Acute left main coronary artery thrombosis as the first manifestation of systemic lupus erythematosus and catastrophic antiphospholipid syndrome.

Most coronary events in young adults are related to atherosclerosis; however, approximately 20% of coronary heart disease in young adults is related to nonatherosclerotic factors such as coronary abnormalities, connective tissue disorders, and autoimmune diseases. Different initial manifestations of systemic lupus erythematosus (SLE) and antiphospholipid syndrome (APS) have been reported. Myocardial infarction is observed in patients with SLE in all age groups; it appears during the course of the disease; and it is unusual in the APS. We present a unique case of a 28-year-old young man previously healthy who has an ST-elevation myocardial infarction by total acute thrombosis of the left main coronary artery. Laboratory studies demonstrated the presence of antibodies for SLE and APS. The patient was treated successfully with percutaneous coronary intervention. He developed catastrophic APS despite an adequate anticoagulation and was treated with intravenous steroids and plasmapheresis. Clinical evolution was satisfactory, and he discharged from the hospital. This case highlights the importance of considering in the emergency department, the prothrombotic states such as SLE and APS in young patients presenting with acute myocardial infarction caused by an unexplained intracoronary thrombosis. Early diagnosis of catastrophic APS and aggressive therapies are essential to help such patients from succumbing to this potentially fatal condition.