Epidemiology of pulmonary embolism.

The diagnosis of venous thromboembolism (VTE) has notoriously been challenging because the disease often has no specific clinical presentation, can at times be completely asymptomatic, and can masquerade as other illnesses. To further complicate matters, the rules for coding VTE in the presence of other illnesses changed in 1983 so that among patients who died of VTE and other causes, VTE was omitted from the coding. The International Cooperative Pulmonary Embolism Registry enrolled 2454 consecutive pulmonary embolism (PE) patients from 52 participating hospitals in 7 countries. The aim was to establish the 3-month all-cause mortality rate and to identify factors associated with death. Three-month follow-up was completed in 98% of the patients. The all-cause mortality rate was 11.4% during the first 2 weeks after diagnosis and 17.4% at 3 months. Especially troubling among survivors was the high rate of recurrent VTE after anticoagulation was discontinued. Age is a potent risk factor for the development of VTE. The two most common genetic mutations that predispose to VTE are the factor V Leiden and the prothrombin gene. VTE can be precipitated by oral contraceptives, pregnancy, or hormone replacement therapy.