Nicolas Massart1, Alexandre Mansour2, James T Ross3, Caroline Piau4, Jean-Philippe Verhoye5, Pierre Tattevin6, Nicolas Nesseler7. 1. Department of Anesthesia and Critical Care, Pontchaillou, University Hospital of Rennes, Rennes, France; Univ Rennes, CHU de Rennes, Rennes, France; Intensive Care Unit, Hospital of St Brieuc, Saint-Brieuc, France. 2. Department of Anesthesia and Critical Care, Pontchaillou, University Hospital of Rennes, Rennes, France; Univ Rennes, CHU de Rennes, Rennes, France. 3. Department of Surgery, University of California, San Francisco, Calif. 4. Department of Clinical Microbiology, Rennes University Hospital, Rennes, France. 5. Thoracic and Cardiovascular Surgery Service, Pontchaillou University Hospital Center, University of Rennes 1, Signal and Image Treatment Laboratory (LTSI), National Institute of Health and Medical Research, Rennes, France. 6. Infectious Diseases and Intensive Care Unit, Pontchaillou University Hospital, Rennes, France. 7. Department of Anesthesia and Critical Care, Pontchaillou, University Hospital of Rennes, Rennes, France; Univ Rennes, CHU de Rennes, Inra, Rennes, France; Univ Rennes, CHU Rennes, (Centre d'Investigation Clinique de Rennes), Rennes, France. Electronic address: nicolas.nesseler@chu-rennes.fr.
Abstract
PURPOSE: Hospital-acquired infections have been associated with significant morbidity and mortality in critically ill surgical patients. However, little is known about mortality due to hospital-acquired infections in cardiac surgery. METHODS: We conducted a retrospective analysis of prospectively collected data from the cardiac surgery unit of a university hospital. All patients who underwent cardiac surgery over a 7-year period were included. Patients with hospital-acquired infections were matched 1:1 with patients with nonhospital-acquired infections based on risk factors for hospital-acquired infections and death after cardiac surgery using propensity score matching. We performed a competitive risk analysis to study the mortality fraction due to hospital-acquired infections. RESULTS: Of 8853 patients who underwent cardiac surgery, 370 (4.2%) developed 500 postoperative infections (incidence density rate 4.2 hospital-acquired infections per 1000 patient-days). Crude hospital mortality was significantly higher in patients with hospital-acquired infections than in matched patients who did not develop hospital-acquired infections, 15.4% and 5.7%, respectively (P < .001). The in-hospital mortality fraction due to hospital-acquired infections in our cohort was 17.1% (12.3%-22.8%). Pseudomonas aeruginosa infection (hazard ratio, 2.09; 95% confidence interval, 1.23-3.49; P = .005), bloodstream infection (hazard ratio, 2.08; 95% confidence interval, 1.19-3.63; P = .010), and pneumonia (hazard ratio, 1.68; 95% confidence interval, 1.02-2.77; P = .04) were each independently associated with increased hospital mortality. CONCLUSIONS: Although hospital-acquired infections are relatively uncommon after cardiac surgery (4.2%), these infections have a major impact on postoperative mortality (attributable mortality fraction, 17.1%).
PURPOSE: Hospital-acquired infections have been associated with significant morbidity and mortality in critically ill surgical patients. However, little is known about mortality due to hospital-acquired infections in cardiac surgery. METHODS: We conducted a retrospective analysis of prospectively collected data from the cardiac surgery unit of a university hospital. All patients who underwent cardiac surgery over a 7-year period were included. Patients with hospital-acquired infections were matched 1:1 with patients with nonhospital-acquired infections based on risk factors for hospital-acquired infections and death after cardiac surgery using propensity score matching. We performed a competitive risk analysis to study the mortality fraction due to hospital-acquired infections. RESULTS: Of 8853 patients who underwent cardiac surgery, 370 (4.2%) developed 500 postoperative infections (incidence density rate 4.2 hospital-acquired infections per 1000 patient-days). Crude hospital mortality was significantly higher in patients with hospital-acquired infections than in matched patients who did not develop hospital-acquired infections, 15.4% and 5.7%, respectively (P < .001). The in-hospital mortality fraction due to hospital-acquired infections in our cohort was 17.1% (12.3%-22.8%). Pseudomonas aeruginosa infection (hazard ratio, 2.09; 95% confidence interval, 1.23-3.49; P = .005), bloodstream infection (hazard ratio, 2.08; 95% confidence interval, 1.19-3.63; P = .010), and pneumonia (hazard ratio, 1.68; 95% confidence interval, 1.02-2.77; P = .04) were each independently associated with increased hospital mortality. CONCLUSIONS: Although hospital-acquired infections are relatively uncommon after cardiac surgery (4.2%), these infections have a major impact on postoperative mortality (attributable mortality fraction, 17.1%).