Long-term outcomes of cardiovascular implantable electronic devices in patients with Staphylococcus aureus bacteremia

The use of cardiovascular implantable electronic devices (CIEDs) is increasing. Staphylococcus aureus bacteremia (SAB) poses a risk for hematogenous seeding of the device. Our aim is to identify risk factors associated with secondary CIED infection, due to hematogenous seeding, during SAB from an unrelated primary focus.

All patients with SAB and CIED were screened. Patients with SAB due to a primary source unrelated to the CIED were included. Patients were classified into cases if CIED infection was documented and controls without CIED infection during a minimum of 12 weeks follow-up. A retrospective review of patients' charts was done.

Thirty patients with CIED and SAB from an unrelated focus were identified. CIED infection developed in 11 patients (36.7%). No significant differences were noted between cases and controls in the source, time-to-therapy, and time-to-intervene but infected devices were more likely to be implantable cardioverter-defibrillators (ICD) versus permanent pacemakers (PPMs) (9/11 [81.8%] vs 2/11 [18.2%] respectively, crude odds ratio 12.6, 95% confidence interval 10.8-14.4; P = 0.003).

Hematogenous seeding of a CIED during SAB from an unrelated focus is not uncommon. The risk factors for CIED seeding are unknown but ICD devices seem to be at greater risk when compared to PPM. The reasons are not yet clear. Larger studies are needed to better define risk factors and design preventive measures.