Vancomycin versus cefazolin prophylaxis for cardiac surgery in the setting of a high prevalence of methicillin-resistant staphylococcal infections

Objective: This study was undertaken to compare the efficacy of vancomycin prophylaxis with that of cefazolin in preventing surgical site infections in a tertiary medical center with a high prevalence of methicillin-resistant staphylococcal infections. Methods: All adult patients (≥18 years) scheduled for cardiac surgery requiring sternotomy were randomly assigned to receive vancomycin (1 g every 12 hours) or cefazolin (1 g every 8 hours). Prophylaxis was started during the induction of anesthesia and continued for only 24 hours. Patients were followed up for at least 30 days (1 year for those receiving a cardiac implant). Surgical site infections were stratified according to the National Nosocomial Infections Surveillance System risk index. Results: Of the 885 patients included in the study, 452 received vancomycin and 433 received cefazolin. The overall surgical site infection rates were similar in the two groups (43 cases in the vancomycin group, 9.5%, vs 39 cases in the cefazolin group, 9.0%, P = .8). Superficial and deep incisional surgical site infection rates were also similar in the two groups. There was a trend toward more frequent organ-space infections and infections with [β-lactam-resistant organisms among patients receiving cefazolin, but this trend did not reach statistical significance. In contrast, surgical site infections caused by methicillin-susceptible staphylococci were significantly more common in the vancomycin group (17 cases, 3.7%, vs 6 cases, 1.3%, P = .04). The durations of post-operative hospitalization and the mortalities were similar in the two groups. Conclusions: This trial suggests that vancomycin and cefazolin have similar efficacy in preventing surgical site infections in cardiac surgery.