Predicting anticoagulant-related bleeding in patients with venous thromboembolism: a clinically oriented review

Abstract
Diagnosis of venous thromboembolism (VTE) requires prompt treatment with anticoagulants in therapeutic doses. Since these drugs are associated with the occurrence of haemorrhage, identification of patients at increased risk of major bleeding is of utmost clinical importance for defining the optimal treatment regimen and duration of anticoagulation. Current suggested prediction scores for bleeding risk in VTE patients have been derived from observational studies of moderate quality, or from patients with various indications for therapeutic anticoagulation other than VTE. To date, none of the scores have been adequately validated in cohorts that underwent dedicated monitoring and independent adjudication of bleeding complications. In addition, while the scarce available evidence has focused on patients treated with heparins and/or vitamin K antagonists, risk stratification scores for bleeding complications in VTE patients treated with non-vitamin K dependent anticoagulants have not yet been developed. This clinically oriented review covers the incidence and risk factors of anticoagulation-related bleeding in VTE patients treated with different anticoagulant drugs as well as the available bleeding-prediction scores. Further, we attempt to provide guidance for bleeding-prevention in clinical practice and speculate on developments in the near future that may fundamentally change our current thinking on VTE management.