Predictive Performance of SYNTAX Score II in Patients With Left Main and Multivessel Coronary Artery Disease

Background:SYNTAX score II (SSII) provides individualized estimates of 4-year mortality after coronary artery bypass grafting (CABG) and percutaneous coronary intervention (PCI) in order to facilitate decision-making between these revascularization methods. The purpose of the present study was to assess SSII in a real-world multicenter registry with distinct regional and epidemiological characteristics.Methods and Results:Long-term mortality was analyzed in 3,896 patients undergoing PCI (n=2,190) or CABG (n=1,796) from the Coronary REvascularization Demonstrating Outcome Study in Kyoto (CREDO-Kyoto) PCI/CABG registry cohort-2. SSII discriminated well in both CABG and PCI patient groups (concordance index [c-index], 0.70; 95% CI: 0.68–0.72; and 0.75, 95% CI: 0.72–0.78) surpassing anatomical SYNTAX score (SS; c-index, 0.50; 95% CI: 0.47–0.53; and 0.59, 95% CI: 0.57–0.61). SSII had the best discriminative ability to separate low-, medium- and high-risk tertiles, and calibration plots showed good predictive performance for CABG and PCI groups. Use of anatomical SS as a reference improved the overall reclassification provided by SSII, with a net reclassification index of 0.5 (P<0.01).Conclusions:SSII has robust prognostic accuracy, both in CABG and in PCI patient groups and, compared with the anatomical SS alone, was more accurate in stratifying patients for late mortality in a real-world complex coronary artery disease Eastern population. (Circ J 2014; 78: 1942–1949)