Copyright
©The Author(s) 2023. Published by Baishideng Publishing Group Inc. All rights reserved.
Chronic thromboembolic pulmonary hypertension is associated with a loss of total lung volume on computed tomography
Nanae Tsuchiya, Yan-Yan Xu, Junji Ito, Tsuneo Yamashiro, Hidekazu Ikemiyagi, David Mummy, Mark L Schiebler, Koji Yonemoto, Sadayuki Murayama, Akihiro Nishie
Nanae Tsuchiya, Junji Ito, Sadayuki Murayama, Akihiro Nishie, Department of Radiology, Graduate School of Medical Science, University of the Ryukyus, Nishihara 903-0125, Okinawa, Japan
Yan-Yan Xu, Department of Radiology, China-Japan Friendship Hospital, Beijing 100029, China
Tsuneo Yamashiro, Department of Radiology, Yokohama City University, Yokohama 2360027, Japan
Hidekazu Ikemiyagi, Department of Cardiovascular Medicine, Nephrology and Neurology, Graduate School of Medicine, University of the Ryukyus, Nishihara 9030125, Okinawa, Japan
David Mummy, Center for In Vivo Microscopy and Department of Radiology, Duke University, Durham, NC 27710, United States
Mark L Schiebler, Department of Radiology, University of Wisconsin-Madison, Madison, WI 53792, United States
Koji Yonemoto, Department of Biostatistics, School of Health Sciences, Faculty of Medicine, University of the Ryukyus, Nishihara 903-0215, Okinawa, Japan
Author contributions: All authors contributed to the study conception and design; Tsuchiya N, Xu YY, and Ito J performed the data collection and image interpretation; Tsuchiya N and Yonemoto K performed the statistical analysis; Tsuchiya N wrote the first draft of the manuscript; and all authors commented on previous versions of the manuscript and read and approved the final manuscript.
Supported by The Japan Society for the Promotion of Science, No. 24591782.
Institutional review board statement: This study was approved by the Ethics Committee for Clinical Research of University of the Ryukyus with waiver of informed consent (Approval No., 1039).
Informed consent statement: Our institutional review board approved this retrospective cohort study and waived the requirement for patient informed consent.
Conflict-of-interest statement: All authors report having no relevant conflicts of interest for this article.
Data sharing statement: The original anonymous dataset is available upon request from the corresponding author at nanae7a50@hotmail.com.
Open-Access: This article is an open-access article that was selected by an in-house editor and fully peer-reviewed by external reviewers. It is distributed in accordance with the Creative Commons Attribution NonCommercial (CC BY-NC 4.0) license, which permits others to distribute, remix, adapt, build upon this work non-commercially, and license their derivative works on different terms, provided the original work is properly cited and the use is non-commercial. See:
https://creativecommons.org/Licenses/by-nc/4.0/ Corresponding author: Nanae Tsuchiya, MD, PhD, Lecturer, Department of Radiology, Graduate School of Medical Science, Tsuchiya, N (reprint author), Graduate School of Medical Science, University of the Ryukyus, 207 Uehara, Nishihara-Cho, Nakagami-Gun, Okinawa 903-0215, Japan. nanae7a50@hotmail.com
Received: November 26, 2022
Peer-review started: November 26, 2022
First decision: March 15, 2023
Revised: April 4, 2023
Accepted: April 24, 2023
Article in press: April 24, 2023
Published online: May 28, 2023
BACKGROUND
Although lung volumes are usually normal in individuals with chronic thromboembolic pulmonary hypertension (CTEPH), approximately 20%-29% of patients exhibit a restrictive pattern on pulmonary function testing.
AIM
To quantify longitudinal changes in lung volume and cardiac cross-sectional area (CSA) in patients with CTEPH.
METHODS
In a retrospective cohort study of patients seen in our hospital between January 2012 and December 2019, we evaluated 15 patients with CTEPH who had chest computed tomography (CT) performed at baseline and after at least 6 mo of therapy. We matched the CTEPH cohort with 45 control patients by age, sex, and observation period. CT-based lung volumes and maximum cardiac CSAs were measured and compared using the Wilcoxon signed-rank test and the Mann-Whitney u test.
RESULTS
Total, right lung, and right lower lobe volumes were significantly reduced in the CTEPH cohort at follow-up vs baseline (total, P = 0.004; right lung, P = 0.003; right lower lobe; P = 0.01). In the CTEPH group, the reduction in lung volume and cardiac CSA was significantly greater than the corresponding changes in the control group (total, P = 0.01; right lung, P = 0.007; right lower lobe, P = 0.01; CSA, P = 0.0002). There was a negative correlation between lung volume change and cardiac CSA change in the control group but not in the CTEPH cohort.
CONCLUSION
After at least 6 mo of treatment, CT showed an unexpected loss of total lung volume in patients with CTEPH that may reflect continued parenchymal remodeling.
Core Tip: The total lung volume, right lower lobe volume, and cardiac cross-sectional area were reduced after at least 6 mo of follow-up after treatment in patients with chronic thromboembolic pulmonary hypertension (CTEPH). This finding suggests that structural lung changes have occurred in CTEPH, possibly from continued infarction with secondary volume loss from fibrosis or bronchoconstriction. The loss of lung volume may prove to be an important clinical consideration in CTEPH treatment because pulmonary function may continue to deteriorate despite improved right heart function in patients with CTEPH.
