D-dimer, FVIII and thrombotic burden in the acute phase of deep vein thrombosis in relation to the risk of post-thrombotic syndrome

Post-thrombotic syndrome (PTS) is the most common complication of deep vein thrombosis (DVT), but few data are available on the risk factors for PTS.To assess whether the time-course of D-dimer, FVIII, and thrombotic burden are related to PTS development.Patients (n=59) with proximal DVT of the lower limbs (age 64; range:20-88years; male 56\%) were enrolled on the day of diagnosis (D0) and all received heparin for 5-7days, overlapped and followed by vitamin K antagonists (VKA) for 3months. Whole-leg compression ultrasound examination was conducted on D0 and 7 (D7), 30 (D30), and 90 (D90) days afterwards, when blood samples were also taken for D-dimer (STA Liatest) and FVIII (chromogenic assay) testing. Thrombotic burden was defined at each time point according to a score, which considered thrombosis extent and occlusion degree. Villalta score was evaluated at D30, D90, and D180.At D90, 12 patients developed PTS (Villalta score ≥5) and the median Villalta score was 1 (IQR 0.3-3.0) and was not correlated with either D-dimer or FVIIII time course. At D180, 13 patients had PTS and they had similar thrombotic score at D0, D30 to those without PTS, but higher at D90 (7.6±5.1 vs. 3.2±3.6; p=0.011). Thrombotic score at D90 was correlated with Villalta score at D90 (rho=0.374, p=0.009) and at D180 (rho=0.436, p=0.006).Thrombotic burden after 90days of VKA is correlated with PTS