Study Finds Defibrillator Implants can be Hazardous to Your Health

For more than three decades, doctors have had little reason to second-guess treatment that involved the implantation of a cardiac defibrillator. The devices consistently have demonstrated their ability to prevent sudden death in those who have suffered a heart attack or patients whose hearts do not properly pump blood. In the last decade alone, a growing number of clinical studies has shown that defibrillators can help reduce mortality rates by about 30 percent.

But now there is evidence these death-defying devices may not live up to their life-saving hype. A new study from researchers at Duke University in Durham, N.C., found that more than 20 percent of patients (about one in five) who received an implantable defibrillator in recent years were not the best candidates for the device. The researchers examined data from nearly 112,000 patients who received implantable cardiac defibrillators (ICDs) between 2006 and 2009 and concluded that more than 25,000 of those patients did not meet evidence-based criteria for receiving the device, according to the study. Patients who received an ICD but did not meet the criteria experienced a significantly higher risk of dying in the hospital, and 1 out of 121 patients in this category suffered complications after surgery.

ICDs—devices that produce electrical impulses to regulate heartbeats—usually are implanted in patients as a preventative measure to help stave off a heart attack or life-threatening arrhythmia (a disorder of the heart rate or rhythm) before they occur. But the Centers for Medicare and Medicaid Services (CMS) claims in a “decision memo” that ICDs should be reserved only for patients with certain serious heart conditions or histories of heart trouble. CMS further states in its memo that patients must meet numerous other qualifications relating to clinical trials and should not have certain serious diseases or conditions that would lower the efficacy of the implant or the patient’s likelihood of long-term survival.

Dr. Robert Michler, chairman of Cardiovascular and Thoracic Surgery at Montefiore-Einstein Heart Center in Tarrytown, N.Y., said the Duke study should serve as a “wake-up call” for doctors, surgeons and patients. “Doctors are well-intentioned, but not all doctors should be determining the use of what is a very sophisticated therapy,” Michler told CNN. He believes electrophysiologists ultimately should determine whether a patient needs an ICD (cardiologists who also are certified as electrophysiologists undergo additional training to diagnose and treat abnormal heart rhythms).

Ironically, electrophysiologists may have helped contribute to the higher incidence of death found in the study. According to the results, cardiologists-electrophysiologists were less likely to implant an ICD in patients who did not meet evidence-based criteria. However, many patients who participated in the study and were implanted with an ICD recently had experienced arrhythmias or heart attacks. Dr. Sana Al-Khatib, the study’s lead author and researcher, said the time factor might help explain the increase in deaths among patients who did not meet the CMS criteria. “These patients were sicker to begin with. They were in a period where they were more prone to complications,” she said. “The physicians haven’t had the time to optimize the patients’ medical therapy before subjecting them to this surgery.”

Despite guidelines from CMS, determining when to use an ICD is not always an easy decision for doctors. For starters, the Duke University study seems at odds with a report by researchers at the University of Maryland Medical Center (in Baltimore) that found about half of all patients who meet nationally accepted guidelines for treatment with ICDs do not receive such treatment. The study was based on records from 167 cardiology practices throughout the United States; it concluded that older patients, African Americans and those without health insurance are less likely than other patients to receive the devices. Patients outside the Northeast who experienced heart failure were less likely to be treated with ICDs, the study found. Compliance, the study’s lead author said, ranged from “wonderful—100 percent of the time—to complete disregard.”

Still, use and determination of ICDs is not always a black-and-white issue. Some patients naturally will fall into a gray area; Al-Khatib suggests that doctors carefully consider each case and use his or her best clinical judgment to decide on ICD use.