A Concept for Long-Term Anticoagulation Based On the Individual Risk of Lethal Pulmonary Embolism (PE) and Lethal Bleeding Using Oral Anticoagulants.

Indications for an indefinite oral anticoagulation are a matter of debate in patients with a first unprovoked proximal DVT.

An individual risk-benefit analysis is made using published prospective studies by determining the patient-specific lethal risk of bleeding under oral anticoagulation compared with the estimation of lethal PE-risk by type of initial thrombosis (spontaneous vs. secondarily caused, with or without PE).

According to this risk-benefit analysis, long-term oral anticoagulation is indicated to prevent lethal PE in all patients with low risk of bleeding (1% per year, 0.1 % lethal bleeding per year) in the risk group with lethal PE > 0.2 % per year. This risk group includes patients with idiopathic proximal thrombosis and PE in the initial event (also without thrombophilic risk factors) and patients with an idiopathic initial event without PE, who have relevant thrombophilic risk factors with a relative risk ≥ 2, such as antithrombin deficiency, homozygous factor V Leiden or a combined heterozygous factor V Leiden and prothrombin G20210A mutation. In case of a higher bleeding tendency (0.3% lethal bleeding per year in a patient group with 1-2 bleeding risk factors like age >65 or diabetes) other risk-benefit estimations are present.

Our individual risk stratification is in contrast to current therapy recommendations, which generally consider long-term oral anticoagulation for patients with an idiopathic initial proximal DVT with a low bleeding risk, but do not specify these in individual cases.

No relevant conflicts of interest to declare.