A Randomised Controlled Trial of Extended Anticoagulation Treatment Versus Standard Treatment for the Prevention of Recurrent VTE and Post-thrombotic Syndrome in Patients Being Treated for a First Episode of Unprovoked VTE (The ExACT Study)

Venous thromboembolism (VTE) is prevalent and impactful, with a risk of death, morbidity and recurrence. Post thrombotic syndrome (PTS) is a common consequence and associated with impaired quality of life (QoL). The ExACT study was a non-blinded, prospective, multi-centred RCT comparing extended versus limited duration anticoagulation following a first unprovoked VTE (Proximal DVT or PE). Adults were eligible if they had completed ≥3 months anticoagulation (remaining anticoagulated). The primary outcome was time to first recurrent VTE from randomisation. The secondary outcomes included PTS severity, bleeding, QoL and D-dimers. 281 patients were recruited, randomised and followed up for 24 months (mean age 63, Male:Female 2:1). There was a significant reduction in recurrent VTE for patients receiving extended anticoagulation (2.75 vs 13.54 events/100 patient years, aHR 0.20(95%CI:0.09 to 0.46, p<0.001)) with a non-significant increase in major bleeding (3.54 vs 1.18 events/100 patient years, aHR 2.99(95%CI:0.81 to 11.05,p=0.10)). PTS and QoL outcomes were no different between groups. D-dimer results (on anticoagulation) did not predict VTE recurrence. In conclusion, extended anticoagulation reduced VTE recurrence but did not reduce PTS or improve QoL and was associated with a non-significant increase in bleeding. Results also suggest very limited clinical utility of D-dimer testing using a standard cut off on anticoagulated patients.