Study is critical of early implants of defibrillators

Implanting defibrillators in patients just weeks after a heart attack does not improve their chances of survival, according to an international study. The researchers suggested instead that patients wait several months before having one of the devices inserted in the chest.

The findings could have big implications for Medicare, which is about to expand coverage for the $25,000 devices to many more people.

Implanted defibrillators, such as the one Vice President Dick Cheney has, shock the heart back into a normal rhythm when it starts beating irregularly. Research has shown these devices save lives, but those studies were done almost exclusively on patients six months to several years after their heart attack.

The new study found that defibrillators offer little benefit in the early days after a heart attack, when patients with damaged and weakened heart muscle are most likely to die. In the study, reported in Thursday's New England Journal of Medicine, lives saved among patients who suffered abnormal rhythms were basically canceled out by deaths from heart problems unrelated to rhythm.

For doctors, this finding will complicate deciding exactly when to install the devices, and in which patients.

"We recommend that you wait at least six months after the heart attack," said the lead researcher, Dr. Stefan Hohnloser, professor of medicine and cardiology at J.W. Goethe University in Frankfurt, Germany.

The study involved patients who suffered a muscle-damaging heart attack just 6 to 40 days earlier, a group at high risk of death from another heart attack or gradual heart failure, or from abnormal rhythms.

In the United States, doctors usually wait at least one to three months after a patient's heart attack before implanting a defibrillator, said American Heart Association spokesman Dr. Kenneth Ellenbogen, a professor at Medical College of Virginia.

Currently, Medicare covers implantation of a defibrillator as little as a month after a heart attack. The federal health program for the elderly is expected to adopt a controversial plan by the end of the month to pay for the devices for many more patients, including people who have not had a heart attack but whose hearts are so damaged they cannot pump enough blood.

"The study provides a lot of important information (on timing of implantation), and we'll definitely be looking at it carefully as we make our final determination," said Dr. Sean Tunis, chief medical officer at the Center for Medicare and Medicaid Services.