Anticoagulation for Mechanical Aortic Valve in a Patient With Aortic Dissection and Pulmonary Hemorrhage: A Case Report.

Acute aortic dissections are considered surgical emergencies because they are catastrophic bleeding events. The risk of bleeding is further increased if the patient requires anticoagulation for other comorbidities, such as a mechanical heart valve.  This case study describes a 73-year-old gentleman who presented with massive hemoptysis due to an acute aortic dissection complicated by pulmonary hemorrhage in the context of previous aortic dissection with multiple repair surgeries and residual chronic aortic dissection. He was also on warfarin for a mechanical aortic valve complicated by supratherapeutic international normalized ratio. His acute aortic dissection was treated conservatively without surgery, and he survived. Concerning the risk of thromboembolism from the mechanical aortic valve, anticoagulation was reintroduced one week after his initial bleeding. We changed warfarin to enoxaparin, which was started at a small dose, 40 mg subcutaneously once a day, then gradually increased to the full therapeutic dose, 90 mg (1 mg/kg) twice daily over a week. He was not fully anticoagulated for two weeks. Fortunately, he did not develop any thrombosis. Hemoglobin and Factor Xa levels were closely monitored. He tolerated the enoxaparin without further bleeding.  This type of case is rare and has not been previously reported, considering the patient survived acute aortic dissection with conservative management, did not develop any thrombosis from the mechanical aortic valve when anticoagulation was withheld, and did not experience rebleeding when anticoagulation was restarted. Further research and guidelines are needed to assist clinicians in managing anticoagulation when facing the dilemmas of the risk of bleeding and the risk of thromboembolism. This is particularly important in complex scenarios, such as for patients with mechanical heart valves who subsequently develop contraindications such as aortic dissection or other life-threatening bleeding events.