Computed tomography identifies sex-specific differences in surgical chronic thromboembolic pulmonary hypertension

Abstract

Background: Registry data suggest women are less likely than men to undergo pulmonary thromboendarterectomy for chronic thromboembolic pulmonary hypertension despite a similar proportion of proximal vs distal disease. We hypothesized that sex-specific differences could be elicited with a computed tomography pulmonary angiography analysis beyond proximal vs distal.

Methods: Preoperative computed tomography pulmonary angiography of patients who underwent pulmonary thromboendarterectomy for chronic thromboembolic pulmonary hypertension from January 2017 to September 2021 was analyzed. The pulmonary vascular tree was divided into 32 named vessels with chronic thromboembolism presence and lesion type recorded for each vessel. If no lesion was identified in a segmental vessel, subsegmental disease was recorded when present.

Results: One hundred forty-four patients (mean age 57 ± 15 years, 78 women) were included. There were no sex differences in baseline hemodynamics. Men had more vessels involved than women (mean 20.3 vs 17.1, p = 0.004) and had fewer disease-free pulmonary segments (mean 4.9 ± 4.3 vs 7.6 ± 5.5, p = 0.001). Men had a greater number of webs, eccentric thickening, and occlusions. The distribution of lesion type did not significantly differ between sexes at the main or lobar level but men had significantly more lesions in the segmental vasculature while women had a higher proportion of subsegmental lesions (p < 0.001).

Conclusions: Sex-specific differences in chronic thromboembolic pulmonary hypertension are demonstrated on computed tomography pulmonary angiography in overall distribution and lesion type at the segmental and subsegmental level with women having fewer and more distal lesions despite similar hemodynamics.

Keywords: chronic pulmonary embolism; chronic thromboembolic pulmonary hypertension; computed tomography; pulmonary angiography; pulmonary thromboendarterectomy.

Figure 1

Flowchart demonstrating patient selection. ASD, atrial septal defect; CABG, coronary artery bypass grafting; CTEPH, chronic thromboembolic pulmonary hypertension, CTPA, computed tomography pulmonary angiography, PTE, pulmonary thromboendarterectomy.

Figure 2

Spectrum of chronic thromboembolic disease encountered on CT pulmonary angiography. (A) Chronic thromboembolism often manifests as eccentric thickening in the proximal vasculature as seen in this 57-year-old man where layering thrombus (arrow) is seen along the posterior wall of the right main pulmonary artery extending into the interlobar pulmonary artery. (B) Sagittal reformat in the same patient demonstrates complete occlusion of the right upper lobe pulmonary artery which is now seen as a thrombosed pouch-like defect (asterisk) superior to the right main pulmonary artery (arrow). (C) The descending branch of the right lower lobe is a common site of disease as seen in this 60-year-old woman where a web is visible across the lateral aspect of the vessel (arrow) and a similar web is also seen in the contralateral lobe (arrow, D). (E) The most common lesions are segmental as seen in this 53-year-old man with a complete occlusion of the right lower lobe superior segment (arrow), flush with the interlobar vessel (asterisk). (F) Eccentric thickening can also be seen at the segmental level as demonstrated here in the posterior basal left lower lobe in a 45-year-old woman. Subsegmental lesions are the most challenging to identify but are well demonstrated here in the posterior basal right lower lobe (G, arrow) and left lower lobe (H, arrow) in a 77-year-old woman. CT, computed tomography.

Figure 3

Box and whisker plots of total number of chronic thromboembolic lesions identified per case at the segmental level in men compared to women. Men had more of each lesion type.