Inherited thrombophilia-related complications in the treatment of a biatrial thrombus.

The study emphasizes the importance of the high risk of thromboembolism with inherited thrombophilic factors. Transesophageal echocardiography revealed large biatrial masses in an 87-year-old woman with history of nonvalvular atrial fibrillation, pulmonary embolism, and prescribed oral anticoagulation for prophylaxis of embolic events. The surgical removal of the presumed thrombus was declined by the patient and intravenous anticoagulation with unfractionated heparin was initiated. Treatment was complicated by additional embolic events and the patient succumbed after 14 days due to multiple organ failure. Testing revealed heterozygosity for both the factor V Leiden and the methylenetetrahydrofolate reductase C677T mutations inducing resistance to activated protein C. The combination of these thrombophilic factors can probably explain the poor anticoagulant response, embolic events, and the failure of resolution of the biatrial masses.