Incidence of

Background: Methods: A registry-based study utilizing Danish nationwide registers and including consecutive Danish patients undergoing first CIED implantation between 2000 and 2020 was conducted. The primary outcome was first-time SAB after CIED implantation. Results: A total of 87 257 patients with first CIED implantation in the study period were identified (median age, 75 years; 62.6% were male; median follow-up, 3.8 years). Patients with pacemakers (PMs) were older and with more noncardiovascular comorbidities compared to patients with implantable cardioverter defibrillators (ICDs) and cardiac resynchronization therapy devices with or without defibrillator capacity (CRTs). In total, 1366 patients (1.6%) developed SAB. The 10-year absolute risk (95% confidence interval) of SAB was 2.0% (1.9%-2.1%) for PM, 2.6% (2.2%-3.1%) for ICD, and 3.7% (3.0%-4.5%) for CRT. A multivariable Cox analysis identified hemodialysis (hazard ratio [HR], 8.51), SAB before CIED (HR, 2.76), liver disease (HR, 2.35), and carrying a CRT device (HR, 1.68) among the covariates associated with increased risk of SAB. Conclusions: The absolute risk of SAB in Danish CIED carriers increased with more advanced CIED systems. The risk was highest within the first 3 months after CIED implantation and increased with the presence of certain covariates including renal dialysis, SAB before CIED, male sex, and advancing age.