Reduced Incidence of Carbapenem-Resistant Klebsiella pneumoniae Infections in Cardiac Surgery Patients after Implementation of an Antimicrobial Stewardship Project.

Infections due to carbapenem-resistant Klebsiella pneumoniae (CR-Kp) are associated with increased mortality in cardiac surgery patients. In this short communication, we report on the changes in the incidence of CR-Kp colonization and CR-Kp infection in cardiac surgery patients from 2014 to 2018 in a teaching hospital in Italy, after the implementation of an antimicrobial stewardship project in 2014. During the study period, 2261 patients underwent open-heart surgery. Of them, 130 were found to be colonized by CR-Kp (5.7%) and 52 developed a postoperative CR-Kp infection (2.3%). The crude in-hospital mortality in patients with CR-Kp infections was 48% (25/52). The incidences of both CR-Kp colonization (incidence rate ratio (IRR) 0.82, 95% confidence intervals (CI) 0.78-0.86, p < 0.001) and CR-Kp infection (IRR 0.76, 95% CI 0.69-0.83, p < 0.001) considerably decreased over the study period. This encouraging result should prompt further concerted efforts, directed towards retaining the positive impact of stewardship and infection-control interventions on CR-Kp-related morbidity in the long term.