High rate of recurrence in renal transplant recipients after a first episode of venous thromboembolism

Background. No data are available about the optimal duration of oral anticoagulant therapy (OAT) after an episode of venous thromboembolism (VTE) occurring in renal transplant (RT) recipients. Our study was undertaken to evaluate the risk of VTE recurrence in patients developing a first episode of VTE after RT. Methods. Among 484 RT patients, 34 (7%) developed a first VTE: 28/34 VTE patients (Group 1) were prospectively studied, after stopping OAT. Group 1 was compared with a group of 84 patients without history of renal disease who had suffered from a first episode of VTE matched for age, sex and type of thrombotic event (Group 2) and with a matched group of 84 RT recipients with no history of VTE (Group 3). After OAT withdrawal, blood samples were obtained for thrombophilia and clotting activation markers (prothrombin fragment 1+2 (F1+2) and D-dimer plasma levels). Results. During follow-up, 14/28 patients of Group 1 and 8/84 patients of Group 2 experienced VTE recurrence (P<0.0005). Homocysteine, F1+2 and D-dimer plasma levels were significantly higher in Group 1 than in Group 2 and 3 (P<0.0001 and <0.05 respectively) for all the three parameters. Conclusions. Our data outline the high risk of VTE recurrence in RT recipients. Strategies for VTE recurrence prevention are needed; Prolonged OAT, in spite of the high bleeding risk of RT patients, should be considered in this respect. Copyright © 2005 by Lippincott Williams & Wilkins.