Abstract
Background: WHO Group 1 pulmonary arterial hypertension is a progressive and potentially fatal disease. Individuals living at higher altitude are exposed to lower barometric pressure and hypobaric hypoxemia. This may result in pulmonary vasoconstriction and contribute to disease progression. We sought to examine the relationship between living at moderately high altitude and pulmonary arterial hypertension characteristics. Methods: Forty-two US centers participating in the Pulmonary Hypertension Association Registry enrolled patients who met the definition of WHO Group 1 pulmonary arterial hypertension. We utilized baseline data and patient questionnaire responses. Patients were divided into two groups: moderately high altitude residence (home ≥4000 ft) and low altitude residence (home <4000 ft) based on zip-code. Clinical characteristics, hemodynamic data, patient demographics, and patient reported quality of life metrics were compared. Results: Controlling for potential confounders (age, sex at birth, body mass index, supplemental oxygen use, race, 100-day cigarette use, alcohol use, and pulmonary arterial hypertension medication use), subjects residing at moderately high altitude had a 6-min walk distance 32 m greater than those at low altitude, despite having a pulmonary vascular resistance that was 2.2 Wood units higher. Additionally, those residing at moderately high altitude had 3.7 times greater odds of using supplemental oxygen. Conclusion: Patients with pulmonary arterial hypertension who live at moderately high altitude have a higher pulmonary vascular resistance and are more likely to need supplemental oxygen. Despite these findings, moderately high altitude Pulmonary Hypertension Association Registry patients have better functional tolerance as measured by 6-min walk distance. It is possible that a “high-altitude phenotype” of pulmonary arterial hypertension may exist. These findings warrant further study.
Original language | English (US) |
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Journal | Pulmonary Circulation |
Volume | 10 |
Issue number | 4 |
DOIs | |
State | Published - Nov 27 2020 |
Bibliographical note
Funding Information:We would like to acknowledge the Pulmonary Hypertension Association (PHA) for providing the data used in this study through their registry (PHAR). The PHAR is supported by Pulmonary Hypertension Care Centers, Inc., a supporting organization of the Pulmonary Hypertension Association. The authors thank the other investigators, the staff, and particularly participants of the PHAR for their valuable contributions. A full list of participating PHAR sites and institutions can be found at www.PHAssociation.org/PHAR. Additional PHAR Investigators: Roblee Allen, MD, Sahil Bakshi, DO, Sonja Bartolome, MD, Charles D. Burger, MD, Linda M. Cadaret, MD, Michael Duncan, MD, Michael Eggert, MD, Jean M. Elwing, MD, Grant Farr, DO, Jeremy Feldman, MD, Jeff Fineman, MD, Raymond J. Foley, DO, Hubert James Ford, MD, Robert P. Frantz, MD, Anna R. Hemnes, MD, Evelyn M. Horn, MD, Steven M. Kawut, MD, MS, Peter J. Leary, MD, PhD, John W. McConnell, MD, Kishan S. Parikh, MD, Kenneth W. Presberg, MD, Amresh Raina, MD, Gautam Ramani, MD, Erika B. Rosenzweig, MD, James R. Runo, MD, Marc A. Simon, MD, MS, John W. Swisher, MD, PhD, Nidhy P. Varghese, MD, Corey E. Ventetuolo, MD, R. James White, MD, PhD, Timothy Williamson, MD, Delphine Yung, MD, Roham T. Zamanian, MD. This research received no specific grant from any funding agency in the public, commercial, or not-for-profit sectors.
Funding Information:
We would like to acknowledge the Pulmonary Hypertension Association (PHA) for providing the data used in this study through their registry (PHAR). The PHAR is supported by Pulmonary Hypertension Care Centers, Inc., a supporting organization of the Pulmonary Hypertension Association. The authors thank the other investigators, the staff, and particularly participants of the PHAR for their valuable contributions. A full list of participating PHAR sites and institutions can be found at www.PHAssociation.org/PHAR .
Publisher Copyright:
© The Author(s) 2020.
Keywords
- 6-min walk distance
- elevation
- pulmonary arterial hypertension
- pulmonary vascular resistance
- vascular