Thrombus in Transit across a Patent Foramen Ovale

: This case report describes a 67-year-old woman with atrial fibrillation who was admitted for an acute ischemic stroke days after withholding apixaban for a colon polypectomy. She suddenly developed hypoxemia and shock; CT pulmonary angiography revealed bilateral pulmonary emboli and a large thrombus straddling a previously unknown patent foramen ovale (PFO). Transthoracic echocardiogram confirmed the thrombus extending from the right atrium to the left atrium. Due to high procedural risk, anticoagulation with heparin was initiated. Four days later, the patient experienced new cerebellar infarcts and hemorrhagic transformation of the original stroke, prompting cessation of anticoagulation. Anticoagulation was resumed on day 20, and she was discharged to a rehabilitation facility 15 weeks later. This case illustrates paradoxical embolism risk from thrombus-in-transit through a PFO and highlights challenges in managing anticoagulation after embolic stroke and intracranial hemorrhage.

: This case report describes a 67-year-old woman with atrial fibrillation who was admitted for an acute ischemic stroke days after withholding apixaban for a colon polypectomy. She suddenly developed hypoxemia and shock; CT pulmonary angiography revealed bilateral pulmonary emboli and a large thrombus straddling a previously unknown patent foramen ovale (PFO). Transthoracic echocardiogram confirmed the thrombus extending from the right atrium to the left atrium. Due to high procedural risk, anticoagulation with heparin was initiated. Four days later, the patient experienced new cerebellar infarcts and hemorrhagic transformation of the original stroke, prompting cessation of anticoagulation. Anticoagulation was resumed on day 20, and she was discharged to a rehabilitation facility 15 weeks later. This case illustrates paradoxical embolism risk from thrombus-in-transit through a PFO and highlights challenges in managing anticoagulation after embolic stroke and intracranial hemorrhage.