Heeding the call to support product claims with outcomes data, Guidant Corp. bankrolled a multicenter clinical study that shows its implantable defibrillators beat drugs in preventing repeat heart attacks in high-risk patients.
Results of the five-year study of almost 200 patients were published in the New England Journal of Medicine the day after Christmas. They show dramatically reduced mortality rates among high-risk heart attack survivors implanted with defibrillators compared with those treated with medicine alone.
"Patients implanted with the defibrillator had a clear survival advantage over those treated with conventional drugs," said Arthur J. Moss, M.D., principal investigator for the study and a professor at University of Rochester (N.Y.) Medical Center.
Implanted defibrillators made by Indianapolis-based Guidant improved patient survival by 54% compared with drug therapy. Patients with defibrillators lived almost 10 months longer than those without them.
Smaller than a cigarette pack, an implantable defibrillator goes beyond the conventional pacemaker by sensing irregular heartbeats and delivering a powerful shock to prevent heart attack.
Moss' findings could spur demand for the devices, which typically carry a list price of $21,000 to $28,000. By Moss' estimate, more than 80,000 at-risk heart attack survivors, or nearly 10% of annual heart attack victims, could live longer with implanted defibrillators.
Patients in the study who had defibrillators incurred $99,000 in net treatment costs, compared with $74,000 for patients treated with drugs alone, according to an analysis being prepared for publication by another University of Rochester researcher, Alvin Mushlin, M.D.
But those increased costs buy extended lives. And while each year of added life cost $31,000, that compares favorably with other cardiac interventions such as surgery, according to Mushlin.
Critics say the study was flawed and insufficient to warrant radical changes in clinical practice.
For instance, to take part in the study, patients had to suffer irregular heartbeats during cardiac testing that went uncorrected by intravenous anti-arrhythmia drugs.
"That predicts a lack of response to many other drugs, and it was in a sense a stacked deck" in favor of defibrillators, said Peter L. Friedman, M.D., a cardiologist at Boston's Brigham and Women's Hospital who co-authored a New England Journal of Medicine editorial criticizing Moss' study that appeared in the same issue.
Using the device in an additional 16,000 patients would cost more than $1 billion a year, Friedman estimated. And that's a heavy burden to undertake based on this 200-patient study alone, he said.
That viewpoint resonated with an influential evaluator of medical technology. "This one study won't conclusively define preferred therapy," said Ronald Puszkar, cardiology program manager at VHA, Irving, Texas. "It's a good start, but let's see what the other studies look like and how they correlate."