Clinical manifestations and management of left ventricular assist device-associated infections

Abstract

Background: Infection is a serious complication of left ventricular assist device (LVAD) therapy. Published data regarding LVAD-associated infections (LVADIs) are limited by single-center experiences and use of nonstandardized definitions.

Methods: We retrospectively reviewed 247 patients who underwent continuous-flow LVAD implantation from January 2005 to December 2011 at Mayo Clinic campuses in Minnesota, Arizona, and Florida. LVADIs were defined using the International Society for Heart and Lung Transplantation criteria.

Results: We identified 101 episodes of LVADI in 78 patients (32%) from this cohort. Mean age (± standard deviation [SD]) was 57±15 years. The majority (94%) underwent Heartmate II implantation, with 62% LVADs placed as destination therapy. The most common type of LVADIs were driveline infections (47%), followed by bloodstream infections (24% VAD related, and 22% non-VAD related). The most common causative pathogens included gram-positive cocci (45%), predominantly staphylococci, and nosocomial gram-negative bacilli (27%). Almost half (42%) of the patients were managed by chronic suppressive antimicrobial therapy. While 14% of the patients had intraoperative debridement, only 3 underwent complete LVAD removal. The average duration (±SD) of LVAD support was 1.5±1.0 years. At year 2 of follow-up, the cumulative incidence of all-cause mortality was estimated to be 43%.

Conclusion: Clinical manifestations of LVADI vary on the basis of the type of infection and the causative pathogen. Mortality remained high despite combined medical and surgical intervention and chronic suppressive antimicrobial therapy. Based on clinical experiences, a management algorithm for LVADI is proposed to assist in the decision-making process.

Keywords: LVAD; device-related infections; driveline infections; endocarditis; heart failure.

Figure 1.

Distribution of causative pathogens of left ventricular assist device (LVAD)–associated infection in 78 patients. A, First or most-severe episodes (n = 78; no culture obtained for 8). B, Local infections (n = 37; no culture obtained for 8). C, Endovascular infections (n = 40; no culture obtained for 0). Data are No. of episodes of infections (%). Gram-positive cocci included methicillin-susceptible Staphylococcus aureus (15), coagulase-negative staphylococci (18), methicillin-resistant S. aureus (4), and Enterococcus species (5). The most common gram-negative bacilli were Pseudomonas aeruginosa (7), Klebsiella species (7), Escherichia coli (6), Stenotrophomonas species (4), and Serratia species (4). Fungal infections included 1 Candida albicans and 2 C. glabrata. Mixed infection included a concurrent infection with C. albicans and Mycobacterium smegmatis in the blood. “Others” included anaerobes, Propionibacterium species, diphtheroids, and Corynebacterium species. The distribution of the 78 single episodes is similar to that for all 101 episodes of infection in the 78 patients.

Figure 2.

Mayo Clinic guidelines for the management of left ventricular assist device (LVAD)–associated infections (LVADIs). Guidelines are referenced from [–25]. These are general guidelines only, and LVADI management should be individualized based on clinical presentation and host factors. ^aChronic suppressive antimicrobial therapy is highly recommended if there is (1) failure to clear bloodstream infection (BSI) despite appropriate antibiotic therapy or removal of the suspect catheter in the setting of catheter-related BSI or (2) relapse of BSI after completing an appropriate antibiotic course, but it should ultimately be guided by clinical judgment. Abbreviations: AHA, American Heart Association; BSI, bloodstream infection; CIED, cardiovascular implantable electronic device; CVC, central venous catheter; IDSA, Infectious Diseases Society of America; IE, infective endocarditis; LVADI, left ventricular assist device–associated infections; TEE, transesophageal echocardiography; VAD, ventricular assist device.