Nosocomial bloodstream infections in patients with implantable left ventricular assist devices

Background. Implantable left ventricular assist devices (LVAD) are used as a bridge to transplantation but are associated with a high risk of infectio n including nosocomial bloodstream infections (BSI). Methods. We retrospectively reviewed the medical records of all patients wi th implantable LVAD at the Cleveland Clinic with 72 hours or longer of LVAD support from January 1992 through June 2000, to determine the attack rate, incidence, and impact of nosocomial BSI in patients with LVAD. A nosocomia l BSI was defined using Centers for Disease Control and Prevention definiti on. An LVAD-related BSI was defined as one where the same pathogen is cultu red from the device and the blood with no other obvious source. Two hundred fourteen patients were included in the study (17,831 LVAD-days). Results. One hundred forty BSI were identified in 104 patients for an attac k rate of 49% and incidence of 7.9 BSI per 1000 LVAD-days. Thirty-eight per cent of the BSI were LVAD associated. The most common pathogens causing BSI were coagulase-negative staphylococci (n = 33), Staphylococcus aureus, and Candida spp. (19 each), and Pseudomonas aeruginosa (16 each). A Cox propor tional hazard model found BSI in patients with LVAD to be significantly ass ociated with death (hazard ratio = 4.02, p < 0.001). Fungemia had the highe st hazard ratio (10.9), followed by gram-negative bacteremia (5.1), and gra m-positive bacteremia (2.2). Conclusions. Patients with implantable LVAD have a high incidence of BSI, w hich are associated with a significantly increased mortality. Strategies fo r prevention of infection in LVAD recipients should focus on the drive line exit site until technical advances can achieve a totally implantable devic e. (C) 2001 by The Society of Thoracic Surgeons