Procedural Results and Long-Term Outcomes of Percutaneous Coronary Intervention for in-Stent Restenosis Chronic Total Occlusion Compared with de novo Chronic Total Occlusion

BACKGROUND: In-stent restenosis (ISR) chronic total occlusion (CTO) represents a challenging subgroup for revascularization of CTO by percutaneous coronary intervention (PCI). There are limited data on the treatment and outcomes of PCI for ISR CTO. OBJECTIVE: We aimed to evaluate the procedural results and 2-year outcomes of PCI for ISR CTO compared with de novo CTO. METHODS: Patients undergoing attempted CTO PCI between January 2017 and December 2019 were prospectively enrolled. We analyzed the procedural results and 2-year major adverse cardiac events (MACE) in patients undergoing ISR CTO and those undergoing de novo CTO PCI. RESULTS: A total of 426 patients undergoing 484 consecutive CTO PCI (ISR CTO PCI, n=84; de novo CTO, n=400) were enrolled during the study period. Patients undergoing de novo CTO PCI had a significantly greater syntax score than those undergoing ISR CTO PCI [23.0 (17.5, 30.5) vs 21.5 (14.5, 27.0), p=0.039]. Technical (73.8% vs 79.0%, p=0.296) and procedural (73.8% vs 78.0, p=0.405) success rates, as well as the incidence of major procedural complications (1.2% vs 2.3%, p=0.842), were comparable between the two groups. After a median follow-up of 20 months, patients who underwent ISR CTO PCI had a significantly higher incidence of MACE (33.3% vs 10.3%, p<0.001), mainly attributed to the higher TVR rates (24.7% vs 7.6%, p<0.001). ISR CTO was the only independent predictor of MACE (hazard ratio, 4.124; 95% confidence interval, 1.951–8.717; p<0.001) during follow-up in patients who underwent CTO PCI. CONCLUSION: ISR CTO PCI shows comparable technical and procedural success, as well as major procedural complications compared with de novo CTO PCI. However, patients who underwent ISR CTO PCI had a significantly worse prognosis than those who underwent de novo CTO PCI, in terms of MACE, driven by TVR. ISR CTO was the only independent predictor of MACE during the follow-up.