Prognostic factors in interstitial lung disease-associated pulmonary hypertension: data from the HYPID cohort and the French Pulmonary Hypertension Registry.

BACKGROUND

Pulmonary hypertension (PH) frequently complicates interstitial lung diseases (ILDs), adversely affecting outcome. Identifying prognostic factors of patients with PH associated with ILD (ILD-PH) could facilitate early identification of patients who may benefit from PH therapy.

METHODS

We included patients with ILD-PH from the prospective HYPID cohort and the French National Pulmonary Hypertension Registry (2007-2022). Univariable and multivariable analyses were performed to identify predictors of 1-year mortality.

RESULTS

A total of 581 patients (mean age 69.4±9.3 years; 450 males) were analysed. ILD diagnoses were combined pulmonary fibrosis and emphysema (CPFE) syndrome (30.8%), idiopathic pulmonary fibrosis (29.6%), unclassifiable ILD (13.1%) and fibrotic hypersensitivity pneumonitis (10.3%). Mean pulmonary arterial pressure was 40.7±9.1 mmHg and mean pulmonary vascular resistance (PVR) was 7.6±3.5 Wood units (WU). Off-label PH therapy was initiated after initial evaluation in 215 patients (37%). The median transplant-free survival time was 17 (95% CI 15.2-not reached) months. Multivariable analysis identified male sex (p<0.001), World Health Organization functional class (WHO FC) III (p=0.003) or IV (p=0.003), 6-min walk distance (6MWD) ≤228 m (p<0.001), PVR >5 WU (p=0.008) and absence of PH therapy (p<0.001) as independent predictors of death or lung transplantation at 1 year.

CONCLUSION

Non-invasive (6MWD and WHO FC) and invasive (PVR) variables are associated with prognosis in patients with ILD-PH, including in patients with CPFE. PH medication might improve outcomes in this patient population.