Table 4. Risk factors and predisposing conditions for CTEPH.

Findings related to the acute PE eventa	Concomitant chronic diseases and conditions predisposing to CTEPHc
Previous episodes of PE or DVT	Ventriculo-atrial shunts
Large pulmonary arterial thrombi on CTPA	Infected chronic i.v. lines or pacemakers
Echocardiographic signs of PH/RV dysfunction	History of splenectomy
CTPA findings suggestive of CTEPDb	Thrombophilic disorders, particularly antiphospholipid antibody syndrome and high coagulation factor VIII levels
	Non-O blood group
	Hypothyroidism treated with thyroid hormones
	History of cancer
	Myeloproliferative disorders
	Inflammatory bowel disease
	Chronic osteomyelitis

^a, obtained at PE diagnosis; ^b, see Table 2; ^c, documented at PE diagnosis or at 3–6 months follow-up. Reproduced from (12) with permission. CTEPH, chronic thromboembolic pulmonary hypertension; PE, pulmonary embolism; DVT, deep vein thrombosis; CTPA, computed tomography pulmonary angiography; PH, pulmonary hypertension; RV, right ventricular; CTEPD, chronic thromboembolic pulmonary disease.