Defibrillators may be overused
DETROIT – As many as a third of Americans who get implantable defibrillators to correct heartbeat irregularities may not need them, a finding that could lead to as much as $690 million in Medicare savings, a University of Michigan Medical Center study says.
Better answers of who is a candidate for a defibrillator implant may come from a test that provides precise information on how well the heart pumps blood, the study found. But more research must be conducted before it is widely accepted as a screening tool, said Dr. Paul Chan, senior author of the study.
The report was published in the January issue of the Journal of the American College of Cardiology.
The test, known as MTWA, for microvolt T-wave alternans, measures changes in calcium levels in the heart, Chan said. It costs about $400 and is conducted much like a treadmill stress test, only less vigorously. Other tests are conducted to determine whether a patient needs a defibrillator but can be more invasive or provide less information.
Medicare has paid for the MTWA test for about a year but many other plans do not, one reason its use has not become more widespread, said Dr. Timothy Shinn, an electrophysiologist at the Michigan Heart and Vascular Institute at St. Joseph Mercy Hospital.
Dr. Sohail Hassan, an electrophysiologist at St. John Hospital & Medical Center in Detroit, said the MTWA test eventually will be used earlier to screen patients before they have a heart attack.
“That’s the way it’s going to be useful,” he said. “That’s where the money is. Once the heart is damaged, it’s different” and costlier to treat, he said.
The cardiology journal study followed 768 Cincinnati patients who received defibrillators between March 2001 and June 2004. The University of Michigan research team analyzed the data. They concluded that up to a third of the patients who got defibrillators got minimal benefit from them.
Shinn said patients should talk to their doctors if they have heartbeat problems. “The smart consumer question to their doctor is: ‘Do I need a defibrillator and, if so, why?’ ” Shinn said.
Many patients with enlarged hearts benefit from the devices. “The risk of failure of the devices” is less than 1 percent, compared with a 7 percent to 8 percent risk of dying if you don’t have one, Shinn said.
He said many patients turned against the devices after 2005 when the federal government recalled several defibrillators following reports of a few patient deaths.
New Medicare eligibility guidelines adopted in 2005 expanded the number of people eligible for defibrillators to as many as an estimated half-million Americans, Chan said.