Clinical SYNTAX score predicts outcomes of patients undergoing coronary artery bypass grafting.

Background: The SYNTAX score (SS) is a determinant of outcome in patients undergoing percutaneous coronary intervention. In addition, it has been recently shown that the clinical SYNTAX score (cSS), obtained by adding clinical variables to the SS, improves the predictive power of the resulting risk model. We assessed the hypothesis that the use of the cSS may predict outcomes of patients undergoing coronary artery bypass grafting (CABG).

Methods: We measured the SYNTAX score in 874 patients undergoing isolated first time on-pump CABG. The clinical SYNTAX score was calculated at the time of the study using age, creatinine clearance and ejection fraction, the modified ACEF score, and analyses performed for major adverse cardiac and cerebrovascular events (MACCE) and all-cause mortality at 3-year follow-up.

Results: The mean age of the study population was 70.9 ± 8.1 years, and the median cSS 14.2 (range 2.1-286.5). The ROC curve analysis showed that a cSS >14.5 (81.4% sensitivity and 67.8% specificity) was a reliable tool in discrimination of patients for the occurrence of MACCE (AUC 0.78) and all-cause mortality (AUC 0.74). Kaplan-Meier survival analysis confirmed that patients belonging to higher cSS quartiles have poorer 3-year survival (P = .0001) and MACCE-free survival (P = .0001), with respect to those with lower cSS.

Conclusions: This observational study has shown that the clinical SYNTAX score, incorporating the lesion-based SS and clinical-based ACEF score, predicted mid-term adverse outcomes of patients undergoing CABG and may play an important role in the risk stratification of this population. Further studies are needed to confirm these findings.