Background: Prosthetic valve thrombosis is a rare but serious complication of valve replacement; it occurs more often in mechanical valves, but it can also be observed in bioprosthesis. It is associated with significant morbidity and mortality, thus the necessity of a prompt diagnosis and adequate treatment.
Case description: A 81-years-old woman presented to the ED for progressive worsening dyspnoea and abnormal heart beat. She had undergone mitral plasty some years before and, few months before the access, a new cardiac surgery had been performed with implantation of a mitral bioprosthetic valve, tricuspid annuloplasty and LAA closure. After discharge she had been hospitalized for genitourinary tract infection, and twice for heart failure and atrial flutter. During this period, the anticoagulant therapy had to be modified for difficult warfarin management, and, after an appropriate period, had been switched to NOAC. At the admission to our ICU, the patient presented pulmonary oedema and transthoracic echocardiogram showed mitral prosthetic valve dysfunction with thicked and ipomobile leaflets and increased transvalvular gradient. In the suspect of IE empiric antibiotic therapy was introduced; UFH and inotropic support was also administered. The patient promptly undergone to TOE, that confirmed the severe thickening of the bioprosthetic valve leaflets resulting in severe stenosis, rising thus the suspect of bioproshetic thrombosis, that was found to be extended to inferior and superior vena cava. Despite the ongoing therapy, the patient hemodynamic kept worsening, and in the end fibrinolytic therapy was administered with rapid improvement in clinical conditions and bioprosthetic transvalvular gradient fall. During the following hospitalization the patient clinical and hemodynamical status kept recovering, and a new TOE confirmed the almost complete resolution of the thrombosis. The patient was then shift again to warfarin and discharged; during the hospitalization IE was excluded. A TOE performed after one month of oral anticoagulation confirmed the regular function of the mitral bioprosthesis.
Conclusion: This case shows a subtle but life-threatening case of prosthetic valve thrombosis and underlines the importance of searching for this condition even in biological prosthetic valves. It also shows the role of TOE in the diagnosis and management, and lets some questions open about anticoagulation therapy.
