Sudden cardiac arrest due to a non-aneurysmal thrombus of the sinus of Valsalva: An unusual presentation of antiphospholipid syndrome

We present the case of a 56-year-old man who was transferred to the cardiac catheterization laboratory for an anterior ST-segment elevation acute myocardial infarction (STEMI). Coronary angiography revealed no culprit lesions in the coronary arteries. The patient subsequently evolved to in-hospital cardiorespiratory arrest due to refractory ventricular fibrillation, requiring extracorporeal cardiopulmonary resuscitation (ECMO-CPR). A thrombus located in the left sinus of Valsalva, in relation to the ostium of the left main coronary artery, without associated aneurysm or aortic pathology, was identified as the underlying cause. The patient was started on systemic anticoagulation, achieving a reduction in thrombus size. He subsequently made a complete recovery and was ultimately diagnosed with an antiphospholipid syndrome (APS) presenting as arterial thrombosis at an atypical location. Thrombosis of the sinus of Valsalva in the absence of structural aortopathy is a rare but potentially life-threatening entity, most commonly presenting as STEMI. A multimodal imaging approach is frequently required to confirm the diagnosis and to differentiate it from other conditions. Hypercoagulable disorders, including APS, represent the most frequent underlying cause. Evidence regarding the optimal treatment strategy is limited; appropriate anticoagulation is critical while the addition of thrombectomy may also be an option. • Initial presentation of antiphospholipid syndrome as a thrombus in the sinus of Valsalva without associated aortic pathology, resulting in obstruction of the ostium of the left main coronary artery. • Cardiorespiratory arrest successfully resuscitated with ECMO-RCP in a patient presenting with ST-segment elevation myocardial infarction due to left main coronary artery obstruction secondary to a thrombus in the sinus of Valsalva. • Multimodal imaging integration , including angiography, transesophageal echocardiography, and aortic computed tomography angiography, for the diagnosis of sinus of Valsalva thrombosis not associated with an aortic aneurysm. • Medical management with anticoagulation in a patient with antiphospholipid syndrome and arterial thrombosis at an atypical location, associated with hemodynamic compromise.