Thrombosis of mechanical prosthetic heart valves – problems of diagnosis and treatment

The main causes of mechanical valve dysfunction are: 1) thrombosis; 2) fibrous ingrowth of pannus; 3) infective endocarditis. Clinical and diagnostic criteria for identifying the cause of prosthesis dysfunction include the timing and rate of development of dysfunction, the presence of signs of systemic inflammation (CRP, rheumatoid factor, positive blood culture) or, conversely, insufficient anticoagulation and thrombosis (low INR, increased levels of D-dimers). Current methods of treating prosthetic thrombosis include: 1) optimization of anticoagulant therapy; 2) thrombolysis; 3) transcatheter manipulations; and 4) surgical valve replacement. A comparative description of surgical and thrombolytic methods of restoring valve function is given. Previously the main method of treating obstructive thrombosis was repeated surgery. However, thanks to modern advances in pharmacology, the relevance of drug thrombotic therapy for prosthetic valve dysfunction is increasing. For instance, the 2020 American College of Cardiology/American Heart Association guidelines suggest an alternative approach to these techniques depending on clinical factors, degree of valve obstruction, comorbidities, and hemodynamic status of the patient. Factors influencing the choice of management method for patients with prosthetic valve thrombosis are highlighted. The material is illustrated by a case of successful thrombolysis in a patient with thrombosis of the aortic and mitral valves.