B50-05 Silent Gene, Sudden Infarct: Prothrombin G20210A Mutation Revealed by an Exertional STEMI

Introduction ST-elevation myocardial infarction (STEMI) in younger patients without traditional atherosclerotic risk factors is uncommon. Inherited thrombophilias, such as the prothrombin G20210A mutation, may predispose to arterial thrombosis in such individuals. Heterozygosity for 20210G>A occurs in 1.7-3% of the General US and European population and 2.2% Hispanic Americans . While often linked to venous thromboembolism, this mutation can also contribute to acute coronary events but data is limited. We report a case of an exertion-related anterior STEMI in a relatively young patient with minimal risk factors, later found to have thrombotic occlusion of the mid-left anterior descending (mLAD) artery and first diagonal branch, attributed to prothrombin II mutation. Case Description A 47-year-old male with dyslipidemia and obstructive sleep apnea presented with sudden severe chest pain, diaphoresis, and nausea beginning two minutes into his routine stationary cycling. Upon arrival paramedics noted hypotension, managed with IV fluids in route to the emergency department (ED). Initial ECG showed no ST elevations but demonstrated hyperacute T waves in the anterior leads. Bedside echocardiography revealed significant anterior and apical wall hypokinesia. Given persistent pain and concerning ECG and echocargiographic findings, a STEMI code was activated, and the patient was taken for urgent coronary angiography.Catheterization revealed thrombotic occlusion of a large first diagonal branch, initially considered the culprit lesion. Further imaging showed the mLAD also occluded with thrombus and Thrombolysis in Myocardial Infaction (TIMI) 0 flow. The diagonal branch was treated with aspiration thrombectomy, achieving 0% residual stenosis. The mLAD was treated with aspiration thrombectomy, balloon angioplasty, and drug-eluting stent placement, with restoration of TIMI 3 flow. Due to his age and absence of major risk factors, a hypercoagulable workup was conducted, revealing heterozygosity for the prothrombin G20210A mutation. No other thrombophilic abnormalities or significant coronary atherosclerosis were identified. Discussion This case highlights an unusual presentation of anterior STEMI in a young individual with thrombotic occlusions and no significant coronary artery disease. The prothrombin mutation likely predisposed him to arterial thrombosis under exertional stress. Early identification of hyperacute T waves and bedside echocardiography were critical in prompt diagnosis and management. This case emphasizes the importance of considering inherited thrombophilias in young patients presenting with myocardial infarction without typical atherosclerotic risk profiles. References: 1. Kujovich JL. Prothrombin Thrombophilia. 2006 Jul 25 [Updated 2021 Feb 4]. In: Adam MP, Feldman J, Mirzaa GM, et al., editors. GeneReviews® [Internet]. Seattle (WA): University of Washington, Seattle; 1993-2025. Available from: https://www.ncbi.nlm.nih.gov/books/NBK1148/ This abstract is funded by: None