Early PAH diagnosis improves five-year survival, study finds
More studies urged to see if results apply to broader disease population
Early diagnosis of pulmonary arterial hypertension (PAH), less than six months after symptom onset, improves five-year survival by 42% compared with delayed diagnosis of about two years or more, a recent study shows.
The study also found that high blood pressure during heart contraction or normal pressure during heart relaxation, normal levels of iron or creatinine (a marker of kidney function), and being a male between the ages of 18.5 and 24 years were among the factors associated with a delayed PAH diagnosis.
“Our results highlight the importance of how an earlier diagnosis of PAH may improve outcomes for patients,” researchers wrote. “Future research to determine whether earlier diagnosis is associated with earlier initiation of treatment at a low‐risk stage of PAH is warranted.”
The study, “Assessing the Impact of Time to Diagnosis and Treatment for Patients With Pulmonary Arterial Hypertension,” was published in Pulmonary Circulation.
PAH diagnosis can be challenging, frequently delayed
PAH is a type of pulmonary hypertension (PH) characterized by narrowing of the pulmonary arteries, blood vessels that transport blood through the lungs. This restricts blood flow, causing high blood pressure, or hypertension, and symptoms such as shortness of breath, fatigue, and dizziness.
As other conditions may cause its symptoms, PAH diagnosis may be challenging and frequently delayed, contributing to worse clinical outcomes.
In this study, researchers in the U.S. “sought to characterize the diagnostic journey in PAH from initial presentation to the healthcare system for signs or symptoms of PAH and to investigate whether shorter time to diagnosis is associated with better outcomes for patients with PAH,” they wrote.
The team analyzed the electronic health records of 160 adults with PAH from the Mayo Clinic, including those with at least one eligible event — a symptom or a diagnosis of a cardiopulmonary condition other than PAH, such as chronic obstructive pulmonary disease, asthma, congestive heart disease, or heart defects — before their PAH diagnosis.
Diagnosis was confirmed by right heart catheterization (RHC), the gold standard test for pulmonary hypertension, in which a thin, flexible tube is inserted into a blood vessel and guided to the right side of the heart and the pulmonary artery.
The most common eligible events were shortness of breath (42.5%) and fatigue (16.9%). The earliest screening procedures following the first eligible event were X‐ray and electrocardiogram (ECG), a test that records the heart’s electrical activity, performed after a median of seven and 13 days, respectively. Other screening procedures included echocardiogram (median of 26 days), which uses sound waves of the beating heart and blood flow, and RHC (median of 123 days).
The median time interval between the first screening test and diagnosis by RHC ranged from 47 days with ECG to 56 days with X-ray.
Having COPD, being a young adult male linked to delayed diagnosis
From the total of 160 eligible patients, 85 were diagnosed early (within six months), 22 had an intermediate time to diagnosis (from six to 22.2 months), and 53 had a longer delay of almost two years or longer since the first eligible event. A higher proportion of patients diagnosed earlier saw a pulmonologist before another provider compared with those who received a delayed diagnosis (35.3% vs. 22.6%).
Further analysis demonstrated that the factors most closely associated with delayed PAH diagnosis included being diagnosed with chronic obstructive pulmonary disease, having normal levels of creatinine or iron, high systolic blood pressure (when the heart beats), normal diastolic blood pressure (when the heart relaxes), and having an acute respiratory infection. These variables increased the risk of a delayed PAH diagnosis by four to 61 times.
The risk of delayed diagnosis was also 3.1 times higher in men between the ages of 18.5 and 24. Men also appeared to have a longer delay to diagnosis than women.
After five years, 73% of patients in the early diagnosis group were alive, compared with 31% whose diagnosis was delayed. According to the researchers, this shows that an earlier time to diagnosis is associated with significantly improved survival, “emphasizing the importance of early diagnosis in PAH.”
The researchers further said that additional studies are needed to determine if the results are generalizable to the broader PAH population. Finally, they said that since the “initial eligible event was defined as the first contact with the healthcare system for potential signs or symptoms of PH,” this “likely underestimates the true time from symptom onset to diagnosis as the duration of symptoms before the eligible event is unknown.”
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