Conservative management of a biological mitral valve thrombosis in a patient with recent covid19 infection

Abstract Prosthetic valve thrombosis is defined as the presence of non–infectious material, within the valve apparatus, that interferes with the normal function of the prosthesis itself. The rate of thrombosis is normally higher in patients with mechanical valves respect to those with a biological valve. It is a potentially fatal complication of valve replacement surgery. Treatment options include: surgery, fibrinolysis, and anticoagulant therapy; those depending on multiple factors: position of the valve, thrombotic burden, surgical risk, clinical presentation and patient‘s wishes. Complications of SARS–CoV2 infections can also extend beyond the respiratory system, triggering sometimes a systemic pro–inflammatory and pro–thrombotic state with potential cardiovascular complications. We present the case of a 74–year–old man with a mitral bioprosthetic valve (Carpentier–Edwards n29) and an aortic bioprosthesis valve (Carpentier–Edwards pericardial n27) taking anticoagulant therapy (Apixaban) for previous episodes of atrial fibrillation. One year after the surgery, the patient was affected by COVID19 infection characterized by fever and asthenia lasting for about 14 days. Subsequently, he experienced exertional dyspnea with a mitral valve thrombosis (25 mm) as echocardiographic finding and with pulmonary hypertension (PAPs 50 mmHg). After a multidisciplinary team discussion, once signs of peripheral embolization had been ruled out and considering NOAC therapy, it was decided to modify the therapy with low–molecular heparin and subsequently with Warfarin (INR 2.5–3.5). Four days later during a follow–up examination, was observed the improvement of dyspnoea and flow parameters and the reduction of thrombus size (21 mm) without any sign of embolic complications. Considering clinical stability in the following period, it was decided to continue with the same therapy. Subsequent checks showed an unchanged echocardiographic examination with same thrombus dimensions. In order to verify echocardiographic findings, a cardiac CT was performed which confirmed the presence of hypodense material compatible with thrombus formation (11 mm by 15 mm) on the mitral prosthesis.