Design and rationale of the clinical trial to obtain the highest efficacy of dual antiplatelet therapy after carotid artery stenting in high bleeding risk patients (CHET): A multicenter, randomized, open-label, superiority trial

Rationale Abbreviated dual antiplatelet therapy (DAPT) strategies effective in percutaneous coronary intervention among patients with high bleeding risk (HBR) may not be applicable to carotid artery stenting (CAS) owing to anatomical and procedural differences. Primary Hypothesis Among patients with HBR undergoing CAS, abbreviated DAPT followed by SAPT will reduce clinically significant bleeding compared to prolonged DAPT, while maintaining noninferiority in net clinical outcomes, including ischemic and major bleeding events. Design CHET trial is a multicenter, randomized, open-label, superiority trial in HBR patients undergoing CAS. Assuming a 38% relative reduction in bleeding (10.4%-6.45%), 1,524 participants (762 per group) provide 80% power with a two-sided alpha of 0.05; the final target is 1,556 (778 per group), allowing 2% dropout. Key HBR criteria include age ≥75 years, ischemic stroke within 6 months, renal insufficiency, anemia, and thrombocytopenia. All patients will receive aspirin and clopidogrel for 30 days after CAS (enrichment period). Event-free patients on day 30 were randomized 1:1 to receive SAPT (aspirin 100 mg daily or clopidogrel 75 mg daily, at the treating physician’s discretion) or continued DAPT for 11 months. The primary safety endpoint is clinically significant bleeding (BARC 2, 3, or 5) from day 30 to 12 months post-CAS. The secondary efficacy endpoint is a composite of nonfatal stroke, nonfatal myocardial infarction, cardiovascular death, and major bleeding (BARC 3 or 5). Enrollment Dates and Current Status CHET began enrollment on July 15, 2024. As of February 5, 2026, the trial is currently enrolling, with 328 participants enrolled. Enrollment is expected to be completed by November 2029, and follow-up by December 2030. Conclusions CHET trial is the first randomized controlled trial to define optimal DAPT duration in HBR patients after CAS. Trial Registration www.clinicaltrials.gov (NCT06276374).