Sommerstein R, et al. - Researchers sought to assess the optimal timing and choice of surgical antimicrobial prophylaxis (SAP) in patients having cardiac surgery in the setting of the Swiss surgical site infection (SSI) national surveillance system with a follow-up rate of >94%. They included a total of 21,007 patients from 14 hospitals who had cardiac surgery from 2009 to 2017 with clean wounds, SAP with cefuroxime, cefazolin or a vancomycin/cefuroxime combination and timing of SAP within 120 min before the incision. Findings suggest a higher efficacy of administering SAP close to the time of the incision than earlier administration before cardiac surgery, making compliance with SAP administration easier. Compared to cefuroxime alone, cefazolin but not vancomycin/cefuroxime combination led to significantly reduced risk of overall SSI.