Predictive value of SYNTAX-Ⅱ score on prognosis of patients with chronic total occlusion undergoing percutaneous coronary intervention

Abstract

Objective: To investigate the predictive value of SYNTAX-Ⅱ score on long term prognosis of patients diagnosed with chronic total occlusion (CTO) and received percutaneous coronary intervention (PCI). Methods: Patients undergoing CTO-PCI in Fuwai hospital from January 2010 to December 2013 were enrolled in this retrospective analysis. The SYNTAX-Ⅱ score of the patients was calculated. According to SYNTAX-Ⅱ score tertiles, patients were stratified as follows: SYNTAX-Ⅱ≤20, 20<SYNTAX-Ⅱ≤27, SYNTAX-Ⅱ>27. Primary endpoint was major adverse cardiac events (MACCE), including all-cause death, myocardial infarction, stroke and any revascularization. Secondary endpoints included stent thrombosis, heart failure and target lesion failure (TLF). Patients were followed up by outpatient visit or telephone call at 1 month, 6 months and 1 year after PCI, and annually up to 5 years. Multivariate Cox regression model was used to analyze the independent risk factors of all-cause death in patients undergoing CTO-PCI. The predictive value of SYNTAX score with SYNTAX-Ⅱ score for all-cause death was evaluated by the receiver operating characteristic (ROC) curve and the area under the curve (AUC). Results: A total of 2 391 patients with CTO and received PCI were enrolled in this study. The mean age was (57.0±10.5) years, 1 994 (83.40%) patients were male. There were 802 patients in lower tertile group (SYNTAX-Ⅱ≤20), 798 patients in intermediate group (20<SYNTAX-Ⅱ≤27) and 791 patients in upper tertile group (SYNTAX-Ⅱ>27). At the end of 5-year follow-up, the loss to follow-up rate of the three groups was 9.10%(73/802), 10.78%(86/798)and 8.85%(70/791), respectively. The rate of all-cause mortality (1.78% (13/729) vs. 3.65% (26/712) vs. 9.02% (65/721), P<0.001), cardiac death (1.37% (10/729) vs. 2.11% (15/712) vs. 4.85% (35/721), P<0.001), target vessel myocardial infarctions (4.25% (31/729) vs. 4.49% (32/712) vs. 7.07% (51/721), P=0.03), probable stent thrombosis (1.51% (11/729) vs. 2.81% (20/712) vs. 3.61% (26/721), P=0.04) and heart failure (1.78% (13/729) vs. 1.97% (14/712) vs. 5.41% (39/721), P<0.001) increased in proportion to increasing SYNTAX-Ⅱ score (all P<0.05). Multivariable Cox regression analysis indicated that female (HR=2.05, 95%CI 1.12-3.73, P=0.01), left ventricular ejection fraction (HR=0.97, 95%CI 0.95-1.00, P=0.05) and SYNTAX-Ⅱ score (HR=1.07, 95%CI 1.02-1.11,P=0.01) were independent predictors for all-cause mortality in patients undergoing CTO-PCI. The predicted value of the SYNTAX-Ⅱ score for all-cause death was significantly higher than the SYNTAX score (AUC 0.71 vs. 0.60, P=0.003). Conclusion: For CTO patients who underwent percutaneous coronary intervention, SYNTAX-Ⅱ score is an independent predictor for 5-year all-cause death, and SYNTAX-Ⅱ serves as an important predictor for all-cause death in these patients.