Prospective Studies on Diagnosis, Prevention, and Management of Deep Vein Thrombosis (DVT), DVT Recurrence and the Post-Thrombotic Syndrome (PTS): From Concept to Study Design in the Primary Care Setting

The requirement for a safe diagnostic strategy of deep vein thrombosis (DVT) should be based on an overall objective post incidence of venous thromboembolism (VTE) of less than 1% during 3 months follow-up. Compression ultrasonography (CUS) of the leg veins has a negative predictive value (NPV) of 97% to 98% indicating the need of repeated CUS testing within one week. A sensitive ELISA VIDAS safely excludes DVT and VTE with a NPV between 99 and 100% when the clinical score is low to zero. The combination of low clinical score and a less sensitive D-dimer test (Simply Red or Simplify) is not sensitive enough to exclude DVT and VTE in routine daily practice. From prospective clinical research studies it may be concluded that complete recanalization within 3 months and no reflux is associated with a low or no risk of PTS obviating the need of MECS 6 months after DVT. Partial and complete recanalization after 3 to more than 12 months is usually complicated by reflux due to valve destruction and symptomatic PTS. Reflux seems to be a main determinant for not only for PTS and but also for DVT recurrence, the latter as a main contributing factor in worsening PTS. This hypothesis is supported by the relation between the persistent residual vein thrombosis (RVT=partial recanalization) and the risk of VTE recurrence in prospective studies. Absence of RVT at 3 months post-DVT and no reflux is predicted to be associated with no recurrence of DVT (1.2%) during follow-up obviating the need of wearing medical elastic stockings and anticoagulation at 6 months post-DVT. The presence of RVT at 3 months post-DVT with reflux after 6 months post-DVT is associated with both symptomatic PTS and an increased risk of VTE recurrence in about one third in the post-DVT period after regular discontinuation of anticoagulant treatment. To test this hypothesis we designed a prospective DVT and PTS Bridging the Gap Study by addressing at least four unanswered questions in the treatment of DVT and PTS. Which DVT patient has a clear indication for long-term compression stocking therapy to prevent PTS after the initial anticoagulant treatment in the acute phase of DVT? Is 3 months the appropriate point in time to determine candidates at risk to develop DVT recurrence and PTS? Which high risk symptomatic PTS patients need extended anticoagulant treatment? Patients with acute ileo femora DVT are at very high risk of PTS and candidate for cather-directed thrombolysis followed by anticoagulation.