Factors Predicting Development of Post-thrombotic Syndrome in Patients with a First Episode of Deep Vein Thrombosis: Preliminary Report

ObjectiveTo investigate the indicative parameters reflecting the progression of post-thrombotic syndrome (PTS) in patients with a first episode of deep vein thrombosis (DVT).Design and methodsThe patients’ initial risk factors were assessed at presentation. Venous occlusion, and reflux and reflux parameters were evaluated at 6 months using venous duplex scanning. Near-infrared spectroscopy (NIRS) was also used to measure calf muscle deoxygenated haemoglobin levels at 6 months. Clinical manifestations were categorised using the clinical, etiologic, anatomic and pathophysiologic (CEAP) classification for chronic venous insufficiency (CVI), and the patients were divided into those having no PTS (C0–3S,Es,As,d,p,Pr,o) and those having PTS (C4–6S,Es,As,d,p,Pr,o).ResultsOf the 121 patients evaluated, 25 (21%) developed PTS with a mean follow-up period of 66 months. At initial presentation, ilio-femoral DVT (odds ratio (OR) 3.4, 95% confidence interval (CI) 1.4–8.6) was associated with development of PTS. At 6 months, venous occlusion combined with reflux (OR 4.4, 95% CI 2.9–20.7), peak reflux velocity >29.7 cm s−1 (OR 13.7, 95% CI 4.1–45.7) and mean reflux velocity >8.6 cm s−1 (OR 4.4, 95% CI 1.5–12.9) in the popliteal vein detected by duplex scanning were strong predictors of PTS. NIRS-derived retention index >3.5 was the strongest predictor of PTS at 6 months (OR 67.4, 95% CI 14.3–318.1).ConclusionsIlio-femoral DVT is associated with the development of PTS at initial presentation. By contrast, occlusion and reflux, high reflux velocity in the popliteal vein and increased NIRS-derived retention index are important time-course predictors of PTS progression.