Thrombosed mechanical heart valve prosthesis in the mitral position

Abstract

We read with interest recent reports of increased thrombotic episodes of the Carbomedics valve in the mitral valve position [1Rosengart T.K. O’Hara M. Lang S.J. et al.Outcome analysis of 245 Carbomedics and St Jude valves implanted at the same institution.Ann Thorac Surg. 1998; 66: 1684-1691Abstract Full Text Full Text PDF PubMed Scopus (29) Google Scholar, 2Chaudhuri N. Hickey M.S.J. Spyt T.J. An unexplained cluster of thrombosed bileaflet mechanical heart valve prostheses.Ann Thorac Surg. 1999; 67: 1542-1543Abstract Full Text PDF PubMed Google Scholar]. In a letter to the editor Chandhuri and associates describe a cluster of clotted Carbomedics valves in the mitral position. In our institution we have recently observed a similar cluster of clotted Carbomedics valves in the mitral position. Between January 1995 and December 1998, 79 Carbomedics valves and 74 St Jude valves were implanted in the mitral position. There were two perioperative mortalities in the St Jude group and three in the Carbomedics group. Before 1995 the St Jude valve was used exclusively. Of all the mitral valves implanted since 1995 there were seven thrombosed valves, all Carbomedics. Four patients were initially treated with thrombolytic therapy, 1 patient failed and recovered well after undergoing mitral valve replacement; and 3 others underwent surgery without thrombolytic therapy because of poor hemodynamics in 2 patients and a large clot in the third. Operative findings consisted of clots with no evidence of pannus formation or trapping of chorda. The clinical data is summarized in Table 1. Table 1Clinial Characteristics of Patients With Clotted Carbomedics Valves in the Mitral PositionPatientValve SizeRhythmINRInterval to ClottingTreatmentOutcome129Atrial fibrillation2.15 moStreptokinaseWell227NSR2.11 y 7 moStreptokinaseWell327NSR1.31 moStreptokinase surgeryWell425NSR2.43 moStreptokinaseDied after recurrent clotting527Atrial fibrillation1.88 moSurgeryWell627Atrial fibrillation> 62 y 6 moSurgeryWell725Atrial fibrillation2.32 y 3 moSurgeryWell Open table in a new tab All of the clotted valves except one had International Normalized Ratio less than 3. The time interval ranged from 1 month to 2 years 6 months. Initial therapy with thrombolytic agents in patients who were hemodynamically stable was successful in 3 of 4 patients; of these, only 1 patient had recurrent thrombosis. In addition, 1 patient with mitral valve replacement who received another Carbomedics valve and is doing well on follow-up. Because the same anticoagulant regimen is applied to all patients with mechanical valves, the greater incidence of clotting in the Carbomedics group valve may indicate a greater susceptibility to clotting whenever the INR in subtherapeutic. In select patients with clotted Carbomedics valves in the mitral position, initial thrombolytic therapy seems appropriate. Strict control of anticoagulation is necessary to avoid clotting events in the Carbomedics valve in the mitral position. Thrombosed mechanical heart valve prosthesis in the mitral position: replyThe Annals of Thoracic SurgeryVol. 70Issue 4Preview Full-Text PDF Thrombosed mechanical heart valve prosthesis in the mitral position: replyThe Annals of Thoracic SurgeryVol. 70Issue 4Preview Full-Text PDF