Chronic thromboembolic pulmonary disease

Abstract

Chronic thromboembolic pulmonary hypertension is a complication of pulmonary embolism and a treatable cause of pulmonary hypertension. The pathology is a unique combination of mechanical obstruction due to failure of clot resolution, and a variable degree of microvascular disease, that both contribute to pulmonary vascular resistance. Accordingly, multiple treatments have been developed to target the disease components. However, accurate diagnosis is often delayed. Evaluation includes high-quality imaging modalities, necessary for disease confirmation and for appropriate treatment planning. All patients with chronic thromboembolic pulmonary disease, and especially those with pulmonary hypertension, should be referred to expert centres for multidisciplinary team decision on treatment. The first decision remains assessment of operability, and the best improvement in symptoms and survival is achieved by the mechanical therapies, pulmonary endarterectomy and balloon pulmonary angioplasty. With the advances in multimodal therapies, excellent outcomes can be achieved with 3-year survival of >90%.

FIGURE 1

Chronic thromboembolic pulmonary disease (CTEPD) imaging modalities. V/Q: ventilation/perfusion; SPECT: single photon emission computed tomography; CT: computed tomography; MRI: magnetic resonance imaging; BPA: balloon pulmonary angioplasty.

FIGURE 2

Chronic thromboembolic pulmonary hypertension (CTEPH) treatment algorithm. MDT: multidisciplinary team; BPA: balloon pulmonary angioplasty; PH: pulmonary hypertension. ^#: CTEPH MDT requires pulmonary endartectomy surgeon, PH expert, BPA specialist and chest radiologist; ^¶: treatment of choice for technically operable disease; ⁺: riociguat therapy prior to BPA: mean pulmonary arterial pressure ≥40 mmHg or pulmonary vascular resistance >4 Wood Units; ^§: other PH medications approved in select regions; ^ƒ: structured follow-up; may include imaging and haemodynamic assessment.