A Prospective Randomized Pilot Study of Early DAPT Discontinuation Based on Optical Coherence Tomography in High-Bleeding Risk Patients With Diabetes Mellitus Following Polymer-Free Amphilimus-Eluting Stent Implantation

This study investigates the safety and feasibility of early DAPT discontinuation guided by OCT findings in high-bleeding-risk patients with DM who undergo PCI with a polymer-free amphilimus-eluting stent. The research focuses on balancing the risks of bleeding and stent thrombosis, two critical complications associated with prolonged DAPT use, particularly in diabetic patients who are predisposed to delayed arterial healing and heightened thrombogenicity.

Study Design This is an investigator-initiated, single-center, prospective, randomized pilot trial designed to compare two DAPT strategies: short DAPT (OCT-guided discontinuation after 1 month) and standard DAPT (6 months). Eligible patients were randomized in a 1:1 ratio into the two groups, and all participants underwent PCI with the implantation of a polymer-free amphilimus-eluting stent (Cre-8, Alvimedica, Turkey). The study adheres to the principles of the Declaration of Helsinki and International Conference on Harmonization-Good Clinical Practice guidelines and was approved by the local ethics committee.

Patient Population The study included patients aged 18 years or older with known diabetes mellitus (type 1 or type 2), coronary artery disease (CAD) suitable for drug-eluting stent (DES) implantation, and a high-bleeding risk as defined by the Academic Research Consortium (ARC) or a Precise-DAPT score ≥ 25. Key exclusion criteria included acute coronary syndrome (ACS) or active bleeding at the time of randomization, severe renal impairment (glomerular filtration rate [GFR] ≤ 20 ml/min), and reduced left ventricular ejection fraction (LVEF ≤ 30%). A total of 40 patients were enrolled and randomized into the two study arms.

Interventions All participants received a loading dose of 300 mg of acetylsalicylic acid (ASA) and 600 mg of clopidogrel before PCI. The procedure was performed under local anesthesia with anticoagulation using unfractionated heparin (UFH) at a dose of 100 IU per kg. Full revascularization and adequate post-dilation were mandatory in both groups. In the short DAPT group, stent implantation was guided by OCT to ensure optimal stent strut apposition.

Within one month after PCI, patients in the short DAPT group underwent another OCT assessment to evaluate arterial healing. Early DAPT discontinuation was based on favorable OCT findings, defined as ≥80% neointimal strut coverage. OCT was performed using a commercially available system (Optis, Abbott, USA) and catheters (DragonFly Optis, Abbott, USA) according to a standardized protocol. Cross-sectional OCT images were analyzed at 2 mm intervals along the entire stented segment. For each analyzed segment, the total number of struts and uncovered struts (with no visible intimal coverage) were counted. Neointimal strut coverage was estimated as the total number of covered struts divided by the total number of analyzed struts.