Posttreatment ultrasound-detected residual venous thrombosis: a risk factor for recurrent venous thromboembolism and mortality

PURPOSE OF REVIEW: The cumulative risk of recurrent venous thrombosis may rise to 30% over 8 years. Extended oral anticoagulation is effective but major bleeding is increased. To balance these risks attention has focused on identifying patients with the highest likelihood of recurrence for whom continued therapy is most beneficial. Another issue of interest has been the increased probability of death after venous thrombosis, due primarily to malignancy but also to vascular disease. RECENT FINDINGS: Unprovoked events and cancer are known to be associated with recurrent thrombosis. Residual posttreatment thrombosis confirmed by compression ultrasound is regarded as another risk for recurrence. Confounders in the published studies are the patient mix and the ultrasound technique employed. Other variables such as gender and D-dimer may also predict risk. Although arterial disease is increased in patients with venous thromboses, the association between idiopathic venous thromboembolism and atherosclerosis remains circumstantial. SUMMARY: There are no validated approaches for predicting recurrent venous events. Ultrasound interrogation for residual thrombosis after primary therapy may improve treatment stratification by defining patients suitable for extended anticoagulation.