Improving Risk Stratification, Diagnostic Accuracy in PAH With Cardiopulmonary Exercise Testing

Pulmonology Advisor checked in for a brief discussion with Jeffery Meadows, MD, FSCAI, associate professor of clinical pediatrics, and director of the Congenital Cardiac Catheterization Laboratory and the Congenital Cardiopulmonary Exercise Laboratory at Benioff Children’s Hospital at the University of California, San Francisco. He noted that while he sees many patients with PH in the cardiac catheterization laboratory, he does not routinely manage them in an outpatient clinic.

Pulmonology Advisor: What are your thoughts on the debate over using CPET vs the 6MWT?

Dr Meadows: There are different studies that provide different information and in my mind are for different patient populations. The 6MWT is a black-box assessment with a good deal of prognostic data behind it. CPET provides far more physiologic data in addition to prognostic data. It has been studied less in PH populations so there is less information, but still plenty of data regarding its safety and utility.

Pulmonology Advisor: Do you think that the 6MWT is sufficient on its own or should this decision be made on a case-by-case basis?

Dr Meadows: The 6MWT is best suited for patients on the more severe end of the spectrum, who probably cannot perform CPET very well. In contrast, patients on the more mild to moderate end of pulmonary hypertension are probably better assessed with CPET. Patients on continuous oxygen are difficult, but not impossible, to study with CPET. Patients with complex congenital heart disease and pulmonary hypertension need special consideration, and so on. So to answer your question, I think it is a case-by-case decision.

Related Articles

Pulmonology Advisor: How might cardiopulmonary testing be better controlled for quality?

Dr Meadows: Quality control in CPET has many components. There is routine equipment calibration and preventative maintenance and appropriate training of testing personnel and of interpreters. There definitely need to be better prediction models based upon contemporary norms, and some standardization of protocols, variable assessment, and interpretation.


  1. Farina S, Correale M, Bruno N, et al; for the “Right and Left Heart Failure Study Group” of the Italian Society of Cardiology. The role of cardiopulmonary exercise tests in pulmonary arterial hypertension. Eur Respir Rev. 2018;27(148).
  2. Wensel R, Opitz CF, Anker SD, et al. Assessment of survival in patients with primary pulmonary hypertension: importance of cardiopulmonary exercise testing. Circulation. 2002;106(3):319-324.
  3. ATS Committee on Proficiency Standards for Clinical Pulmonary Function Laboratories. ATS statement: guidelines for the six-minute walk test. Am J Respir Crit Care Med. 2002;166(1):111-117.
  4. Sun XG, Hansen JE, Oudiz RJ, et al. Exercise pathophysiology in patients with primary pulmonary hypertension. Circulation. 2001;104(4):429-435.
  5. Ferrazza AM, Martolini D, Valli G, et al. Cardiopulmonary exercise testing in the functional and prognostic evaluation of patients with pulmonary diseases. Respiration. 2009;77(1):3-17.
  6. Yasunobu Y, Oudiz RJ, Sun XG, et al. End-tidal PCO2 abnormality and exercise limitation in patients with primary pulmonary hypertension. Chest. 2005;127(5):1637-1646.
  7. Zhao QH, Wang L, Pudasaini B, et al. Cardiopulmonary exercise testing improves diagnostic specificity in patients with echocardiography-suspected pulmonary hypertension. Clin Cardiol. 2017;40(2):95-101.
  8. Groepenhoff H, Vonk-Noordegraaf A, Boonstra A, et al. Exercise testing to estimate survival in pulmonary hypertension. Med Sci Sports Exerc. 2008;40(10):1725-1732.
  9. Schwaiblmair M, Faul C, von Scheidt W, et al. Ventilatory efficiency testing as prognostic value in patients with pulmonary hypertension. BMC Pulm Med. 2012;12:23.
  10. Wensel R, Francis DP, Meyer FJ, et al. Incremental prognostic value of cardiopulmonary exercise testing and resting haemodynamics in pulmonary arterial hypertension. Int J Cardiol. 2013;167(4):1193-1198.
  11. Groepenhoff H, Vonk-Noordegraaf A, van de Veerdonk MC, et al. Prognostic relevance of changes in exercise test variables in pulmonary arterial hypertension. PLoS One. 2013;8(9):e72013.