Procedural and Long-Term Outcomes of Percutaneous Coronary Intervention for In-Stent Chronic Total Occlusion

This study examined procedural success and long-term outcomes of percutaneous coronary intervention (PCI) for in-stent chronic total occlusion (IS-CTO) compared with de novo CTO. While contemporary techniques have improved acute success rates for IS-CTO PCI, data on long-term outcomes remain limited.

We aimed to examine procedural success rates for IS-CTO PCI using contemporary techniques, evaluate long-term clinical outcomes with extended follow-up, identify independent predictors of major adverse cardiac events, and compare our findings with recent multicenter registries.

We analyzed 501 consecutive CTO PCI procedures in 456 patients at our institution between January 2018 and December 2023. Patients were stratified into IS (n = 82, 16.4%) and de novo CTO (n = 419, 83.6%) groups. The primary endpoint was a composite of in-stent restenosis requiring revascularization, heart failure hospitalization, myocardial infarction, and stroke at median follow-up of 713.5 days. Cox proportional hazards regression identified predictors of adverse events.

Patients with IS-CTO had a higher prevalence of diabetes (58.5% vs. 47.5%, p = 0.067) and prior myocardial infarction (46.3% vs. 27.5%, p = 0.001). Procedural success was similar (86.6% vs. 79.5%, p = 0.136) with comparable in-hospital complications. However, at median follow-up of 713.5 days, patients with IS-CTO experienced higher rates of the composite endpoint (26.4% vs. 12.8%, p = 0.003), driven by in-stent restenosis (20.8% vs. 5.2%, p < 0.001). After adjustment, IS-CTO showed a trend toward increased risk for composite outcome (HR 2.03, 95% CI 1.00-4.11). Independent predictors of composite outcome included heart failure (HR 2.15, 95% CI 1.17-3.94) and male sex (protective: HR 0.49, 95% CI 0.26-0.90).

Despite achieving procedural success comparable to de novo CTO, IS-CTO PCI is associated with significantly worse long-term outcomes over extended follow-up, particularly recurrent restenosis. These findings underscore the need for improved therapeutic strategies in this challenging population.