"Despite millions of pacemaker and ICD implants worldwide and their increasingly frequent use, surprisingly little is known about device reliability," says the studies' lead author William H. Maisel, MD, MPH, director of the Pacemaker and Device Service at Beth Israel Deaconess Medical Center (BIDMC) and Assistant Professor of Medicine at Harvard Medical School. The devices work to stabilize abnormal heart rhythms, pacemakers by treating hearts that beat too slowly and ICDs by treating heart rhythms that have become dangerously fast.
In the first study, which Maisel performed with colleagues at the U.S. Food and Drug Administration (FDA), he found that, between the years of 1990 and 2002, there were 2.25 million pacemakers and almost 416,000 ICDS implanted in the U.S. During this same time period, 17,323 devices (8,834 pacemakers and 8,489 ICDs) were surgically removed from patients due to a confirmed device malfunction. (Battery, capacitor and electrical abnormalities accounted for approximately half of the device failures.) In addition, 61 patient deaths were attributed to pacemaker or ICD malfunction during this 13-year period.
"Overall, the annual ICD malfunction replacement rate of 20.7 per 1,000 implants was significantly higher than the pacemaker malfunction replacement rate of 4.6 per 1,000 implants," notes Maisel. "While pacemakers became increasingly reliable during the study period, a marked increase in the ICD malfunction replace
Contact: Bonnie Prescott
Beth Israel Deaconess Medical Center