The impact of deep sternal wound infection on long-term survival after coronary artery bypass grafting

Abstract

Objectives: To identify the impact of deep sternal wound infection (DSWI) on long-term survival after coronary artery bypass grafting (CABG).

Background: 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.

Methods: 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.

Results: 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).

Conclusions: We found that DSWI following CABG was associated with increased long-term mortality during a 10-year follow-up study.