Prospective Cohort Study on the Determinants of Venous THromboembolic Recurrence. BREIZH-Cohorte

Deep vein thrombosis (DVT) and pulmonary embolism (PE) are two clinical manifestations of the same entity, thromboembolic venous disease. This disease is frequent: the annual incidence of thromboembolic venous disease estimated between 1 and 2 cases per 1000 inhabitants per year in France, comparable to that observed in North America. This disease is potentially serious: the mortality from PE, the most severe manifestation of thromboembolic venous disease (one third of PE for two thirds of DVT) is 10% at 3 months, twice as high as that of myocardial infarction. However, the risk of PE in isolated DVT is major (more than 50% of cases). Thus, whether it is a PE or a DVT, anticoagulant treatment, a cornerstone of therapeutic management, must therefore be initiated urgently, without waiting for the results of diagnostic confirmatory examinations.

The major complications occurring after a thromboembolic venous disease are venous thromboembolic recurrence (VTE) and the long-term consequences: post-thrombotic syndrome and the development of post-embolic pulmonary hypertension. VTE recurrence has significant mortality, particularly in the form of PE (15%, compared to 2% in the form of DVT). As for long-term complications of VTE, about 20-30% of patients with DVT develop post-thrombotic syndrome at 5 years (27), while 0.15% to 5% of patients with PE develop post-embolic pulmonary hypertension at 1 year.

While major progress has been made over the past 20 years in terms of diagnosis, primary and secondary prevention, identification of risk factors for VTE and prognostic factors, however, two particular subgroups deserve to be specifically investigated: young subjects, whether women (hormonal exposure) or men (often idiopathic thromboembolic venous disease), and cancer patients. In the latter, the progress made on anti-cancer treatments is helping to modify the data on the risk of VTE as well as the duration of treatment of VTE in these patients.

Thus, this prospective cohort covers two subgroups of patients with thromboembolic venous disease: young subjects (≤50 years) or those who have cancer.