Expensive defibrillators may be worth every penny
BY MICHELLE L. BRANDT
It might sound like a stretch to call the implantable cardioverter defibrillator a bargain. But not to a team of researchers at the School of Medicine, Duke University and the Veterans Affairs Palo Alto Health Care System, who report that the ICD—one of the priciest medical devices on the market—is a relatively cost-effective way to help prevent sudden cardiac deaths among certain patients.
"In the appropriate patients, these devices provide value, despite their expense," said Douglas Owens, MD, senior investigator at the VA-Palo Alto and associate professor of medicine at Stanford. He is co-author of an analysis of ICD use that appeared in the Oct. 6 issue of the New England Journal of Medicine.
In examining eight studies on the effectiveness of ICDs in various patient populations, Owens and his colleagues found that the device costs as little as $34,000 per quality-adjusted life year, a common measurement that takes into account quality of life as well as length of survival. By comparison, the use of automated external defibrillators on large planes costs $36,000 per quality-adjusted life year and stent therapy for heart attack patients costs $24,000 per quality-adjusted life year.
ICDs are implanted under the skin of patients whose lower heart chambers beat too quickly (ventricular tachycardia) or quiver ineffectively (ventricular fibrillation) and who are at risk of cardiac arrest. The device monitors the rate and rhythm of the heart and sends an electrical shock if it detects dangerous rhythms, helping to avert sudden cardiac death. According to the U.S. Food and Drug Administration, 416,000 defibrillators were implanted between 1990 and 2002.
ICDs were originally used in the 1980s on patients who were resuscitated from a cardiac arrest, but heart specialists saw an opportunity to expand the use of the device. "Doctors began to say, 'we shouldn't wait for people to drop dead; let's use this as a preventive tool,'" recalled study co-author Mark Hlatky, MD, professor of health research and policy and of medicine.
Researchers began examining the use of ICDs to prevent cardiac arrest, resulting in eight large, randomized clinical trials that were published between 1996 and 2004. Each study involved a different type of high-risk patient, and six of the eight studies found that ICDs improved patient survival.
"The gain for patients in these studies is quite important, because the benefit is life," said Paul Wang, MD, a professor of medicine who has treated many high-risk cardiac patients with ICDs. "It's pretty straightforward: patients who receive defibrillators are more likely to survive."
Owens, who is part of the Center for Primary Care and Outcomes Research and the Center for Health Policy in the Freeman Spogli Institute for International Studies, said the pool of patients who could potentially benefit from an ICD continued to grow with the completion of each trial. And the Centers for Medicare and Medicaid Services now estimate that as many as 500,000 Medicare beneficiaries might be eligible for a prophylactic ICD in the United States.
But the devices—with implantation costs usually exceeding $25,000 per patient—don't come cheap. "The device costs more than a new car," pointed out Hlatky. "The total number of budgetary dollars that the government and private insurers could put towards this is staggering."
The hefty tab that accompanies an ICD poses a difficult challenge to insurers, who must decide exactly which patients to provide coverage for: Any person at risk of cardiac arrest? Just those patients with prior heart attack or heart failure?
Owens, Hlatky and co-author Gillian Sanders, PhD, from Duke University, conducted their study in an effort to help guide such decisions. Using data from the eight trials, the team developed a decision model to estimate the length of life and the expenditures for patients who either had or did not have an ICD implanted for preventive purposes. The researchers assumed that the benefit of the defibrillator would continue throughout the patient's lifetime, and that the device would be replaced every five years.
Although two of the trials found no benefit from the device in reducing mortality, the researchers found that ICD use was projected to add between 1.01 and 2.99 quality-adjusted life years in the six other studies. "These are very substantial benefits," said Hlatky. "Quite a few people got a meaningful increase in life expectancy from the ICD."
The researchers also found that the cost-effectiveness of the ICD compared with the control therapy in these six populations ranged from $34,000 to $70,200 per quality-adjusted life year. These figures indicate that the device is cost-effective for those populations in which a significant reduction in mortality has been demonstrated.
"This increment in life expectancy is substantial compared with many other medical interventions," wrote the authors in the paper. "The incremental cost-effectiveness of the ICD, in appropriately selected patients, is similar to that of other interventions often accepted as cost-effective."
Hlatky said federal officials don't formally consider cost-effectiveness when making Medicare coverage decisions, but private insurers could use this type of information to guide future decisions. Indeed, the Blue Cross Blue Shield Association Technology Evaluation Center, which provides such guidance to certain private insurers, helped fund this study and is likely to share the information with its clients.
The Department of Veterans Affairs and the Agency for Healthcare Research and Quality also provided support for this study.