PURPOSE: Cardiac surgery in patients with cardiac implantable electronic devices (CIEDs) has been associated with a higher risk of infective endocarditis, but how it influences risk of CIED-specific infections is not known. Our aim was to examine risk of systemic CIED infections after cardiac surgery in patients with CIEDs.
METHODS: Based on data obtained from Danish administrative registries and the Danish Pacemaker and ICD Register, we conducted a case-control study nested within a nationwide cohort of patients who underwent a de novo CIED implantation in Denmark between 1998 and 2017. We defined cases as incident systemic CIED infections resulting in device system extraction. Controls were sampled 1:100 on time, age, sex and device type using risk set sampling. Exposure was defined as coronary artery bypass graft, or cardiac heart valve replacement or repair surgery.
RESULTS: From a study cohort comprising 67,621 patients, we identified 170 cases and 16,788 controls. In the minimally adjusted model, the incidence rate ratio (IRR) for systemic CIED infection was 6.4 (95% confidence interval (CI) 3.8-10.7) with cardiac surgery, and after additional confounder adjustment, 5.4 (95% CI 3.2-9.2). IRRs were higher with restriction to heart valve replacement surgery (adjusted IRR 7.5, 95% CI 4.0-16.6), and when limiting our exposure time window to one year (adjusted IRR 10.1, 95% CI 4.5-22.3).
CONCLUSION: Cardiac surgery in patients with de novo CIEDs was associated with a high risk of systemic CIED infections. Highest risk was observed after heart valve replacement surgery and within the first year of surgery.