Abstract
BACKGROUND: The primary objective of this research was to determine the predictive value of the residual SYNTAX (Synergy Between Percutaneous Coronary Intervention With Taxus and Cardiac Surgery) score II (rSS-II) for long-term outcomes in individuals with complex coronary artery disease (CAD) and chronic renal insufficiency (CRI) who have undergone percutaneous coronary intervention (PCI). METHODS: A total of 1161 consecutive patients with complex CAD and CRI after PCI were retrospectively recruited from Cangzhou Central Hospital affiliated with Hebei Medical University between January 2014 and September 2017. The patients were stratified into three categories based on rSS-II tertiles: low rSS-II (n = 388), medium rSS-II (n = 389), and high rSS-II (n = 384). The primary endpoints were all-cause mortality (ACM) and cardiac mortality (CM), while the secondary endpoint was major adverse cardiovascular and cerebrovascular events (MACCEs), which included ACM, myocardial infarction, stroke, or unplanned revascularization. The discrimination, calibration, and clinical utility of the rSS-II for predicting long-term outcomes were examined. RESULTS: The median follow-up period was 37 months (19 to 61 months). The Kaplan-Meier estimate rates of ACM (2.4% vs. 5.9% vs. 13.9%; p < 0.001) and CM (1.9% vs. 2.8% vs. 9.2%; p < 0.001) revealed significant differences among the three categories. Multivariate Cox regression analysis demonstrated that the rSS-II could independently predict ACM (hazard ratio: 1.08, 95% confidence interval: 1.04-1.12; p < 0.001) and CM (hazard ratio: 1.07, 95% confidence interval: 1.02-1.12; p = 0.009). The rSS-II performed satisfactorily in both discrimination (area under the curve for ACM and CM was 0.710 and 0.728, respectively) and calibration (Greenwood-Nam-D' Agostino goodness-of-fit test for long-term outcomes; p > 0.05 for all). Additionally, decision curve analysis showed that the rSS-II had a high net benefit for long-term outcomes over threshold probabilities, indicating its superiority in daily practice. CONCLUSIONS: The rSS-II is beneficial for predicting and stratifying the risk of long-term outcomes in individuals with complex CAD and CRI who have undergone PCI.