Mechanical Aortic Valve Thrombosis with Heart Failure Successfully Treated with Oral Anticoagulation: A Case Report

Abstract

Background:The use of anticoagulation is mandatory for prevention of prosthetic valve thrombosis (PVT) worldwide, regardless of the valve type or position in the heart. In case a thrombosis causes symptomatic dysfunction, treatment usually includes the use of thrombolytic therapy or surgery. We report a case of PVT involving a patient with a mechanical aortic valve which was treated entirely with the use of anticoagulation therapy (warfarin). Case Presentation: A 58-year-old man had an aortic valve replacement using a Carbomedics ® mechanical valve due to severe aortic stenosis as a result of a calcific bicuspid native aortic valve. He was commenced on warfarin after surgery which was continued thereafter. He presented to our hospital after three years with shortness of breath at rest. On clinical examination, his condition was poor with a New York Heart Association functional classification of IV. He was in sinus rhythm and had an enlarged heart shadow on chest X-ray. Transesophageal echocardiography (TEE) revealed aortic valve regurgitation with vegetations on the anterior valve leaflet causing reduced hemi leaflet motility and a mean pressure gradient of 50 mmHg. Cinefluoroscopy revealed a dysfunctional mechanical valve leaflet. Surgery was at high risk of mortality due to the patient's clinical status and he was continued on warfarin therapy with close monitoring. Cinefluoroscopy and echocardiography done six months later revealed complete dissolution of thrombus and a normally functioning mechanical aortic valve. Conclusion: Only a few cases of symptomatic, thrombotic mechanical aortic valve were entirely treated with anticoagulation only. Our patient is one such case who had resolution of symptoms and improvement on NYHA functional classification (IV to I).

Warfarin and Thrombotic Mechanical Aortic Valve – Be Cautious to Avoid Severe Warfarin Drug Interactions in Patients with Suspected Infective Endocarditis after Mechanical Aortic Valve Replacement [Letter]

“…However, achieving a therapeutic level of anticoagulation was difficult despite escalating doses of warfarin, even a 5- to 6-fold increase in warfarin dose was insufficient to maintain the international normalized ratio (INR) in the therapeutic range. 2 Similarly in this case, 1 the patient had recurrent sub-therapeutic INR readings of 1.2–1.8 despite warfarin dosage adjustment. Furthermore, an excessively high INR would be observed after rifampin discontinuation due to the disappearance of enzyme induction.…”

“…We read with great interest the case report presented by Ababneh et al, 1 which shows a patient with mechanical aortic valve thrombosis and heart failure was entirely treated with warfarin. We especially appreciate their successful experiences.…”