Abstract
BACKGROUND: Chronic coronary total occlusion (CTO) represents a formidable challenge in interventional cardiology, occurring either within previously implanted stents (in-stent CTO) or in non-stented native vessels (de novo CTO). We aimed to compare the outcomes of percutaneous coronary intervention (PCI) between patients with in-stent and de novo CTO through a systematic review and meta-analysis. METHODS: PubMed, Embase, ScienceDirect, CENTRAL, and Google Scholar databases were searched for comparative studies published up to 20(th) September 20, 2025. A meta-analysis was conducted to calculate the odds ratios (OR) using a random effects model. RESULTS: Nineteen studies that compared 73,945 patients with in-stent CTO and 651,961 patients with de novo CTO were included. There was no statistically significant difference in technical success between the two groups (OR, 0.97; 95% CI, 0.87, 1.08; I(2)=0%; p=0.67). Pooled analysis of early outcomes demonstrated no statistically significant difference in the risk of all-cause mortality, major adverse cardiovascular events (MACE), myocardial infarction (MI), stent thrombosis, or tamponade between the two groups. We also noted no statistically significant differences in long-term all-cause or cardiac mortality between the two groups. However, a meta-analysis of long-term data indicated that patients with in-stent CTO have a statistically significantly increased risk of MACE, MI, and target vessel revascularization (TVR) compared to those with de novo CTO. CONCLUSION: Our results indicate that in-stent CTO-PCI has success rates similar to those of de novo CTO-PCI. There was no difference in short-term adverse outcomes between the two groups; however, patients undergoing in-stent CTO PCI had an increased risk of MACE and MI, mainly driven by the significantly increased need for TVR.