[A case of valve thrombosis of CarboMedics prosthesis four years after mitral valve replacement: relationship of anticoagulant therapy to coagulation and fibrinolysis activating factors]

Abstract

A 50-year-old man experienced acute heart failure four years after initial mitral valve replacement (MVR) for left atrial thrombosis using a CarboMedics prosthesis, despite satisfactory coagulation control with warfarin. After initial MVR, late cardiac tamponade occurred twice and left circumflex branch stenosis was treated with percutaneous transluminal coronary angioplasty (PTCA). Re-MVR with an Edwards-TEKNA valve was performed after echocardiography and cineradiography showed mitral valve thrombosis, with thrombi on both mitral valve leaflets and covering most of the left atrial wall. Post-surgery progress was favorable with warfarin and dipyridamole therapy. After six weeks cardiac catheter revealed complete right external iliac artery occlusion. Cardiac dysfunction and atrial flutter apparently accelerated thrombosis after a common cold activated coagulation. Cardiac tamponade, circumflex branch stenosis, and right external iliac artery occlusion occurred despite satisfactory coagulation control by warfarin. Warfarin suppresses some coagulation factors but cannot always correct hypercoagulability. Two months after re-MVR, coagulation tests showed normal TT, F1 + 2, and D-Dimer but an increase in TAT, suggesting involvement of additional coagulation factors. After artificial valve replacement, therapy should achieve a PT-INR level of 3.0-4.5, with close follow-up using other indices of fibrinolysis and coagulation activity in addition to TT.