Predictors and Outcomes of Sternal Wound Complications in Patients after Coronary Artery Bypass Graft Surgery

Abstract

We sought to assess predictors and outcomes of sternal wound complications in patients after coronary artery bypass grafting (CABG). A nested, case-control study from a 10-year hospitalization cohort with prospective data collection was conducted. Included in the cohort were patients age 18 and above undergoing CABG surgery between March 1997 and July 2003 (n = 7889). Patients who underwent any surgery other CABG were excluded. Cases were matched to controls 1:3 on year of surgery. Cases were CABG patients with sternal wound complications, which was defined as requiring antibiotics and/or topical treatment, requiring extra nursing care, dehiscence, or requiring surgical intervention (n = 89). Controls were CABG patients without sternal wound complications (n = 267). The study examined 29 risk factors and 10 outcome variables. Univariate analysis on the risk factors revealed 10 significant risk factors. Logistic regression analysis was conducted and the risk factors that significantly predicted sternal wound complications after CABG surgery included older age (odds ratio [OR] = 0.85, 95% confidence interval [CI] 0.808-0.892), previous CABG surgery (OR = 3.9, 95% CI 1.03-15.37), and in class three or four of the New York Heart Association functional class (OR = 2.8, 95% CI 1.27-6.12). There was a significant difference between CABG patients with and without sternal wound complications on nine outcome variables. Of the 29 predictors of post-CABG sternal wound infections being examined, 10 proved to be significant. Further analysis demonstrated only three variables that significantly predicted sternal wound complications. Older age, previous CABG surgery, and class three or four of the New York Heart Association functional class predispose CABG patients to sternal wound infections.