Preoperative risk stratification of deep sternal wound infection after coronary surgery

Abstract

OBJECTIVE: To develop a risk score for deep sternal wound infection (DSWI) after isolated coronary artery bypass grafting (CABG). DESIGN: Multicenter, prospective study. SETTING: Tertiary-care referral hospitals. PARTICIPANTS: The study included 7,352 patients from the European multicenter coronary artery bypass grafting (E-CABG) registry. INTERVENTION: Isolated CABG. METHODS: An additive risk score (the E-CABG DSWI score) was estimated from the derivation data set (66.7% of patients), and its performance was assessed in the validation data set (33.3% of patients). RESULTS: DSWI occurred in 181 (2.5%) patients and increased 1-year mortality (adjusted hazard ratio, 4.275; 95% confidence interval [CI], 2.804-6.517). Female gender (odds ratio [OR], 1.804; 95% CI, 1.161-2.802), body mass index ≥30 kg/m2 (OR, 1.729; 95% CI, 1.166-2.562), glomerular filtration rate <45 mL/min/1.73 m2 (OR, 2.410; 95% CI, 1.413-4.111), diabetes (OR, 1.741; 95% CI, 1.178-2.573), pulmonary disease (OR, 1.935; 95% CI, 1.178-3.180), atrial fibrillation (OR, 1.854; 95% CI, 1.096-3.138), critical preoperative state (OR, 2.196; 95% CI, 1.209-3.891), and bilateral internal mammary artery grafting (OR, 2.088; 95% CI, 1.422-3.066) were predictors of DSWI (derivation data set). An additive risk score was calculated by assigning 1 point to each of these independent risk factors for DSWI. In the validation data set, the rate of DSWI increased along with the E-CABG DSWI scores (score of 0, 1.0%; score of 1, 1.8%; score of 2, 2.2%; score of 3, 6.9%; score ≥4: 12.1%; P < .0001). Net reclassification improvement, integrated discrimination improvement, and decision curve analysis showed that the E-CABG DSWI score performed better than other risk scores. CONCLUSIONS: DSWI is associated with poor outcome after CABG, and its risk can be stratified using the E-CABG DSWI score. TRIAL REGISTRATION: clinicaltrials.gov identifier: NCT02319083.