Chronic total occlusions (CTO) of the coronary arteries are usually treated with drug-eluting stents (DES) after successful recanalization. Permanent metallic scaffolds carry recognized long-term limitations, including late malapposition, very late stent thrombosis, impairment of positive vascular remodeling, and edge restenosis after geographic miss. Drug-coated balloons (DCB) deliver an antiproliferative agent to the vessel wall without leaving a permanent implant, and may be particularly attractive in long, fibrocalcific recanalized CTO segments.
NoTrace-CTO is a prospective, single-center, investigator-initiated, single-arm pilot study evaluating an exclusive DCB-only strategy, with no stent implantation, after successful CTO recanalization. Thirty-eight patients are planned, to yield thirty evaluable patients with paired angiographic follow-up.
The primary endpoint is in-balloon late lumen loss at nine months, measured by quantitative coronary angiography (QCA) and tested against a pre-specified performance goal of 0.50 mm derived from a pooled contemporary second-generation DES benchmark. The proportion of lesions completing the DCB-only strategy without bailout stenting is reported descriptively alongside it. Serial intravascular ultrasound (IVUS) performed at baseline, immediately after DCB delivery and at nine months is the mechanistic centerpiece of the study, assessing vascular remodeling directly. Secondary assessments include quantitative flow ratio (QFR), Seattle Angina Questionnaire (SAQ) scores, binary restenosis, reocclusion, target lesion and target vessel revascularization, major adverse cardiovascular events (MACE), bleeding classified by the Bleeding Academic Research Consortium (BARC) criteria, and acute kidney injury defined by the Kidney Disease: Improving Global Outcomes (KDIGO) criteria.
The study is not powered for comparative clinical superiority or non-inferiority against DES; its findings are hypothesis-generating and intended to inform the design of an adequately powered multicenter trial.