Chronic Thromboembolic Pulmonary Hypertension

While the majority of patients have complete resolution of their acute pulmonary embolism (PE) after an adequate course of anticoagulation, some patients remain symptomatic with evidence of chronic PE. Chronic Thromboembolic Pulmonary Hypertension (CTEPH) and Chronic Thromboembolic Pulmonary Disease (CTEPD) are terms that describe symptomatic patients with chronic thromboembolic occlusions of the pulmonary arteries with or without pulmonary hypertension, respectively. Here, we review the definitions, epidemiology, pathobiology, diagnosis and management of CTEPH. The chronic PE in CTEPH is essentially a scar in the pulmonary vasculature and is accompanied by a pulmonary arteriolar vasculopathy. Ventilation-perfusion scanning is the most sensitive screening test for CTEPH, and diagnosis must be confirmed by right heart catheterization (RHC). Treatment decisions require a multidisciplinary team and guidance from additional imaging, usually CT or pulmonary angiography. While pulmonary endarterectomy (PEA) to remove the chronic PE surgically is still the first-line treatment for appropriate candidates, there is an expanding role for balloon pulmonary angioplasty (BPA) and medical treatment, as well as multimodality treatment approaches that incorporate all of those options. New imaging modalities and treatment strategies hold the promise to improve our care and management of CTEPH patients in the future.