Usefulness of SYNTAX score II in complex percutaneous coronary interventions in the setting of acute coronary syndrome

BACKGROUND: SYNTAX score II (SS II) integrates anatomical SS with clinical characteristics allowing an individualized prediction of long-term mortality. AIMS: We sought to assess to evaluate the usefulness of SS II in a real-world acute coronary syndromes (ACS) population with severe coronary artery disease (CAD) undergoing percutaneous coronary intervention (PCI). METHODS: From August 2011 to May 2013, out of 1591 consecutive patients admitted for ACS, 217 (13.6%) showed severe CAD (three-vessel disease and/or left main involvement). Among the latter, 100 patients underwent PCI and were enrolled into the study. SS II was calculated in all patients. One-year clinical follow-up was performed; major adverse cardiac and cerebrovascular events (MACCE) were defined as a composite of death, nonfatal myocardial infarction, stroke, or repeat revascularization. RESULTS: The median SS II was 29 (range, 14-59). Overall, MACCE occurred in 25% of patients (cardiac death 4%, myocardial infarction 4%, stroke 0%, and repeat revascularization 17%). The 1-year MACCE-free survival was significantly lower in patients with SS (⩾29), than in those with SS II (<29) (64.2% vs. 87.2%, respectively; p = 0.007). In multivariate Cox regression analysis, the presence of unprotected left main stenosis [hazard ratio 2.52, 95% confidence interval (CI): 1.02-5.85; p = 0.031] and SS II ⩾29 (hazard ratio 2.74, 95% CI: 1.30-8.21; p = 0.011) were the only predictors of MACCE at 1-year clinical follow-up. The c-index of SS score II was 0.70 (95% CI: 0.58-0.81). For patients who experienced MACCE, the SS II reclassification improved by 36%, while in nonevent patients the reclassification improved by 22%. The net reclassification index was 0.24 (p = 0.09). CONCLUSION: SS II might represent a useful tool to predict clinical events in not only ideal stable patients, but also an unrestricted, real world population of patients with ACS and severe CAD undergoing PCI.