The incidence of recurrent venous thromboembolism and chronic thromboembolic pulmonary hypertension following a first episode of pulmonary embolism

Abstract

Pulmonary embolism is the most serious complication of venous thromboembolism, with an elevated case/fatality rate. Patients who survived a first episode of pulmonary embolism should be evaluated for the risk of recurrence and of chronic thromboembolic pulmonary hypertension (CTEPH). The risk of recurrence is higher in patients with unprovoked pulmonary embolism than in those with transient risk factors. Persistent risk factors, such as active cancer and antiphospholipid antibodies, are associated with high risk of recurrence. Recently, elevated D-dimer levels after discontinuation of therapy have been identified as a risk factor for recurrence. CTEPH is characterized by intravascular organization of emboli and occurs in 0.5-1% of cases. Some patients with CTEPH have impaired fibrinolysis, likely due to a structural abnormality of fibrin or fibrin clot. Echocardiography often reveals signs of pulmonary hypertension. This should be confirmed by direct measurement of pulmonary artery pressures at right heart catheterization. CTEPH patients should receive life-long anticoagulation for preventing recurrent pulmonary embolism. Pulmonary endarterectomy is the treatment of choice for patients with proximal pulmonary vascular occlusion. Patients with predominantly distal pulmonary vascular occlusion are candidates for pharmacological treatment. All patients with unprovoked pulmonary embolism should be evaluated for long-term anticoagulation.