claims to examine long-term outcomes.

• The main outcome measure was all-cause mortality over 3 years.

ResultsResults• Mortality was significantly lower among patients who received Mortality was significantly lower among patients who received

an ICD compared with those who did not over the three year an ICD compared with those who did not over the three year period (19.8% vs. 27.6% at one year, 30.9% vs. 41.9% at 2 period (19.8% vs. 27.6% at one year, 30.9% vs. 41.9% at 2 years and 38.1% vs. 52.3% at 3 years; P> .001 for all years and 38.1% vs. 52.3% at 3 years; P> .001 for all comparisons).comparisons).

• No differences in were seen in the risk of mortality based on No differences in were seen in the risk of mortality based on age, sex and etiology of HF.age, sex and etiology of HF.

• A beneficial effect of ICD therapy on mortality was seen A beneficial effect of ICD therapy on mortality was seen among patients who had a LVEF of 30% or less and among among patients who had a LVEF of 30% or less and among patients discharged with both ACE inhibitors/ARBs and Beta-patients discharged with both ACE inhibitors/ARBs and Beta-blockers.blockers.

• Medicare beneficiaries hospitalized with HF and LVEF of Medicare beneficiaries hospitalized with HF and LVEF of 35% or less who were selected for ICD therapy had a lower 35% or less who were selected for ICD therapy had a lower risk-adjusted long-term mortality as compared with those who risk-adjusted long-term mortality as compared with those who did not receive an ICD.did not receive an ICD.

LimitationsLimitations• The analysis included only fee-for-service Medicare

beneficiaries who were included in the clinical registries. We also excluded patients aged 85 years or older, patients discharged to a skilled nursing facility, and elective admissions. Thus, our findings may not be generalizable to these populations.

• The registries may disproportionately include hospitals that are The registries may disproportionately include hospitals that are more likely to follow evidence-based recommendations, which more likely to follow evidence-based recommendations, which in turn may influence long-term outcomes. in turn may influence long-term outcomes.

• Patients with prior ICD implantations were not included Patients with prior ICD implantations were not included because implantation dates were not available long-term because implantation dates were not available long-term survival could not be estimated accurately. survival could not be estimated accurately.

• The data on doses of medications such as ACE inhibitors, beta-The data on doses of medications such as ACE inhibitors, beta-blockers, and diuretics or follow-up data on changes in blockers, and diuretics or follow-up data on changes in medications after discharge were not available.medications after discharge were not available.

• Complications of device implantation, measures of appropriate Complications of device implantation, measures of appropriate and inappropriate device discharges, NYHA functional class, and inappropriate device discharges, NYHA functional class, quality of life, socioeconomic factors, and post-discharge quality of life, socioeconomic factors, and post-discharge health status were not available, though all are important health status were not available, though all are important considerations in evaluating the use of ICD therapy.considerations in evaluating the use of ICD therapy.

ConclusionConclusion

Medicare beneficiaries hospitalized with heart failure and LVEF of 35% or less who were eligible for ICD therapy had significantly lower adjusted risk of death over 3 years compared with patients discharged without an ICD. These findings are consistent with the results of randomized clinical trials of ICD therapy.