MEDIASTINITIS AFTER CORONARY-ARTERY BYPASS GRAFT-SURGERY - RISK-FACTORS AND LONG-TERM SURVIVAL

Background Mediastinitis is a severe complication of coronary artery b ypass graft surgery (CABG). The purpose of the present study was to de termine preoperative and intraoperative variables that predict mediast initis and to determine the impact of this complication on long-term s urvival. Methods and Results Data on 20 preoperative and intraoperativ e variables were collected prospectively on 6459 consecutive patients who underwent CABG between January 1987 and January 1994. Eighty-three patients (1.3%) developed mediastinitis postoperatively, and a total of 24 patients (29%) died. Multivariate analysis identified 4 of the 2 0 variables as highly significant independent predictors for the devel opment of mediastinitis: obesity (P=.0002), New York Heart Association congestive heart failure class (P=.002), previous heart surgery (P=.0 08), and duration of cardiopulmonary bypass (P=.05). A comprehensive r eview of the literature identified 13 other studies that evaluated 48 factors as predictors of mediastinitis; these data were critically ana lyzed and compared with the results from this series. In this series, postoperative interval mortality during the first 90 days after surger y for the patients with mediastinitis was 11.8% compared with 5.5% for the patients without mediastinitis. Interval mortality between 1 and 2 years after surgery remained high for the mediastinitis group (8.1%) relative to the nonmediastinitis group (2.3%). These differences were not eliminated by adjusting for important variables that influenced l ate survival in this population. Conclusions The present study and a r eview of the literature suggest that obesity and duration of surgery a re the most important predictors of mediastinitis. Furthermore, althou gh the early increase in mortality has been well described, the presen t study documents for the first time that mediastinitis has a signific ant negative influence on long-term survival independent of the patien t's preoperative condition.