Implantable heart defibrillator is effective in reducing deaths among older heart failure patients

Outcomes and Effectiveness Research
Implantable heart defibrillator is effective in reducing deaths among older heart failure patients

Use of implanted cardioverter-defibrillators (ICDs) reduced 3-year mortality by nearly 30 percent among Medicare patients with heart failure, found a new study. At the end of 1 year, heart failure patients who received ICDs experienced lower mortality than those who did not (19.8 vs. 27.6 percent). At 3 years, patients who received ICDs had a cumulative mortality of 38.1 percent compared with 52.3 percent for those not receiving the devices.

The researchers found no significant difference in mortality outcome based on age (65 to 74 years vs. 75 to 84 years), sex, and cause of heart failure. They observed a beneficial effect of ICDs among patients with poor left ventricle function, a measure of the heart's pumping power (left ventricular ejection fraction [LVEF] less than 30 percent) and those who were discharged on an angiotensin-converting enzyme inhibitor or an angiotensin receptor blocker and a beta-blocker. The researchers conducted the study, because earlier randomized clinical trials underrepresented patients aged 65 years or older, who make up more than 70 percent of the heart failure population. To study this age group, the researchers used data from two heart failure registries and long-term outcome data from Medicare claims files. The analysis was conducted on data from 4,685 older patients with heart failure who were eligible for ICD therapy and discharged alive and who had LVEF of 35 percent or less.

Because retrospective studies do not routinely collect data on health status and quality of life, the researchers call for prospective studies to judge the clinical effectiveness of ICDs and the impact of health status on the decision to use ICD therapy. Their study was funded in part by the Agency for Healthcare Research and Quality (HS16964).

More details are in "Clinical effectiveness of implantable cardioverter-defibrillators among Medicare beneficiaries with heart failure," by Adrian F. Hernandez, M.D., M.H.S., Gregg C. Fonarow, M.D., Bradley G. Hammill, M.S., and others in the January 2010 Circulation: Heart Failure 3(1), pp. 7-13.