Researchers reported that the mean pulmonary artery pressure (mPAP) calculator traditionally used by physicians to screen patients for pulmonary hypertension was able to identify a phenotype of patients who had less physiologically impaired idiopathic pulmonary fibrosis (IPF) with probable pulmonary hypertension, according to a study published in CHEST.
Patients who have pulmonary hypertension associated with IPF tend to have poorer outcomes. It is therefore vital that pulmonary hypertension is diagnosed early so that early intervention can be initiated.
“An equation based on peripheral oxygen saturation and percent predicted forced vital capacity (%FVC) and diffusing capacity for carbon monoxide (%DLco) for mean pulmonary artery pressure (mPAP) has been validated to screen for [pulmonary hypertension] in patients with advanced IPF,” the authors wrote.
The authors sought to investigate whether the “mPAP calculator” could truly be of use to identify patients who may have less physiologically impaired IPF but be at risk of poorer outcomes due to the presence of pulmonary hypertension. Their goal was to compare clinical outcomes between patients who probably have pulmonary hypertension (mPAP >21 mmHg) against patients who are unlikely to have pulmonary hypertension (mPAP ≤21 mmHg), as well as placebo-treated patients.
Read more about IPF etiology
A total of 345 patients was recruited; 97 had probable pulmonary hypertension and 248 were unlikely to have pulmonary hypertension. The research team used clinical data, including all-cause mortality, all-cause hospitalizations, FVC, and 6-minute walk distance test to determine their progress from baseline over 72 weeks.
The results indicated that patients who were deemed to have probable pulmonary hypertension based on the mPAP calculator were slightly older, more likely to be male, are current/former smokers, have a higher mean %FVC, a lower mean diffusing capacity for carbon monoxide, and lower 6-minute walk distance compared to the group who were unlikely to have pulmonary hypertension. In addition, patients who had probable pulmonary hypertension had higher rates of all-cause mortality, hospitalization, and respiratory-related hospitalization compared to the group who were unlikely to have pulmonary hypertension.
“The mPAP calculator was able to identify a phenotype of patients with less physiologically impaired IPF with probable [pulmonary hypertension],” the authors concluded. “Some clinical outcomes were numerically worse in patients with probable vs unlikely [pulmonary hypertension], while others were similar.”
Saggar R, Nathan SD, Chakinala MM, et al. Post hoc analysis of clinical characteristics and outcomes in patients with idiopathic pulmonary fibrosis by pulmonary vascular phenotype from capacity. Chest. Published online October 1, 2022. doi:10.1016/j.chest.2022.08.997