Rapid Inpatient Uptitration of Inhaled Treprostinil in PH-ILD Patients with Severe Phenotype

Pulmonary hypertension associated with interstitial lung disease (PH-ILD) is a progressive condition with limited treatment options and associated with high mortality rates. Inhaled treprostinil (iTre) is the only approved therapy for PH-ILD and has been shown to improve exercise capacity and delay disease progression. However, the conventional outpatient titration schedule requires 8-16 weeks to achieve therapeutic dosing, which may delay clinical benefit in those with advanced disease. We conducted a retrospective study of six patients with severe PH-ILD admitted to a tertiary academic center for initiation of iTre using a rapid inpatient uptitration protocol. iTre was started at 3 breaths four times daily (QID) and increased by 2 additional breaths every 12-24 h as tolerated, aiming for ≥9-12 breaths QID within one week under close monitoring. All six patients achieved target dosing without dose reduction or interruption. At three-month follow-up, mean pulmonary artery pressure decreased from 42 ± 5.5 to 35.2 ± 4.5 mmHg, pulmonary vascular resistance from 8.0 ± 1.2 to 6.0 ± 0.9 WU, and cardiac index increased from 2.05 ± 0.13 to 2.15 ± 0.12 L/min/m². No readmissions occurred within 90 days. This study demonstrates that rapid inpatient uptitration of iTre in severe PH-ILD is feasible and well-tolerated, with preliminary evidence of short-term hemodynamic improvement.