Mechanical Mitral Valve Prosthesis Thrombosis: A Case Report

Introduction Prosthetic valve thrombosis (PVT) is a life-threatening complication following heart valve replacement surgery [1]. Mechanical valves are more thrombogenic than bioprosthetic valves. The annual rate of mechanical valve thrombosis ranges from 0.1% to 5.7% [2]. Case Presentation A 56-year-old male presented with severe shortness of breath, which only decreased when he sat down. In 2012, the patient was diagnosed with rheumatic heart disease, which led to mitral valve (MV) stenosis and third-degree MV prolapse. Therefore, a mechanical MV prosthesis was implanted. Laboratory tests showed a significant increase in NT-proBNP (6223 pg/ml). Additionally, therapeutic hypocoagulation was not achieved, as the INR was 0.97. Suspecting MV dysfunction, a transthoracic echocardiogram was performed, revealing decreased systolic function of the left ventricle due to dyssynchronous contraction and tachysystolic atrial fibrillation. The left atrium was significantly enlarged, and blood flow velocity through the MV prosthesis significantly increased. It was decided to initiate ultraslow thrombolysis with alteplase. After thrombolytic treatment, there was a significant improvement in the patient's clinical condition, and sinus rhythm was restored. The function of the mechanical valve prosthesis normalized, and the patient was discharged from the hospital. Discussion PVT clinical manifestations can vary from severe conditions, such as acute heart failure, to milder symptoms like reduced exercise tolerance, fatigue and shortness of breath [3]. The treatment strategy for mechanical PVT is controversial due to the lack of randomized controlled trials. The most recent American College of Cardiology/ American Heart Association guidelines recommends low-dose ultraslow or slow systemic intravenous fibrinolytic treatment [4]. However, the European Society of Cardiology guidelines prioritize surgery [5]. Conclusions Managing PVT poses significant challenges, primarily due to the similarities in clinical features across various diagnoses and the lack of randomized controlled trials comparing different treatment methods. Ultraslow infusion of alteplase can be a life-saving therapy and an important strategy to prevent the necessity for high-risk, repeated surgeries.