Patients prone to developing CTEPH are thought to have defective fibrinolytic systems, have partially organised emboli that are less likely to undergo fibrinolysis, a chronic and unrecognised source of recurrent embolisation, or a hypercoagulable state. The presence of lupus-like anticoagulant was prevalent in 10 to 30 percent of patients seen in two case series. Other coagulation abnormalities include protein C, protein S, and antithrombin III deficiency.For a majority of patients with CTEPH, however, no defects can be demonstrated.

There is also some association between CTEPH and malignancy, the presence of indwelling venous catheters, and atrial septal defects.

Jamieson SW, Auger WR et al. Experience and results with 150 pulmonary thromboendarterectomy operations over a 29-month period. Journal of Thoracic & Cardiovascular Surgery 1993; 106:116-127.

Simonneau G, Azarian R et al. Surgical management of unresolved pulmonary embolism: a personal series of 72 patients. Chest: the Cardiopulmonary Journal 1995; 107.