[Pulmonary embolism. Risk factors of venous thromboembolic disease]

Management of deep venous thromboembolism both in terms of diagnosis and therapeutic and prophylactic strategies has been greatly improved by advances in knowledge of the main acquired and intrinsic risk factors.

This is by far the most frequent coagulation disorder predisposing to venous thromboembolism. Other intrinsic factors favoring thrombus formation (anti-thrombin II, protein C or protein S deficiencies) are much more uncommon. Laboratory tests in search for these anomalies are indicated essentially for patients who develop repeated episodes of venous thrombus formation.

Excepting specific cases, anticoagulant prophylaxis is not indicated in any of these anomalies beyond the usual treatment of a first episode. Among the risk factors for acquired deep vein thromboembolism, only surgery and certain obstetrical indications have been investigated sufficiently to define validated prophylaxis strategies. For medical risks, the benefit of anticoagulant prophylaxis has been demonstrated in certain disease states such as cancer, antiphospholipid syndrome and the acute phase of myocardial infarction although no widely accepted strategy has yet been established.