Divergent management of a distal left main coronary artery aneurysm presenting as non-ST-elevation myocardial infarction: surgical versus medical strategy in two cases: a case report

Abstract Background Left main coronary artery (LMCA) aneurysms are exceedingly rare, found in approximately 0.1% of coronary angiograms, and acute coronary syndromes are an uncommon first presentation. When the aneurysm involves the distal LMCA and its bifurcation, percutaneous covered-stent treatment is generally not feasible, leaving surgical and medical therapy as the only realistic options, with no controlled data to favour either. Case summary We report two male patients presenting with non–ST-segment elevation myocardial infarction (NSTEMI) and thrombosed distal LMCA aneurysms. Both patients were evaluated by a multidisciplinary heart team but received divergent therapeutic strategies. Case 1 (44-year-old male) underwent surgical revascularization with coronary artery bypass grafting (CABG) and aneurysm ligation following unsuccessful percutaneous recanalization of the left circumflex (LCx) artery. Case 2 (65-year-old male) declined surgery and was managed medically with intensive antiplatelet and anticoagulation therapy. Both remained asymptomatic during three months of follow-up. Discussion This case series underscores the diagnostic and therapeutic complexity of thrombosed distal LMCA aneurysms. Although surgical exclusion of the aneurysmal sac may, on anatomical grounds, be hypothesized to reduce the risk of recurrent thromboembolism, medical management remains a legitimate option in selected patients who decline or are unsuitable for surgery. The risk of recurrent thrombosis in medically managed patients remains incompletely characterized, and the short follow-up in our cases limits long-term conclusions. In the absence of randomized controlled trials, management decisions must be individualized through multidisciplinary heart team discussion, incorporating aneurysm size, morphology, thrombus burden, clinical presentation, and patient preferences.