Abstract Introduction Pulmonary hypertension (PH) is a recognized complication of advanced cystic fibrosis (CF), contributing to morbidity and mortality. While hypoxia and parenchymal destruction are typically central to PH development, some patients exhibit pre-capillary PH with elevated pulmonary vascular resistance, resembling Group 3 PH. Treatment options remain limited, and evidence supporting specific therapies in this population is lacking. Treprostinil, an inhaled prostacyclin analogue approved for pulmonary arterial hypertension, improved exercise capacity and pulmonary vascular resistance in the INCREASE trial of interstitial lung disease (ILD)-related PH. However, data on its use in CF-associated PH are scarce. We present a case of CF-related pre-capillary PH demonstrating symptomatic and functional improvement following inhaled treprostinil initiation, supporting its potential therapeutic role in this population. Case Description A young adult male with cystic fibrosis, chronic hypoxic respiratory failure, and pancreatic insufficiency was noted to have elevated right ventricular systolic pressure (44 mmHg) and severe right ventricular dilation on echocardiogram. Three years later, right heart catheterization revealed: right atrial pressure 4 mmHg, right ventricular pressure 46/8 mmHg, pulmonary artery pressure 43/25 mmHg (mean 31 mmHg), pulmonary capillary wedge pressure 8 mmHg, cardiac output 5.35 L/min, and pulmonary vascular resistance 4.3 Wood units. CT chest demonstrated extensive right-lung cystic bronchiectasis, compensatory hyperinflation of the left lung with bronchiectasis, and mosaic attenuation. He was started on nebulized treprostinil but later transitioned to a dry powder inhaler to improve adherence. Over the following year, he reported substantial improvement in dyspnea, exercise tolerance, and ability to perform daily activities, with fewer limitations from exertional symptoms. Repeat echocardiogram suggested possible improvement in right ventricular appearance, although image quality limited definitive comparison. Discussion This case highlights that inhaled treprostinil may provide meaningful symptomatic and functional benefit in patients with CF and pre-capillary PH. The patient demonstrated elevated pulmonary vascular resistance on right heart catheterization and experienced notable clinical improvement after one year of therapy. These findings parallel outcomes seen in the INCREASE trial for ILD-related PH, suggesting potential cross-applicability to CF-associated disease. Improved adherence after switching to the dry powder formulation underscores the importance of optimizing delivery methods for long-term treatment success. Importantly, this represents one of the few documented cases showing symptomatic improvement with prostacyclin therapy in CF-related PH, suggesting a potential new therapeutic avenue that could influence future management strategies. This abstract is funded by: None
Kurian et al. (Fri,) studied this question.