[Late thrombosis of mitral valve prosthesis in 27 cases].

Twenty seven cases of late thrombosis of ball and floating or tilting disc prostheses were studied. All patients were on anticoagulant therapy which appeared to be well adapted in 33% patients. Signs suggestive of thrombosis were inconsistant and the diagnosis was made on the association of severl of the following features: -- systemic embolism (44%); -- radiographic signs of left ventricular failure (51%); -- absence of opening click, variable A2 -- opening click intervals, apparition or aggravation of a systolic regurgitant murmur or a distolic murmur suggestive of obstruction on the phonocardiogramme; -- delayed opening of the mobile component or the presence of abnormal echos between the ball and anterior cage echo on the echocardiogramme; -- a gradient of over 12 mmHg across the prosthesis. An isolated episode of systemic embolism when the rest of the work-up is negative may be managed by the addition of a platelet antiaggregant and reinforcement of the anticoagulant therapy; further investigaton is advisable in the face of progressive symptoms. Fibrinolytic treatment and/or surgery is justified when systemic emboli recur or if the work-up is positive.