Incidence of Staphylococcus aureus bacteraemia in patients following implantation of cardiac implantable electronic devices: a Danish nationwide cohort study

Background and aims Staphylococcus aureus bacteraemia (SAB) is a high-risk condition associated with high morbidity and mortality. In the presence of cardiac implantable electronic devices (CIEDs) SAB may cause or clinically indicate device infection. We aimed to estimate the 10-year absolute risk of SAB in adult Danish first-time CIED carriers. Secondary aims included identification of risk factors associated with SAB. 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 87,257 patients with first CIED implantation in the study period were identified (median age 75 years, 62.6% males, median follow-up 3.8 years). Patients with pacemakers (PM) were older and with more non-cardiovascular comorbidities compared to patients with implantable cardioverter defibrillators (ICD) and cardiac resynchronization therapy devices w/wo defibrillator capacity (CRT). In total 1,366 patients (1.6%) developed SAB. The 10-year absolute risk 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-patients. A multivariable Cox analysis identified haemodialysis (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.