Staphylococcus aureus bacteremia in patients with permanent pacemakers or implantable cardioverter-defibrillators

Background-Although cardiac device infections (CDIs) are a devastating comp lication of permanent pacemakers or implantable cardioverter-defibrillators , the incidence of CDI in patients with bacteremia is not well defined. The objective of this study was to determine the incidence of CDI among patien ts with permanent pacemakers or implantable cardioverter-defibrillators who develop Staphylococcus aureus bacteremia (SAB). Methods and Results-A cohort of all adult patients with SAB and permanent p acemakers or implantable cardioverter-defibrillators over a 6-year period w as evaluated prospectively. The overall incidence of confirmed CDI was 15 o f 33 (45.4%). Confirmed CDI occurred in 9 of the 12 patients (75%) with ear ly SAB (<1 year after device placement). Fifteen of 21 patients (71.5%) wit h late SAB (<greater than or equal to>1 year after device placement) had ei ther confirmed (6 of 21, 28.5%) or possible (9 of 21, 43%) CDI. In 60% of t he patients (9 of 15) with confirmed CDI, no local signs or symptoms sugges ting generator pocket infection were noted. Conclusions-The incidence of CDI among patients with SAB and cardiac device s is high. Neither physical examination nor echocardiography can exclude th e possibility of CDI. In patients with early SAB, the device is usually inv olved, and approximate to 40% of these patients have obvious clinical signs of cardiac device involvement. Conversely, in patients with late SA-B, the cardiac device is rarely the initial source of bacteremia, and there is a paucity of local signs of device involvement. The cardiac device is involve d, however, in greater than or equal to 28% of these patients.