Implantable cardioverter-defibrillators (ICDs) are apparently doing their jobs so well, they need to be able to do them for a longer period of time. According to researchers at the Minneapolis Heart Institute, patients with ischemic cardiomyopathy (ICM) and dilated cardiomyopathy (DCM) who have ICDs are outliving those devices by 1–3 years. 

The researchers examined 1555 patients who had single-chamber, dual-chamber, or cardiac resynchronization ICDs implanted between 2000 and 2009. On average, these patients, who had a mean age of 64.9 years, lived seven years. Patients with hereditary heart conditions and ICDs usually had the devices implanted earlier, and lived with them for decades, according to the study.

"Typically, ICDs last between four to six years, but these findings indicate that the devices require long-lived batteries," said Robert Hauser, MD, a cardiologist at the Minneapolis Heart Institute, in a press release. Researchers also said that ICD pulse generators and leads will have to last longer to accommodate patients' longer life expectancies. A paper on the study was to be presented at the American College of Cardiology Scientific Sessions this past weekend.

The study would seem to represent yet another adjustment to how ICDs are viewed and used. The devices have been somewhat controversial, between discussions of over- (and under-) use and high-profile failures and recalls. 

— Thomas Blair