High Risk of Recurrence in Renal Transplant Recipients after a First Episode of Venous Thromboembolism

Abstract number: P0456

Poli¹ D, Antonucci¹ E, Cecchi¹ E, Marcucci¹ R, Bolli¹ P, Zanazzi² M, Salvadori² M, Abbate¹ R, Gensini¹ GF, Prisco¹ D

¹¹Department of Medical and Surgical Critical Care, Thrombosis Centre, University of Florence; Azienda Ospedaliero-Universitaria Careggi, Florence, Italy ¹¹Department of Medical and Surgical Critical Care, Thrombosis Centre, University of Florence; Azienda Ospedaliero-Universitaria Careggi, Florence, Italy ²²UO Nefrologia e Trapianti Azienda Ospedaliero-Universitaria Careggi, Firenze, Italy

Renal transplantation is associated with an increased risk of venous thromboembolism (VTE). No data are available about the optimal duration of oral anticoagulant therapy (OAT) in renal transplant (RT) recipients. Our study was performed to evaluate the risk of VTE recurrence in patients developing a first episode of VTE after RT. We prospectively studied 28 RT recipients who had suffered from a first episode of VTE after stopping OAT (Group 1). Group 1 was compared with a group of 84 patients without history of renal disease who had suffered from a first episode VTE matched for age, sex and type of thrombotic event (Group 2) and with a matched group of 28 RT recipients without history of VTE (Group 3). After OAT withdrawal, thrombophilia (AT, protein C, protein S, prothrombin gene variant, factor V Leiden, homocysteinemia) and clotting activation markers (prothrombin fragment 1+2 (F1+2) and D-dimer plasma levels) were evaluated. During follow-up, 14/28 patients of Group 1 and 8/84 patients of Group 2 experienced VTE recurrence (P= 0.0001). As thrombophilia is concerned, no difference was found among the 3 groups, except for homocysteine. Hyperhomocisteinemia was found in 24/28 Group 1 patients, in 23/84 Group 2 patients (P < 0.000) and in 23/28 Group 3 patients (P= NS). No relationship was found among homocysteine, creatinine and Glomerular Filtration Rate in the 3 groups. F1+2 and D-dimer levels were significantly higher in Group 1 than in Group 2 and 3 (P= 0.000 and <0.05 respectively). In conclusion our data outline the presence of hyperhomocysteinemia and of hypercoagulability in RT patients, both alteration were more marked in RT patients with history of VTE. The high risk of VTE recurrence in these patients requires strategies for its prevention, taking into account either vitamin supplementation or prolonged OAT. The choice of long-term of OAT needs a careful risk/benefit evaluation, in the light of the high bleeding risk of RT patients.