Importance of computed tomography in defining segmental disease in chronic thromboembolic pulmonary hypertension

Micheal C McInnis; David Wang; Laura Donahoe; John Granton; John Thenganatt; Kongteng Tan; John Kavanagh; Marc de Perrot

doi:10.1183/23120541.00461-2020

Importance of computed tomography in defining segmental disease in chronic thromboembolic pulmonary hypertension

ERJ Open Res. 2020 Dec 7;6(4):00461-2020. doi: 10.1183/23120541.00461-2020. eCollection 2020 Oct.

Authors

Micheal C McInnis¹, David Wang¹, Laura Donahoe², John Granton³, John Thenganatt³, Kongteng Tan¹, John Kavanagh¹, Marc de Perrot²

Affiliations

¹ Dept of Medical Imaging, University of Toronto, Toronto, ON, Canada.
² Division of Thoracic Surgery, Dept of Surgery, University of Toronto, Toronto, ON, Canada.
³ Division of Respirology, Dept of Medicine, University of Toronto, Toronto, ON, Canada.

Abstract

Background: Radiological assessment of patients with chronic thromboembolic pulmonary hypertension (CTEPH) is critical to decide whether patients should be treated with pulmonary endarterectomy (PEA). Although computed tomography pulmonary angiography (CTPA) is increasingly used for decision making in CTEPH, the value of CTPA to predict surgical findings and outcome has never been explored.

Methods: We retrospectively reviewed 100 consecutive patients with high-quality CTPA undergoing PEA for CTEPH between May 2015 and December 2017. The most proximal level of disease in the pulmonary artery on CTPA was classified by two blinded radiologists as level 1 (main pulmonary artery), 2a (lobar pulmonary artery), 2b (origin of basal segmental pulmonary artery), 3 (segmental pulmonary artery) or 4 (predominantly subsegmental pulmonary artery).

Results: CTPA demonstrated level 1 in 20%, level 2a in 43%, level 2b in 11%, level 3 in 23% and level 4 in 3%. A majority of males presented with level 1 (55%) and level 2 (57%), and a majority of females (83%) with level 3 (p=0.01). Levels 3 and 4 were associated with longer duration of circulatory arrest (p=0.03) and higher frequency of Jamieson type III disease at surgery (p<0.0001). Requirement for targeted pulmonary hypertension therapy after PEA was 28% at 3 years in level 2b/3/4 compared with 6% in level 2a and 13% in level 1 (p=0.002). Level 2b/3/4 was an independent predictor for targeted pulmonary hypertension therapy after PEA (hazard ratio 4.23, 95% CI 1.24-14.39; p=0.02).

Conclusions: High-quality CTPA provides accurate evaluation of CTEPH patients. The level of disease on CTPA can help guide peri-operative planning and post-operative monitoring.