A combined anti-thrombotic therapy for thrombosis of mitral prosthetic valves

Background For patients with prosthetic heart valves, thrombosis of the valves is dangerous. A second surgery for re-replacing the thrombosed valve is quite traumatic. There have been some researches on noninva-sive therapies for thrombosis of prosthetic heart valves. But the combined anti-thrombotic therapy including anti-coagulants and anti-platelet agents was seldom studied. Methods Fourteen patients suffered from throm-bosis of the mitral prosthetic valve with stable hemodynamics were studied retrospectively. Thrombosis of the valves was demonstrated by transesophageal echocardiography. All the patients were given a combined anti- thrombotic therapy with clopidogrel and warfarin during the whole treatment with close monitoring. Low molecular weight heparin （LMWH） was given twice a day during the first 5 days of further treatment in four inpatients. Transthoracic echocardiography was performed repeatedly to observe the function of the mitral prosthetic valves and changes of the thrombus. Results This study included 4 males and 10 females. In these patients, 13 suffered from thrombosis of the mechanical mitral valves, and one patient had thrombosis of the bioprosthetic mitral valve. After an average of 32.0 - 20.4 days＇ treatment, eleven （78.6%） patients＇ thrombi disappeared thoroughly with normalized valvular function, only three （21.4%） patients＇ thrombi still existed, but no deterioration of valvular functions. For the patients with successful treatment, sizes of the left atriums decreased after treatment （P = 0.01）. No significant changes of other chambers and left ventricular ejection fraction were observed （P 〉 0.05）. None experienced major bleeding except for two cases of mild subcuta- neous hemorrhage. Conclusions The combined anti-thrombotic therapy based on clopidogrel and warfarin （plus LMWH） is a feasible treatment of thrombosis of prosthetic heart valves under a close monitoring, for both inpatients and outpatients.