EROSION (Effective anti-thrombotic therapy without stenting: intravascular optical coherence tomography-based management in plaque erosion) study, a single-center, uncontrolled, prospective, proof-of concept study, showed that for patients with ACS caused by non-obstructive plaque erosion, conservative treatment with anti-thrombotic therapy without stenting may be an option. However, it is unknown whether plaque rupture with large lumen area and non-obstructive stenosis can be treated medically without stenting. EROSION II study is a prospective, multi-center, observational study to test the hypothesis that patients with STEMI caused by plaque rupture or plaque erosion without obstructive stenosis (diameter stenosis <70% by visual assessment) can be stabilized and healed by effective antithrombotic treatment without stent implantation. Patients presenting with STEMI within 24 hours from the onset of ischemic symptoms will be included for screening. Thrombus aspiration will be performed in patients with large thrombus burden and TIMI flow grade less than 2 to restore blood flow. OCT will be performed after antegrade blood flow restored to assess the underlying mechanism of culprit lesion including plaque rupture, plaque erosion, calcified nodule, spontaneous coronary artery dissection, and other uncommon reasons. OCT imaging of non-culprit vessels will be performed if feasible. Patients caused by plaque erosion or plaque rupture with minimal lumen area > 1.6mm2 or non-obstructive stenosis (diameter stenosis <70% by visual assessment) will be treated medically only with dual anti-platelet therapy for 12 months after discharge.~Serial OCT examination will be performed at 1-month and 12-month follow-up to assess the healing of original culprit lesion. Physiological assessment (either wire-based FFR or angio-based FFR) will also be performed to assess the hemodynamic function of culprit lesion. The primary endpoint is the reduction of thrombus burden assessed by OCT at 1-month follow-up. Presence of recurrent ischemia symptoms or positive FFR value are the indications for target lesion revascularization. Patients will be followed by phone calls by study coordinators or clinical visit at 1 month, 3 months, 6 months, 9 months and 12 months. Major cardiovascular adverse events (MACE) will be collected in all patients throughout the whole follow-up period. MACE is a composite of cardiac death, recurrent myocardial infarction, stroke, target lesion revascularization, major bleeding and unstable angina-induced rehospitalization.~Patients who do not meet the criteria after OCT imaging will be enrolled in registry cohort.~Blood sample will be obtained from artery sheath or coronary artery by aspiration catheter during the PCI procedure in selected sites. Blood samples will be stored at -80°C for potential biomarker test and multi-omics analysis.
This protocol describes a prospective, multi-center study intended to test the hypothesis that patients with STEMI caused by plaque rupture or plaque erosion without obstructive stenosis (diameter stenosis <70%) can be stabilized by effective antithrombotic treatment without stent implantation, thereby avoiding both early and late complications related to percutaneous coronary intervention (PCI) with stent implantation. All the patients will be followed by intracoronary OCT and physiological assessment at 1-month and 12-month follow-up.