Borderline pulmonary hypertension is associated with exercise intolerance and increased risk for acute exacerbation in patients with interstitial lung disease

Background Pulmonary hypertension (PH) is traditionally defined as a resting mean pulmonary artery pressure (mPAP) of ≥25 mmHg, while mPAP in the range of 21 to 24 mmHg is recognized as “borderline PH.” Interstitial lung disease (ILD) is complicated by the development of PH, which is known to be linked with exercise intolerance and a poor prognosis. Even though it has recently been recommended that PH is redefined as a mPAP of > 20 mmHg, little is known about the clinical significance of borderline PH in ILD. We evaluated whether borderline PH has an impact on the exercise capacity, risk of acute exacerbation (AE), and mortality in patients with ILD.