In late March 2020, the Pulmonary Hypertension Association (PHA) queried health care professionals on the PH Professional Network (PHPN) and PH Clinicians and Researchers (PHCR) listservs to ask whether their pulmonary hypertension (PH) patients were becoming ill with COVID-19. As patients with pulmonary and cardiac diseases are thought to be in a high-risk group, PHA was interested in understanding the impact of COVID-19 on the PH patient community.

Health care professionals from more than 32 PH-treating centers responded to the query. Responses to PHA’s query indicated surprisingly few — only 13 — patients with COVID-19 and one death. In addition, it appeared that those PAH patients who were infected with the virus had more mild symptoms, fewer hospitalizations and quicker recovery than expected.

PHA-member physicians Evelyn Horn, M.D., Murali Chakinala, M.D., Ronald Oudiz, M.D., and Erika Rosenzweig, M.D., along with Elizabeth Joseloff, Ph.D., PHA vice president of quality care and research, published an article1 in the journal Pulmonary Circulation in April to examine why this might be the case.

The authors suggest several possibilities why there were so few COVID-19/PAH positive patients. The first possibility is that the PH patient community responded early and quickly to recommendations for social distancing to protect against coronavirus infection. An alternative hypothesis is that the altered blood vessels or immune cells in the lung in PAH patients may prevent severe COVID-19 from developing by blocking signals that cause the immune system to overreact in response to infection. Finally, some of the PAH-targeted medications may play a protective role against a patient developing severe COVID-19 by blocking virus entry into the cell or protecting against lung distress and injury.

More systematic surveying and additional data to understand the impact of COVID-19 on PH patients are needed to test the authors’ hypotheses. If there is truly a lower risk of severe COVID-19 in PAH patients, this may give new clues to understanding coronavirus infection and lead to new treatments.

1Horn, E., Chakinala, M. M., Oudiz, R., Joseloff, E., & Rosenzweig, E. B. (2020). Could pulmonary arterial hypertension (PAH) patients be at a lower risk from severe COVID-19? Pulmonary Circulation