MARSHFIELD RESEARCHERS LEAD STUDY: IMPLANTABLE CARDIOVERTER-DEFIBRILATOR CAN PROLONG LIVES OF CONGESTIVE HEART FAILURE PATIENTS

Dr. Sherief Rezkalla

Congestive Heart Failure (CHF) affects 5 million Americans, with an additional half a million new cases diagnosed each year. As the population ages, CHF will increase to epidemic proportions. CHF can be managed, but the fact is that sudden death from cardiac causes remains a leading cause of mortality among those who suffer from the condition.

The good news, however, is that a study published today in the New England Journal of Medicine has proven that an implantable cardioverter-defibrilator (ICD) can significantly prolong the lives of CHF patients, above and beyond that of conventional therapies.

John Hayes, an electrophysiologist and Sherief Rezkalla, an interventional cardiologist, both Marshfield Clinic physicians on staff at Saint Joseph's Hospital, were two of the principal investigators in the study, which involved 2,521 patients from throughout the country.

Dr. John Hayes

The patients were grouped roughly in thirds, with one group randomly assigned to receive amiodarone, (a medication beneficial in treating cardiac arrhythmias); another a placebo, and a third a conservatively programmed, shock-only single-lead ICD. According to the nearly four-year study, the ICD therapy was clearly the best option, reducing overall mortality by 23 percent, whereas amiodarone had virtually no favorable effect on survival in those patients.

According to the two Marshfield researchers, the findings actually proved two things: "First that simple, shock-only ICD therapy improves survival even beyond the improvement afforded by sophisticated drug therapies and second that amiodarone, at least in this particular study, had no beneficial effect on survival."

The ICD, much like a pacemaker, is inserted beneath the skin with leads to the heart, monitoring it 24 hours a day. In the event of sustained ventricular tachycardia or ventricular fibrillation, it delivers a small electric shock to get the heart back into rhythm.

"This is good news for people suffering from congestive heart failure," said Dr. Rezkalla. "It gives them another, proven method to help them manage their disease and live a longer life."

Other Marshfield cardiologists participating in the study were Humberto Vidaillet, Peter Smith, Param Sharma and Kelly Anderson.