Introduction: SYNTAX-score II as newer tool to select revascularization strategy between percutaneous coronary intervention (PCI) and coronary artery bypass grafting (CABG) may be useful to assess appropriateness of PCI for chronic total occlusion (CTO-PCI).
Methods: We investigated 343 patients who underwent CTO-PCI. The patients were assessed by SYNTAX-score II by using SYNTAX-score website, and were divided into three groups by tertile of the SYNTAX-score II for PCI (low<33.5, intermediate; 33.5-43.5, high;>43.5). Recommended strategy (chosen from CABG, PCI, or equipoise) was provided for each cases. Endpoint of this study was all-cause death. Complete revascularization (CR) was defined as 0 residual angiographic SYNTAX-score after PCIs.
Results: Of all, angiographic SYNTAX-score was 26.9±14, SYNTAX-score II for PCI was 39.9±12, and that score for CABG was 32.5±14. According to the recommended strategy, only 0.9% of the patients were recommended PCI, 37.1% was recommended CABG, and 62.0% was regarded as equipoise. Long-term outcomes (median: 793 days) revealed that estimated all-cause mortality at 4-years after CTO-PCI was 11.0%. The SYNTAX-score II for PCI well stratified patients at risk for death after CTO-PCI (Hazard ratio; HR:1.07, 95% confidence interval; 95%CI: 1.04-1.10, P<0.0001), and as compared to low SYNTAX-score II, high SYNTAX-score II was strongly related to death after CTO-PCI (intermediate; HR 4.89, 95%CI: 0.57-41.85, P=0.15, high; HR: 19.7, 95%CI: 2.62-147.3, P=0.004). Mortality rate at 4-years after CTO-PCI was not different among recommended strategies (PCI: 0%, CABG: 12.2%, and equipoise: 10.4%, P=0.75). However, effect of CR on 4-year mortality was only seen in patients with low SYNTAX-score II (CR vs non-CR; low: 0% vs.4.5% P=0.04, intermediate: 6.2% vs. 7.2%, P=0.60, high: 16.8% vs.25.1%, P=0.44).
Conclusions: SYNTAX-score II was useful to identify high risk subset for death among patients who underwent CTO-PCI. CTO-PCI might be acceptable in selection of revascularization strategy among not only patients who has equivalent risk between PCI and CABG but also patients who are regarded as candidate of CABG. However, effect of PCI on long-term mortality of patients with CTO may be attenuated by their comorbidity.