New Implantable Defibrillator Devices More Dangerous Than Old, Study Finds
Newer and "more sophisticated" implanted cardiac defibrillators known as dual-chamber devices, which stimulate both the heart's right atrial chamber and its right ventricle, may be more likely to lead to heart failure or death in patients than older, more simple devices that stimulate the ventricle only, according to an early release of a study to be published in next week's Journal of the American Medical Association, the Washington Post reports. The study, conducted by researchers at the Cleveland Clinic and other facilities, studied 506 defibrillator patients at 37 hospitals nationwide. Half of the participants received devices set to stimulate both chambers of the heart, while the other half had defibrillators programmed to stimulate only the ventricle. The study was terminated in September after two years after researchers found that about 26% of patients with the dual-chamber device were hospitalized for heart failure or died, compared to 16% of those with ventricle-only stimulation. While it is not completely clear why the dual-chamber devices are more dangerous, study lead author Bruce Wilkoff said stimulating both parts of the heart may cause the beating to become "dangerously uncoordinated," according to the Post (Stein, Washington Post, 12/20). The study does not question the benefit of implanted defibrillators (Tanner, AP/Las Vegas Review-Journal, 12/19).
The dual-chamber devices cost around $25,000 each, while the older models cost around $20,000 each (Burton, Wall Street Journal, 12/20). The older and newer devices had never previously been tested against each other, the Post reports. The study is the most recent of several that have found that "the newest, more complicated medical treatments and technologies are not necessarily the most effective," the Post reports. This week, another study found that diuretics, an older class of blood pressure medications, appear to be preferable to newer and more expensive blood pressure drugs. David Kass of the Johns Hopkins Medical Institutions in Baltimore said, "Just because we can do something doesn't necessarily mean we should do it" (Washington Post, 12/20). The early release of the study is available online.This is part of the California Healthline Daily Edition, a summary of health policy coverage from major news organizations. Sign up for an email subscription.