A Study Evaluating the Vascular Healing and Neointimal Transformation at 1 Month After Implantation of BioFreedom™ Drug-coated Stents and the Xience Drug-eluting Stent System in Patients With Acute Coronary Syndrome and High Bleeding Risk Using Optical Coherence Tomography
BioFreedom™ is the world's first polymer-free drug-coated stent (DCS), utilizing a proprietary microstructured surface technology. Its abluminal microporous surface directly carries BA9™ (a sirolimus derivative) with high lipophilicity. This design mitigates inflammatory responses while promoting early vascular healing and reducing thrombotic risk. Extensive clinical evidence has validated BioFreedom™'s superior performance in high-bleeding-risk (HBR) populations. However, comprehensive assessments of neointimal coverage and quantitative neointimal transformation post-implantation remain insufficient. With advancements in ultra-high-resolution optical coherence tomography (OCT), detailed evaluation of coronary stent healing has become feasible. This study will employ OCT to comparatively assess vascular healing patterns-including neointimal transformation and strut coverage-in ACS patients with HBR receiving either the commercially available BioFreedom™ DCS or Xience drug-eluting stent system. The findings will provide multidimensional insights into the devices' post-implantation efficacy and safety profiles.
• Age ≥18 years
• Male or non-pregnant female
• Acute coronary syndrome (ACS) patients requiring percutaneous coronary intervention (PCI)
• No contraindications for coronary artery bypass grafting (CABG)
• High bleeding risk (HBR) patients per ARC-HBR definition (meeting ≥1 major or 2 minor criteria):
• Major Criteria:
⁃ Expected long-term oral anticoagulation
⁃ Severe/end-stage chronic kidney disease (eGFR \<30 mL/min)
⁃ Moderate/severe anemia (Hb \<110 g/L)
⁃ Spontaneous bleeding requiring hospitalization/transfusion within 6 months (or recurrent)
⁃ Chronic bleeding diathesis
⁃ Moderate/severe thrombocytopenia pre-PCI (platelet count \<100×10⁹/L)
⁃ Liver cirrhosis with portal hypertension
⁃ Active malignancy in past 12 months (excluding non-melanoma skin cancer; defined as diagnosis/treatment within 12 months)
⁃ History of spontaneous intracranial hemorrhage
⁃ Traumatic intracranial hemorrhage within 12 months
⁃ Known cerebral arteriovenous malformation
⁃ Moderate/severe ischemic stroke within 6 months
⁃ Major surgery/severe trauma within 30 days pre-PCI
⁃ Planned non-deferrable major surgery during dual antiplatelet therapy
• Minor Criteria:
⁃ Age ≥75 years
⁃ Moderate chronic kidney disease (eGFR:30\
‣ 59 ml/min)
⁃ Mild anemia (male: Hb=110\
‣ 129 g/L; female: Hb=110\
‣ 119 g/L)
⁃ Spontaneous bleeding requiring hospitalization/transfusion within 6-12 months pre-PCI
⁃ Chronic NSAID/steroid use post-PCI
⁃ Ischemic stroke \>6 months pre-PCI
• Capable of understanding trial objectives and providing informed consent
‣ Angiographic Inclusion Criteria:
• Target lesion must be primary native coronary artery lesion
• Target lesion with ≥70% diameter stenosis (visual estimate), or 50-70% diameter stenosis (visual estimate) with ischemic evidence
• ≥1 non-target lesion requiring intervention
• Non-target lesions eligible for elective treatment within 1 month