Introduction: Despite the poor prognosis of interstitial lung disease (ILD) with pulmonary hypertension (PH), evidence-based guidelines for PH screening in ILD are lacking. PHINDER (NCT05776225) aims to develop a validated PH screening tool in patients with ILD.

Objectives: This PHINDER interim analysis assessed the accuracy of study clinicians’ suspicion of PH compared to hemodynamically confirmed PH.

Materials and Methods: PHINDER is a prospective, multicenter study where ILD patients undergo routine non-invasive assessments followed by right heart catheterization (RHC) to confirm pre-capillary PH (mPAP>20 mmHg, PVR>2 WU, PCWP≤15 mmHg). After reviewing all non-invasive test results but prior to RHC, study clinicians are asked to rank their suspicion of PH as low, medium, or high.

Results: At the time of this interim analysis (May 2025), data were available for 189 patients, of whom 15% were deemed low suspicion for PH, 46% deemed medium suspicion, and 39% deemed high suspicion by their clinician prior to RHC. Parameters that trended along with and may have driven suspicion of PH, included 6-minute walk distance, natriuretic peptide levels, supplemental oxygen requirements, peripheral edema or loud second heart sounds, FEV, FVC, DLCO, FVC/DLCO, RV pressure, tricuspid regurgitant velocity, pulmonary artery (PA) enlargement, PA/aorta diameter, and RV/LV diameter. Pre-capillary PH was then confirmed by RHC in 32% of the low-suspicion group (median mPAP 29 mmHg), 51% of the medium-suspicion group (mPAP 26 mmHg), and 69% of the high-suspicion group (mPAP 28 mmHg).

Conclusions: A high level of discrepancy was observed between clinicians’ gestalt assessment of PH likelihood and RHC hemodynamics. Pre-capillary PH was confirmed in almost a third of patients believed to have low likelihood of PH and was ruled out in almost a third of patients believed to have high likelihood of PH. These results underscore the need for more objective PH screening in patients with ILD.