Thrombosis of Mechanical Mitral Valve Prosthesis Treated With Fibrinolysis

ABSTRACT

Background: Mechanical prosthetic valve thrombosis is an uncommon but serious complication associated with high mortality and morbidity. Conventionally, prosthetic valve thrombosis is treated with surgical intervention, but recent literature has shown that slow-infusion of low-dose fibrinolytic therapy could be of equal efficacy. Case A 27-year-old lady presented to the emergency department with a three-week history of worsening shortness of breath on background of mechanical mitral valve replacement for rheumatic mitral stenosis. She had recently been non-compliant with international normalised ratio (INR) checks for warfarin dosing in the setting of local lockdown for the COVID-19 pandemic. Transthoracic echocardiography revealed mechanical mitral valve thrombosis resulting in an immobile medial disc and severely restricted lateral disc, associated with severely elevated mitral inflow gradient (mean 42mmHg at 98 beats per minute) and severe pulmonary hypertension (right ventricular systolic pressure of 92mmHg). After discussion in a multidisciplinary cardiology and cardiothoracic surgical conference, the patient was treated with three daily doses of slow-infusion low-dose fibrinolytic therapy (25mg alteplase over six hours). On day three, there was complete resolution of symptoms, associated with resolution of valve thrombosis on repeat echocardiography. There were no bleeding or embolic complications, and the patient was discharged home three days later. Conclusions: This case highlights the utility of slow-infusion low-dose fibrinolytic therapy in the management of mechanical prosthetic valve thrombosis. This conservative approach may be a useful alternative in patients with high pre-operative surgical risk.