SAN FRANCISCO – The incidence of pacemaker infections is climbing in the United States, while the rate of infections involving implantable cardioverter-defibrillators has remained fairly stable over time.
The incidence of infection in U.S. pacemaker recipients rose 224% during 1993-2008, from 1.6% to 3.5%, Jasmine Patel, Ph.D., reported at the annual meeting of the Heart Rhythm Society.
She examined trends over time in the infection burden related to pacemakers and ICDs by analyzing data from the National Inpatient Survey, a statistically valid annual survey of roughly 1,000 U.S. hospitals. During the period 1993-2008, an estimated 3.2 million patients received pacemakers and 1.1 million got ICDs.
Several comorbid conditions were related to an increased risk of infection in pacemaker recipients. Most notably, renal failure was associated with a 2.38-fold increased risk of infection.
At the same time, the epidemiology of renal failure is changing. In 2008, one-third of patients with an infected pacemaker or ICD had renal failure; in 1993 that was the case among only 3.6% of patients with an infected pacemaker and 2.8% of those with an ICD infection, according to Dr. Patel, a biomedical engineer in the Philadelphia office of Exponent, a large engineering and consulting firm.
Other comorbidities linked to pacemaker infection were respiratory failure, with an associated 2.25-fold increased risk; heart failure, with a 1.46-fold risk; and diabetes, which increased the risk of pacemaker site infection 1.12-fold.
The incidence of ICD-site infection was increased 2.18-fold with comorbid renal failure, 1.3-fold with respiratory failure, and 1.28-fold with heart failure.
Overall, the incidence of infection was 75% greater in pacemaker recipients than in patients with an ICD.
Dr. Mihaly de Bie of Leiden ( the Netherlands) University Medical Center reported that an ICD or cardiac resynchronization therapy defibrillator (CRT-D) device infection is associated with a twofold increased risk of mortality during the next year.
Among 2,574 patients who received an ICD or CRT-D at the medical center during January 2000 through September 2009, the incidence of a device infection during the first year post implant was 1.1%, climbing to 2.6% after 3 years.
The 1-year mortality following a first cardiac device infection was 14.4%. After adjustment for age, sex, diabetes, and renal clearance as potential confounding variables, a first cardiac device infection was associated with a 2.4-fold increased risk of mortality over the next year compared with patients who didn’t experience a device infection.
Dr. Patel and Dr. de Bie said they had no relevant financial disclosures.