New tool helps predict lung disease-related PH mortality risk
Assessment uses risk factors including age, disease type to gauge prognosis
Researchers in the U.S. have developed a tool to help predict mortality risk in people with chronic lung disease and pulmonary hypertension (PH).
The tool, PVD-B65, accounts for risk factors related to both conditions, including age, lung disease type, PH severity, exercise capacity, and blood levels of a heart disease biomarker.
“The PVD-B65 risk assessment tool is a novel tool for prognostication in patients with chronic lung disease and PH,” the researchers wrote. “Earlier identification of higher risk patients and initiation of appropriate interventions may help reduce the morbidity and mortality associated with this serious yet underrecognized condition.”
The development and validation of the tool were described in the study, “Development of the pulmonary fibrosis, pulmonary vascular resistance, six minute walk distance, B-type natriuretic peptide, age (PVD-B65) risk score for patients with chronic lung disease and pulmonary hypertension,” published in BMC Pulmonary Medicine.
PH is characterized by elevated pressure in pulmonary arteries, the blood vessels that carry blood from the heart to the lungs. It commonly develops in people with chronic lung diseases and is associated with a worse prognosis.
Assessing prognosis ‘challenging’
Risk assessment tools to predict a person’s prognosis based on various clinical factors can help guide treatment choices. Such tools have been developed for people with pulmonary arterial hypertension (PAH), a form of PH that develops because the pulmonary arteries become narrowed for a variety of reasons.
However, “effectively prognosticating patients with chronic lung disease and PH remains challenging,” the researchers wrote, as factors related to each disease have to be accounted for.
The team set out to develop and validate a risk assessment tool for this patient population. To build their model, they retrospectively examined data from 793 patients with chronic lung disease who were diagnosed with PH from 2011 to 2023 at the researchers’ hospital in Philadelphia.
Patient’s average age was 63.3, and 50.8% were men. Their chronic lung diseases included chronic obstructive pulmonary disease, pulmonary fibrosis, interstitial lung diseases without scarring, and pulmonary sarcoidosis.
Overall, 248 people met recent criteria for severe PH: a pulmonary vascular resistance (PVR) of greater than 5 Wood Units (WU). PVR is a measure of the resistance to blood flow through the pulmonary blood vessels.
A total of 55 patients (6.9%) died within a year of their PH diagnosis without having undergone a lung transplant, with a mean time to death of 8.4 months.
Statistical analyses identified five clinical factors as independent predictors of one-year mortality, including being older than 65, having a PVR over 5 WU, and having pulmonary fibrosis without emphysema.
Pulmonary fibrosis is marked by lung tissue scarring, making breathing harder. Emphysema occurs when the air sacs in the lungs become damaged or destroyed.
Blood levels of BNP, a heart failure marker, higher than 200 picograms per deciliter (pg/dL) and being unable to walk 150 or more meters in the six-minute walk distance test — a measure of exercise capacity — were also mortality predictors.
The team developed the PVD-B65 risk assessment tool taking into account all of the identified risk factors to predict a patient’s risk of death in the next year, weighing each factor based on how strongly it predicted mortality. Sores range from 0-14 points, with a higher score equating to greater mortality risk.
“By identifying predictors of one-year mortality … we composed a risk assessment tool that captures the multifaceted and complex nature of factors that affect outcomes in patients with lung disease and PH,” the researchers wrote.
Applying the tool to the 407 patients with enough available clinical data, 155 patients were deemed to have a low risk of death (0-3 points), 212 patients were classified as having an intermediate risk (4-10 points), and 40 were considered to have a high mortality risk (11-14 points).
One-year mortality rates were 3.9% in the low-risk group, 9.4% in the intermediate risk group, and 17.5% in high-risk group. Compared with patients in the low-risk group, those in the intermediate-risk group had a 2.5 times higher risk of death, and those in the high-risk group had a sixfold higher risk. This helped to validate the tool works as intended.
“While external validation of our risk assessment tool is necessary, the PVD-B65 risk score can help aid in prognosticating patients diagnosed with lung disease and PH and, in turn, help guide therapeutic decisions,” the team concluded.
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