Hemodynamics and Phosphodiesterase-5 Inhibitor Treatment Associated with Survival in ILD-PH: A PVRI GoDeep Meta-Registry Analysis

Background. Pulmonary hypertension (PH) in interstitial lung disease (ILD) lacks approved therapies. The PVRI GoDeep meta-registry collects real-world data of PH patients from international PH referral centers. Methods. ILD-PH patients and relevant subgroups (IIP, IPF) were stratified by pulmonary vascular resistance (PVR). Kaplan-Meier survival analyses, adjusted Cox proportional hazards models, additionally accounting for immortal time bias, sensitivity analyses, Heller explained relative risk statistics and target trial emulation framework analysis were employed. Results. Among 34,482 patients, 940 hemodynamically fully characterized incident ILD-PH patients (median age 67[59,74] years) were identified. 62% had severe ILD-PH with PVR >5 WU and poor survival rates (29% and 18% at 3 and 5 years), significantly worse than ILD-PH patients with PVR ≤5 WU and PAH patients. Survival was poorest in severe IPF-PH. 59% of all ILD-PH patients received PH-targeted therapy, predominantly phosphodiesterase-5 inhibitors (PDE5i). PDE5i-treatment was consistently associated with significantly improved survival in patients with severe PH (hazard ratios 0.537[0.370,0.781], 0.461[0.233,0.913] and 0.435[0.215,0.8] for IIP-PH, IPF-PH and IIP-PH on nintedanib/pirfenidone background therapy), but not in patients with less severe hemodynamic impairment, supported by sensitivity analyses, Heller statistics and target trial emulation framework analysis. The survival statistics of PDE5i-treated IIP-PH/IPF-PH patients were validated in the independent COMPERA registry. Combination therapy with PDE5i and inhaled prostacyclin analogue was superior to monotherapy using PDE5i (HR 0.341 [0.205, 0.566]). Conclusion. Prognosis in ILD-PH was generally very poor, related to PH severity. PDE5i treatment in severe IIP-PH and IPF-PH was associated with improved survival, to be further verified in controlled trials.