Mediastinitis and long-term survival after coronary artery bypass graft surgery

Background. Mediastinitis is a dreaded complication of coronary artery bypass surgery (CABG). The long-term effect of mediastinitis on mortality after CABG has not been well studied. Methods. We examined the survival of 15,406 consecutive patients undergoing isolated CABG surgery from 1992 through 1996. Patient records were linked to the National Death Index. Mediastinitis was defined as occurring during the index admission and requiring reoperation. Results. Mediastinitis occurred in 193 patients (1.25%). Patients with mediastinitis were older and more likely to have had emergency surgery, diabetes, peripheral vascular disease, chronic obstructive pulmonary disease, and preoperative dialysis-dependent renal failure. Patients with mediastinitis were also more likely to be severely obese and had somewhat lower preoperative ejection fraction. After multivariate adjustment for these factors, the first year post-CABG survival rate was 78% with mediastinitis and 95% without, and the hazard ratio for mortality during the entire follow-up period was 3.09 (CI 95% 2.28, 4.19; p< 0.0001). Conclusions. Mediastinitis is associated with a marked increase in mortality during the first year post-CABG and a threefold increase during a 4-year follow-up period.