Impact of perioperative myocardial injury on early and long-term outcome after coronary artery bypass grafting

AIMS: To establish the influence of perioperative myocardial injury on short- and long-term survival after coronary artery bypass grafting (CABG). METHODS AND RESULTS: The correlation of postoperative serum aspartate aminotransferase and creatine kinase MB to early cardiac-related death and to late survival was evaluated in 4911 patients who underwent CABG consecutively during a 6-year period. There were 93 early deaths (1.9%), 73 of them cardiac-related (1.5% of 4911). After a mean follow-up of 5 years, 409 additional deaths (8.5% of 4818) had occurred. Elevated enzyme levels on day 1 postoperatively highly increased the risk of early cardiac death (serum aspartate aminotransferase >or=2.35 microkat.l(-1): odds ratio 9.2; serum creatine kinase MB >or=61 microg.l(-1): odds ratio 6.0), and increased the risk of late death by approximately 50% (serum aspartate aminotransferase >or=2.35 microkat.l(-1): relative hazard 1.5; serum creatine kinase MB >or=61 microg.l(-1): relative hazard 1.4). This increased risk of death was independent of other risk factors and remained constant over time. CONCLUSIONS: Enzyme elevation after CABG implied an increased risk of both early and late death. The long-term effect persisted many years after surgery.