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.