Clinical scores to predict recurrence risk of venous thromboembolism

Venous thromboembolism (VTE) is a common and chronic disease with a considerable risk of recurrence. Patients with unprovoked (in the absence of a transient risk factor) VTE have a recurrence risk as high as 30% within five years after cessation of anticoagulation. Depending on patient selection the case-fatality rate of recurrence ranges between 3.6%-10%. Thus, indefinite anticoagulation treatment should be considered in these patients. However, anticoagulation confers a considerable risk of bleeding (fatal bleedings 0.1%-0.5%/year). It is therefore of utmost clinical importance to identify those patients, who will not benefit from indefinite anticoagulation, i.e. patients, in whom the bleeding risk during anticoagulant treatment is higher than the risk of recurrence. Several attempts to discriminate patients with a high from those with a low risk of recurrence including screening for acquired and inherited thrombotic risk factors or measurement of coagulation activation markers have either failed (thrombophilia screening) or were of moderate success (stratification according to D-dimer only). A novel approach for assessing risk of recurrent VTE consists of linking clinical patient characteristics with laboratory testing. Several such scoring models which can be used to assess the risk of recurrent VTE have been developed and await prospective validation before they can be applied in daily routine care. The aim of this report is to describe currently available scoring systems in more detail.