30th May 2026

Aetiology & Pathophysiology

UA is caused by a non-occlusive thrombus on a ruptured atherosclerotic plaque, leading to partial obstruction of the coronary artery and myocardial ischemia without infarction. The severity of symptoms is determined by the degree of ischemia, collateral circulation, and comorbidities. Key features include plaque rupture at thin-cap regions and thrombus formation that is typically non-occlusive.