Catastrophic Antiphospholipid Syndrome

BACKGROUND: Antiphospholipid syndrome (APS) is an uncommon cause of ST-segment elevation myocardial infarction (STEMI) in patients without traditional cardiovascular risk factors. CASE SUMMARY: A 50-year-old man with 1 week of urticaria presented with acute abdominal pain and inferior STEMI. Coronary angiography revealed thrombotic occlusion of the right coronary artery posterolateral branch with minimal atherosclerosis, treated with balloon angioplasty and thrombectomy. Despite reperfusion, he developed progressive mesenteric ischemia, left renal infarction, and right cerebellar infarction. Transesophageal echocardiography demonstrated a mobile aortic valve echodensity concerning for nonbacterial thrombotic endocarditis. Laboratory testing revealed triple-positive antiphospholipid antibodies, concerning for catastrophic APS. He underwent multiple laparotomies with superior mesenteric artery thrombectomy and resection of necrotic jejunum, surviving with anticoagulation and multidisciplinary care. DISCUSSION: This case illustrates an arterial-predominant presentation of catastrophic APS initially manifesting as STEMI. Multiterritory arterial thromboses in patients without atherosclerotic disease should prompt evaluation for systemic thrombophilia. TAKE-HOME MESSAGE: Early anticoagulation and multidisciplinary intervention are essential to prevent ischemic complications.