CONTACTS: At Stanford, Rosanne Spector, (415) 725- 5374 or 723-6911; email [email protected]. At the Veterans Affairs Palo Alto Health Care System, Irene Ohlendorf, (415) 858-3925.
FOR COMMENT: Dr. Douglas Owens, (415) 852-3343. A Web site focusing on the study is available: http://www-smi.stanford.edu/projects/scd/
12/31/96
TO BE COST-EFFECTIVE, HEART-SHOCKING TREATMENT MUST WORK MUCH BETTER THAN DRUGS
STANFORD -- Thousands of people at risk of sudden cardiac death walk around wearing an implanted device that will shock the heart back into the right rhythm if it starts malfunctioning. The device, called an implantable cardioverter defibrillator (ICD), is popular and growing more so.
The ICD is also under scrutiny because of its considerable expense, said Dr. Douglas Owens, a senior research associate in health services research and development at the Veterans Affairs Palo Alto Health Care System.
"The question is whether the treatment extends a patient's life enough to warrant its very high price, which is $40,000 to $60,000 per patient, not including maintenance and other long-term expenses, which are substantial," said Owens, who also serves as an assistant professor of medicine and of health research and policy at Stanford University School of Medicine.
Health policy researchers are particularly interested in the cost-effectiveness of the ICD because its use has been rising dramatically. The device has a potentially vast market. Every day, in the United States alone, about 1,000 sudden deaths occur as a result of cardiac disease, according to Kathryn McDonald, a researcher in Stanford's Department of Health Research and Policy.
In 1991, about 6,000 people in the United States received an ICD. By 1993, that number more than doubled, said McDonald, who co-authored a cost-effectiveness analysis of ICDs with Owens and colleagues.
The analysis appears in the Jan. 1 issue of the journal Annals of Internal Medicine.
"The comparison of the cost-effectiveness of an ICD with drug treatment is of great interest to companies that make ICDs and to those groups that pay for treatments, such as insurance companies and Medicare, as well as to patients and their families," Owens said.
The analysis was part of a five-year multicenter study evaluating strategies to prevent sudden cardiac death. That project, called the Cardiac Arrhythmia and Risk of Death Patient Outcome Research Team (CARD PORT), is led by cardiologist Dr. Mark Hlatky, who chairs the Department of Health Research and Policy at Stanford. McDonald directs the day-to-day activities of the project.
While other researchers are conducting clinical trials to assess the ICD's benefits, Owens and his colleagues have looked ahead to determine how effective the device must be to justify its high cost.
Health interventions that cost more than about $50,000 per year of life gained are commonly considered too expensive, Owens said. Owens' study found that in order to meet this threshold, an ICD would have to reduce the patient's annual risk of dying by at least 30 percent compared with the standard drug treatment, amiodarone.
The jury is still out on the benefits of ICDs in comparison with amiodarone, Owens said. One small clinical trial that recently yielded interim results found ICD and drug treatment had equal benefits, while another trial showed clear benefits for ICD, he said. Final results of several large clinical trials are expected in the next two years.
When clinicians began treating patients with ICDs in the early 1980s, the procedure required open heart surgery with a long and painful recovery period. But in the last three to five years, new ICDs were developed that did not require open heart surgery.
Since 1992, Stanford clinicians have offered patients ICD implantation without the need for major surgery. The current procedure is very similar to pacemaker implantation, said Dr. Hingson M. Chun, associate director of the Cardiac Electrophysiology and Arrhythmia Service at Stanford University Medical Center.
In the less invasive implantation procedure, the defibrillator lead is threaded through a vein into the patient's heart. The defibrillator generator is implanted in the left chest, behind the pectoral muscle. The electrode on the lead can sense heartbeat abnormalities when they occur and, in turn, trigger the cardioverter defibrillator to deliver a shock to correct them.
One of Chun's patients, a man who had once been kicked in the chest by a mule, said the shock from his ICD felt much the same. "It's a jolt. But it's over very quickly -- and it often saves lives," Chun said.
"The ICD has very few side effects compared with drug therapy," he added. "And it's incomparable in terms of reassurance to patients and clinicians. The natural tendency for patients and clinicians is to favor defibrillator implantation if the patient is at risk of sudden cardiac death.
"However, Dr. Owens' study is a sobering reminder that there are economic consequences of non-rigorous patient selection for device implantation. Out-of-hand implantation of devices in this heterogeneous group of patients is not only bad medicine, but also very costly," Chun said.
"The good thing about Owens' study is that it opens the table for rational and compassionate discussions about therapy for preventing sudden cardiac death," Chun said. "But a potential misuse of studies like this is that in today's corporate climate of medical care, the findings can be used to make blanket decisions about treatment based on economics alone."
Decisions on how best to treat patients at risk of sudden cardiac death are complex and should be individualized for each patient, Chun said.
Owens' co-authors, in addition to Hlatky and McDonald, included Gillian Sanders, a graduate student in Stanford's Medical Information Sciences Program who developed the computer model and performed many of the analyses; Dr. Anne Dembitzer, an ambulatory care fellow at the VA; Ryan Harris, a medical student at the University of California, San Francisco; and Dr. Paul Heidenreich, a fellow in Stanford's Department of Health Research and Policy.
The research was funded in part by the U.S. Agency for Health Care Policy and Research and by the Veterans Affairs Health Services.
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