Cardiac implantable electronic device infections: Incidence, risk factors, and the effect of the AigisRx antibacterial envelope

BACKGROUND Cardiac implantable electronic device (CIED) infection is associated with morbidity and mortality. OBJECTIVES To determine the incidence and risk factors for CIED infection, to develop a scoring index for risk stratification, and to analyze the effect of the AIGIS(RX) envelope on infection rates. METHODS Consecutive patients who underwent a CIED procedure were identified and surveyed for 6 months for the development of an infection necessitating removal of all implanted hardware. RESULTS In the pre-envelope era, an infection occurred in 25 (1.5%) of 1651 patients. After its availability, an envelope was used in 275 (22%) of 1240 patients; an infection occurred in 8 (0.6%) patients in this era (P = .029 vs pre-envelope). In the overall cohort of 2891 patients, the infection rate was 1.2% and 3.5% in patients with an implantable cardioverter-defibrillator device and those with a cardiac resynchronization therapy defibrillator device, respectively (P = .018); in these patients, 7 independent risk factors predicted infection: early pocket re-exploration, male sex, diabetes, upgrade procedure, heart failure, hypertension, and glomerular filtration rate < 60 mL/min. A composite risk score (0-25; C index 0.72; 95% confidence interval 0.61-0.83) was created by weight, adjusting these 7 factors: 3 groups emerged- low risk (score 0-7; 1% infection), medium risk (score 8-14; 3.4% infection), and high risk (score >= 15; 11.1% infection). The envelope reduced infections by 79% and 100% in the medium- and high-risk groups, respectively. CONCLUSIONS CIED infection most commonly occurred in patients with an implantable cardioverter-defibrillator device and those with a cardiac resynchronization therapy defibrillator device. A composite score based on clinical variables appeared feasible for infection risk stratification. The AIGIS(RX) envelope significantly lowered the risk of CIED infection. Randomized clinical data are warranted.