Usefulness of the Baseline Syntax Score to Predict 3-Year Outcome After Complete Revascularization by Percutaneous Coronary Intervention

Although we strive to achieve complete revascularization (CR) in those receiving percutaneous coronary intervention, it is uncertain which of these patients are at increased risk of clinical events. In this study, we aimed to investigate whether the baseline SYNTAX score (bSS) can predict adverse clinical events in patients receiving CR. From the Efficacy of Xience/Promus Versus Cypher in Reducing Late Loss After Stenting registry, the 3-year patient-oriented composite end point (POCE; all cause death, any myocardial infarction, and any revascularization) was compared according to bSS tertiles (1 ≤ low bSS < 6, 6 ≤ mid-bSS < 10, high bSS ≥ 10). Of the 5,088 patients, CR was achieved in 2,173 by percutaneous coronary intervention. The 3-year POCE increased significantly along with bSS tertile (7.3% vs 8.4% vs 14.8%, p <0.001). Multivariate analysis showed that, despite having the same residual SS of 0, the bSS was an independent predictor of 3-year POCE (hazard ratio 1.038, 95% confidence interval 1.018 to 1.058, p <0.001 per bSS point). In subgroup analysis, bSS was a predictor for 3-year POCE in multivessel diseases (hazard ratio 1.029, 95% confidence interval 1.004 to 1.054, p = 0.025 per bSS point), whereas in single-vessel diseases, the discriminative value of bSS was less significant. Also the clinical SYNTAX score, which added age, creatinine level, and ejection fraction to the bSS, was superior to the bSS in predicting 3-year POCE (area under the curve 0.595 vs 0.649, p = 0.008). In conclusion, the bSS was an independent predictor of long-term clinical outcomes in patients receiving CR, especially in those with multivessel coronary artery disease. Adding clinical factors to the bSS could increase the predictive power of clinical outcomes.