Chronic Thromboembolic Pulmonary Hypertension: the Bedside

Abstract

Purpose of review: Chronic thromboembolic pulmonary hypertension (CTEPH), included in group 4 PH, is an uncommon complication of acute pulmonary embolism (PE), in which emboli in the pulmonary vasculature do not resolve but rather form into an organized scar-like obstruction which can result in right ventricular (RV) failure. Here we provide an overview of current diagnosis and management of CTEPH.

Recent findings: CTEPH management is complex with treatments that range from surgery, percutaneous interventions, to medical therapies. Current CTEPH medical therapies have largely been repurposed from pulmonary arterial hypertension (PAH). The diagnosis of CTEPH can be challenging, requiring a multimodality approach to differentiate from disease mimics. While these treatments improve symptoms, they may not reverse the underlying pathology of CTEPH.

Keywords: Balloon pulmonary angioplasty; Chronic thromboembolic pulmonary hypertension; Pulmonary embolism; Pulmonary endarterectomy; Pulmonary hypertension.

Figure 1.

Approach to CTEPH diagnosis. Patients with suspected CTEPH should first undergo a VQ scan, which can effectively rule out the disease due to its high sensitivity. Due to the low specificity of VQ scan, the next step is a CTPA, which confirms the diagnosis of CTEPH in patients with proximal disease. For patients with distal disease, pulmonary angiography aids in the planning of PTE or BPA at expert centers. *Some patients may have findings on CTPA consistent with alternative diagnoses, such as sarcoidosis or mediastinal fibrosis, in the absence of other typical CTEPH findings, such as mosaicism and bronchial collaterals.

Figure 2.

Imaging and thrombus in CTEPH. A V/Q scan in the same patient showing multiple bilateral mismatched defects. B CT scan showing clear vascular mosaicism. C The white arrow highlights an angiographic “pouch” occlusion of the right interlobar vessel. The presence of organized thromboembolic disease is also evident by “web” narrowing of the proximal anterior upper lobe artery (green arrow). D The lateral right pulmonary arteriogram in the same patient shows another “web” narrowing (white arrow) of the proximal posterior upper lobe vessel not appreciated on the AP films. (The figure was published in Fedullo PF, Auger WR. “Medical Management of the Thoracic Surgery Patient”, 2010 pp: 477-482, copyright Elsevier [2010]) [37]. E University of California San Diego classification of PEA disease levels with illustrative figures for each level (Reprinted with permission of the American Thoracic Society. Copyright © 2021 American Thoracic Society. All rights reserved. Madani M, M. E. Ann Am Thorac Soc, 2016, 13 Suppl 3, S240-S247. Annuals of the American Thoracic Society is an official journal of the American Thoracic Society.) [42].

Figure 3.

Approach to CTEPH management. For patients with operable disease, PTE surgery is the gold standard treatment. For those with non-operable disease (*must be confirmed at CTEPH center), an approach of BPA and medical therapy can be used. Some patients who were not initially operable candidates due to medical illness may improve with BPA and medical therapy to the point where they can undergo PTE surgery.