High Plasma Levels of Factor VIII and Factor IX Increased the Incidence of Recurrent VTE.

Abstract 5070

The aim of this study was to evaluate the diagnostic accurancy of the measurement of procoagulant factors FVIII and FIX levels and the risk of recurrence of venous thromboembolism (VTE). We have studied 56 patients (14 male, 42 female) with an objectively diagnosis of first deep vein thrombosis enrolled from February 2003 to February 2008, all patients were <60 years, without known malignancies, heart failure, chronic lung disease, infection, recent surgery, or genetic defects as Factor V Leiden (FV-Arg 506 Glu), prothrombin G20210A, deficiencies of Protein S or C or ATIII, hyperhomocysteinemia, dysfibrinogenemias; with increased levels of FVIII (>218 IU/dl), and FIX (>136 UI/dl). FVIII and FIX antigen levels were measured by ELISA. All patients received subcutaneous low molecular-weight eparin as thromboprophylactic treatment for the first 3 month after primary VTE, color Doppler ultrasonography (DUS) was performed periodically after primary VTE, the venous hemodynamic parameters studied included: blood flow velocity (cm/sec), vein cross sectional area (cm/2) blood volume flow (ml/sec), and microvascular injury was evaluated. Our studies have confirmed that a markedly elevated plasma levels of FVIII >256 IU/dl (range 218-294), and FIX >164IU/dl (range 136-192) among the patients with first episode of VTE are independent predictors of early recurrence about 52-74%: these patients have increased fibrin formation, D-Dimer levels (234.6ng/ml), and blood rheologic variables such as plasma viscosity are still present in all patients: plasma viscosity mPa/s shear rate >1.98 and blood viscosity mPa/s shear rate >3.48 especially under low shear conditions. These factors show to be associated with VTE and above all with the recurrence (54 patients), and emerged as relatively independent of other thrombophilic factors. The higt risk of VTE recurrence in these patients requires strategies for its prevention: secondary prophylaxis with the administration of standard oral anticoagulant at moment the use of coumarins (INR: 2.0-3.0) and possibly the need for prolonged, probably life-long treatment.