Prediction of long‐term patient outcome after contemporary left main stenting using the SYNTAX and SYNTAX II scores: A comparative analysis from the FAIL‐II multicenter registry (failure in left main study with 2nd generation stents‐Cardiogroup III study)

Abstract Aims To establish the value of the SYNTAX Score‐II (SS‐II) in predicting long‐term mortality of patients treated with left main PCI (LM‐PCI) using second‐generation drug‐eluting stents (DES). Methods and Results The SYNTAX score (SS) and the SS‐II were calculated in 804 patients included in the FAILS‐2 registry (failure in left main study with 2nd generation stents). Patients were classified in low (SS‐II ≤33; n = 278, 34.6%), intermediate (SS‐II 34–43; n = 260, 32.3%) and high (SS‐II ≥44; n = 266, 33.1%) SS‐II tertiles. Primary endpoint was all‐cause mortality. A significant difference in long‐term mortality was noted (5.2 ± 3.6 years): 4.1, 7.5, and 16.7% in low, mid and high SS‐II tertiles respectively ( p < .001). SS‐II score was more accurate in predicting mortality than SS (AUC = 0.73; 95%CI: 0.67–0.79 vs. AUC = 0.55; 95%CI: 0.48–0.63, respectively; p < .001). SS‐II led to a reclassification in the risk of all‐cause mortality re‐allocating 73% of patients from the CABG‐only indication to PCI or equipoise PCI‐or‐CABG indication. Using multiple Cox regression analysis, SS‐II (HR: 1.07; 95%CI: 1.05–1.09; p < .001), along with Acute coronary syndrome (ACS) (HR: 1.66; 95%CI: 1.03–2.66; p = .07) and Cardiogenic shock (CS) (HR: 2.82 (95%CI: 1.41–5.64; p = .003) were independent predictors of long‐term mortality. SS‐II (HR: 1.05; 95%CI: 1.04–1.06; p < .001) along with Insulin dependent Type 2 DM (HR: 1.58, 95%CI: 1.09–2.30.; p < .05), ACS (HR: 1.58, 95%CI: 1.16–2.14; p < .001) and CS (HR: 2.02 95%CI 1.16–3.53; p < .05), were independent predictors of long‐term MACE. Conclusion The SS‐II was superior to the SS in predicting outcomes associated with contemporary LM‐PCI. In this real‐world population, two clinical variables not included in the SS‐II, ACS and T2DM, were identified as additional markers of poor outcome.