Prognostic usefulness of residual SYNTAX score combined with clinical factors for patients with acute coronary syndrome who underwent percutaneous coronary intervention from the SHINANO Registry

The optimal strategy for percutaneous coronary intervention (PCI) for acute coronary syndrome (ACS) with multi-vessel disease (MVD) is still controversial. Residual anatomical features alone are not sufficient to appropriately stratify patient risk. Our aim was to assess the effectiveness of the residual Synergy between Percutaneous Coronary Intervention with Taxus and Cardiac Surgery (SYNTAX) score (rSS) combined with clinical factors to predict long-term clinical outcomes in ACS patients. A total of 120 patients with ACS and MVD undergoing PCI were recruited from the SHINANO 5-year registry: a prospective, multi-center, cohort study. The rSS combined with clinical factors (Combined Score) were calculated based on the residual coronary angiogram and each clinical feature after primary PCI. The Combined Score was calculated by replacing SS with rSS using the SYNTAX score II (SSII) calculator. We grouped the Combined Score in two groups according to the cut-off value calculated by the ROC curve (the C-statistic was 0.82 [95% CI 0.74–0.91]) for all-cause mortality. The primary endpoint was all-cause mortality during the 5-year follow-up. The Combined Score was associated with long-term mortality in Cox-regression analysis (HR 1.08, 95% CI 1.05–1.11, P < 0.001). The mortality rate was significantly higher in the high-score group compared with the low-score group (5.7% vs 38.0%; P < 0.001). In ACS with MVD, the Combined Score might be considered an important tool to predict long-term mortality following PCI.