Is the SYNTAX score a predictor of long-term outcome after coronary artery bypass surgery?

Background: The SYNTAX score was introduced to measure the complexity of coronary artery disease. Although a high SYNTAX score is indicative of a worse long-term outcome after percutaneous coronary intervention (PCI), it remains unclear whether it is also true for coronary artery bypass grafting (CABG).
Methods: We analyzed 200 consecutive CABG patients who underwent operations in 2002. Demographic and intraoperative data, perioperative outcomes, and 5-year outcomes were obtained. The SYNTAX score was calculated retrospectively by reviewing the original diagnostic angiograms. After excluding patients who had undergone CABG or PCI treatment within 6 months before surgery, we included 154 patients in the study. Patients were partitioned into tertiles according to the SYNTAX score (low, < or =18; intermediate, >18-26; high, >26). Cox regression analysis was used to identify baseline and procedural predictors for the combined end point of 5-year major adverse cardiac and cerebrovascular events (MACCE) and its components. Cumulative event rates were estimated by Kaplan-Meier methods.
Results: The mean (+/-SD) age was 66.6 +/- 8.5 years, the mean ejection fraction was 56.4% +/- 13.6%, and the mean logistic EuroSCORE was 4.2% +/- 4.7%. The SYNTAX score ranged between 2 and 52. The overall survival rate was 94.8% at 1 year and 84.1% at 5 years. The rate of freedom from MACCE was 92.9% and 78.0% at 1 and 5 years, respectively. Only a higher EuroSCORE, a New York Heart Association class of III to IV, and smoking could be identified with Cox regression as risk factors for MACCE during follow-up. The overall survival and MACCE rates of the 3 SYNTAX score subgroups were not significantly different.
Conclusions: Complex coronary pathology as measured by the SYNTAX score did not affect the long-term outcome after CABG in this study.