The wearing of face masks does not reduce arterial oxygen saturation (SpO2) or exercise capacity or change the perceptual responses to exercise (RPE) in patients with moderate-to-severe pulmonary arterial hypertension (PAH), according to a new study published in Mayo Clinic Proceedings: Innovations, Quality & Outcomes

The study found that patients with stable PAH who performed a 6-minute walk test (6MWT) before and after being required to wear a face mask had no significant differences in distance walked (P =.81), end-test RPE (P =.91), or SpO2 (P =.55).

“Our findings demonstrate that wearing a face mask has no discernable impact on the arterial oxygen saturation and perceptual responses to exercise or exercise capacity in patients with moderate-to-severe PAH. This study reinforces the evidence that face masks are safe in PAH patients, even during exercise,” according to the authors.

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Between October 1, 2019, and October 31, 2020, 45 PAH patients completed a 6MWT before and after being mandated to wear masks at the hospital. The 2 tests were performed consecutively with 81±51 days of separation between them.

The SpO2 was monitored using a pulse oximeter finger probe at rest during the 6MWT, and up to 5 minutes after the 6MWT. Values of the RPE were obtained using the Borg category-ratio 10 scale within 15 seconds after completing the 6MWT.

The patients also underwent echocardiograms, blood laboratory tests, and a submaximal cardiopulmonary exercise test (CPET), without wearing face masks during the CPET.

Compared to the New York Heart Association functional class, the Registry to Evaluate Early and Long-Term PAH Disease Management (REVEAL) Lite 2.0 risk assessment was calculated. Right ventricular systolic pressure, right ventricular function, brain-type natriuretic peptide (BNP) levels, and pulmonary gas exchange responses at both tests revealed that the patients’ PAH was stable.

The authors suggested examination of the effect of face masks during higher intensity exercise, since the 6MWT was only a moderate level of activity.

The study also did not investigate what effect masks with higher resistance to airflow would cause. Patients only wore level 2 procedural masks during the activity. However, the authors mentioned that N95 masks have similar airflow resistance to the face mask and tubing used during cardiopulmonary exercise tests and believed it would not cause much change to the results.


Helgeson SA, Burger CD, Moss JE, Zeiger TK, Taylor BJ. Facemasks and walk distance in pulmonary arterial hypertension patients. Mayo Clin Proc Innov Qual Outcomes. 2021;5(5):835-838. doi:10.1016/j.mayocpiqo.2021.08.003