A multi-institutional cohort study confirming the risks of Clostridium difficile infection associated with prolonged antibiotic prophylaxis.

Objectives: The incidence and severity of Clostridium difficile infection (CDI) have increased rapidly over the past 2 decades, particularly in elderly patients with multiple comorbidities. This study sought to characterize the incidence and risks of these infections in cardiac surgery patients.

Methods: A total of 5158 patients at 10 Cardiothoracic Surgical Trials Network sites in the US and Canada participated in a prospective study of major infections after cardiac surgery. Patients were followed for infection, readmission, reoperation, or death up to 65 days after surgery. We compared clinical and demographic characteristics, surgical data, management practices, and outcomes for patients with CDI and without CDI.

Results: C difficile was the third most common infection observed (0.97%) and was more common in patients with preoperative comorbidities and complex operations. Antibiotic prophylaxis for >2 days, intensive care unit stay >2 days, and postoperative hyperglycemia were associated with increased risk of CDI. The median time to onset was 17 days; 48% of infections occurred after discharge. The additional length of stay due to infection was 12 days. The readmission and mortality rates were 3-fold and 5-fold higher, respectively, in patients with CDI compared with uninfected patients.

Conclusions: In this large multicenter prospective study of major infections following cardiac surgery, CDI was encountered in nearly 1% of patients, was frequently diagnosed postdischarge, and was associated with extended length of stay and substantially increased mortality. Patients with comorbidities, longer surgery time, extended antibiotic exposure, and/or hyperglycemic episodes were at increased risk for CDI.