Outcomes of the retrograde approach through epicardial versus non-epicardial collaterals in chronic total occlusion percutaneous coronary intervention

Background The retrograde approach through epicardial collaterals (EC) for chronic total occlusion (CTO) percutaneous coronary intervention (PCI) is a challenging procedure. Our study aim was to evaluate the outcomes of patients undergoing CTO PCI using a retrograde approach through epicardial versus non-epicardial collaterals (NEC). Methods We collected data from our single-center registry of consecutive patients undergoing retrograde CTO PCI, performed by an experienced operator through EC and NEC (septals and bypass grafts). Clinical, angiographic and procedural data were recorded. The primary endpoint (major adverse cardiac events, MACE) was a composite of cardiac death, target-vessel myocardial infarction (MI) and target-vessel revascularization (TVR) on follow-up. Results During the study period, 318 CTO PCIs were performed. Of these, 81 procedures (25%) were performed retrogradely in 75 patients (38 using NEC [31 septals, 7 bypass grafts], 37 through EC [34 contralateral, 3 ipsilateral]). Clinical characteristics were balanced between EC and NEC. J-CTO score was 2.1±1.1 and 2.2±1.2, respectively (p=0.92). Collateral tortuosity was more marked in EC. Technical and procedural success was lower in EC (35% vs. 76%, p<0.001; 30% vs. 76%, p<0.001; respectively). There were two perforations (5%) with need for intervention in EC, and none in NEC (p=0.15). After a median follow-up of 443 (331â 744) days, MACE were observed in 12.9% (n=4) of EC vs. 5.4% (n=2) in NEC patients (p=0.28). Conclusions In our experience, retrograde CTO PCI through EC was associated with lower success rate, and a numerically higher rate of perforation, as compared with NEC. Clinical outcomes on follow-up were similar.