Multicenter Trial of Antithrombotic Strategies in Acute Coronary Syndrome With Coronary Artery Ectasia

Inclusion Criteria: * Adults aged 18 to 80 years, of either sex, hospitalized with acute coronary syndrome (ACS) with or without ST-segment elevation. * Recent ACS within 7 days prior to enrollment, defined by all of the following: * Clinical presentation consistent with acute coronary syndrome. * Elevated high-sensitivity cardiac troponin above the 99th percentile. * Presence or absence of persistent ST-segment elevation. * Coronary artery ectasia in the culprit coronary artery, defined by all of the following: * The presence of ectasia will be determined by agreement of two expert interventional cardiologists, and will be confirmed by quantitative coronary angiography (QCA). * Identification of a culprit artery consistent with the electrocardiographic territory involved (in cases with ST-segment elevation) or with angiographic features suggestive of an atherothrombotic event, such as the presence of thrombus or reduced coronary flow. * Hospital admission lasting more than 24 hours. * Management with either percutaneous coronary intervention or medical therapy, as determined by the treating medical team. Intracoronary interventions such as stent implantation, balloon angioplasty, or thrombus aspiration are permitted. * Ability and willingness to provide written informed consent and to participate in the study. Exclusion Criteria: * Pregnant women. * Current indication for temporary or long-term anticoagulation therapy at the time of enrollment. * Severe chronic kidney disease, defined as KDIGO stage G4 or higher (estimated glomerular filtration rate \[eGFR\] \<30 mL/min/1.73 m²). * Estimated glomerular filtration rate (eGFR) \<30 mL/min/1.73 m² at hospital discharge. * History of major bleeding, active bleeding, or high bleeding risk, including but not limited to gastrointestinal bleeding, intracranial hemorrhage, or other conditions considered by the treating physician to confer a high risk of bleeding. * Advanced heart failure, defined as left ventricular ejection fraction (LVEF) \<30% plus at least one of the following: * More than two hospitalizations or unplanned emergency department visits for heart failure in the past year, or * NYHA functional class III or IV symptoms despite optimal medical therapy at enrollment or within the previous 3 months.