At diagnosis, Black PAH patients have more severe disease: Study
'Important' health disparities highlight need for better recognition by clinicians
At diagnosis, Black people with pulmonary arterial hypertension (PAH) tend to have more severe disease than their non-Black counterparts, a new U.S. study shows.
The study, done using data from the University of Illinois Health Pulmonary Hypertension Clinic, further indicated that Black people being evaluated for PAH also tend to experience longer delays before receiving definitive testing than non-Black patients.
According to the researchers, these findings highlight a need for efforts to improve recognition of the rare disease among healthcare providers.
“In this study we have identified important health disparities in non-Hispanic Black patients with PAH,” the researchers wrote, noting that the results of “clinical severity indices … were significantly worse in non-Hispanic Black patients with PAH at [the] time of diagnosis.”
Titled “Important Differences in Disease Severity, Echocardiography Findings, and Referral Delays in Non-Hispanic Black Patients With Pulmonary Arterial Hypertension,” the study was published in the journal Pulmonary Circulation by University of Illinois at Chicago researchers.
Health disparities across racial and ethnic groups in the U.S. are well-documented in many diseases, including pulmonary disorders. However, there has not been much research specifically into how race is linked with outcomes in people with PAH, a rare disorder marked by elevated pressure in the vessels that carry blood through the lungs.
“It is not unreasonable to assume that health disparities may be accentuated when considering a rare disease that requires care at specialized expert centers,” the researchers wrote. “Little is known about the variations in presentation, clinical progression, and response to therapies with respect to historically marginalized racial and ethnic groups suffering from PAH.”
More Black patients had notable symptoms at diagnosis
To learn more, the scientists analyzed data from 110 people diagnosed with PAH at the university’s clinic between 2010 and 2019. Among the patients, 50 self-identified as non-Hispanic Black; the remaining 60 identified as either non-Hispanic white, Hispanic white, or non-Hispanic Asian. The researchers noted that median income was significantly lower among the Black individuals compared with the patients of other races ($43,407 vs. $61,840 ).
The results of the anaylsis showed that the median age at PAH diagnosis was comparable among Black and non-Black patients (54 vs. 50 years). However, Black patients tended to have more severe disease at the time of diagnosis, with poorer scores on measures of exercise capacity, and worse results on tests of blood flow.
At the time of diagnosis, nearly 1 in 7 Black patients (14%) were classified as functional class IV, meaning they were experiencing notable symptoms even when at rest. By contrast, less than 2% of non-Black patients were in functional class IV when they were diagnosed.
“Both by clinical assessments and invasive [blood flow] measures from the gold standard diagnostic test for PAH, non-Hispanic Black patients had more severe disease than did their non-Black counterparts at the time of diagnosis,” the researchers concluded. The scientists noted that there was a statistical association between household income and cardiac output, or the amount of blood the heart pumps out per minute.
Researchers call for ‘comprehensive strategies’ to address disparities
When someone is being evaluated for possible PAH, often the first sign pointing to this disease is a noninvasive test called transthoracic echocardiogram (TTE), which uses sound waves to image the heart. The gold standard to definitively diagnose PAH is a more invasive test called right heart catheterization (RHC), in which a thin, flexible tube is passed through to the right ventricle and pulmonary artery to measure the pulmonary arteries’ pressure and show the heart’s capacity to pump blood.
The researchers found that the average time between an initial abnormal TTE and a first RHC to diagnose PAH was about nine months in non-Black patients. But for Black patients, the average time between these two tests was approximately 2.5 years. This longer delay among Black patients couldn’t be fully explained by factors like income, the team noted.
According to the team, the time from TTE to RHC “could reasonably approximate the time a provider suspected PAH and referred a patient for [definitive diagnostic testing].” As such, the longer delay seen for Black patients “must, at least in part, be attributed to biased recognition,” they said — in other words, it appears like providers may be less likely to suspect or recognize PAH in Black patients.
These results implicate concerning health disparities in non-Hispanic Black patients with PAH. More severe disease at time of diagnosis and longer delays from time of symptom onset to PAH diagnosis have both been associated with increased mortality in this population.
The researchers emphasized a need for further work to understand why this might be, and to develop programs to help improve diagnostic delays for Black PAH patients.
“These results implicate concerning health disparities in non-Hispanic Black patients with PAH. More severe disease at time of diagnosis and longer delays from time of symptom onset to PAH diagnosis have both been associated with increased mortality in this population,” the researchers wrote.
According to the team, “increased social vulnerability and income inequality [were] evident between” Black patients and their non-Black counterparts.
“Future work will be aimed [toward] a community-based intervention to address the health disparities identified in this study,” the scientists wrote, calling for “comprehensive strategies to reduce this disparity.”
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