20% patients not qualified for Implantable cardioverter-defibrillators

About 20 percent of patients who received implantable cardioverter-defibrillators (ICDs) were actually not qualified for the medical device, a study in the January 5 issue of Journal of American Medical Association found.

The study led by Sana M. Al-Khatib, M.D., M.H.S., of the Duke Clinical Research Institute in Durham, N.C., and colleagues found those unqualified recipients were at higher risk of in-hospital death, compared with those who were qualified.

Implantable cardioverter-defibrillators are indicated for preventing sudden cardiac death in patients with advanced systolic heart failure, but not recommended for patients with myocardial infarction or heart attack, or coronary artery bypass graft surgery or those with severe heart failure or recently diagnosed heart failure, JAMA stated in a press release.

For the study, Al-khatib et al. examined data for more than 100,000 patients who received implantable cardioverter-defibrillators included in the National Cardiovascular Data Registry-ICD Registry between Jan 2006 and June 2009.

The researchers found 111,707 patients received ICDs for primary prevention while 25,145 patients or 22.5 percent received ICDs for a non-evidence-based indication.   Of the non-evidence-based recipients, 36.8 percent were those who suffered myocardial infarction within 40 days of the treatment and 62.1 percent were newly diagnosed with heart failure before the implantation.

Those who received a non-evidence based device were three times as likely as those who received an evidence-based device to die in hospital, 0.57 percent versus 0.18 percent. The post-procedure complication rate was 3.23 percent among those who received a non-evidence-based ICD, compared to 2.41 percent among the evidence based patients.

Other adverse event and death rates were significantly higher in non-evidence-based recipients. For instance, those who were not qualified needed on average three days of hospital stay compared to one day for those who were qualified.

Nonelectrophysiologists were more likely than electrophysiologists to perform non-evidence-based ICDs implants.

An implantable cardioverter-defibrillator is a small battery-powered electrical impulse generator indicated for reducing risk of sudden cardiac death due to ventricular fibrillation and ventricular tachycardia

With ventricular fibrillation, a patient has uncoordinated contraction of the cardiac muscle of the ventricles in the heart, making them quiver rather than contract properly.  Ventricular tachycardia means fast heart rhythm, which originates in one of the ventricles of the heart.

David Liu and editing by Denise Reynolds