The Impact of Deep Sternal Wound Infection on Long-term Survival After Coronary Artery Bypass Grafting

Abstract

To identify the impact of deep sternal wound infection (DSWI) on long-term survival after coronary artery bypass grafting (CABG). DSWI following CABG is an infrequent, yet devastating complication with increased morbidity and mortality. However, little has been published regarding the impact of DSWI on long-term mortality. We studied 3,760 consecutive patients who underwent isolated CABG between 1992 and 2002. Patients with CABG and no DSWI were compared with those in whom DSWI developed. Long-term survival data (mean follow-up, 5.2 years) were obtained from the National Death Index. Groups were compared by Cox proportional hazard models and Kaplan-Meier survival plots. The propensity for DSWI was determined by logistic regression analysis, and each patient with DSWI was then matched to 10 patients without DSWI. DSWI developed in 40 of 3,760 patients (1.1%). Independent predictors for DSWI were diabetes (odds ratio [OR], 5.5; 95% confidence interval [CI], 2.7 to 11.6; p < 0.001), hemodynamic instability preoperatively (OR, 4.0; 95% CI, 1.2 to 13.9; p = 0.026), preoperative renal failure on dialysis (OR, 3.4; 95% CI, 1.0 to 13.6; p = 0.049), use of bilateral internal thoracic arteries (OR, 2.6; 95% CI, 1.3 to 5.3; p = 0.010), and sepsis and/or endocarditis after CABG (OR, 29.9; 95% CI, 11.7 to 76.4; p < 0.001). Patients with DSWI had prolonged length of stay (35.0 days vs 16.4 days; p < 0.001); however, there was no difference in early mortality between matched groups. After adjustment for preoperative, intraoperative, and postoperative factors, the adjusted hazard ratio of long-term mortality for patients with DSWI was 2.44 (95% CI, 1.51 to 3.92; p < 0.001). Patients without DSWI had a better 5-year survival rate (72.8 +/- 2.4% vs 50.8.6 +/- 8.5% [mean +/- SE]; p = 0.0007 between matched groups). We found that DSWI following CABG was associated with increased long-term mortality during a 10-year follow-up study.