Thromboembolic NSTEMI from a 9.4 × 7.3 mm mid-left circumflex artery aneurysm with a zero calcium score and non-obstructive coronary arteries

Introduction: Coronary artery aneurysms (CAAs) are uncommon and can cause acute coronary syndromes due to thromboembolism despite the absence of obstructive coronary disease. Case description: We report the case of a 51-year-old patient with hypertension and hypercholesterolemia with the chief complaint of chest pain and elevated troponin, which is typical of non-ST-segment elevation myocardial infarction (NSTEMI). Coronary angiography showed non-obstructive coronary arteries and a calcium score of 0 with 9.4 × 7.3 mm middle-left circumflex artery aneurysm with thrombosis. Thrombus aspiration was effectively done without stenting. The patient was treated using dual antiplatelet therapy and statin therapy, and clinical improvement was achieved. The case in point demonstrates an infrequent pathophysiology of NSTEMI due to thromboembolism in a tiny aneurysm without severe atherosclerosis. Multimodality imaging was essential for diagnosis. Management was conservative. Transthoracic echocardiography revealed mild left ventricular hypertrophy with inferior hyperkinesia along with preserved ejection fraction. The patient was hemodynamically stable throughout hospitalization and was discharged on optimal medical therapy having no recurrent symptoms. Conclusion: NSTEMI may be caused by small CAAs through thromboembolism even though the coronary artery calcium score is zero. Personalized care (thrombus aspiration and optimal medical therapy) can yield excellent outcomes. LEARNING POINTS: A non-ST-segment elevation myocardial infarction can occur in the absence of obstructive coronary disease because of thromboembolism from a small coronary aneurysm, even with a coronary artery calcium score of zero.Multimodality imaging is crucial for precise diagnosis along with management of coronary artery aneurysms.Conservative management with thrombus aspiration along with medical therapy may be effective in selected patients.