Despite Many Concerns, ICDs Are Here to Stay

Despite Many Concerns, ICDs Are Here to Stay

BOCA RATON, Fla—In January 2005, theNew England Journal of Medicine (2005;352:225-237) reported the results of a trial involving 2521 patients, which showed that implantable cardiac defibrillators (ICDs) reduce all-cause mortality by 23%. The Sudden Cardiac Death in Heart Failure Trial (SCD-HeFT) found the same mortality benefit in patients who had undergone drug therapy.

Nevertheless, fundamental questions about ICDs, such as effectiveness, costs, or appropriate use, remain. These issues were discussed at a symposium held at the 9th Annual Scientific Meeting of the Heart Failure Society of America.

Lynne Warner Stevenson, MD, of Harvard Medical School, Boston, said that while defibrillators are very effective in reducing mortality, some subpopulations do not seem to get the electrical impulse or “shock” needed when a heartbeat becomes too slow or irregular. In addition, it is fairly difficult to identify these patients.

Another problem is that the cost of ICDs tends to reduce their societal usefulness, according to moderator Bruce L. Wilcoff, MD, of The Cleveland Clinic Foundation, Ohio. “Despite their effectiveness, there is a fair amount of cost to defibrillators, and the question is whether we can afford to do all of this,” he told IMWR, adding that this is a difficult question to answer.

According to Dr Stevenson, there are approximately 1.6 million Americans who would benefit from having an implanted defibrillator. But Dr Wilcoff regards this number as too high. “I think she overestimated the number of patients that would get defibrillators by confusing incidence and prevalence. There are only about 300,000 patients per year, at most, who will have those indications and would benefit from having a defibrillator.”

Dusan Kocovic, MD, a cardiologist practicing in Wynnewood, Pa, reported on the biventricular pacing defibrillators and how this technology has progressed. He noted that new devices are not only significantly improving patients’ heart failure symptoms, but they are also reducing the rate of mortality and bettering ejection fractions. ICDs improve the size and shape of the heart and patients’ symptoms, and also help patients live longer, he stressed.

Defibrillators are extremely effective in reducing mortality, Dr Wilcox said, noting that they seem to be most effective in the large group of patients with heart failure. “We have [2] difficult problems—affording the therapy and figuring out which patients are going to benefit the most. Currently, we need to put defibrillators into most patients with significant heart failure,” he said. —L.D.