For patients with certain heart problems, getting a defibrillator implanted to shock the heart if it starts beating irregularly can keep them from dropping dead. Over the short term, a defibrillator accomplishes this better than the drug amiodarone, but researchers at St. Michael's Hospital in Toronto compared the two options long term.

What the researchers wanted to know: Does an implantable cardioverter defibrillator protect against sudden cardiac death better than the drug amiodarone long term?

What they did: The researchers followed up on some of the patients in the Canadian Implantable Defibrillator Study, one of the big studies that originally compared defibrillators to drugs. Patients with malfunctioning ventricles were randomly assigned to get a defibrillator or to take drugs. Ventricles are chambers of the heart that pump blood to the rest of the body. That study involved 659 patients; this study follows only the 120 who enrolled through St. Michael's Hospital. All had stuck with the therapy they were originally assigned. The researchers checked up on them every six months with an exam, lab tests, and an EKG. Patients were followed until April 2002, an average of five and a half years (up to 11 1/2 years in some patients).

What they found: More of the drug-taking patients died during the follow-up period than did the patients with implantable defibrillators. Nearly a third of the amiodarone patients eventually switched over to implantable defibrillators because of adverse effects or because the drug wasn't taming their arrhythmia, while none of the defibrillator patients had their devices removed, although several did get shocks when they weren't supposed to. Two had theirs switched off because they had terminal cancer.

What the study means to you: Amiodarone seems to be riskier than an implantable defibrillator in the long term, as it was in the short term.

Caveats: Patients and doctors knew which therapy everyone was on—there was no placebo. Interestingly, the authors point out that this study is probably impossible to repeat. It could be considered unethical to run another trial in which some patients are prevented from getting implantable defibrillators, now that there's enough evidence to recommend implantable defibrillators rather than amiodarone for these particular heart problems.

Find out more: Information about amiodarone (also known as Pacerone and Cordarone) from online database drugs.com, which is not affiliated with pharmaceutical companies

The American Heart Association explains implantable cardioverter defibrillators: http://www.americanheart.org/

Read the article: Bokhari, F., et al. "Long-Term Comparison of the Implantable Cardioverter Defibrillator Versus Amiodarone." Circulation. July 13, 2004, Vol. 110, pp. 112-116.

Abstract online: http://circ.ahajournals.org/