Design and rationale of the drug-coated balloon coronary angioplasty versus stenting for treatment of disease adjacent to a chronic total occlusion (Co-CTO) trial

Background: Percutaneous coronary intervention (PCI) of chronic total coronary occlusions (CTOs) typically involves extensive drug-eluting stent (DES) implantation. As a result, patients undergoing CTO PCI are exposed to a relatively high risk of in-stent restenosis and target lesion revascularization. While the application of drug-coated balloons (DCBs) may improve patient outcome by reducing stent burden, randomized controlled trials investigating the use of DCB in CTO PCI are lacking. Methods: The Co-CTO trial (NCT04881812) is a single-blind, noninferiority randomized controlled trial enrolling 144 patients undergoing CTO PCI. A hybrid strategy (stenting of the CTO body and DCB treatment of adjacent disease) will be compared to a complete stenting strategy. The primary study endpoint is in-segment percentage diameter stenosis at 1 year follow-up determined by intravascular ultrasound. Secondary endpoints include major adverse cardiovascular events (a composite of cardiac death, nonfatal myocardial infarction, and ischemia-driven target lesion revascularization) at 1 year, angiographic outcomes, and cardiac symptoms (Canadian Cardiovascular Society Grading Scale, New York Heart Association Classification of Dyspnea). Conclusion: The Co-CTO trial is the first randomized controlled trial exploring a hybrid strategy (DES + DCB) in patients undergoing CTO PCI. Trial registration: Registered at ClinicalTrials.Gov under registration number: NCT04881812 (https://clinicaltrials.gov/study/NCT04881812?cond=cto&intr=drug-coated%20balloon&rank=1).