An Uncommon Cause of Acute Coronary Syndrome: The Essence of a Broad-Minded Approach

Acute coronary syndrome(ACS) can occur due to various mechanisms like plaque rupture, plaque erosion, vasospasm and embolism. Identifying the exact mechanism of ACS is vital for appropriate management and to prevent inappropriate interventions. A 42-year-old female with no comorbidities presented with acute onset chest pain. Electrocardiogram showed sinus rhythm with ST depression in V4 to V6. Trop-T was positive. Patient was diagnosed with non-ST-elevation ACS. Echocardiography revealed rheumatic heart disease(RHD) with severe mitral stenosis(MS)/moderate mitral regurgitation (MR). Coronary angiogram revealed total occlusion of distal circumflex artery (LCX) at the level of 2nd obtuse marginal(OM2) with total occlusion of terminal obtuse marginal(OM) plus organized clot in left anterior descending artery. Absence of coronary artery disease risk factors and presence of severe MS raised suspicion of coronary embolism. Subsequently, trans-oesophageal echocardiography showed a clot in left atrial appendage. Patient was continued on parenteral anticoagulation. After a week, repeat coronary angiogram showed improvement of blood flow in distal LCX and OM2. MRI brain showed chronic lacunar infarcts in bilateral cerebellar hemispheres and corona radiata, indicating previous silent cerebral embolism. Patient was started on warfarin and discharged. Repeat angiogram after 6 weeks showed complete resolution of OM2 occlusion, distal LCX occlusion as well terminal OM occlusion, hence confirming coronary embolism as the cause of ACS. This case highlights the need for a good clinical sense and a broad minded approach as it can avoid unnecessary intervention with associated complications of the procedure as well as long term dual antiplatelet therapy.