Background The development of the technique has improved the success rate of percutaneous coronary intervention (PCI) for in-stent chronic total occlusion (IS-CTO). However, long-term outcomes remain unclear. The present study sought to investigate long-term outcomes of PCI for IS-CTO. Methods A total of 474 IS-CTO patients were enrolled at two cardiac centers from 2015 to 2018 retrospectively. These patients were allocated into either successful or failed IS-CTO PCI groups. The primary endpoint (major adverse cardiac events [MACE]) consisted of recurrent angina pectoris (RAP), target-vessel myocardial infarction (MI), heart failure, cardiac death, or ischemia-driven target-vessel revascularization (TVR) at follow-up. Multivariable Cox regression analysis was used to investigate the association between treatment appropriateness and clinical outcomes. Results A total of 367 patients were successfully treated with IS-CTO PCI while 107 patients had failed recanalization. After a median follow-up of 30 months (interquartile range: 17–42 months), no significant difference was observed between the two groups for the following parameters: cardiac death (successful PCI vs. failed PCI: 0.9% vs. 2.7%; adjusted hazard ratio [HR]: 1.442; 95% confidence interval [CI]: 0.21–9.887; P = 0.709), RAP (successful PCI vs. failed PCI: 40.8% vs. 40.0%; adjusted HR: 1.025; 95% CI: 0.683–1.538; P = 0.905), heart failure (successful PCI vs. failed PCI: 6.1% vs. 2.7%; adjusted HR: 0.281; 95% CI: 0.065–1.206; P = 0.088), target-vessel related MI (successful PCI vs. failed PCI: 1.5% vs. 2.7%; adjusted HR: 1.150; 95% CI: 0.221–5.995; P = 0.868), MACE (successful PCI vs. failed PCI: 44.2% vs. 45.3%; adjusted HR: 1.052; 95% CI: 0.717–1.543; P = 0.797). More patients were free of angina in the successful IS-CTO PCI group compared with failed PCI in the first (80.4% vs. 60%, P < 0.01) and second years (73.3% vs. 60.0%, P = 0.02) following up. Successful IS-CTO PCI had a lower incidence of MACE in the first and second years (20.2% vs. 40.0%, P < 0.01; 27.9% vs. 41.3%, P = 0.023) compared with failed PCI. After a median follow-up of 30 months, the reocclusion rate was 28.5% and TVR was 26.1% in the successful IS-CTO PCI group. Receiving >18 months of dual antiplatelet therapy (DAPT) was an independent predictor of decreased risk of TVR (HR: 2....

No abstract