Acute Effect of Inhaled Iloprost on Exercise Dynamic Hyperinflation in COPD Patients: A Randomized Crossover Study
Background and objective: We tested whether the prostacyclin analog inhaled iloprost modulates dead space, dynamic hyperinflation (DH), and systemic inflammation/oxidative stress during maximal exercise in subjects with chronic obstructive pulmonary disease (COPD) who were not selected based on pulmonary hypertension (PH). Methods: Twenty-four COPD patients with moderate-severe obstruction (age 59 ± 7 years, FEV1 53 ± 13% predicted) participated in a randomized, double-blind, placebo-controlled crossover trial. Each subject received a single nebulized dose of 5.0 μg iloprost or placebo on non-consecutive days followed by maximal cardiopulmonary exercise tests. The primary outcome was DH quantified by end-expiratory lung volume/total lung capacity ratio (EELV/TLC) at metabolic isotime. Results: Inhaled iloprost was well-tolerated and reduced submaximal alveolar dead-space fraction but did not significantly reduce DH (0.70 ± 0.09 vs 0.69 ± 0.07 following placebo and iloprost, respectively, p = 0.38). Maximal exercise time (9.1 ± 2.3 vs 9.3 ± 2.2 min, p = 0.31) and peak oxygen uptake (17.4 ± 6.3 vs 17.9 ± 6.9 mL/kg/min, p = 0.30) were not significantly different following placebo versus iloprost. Conclusions: A single dose of inhaled iloprost was safe and reduced alveolar dead space fraction; however, it was not efficacious in modulating DH or improving exercise capacity in COPD patients who were not selected for the presence of PH.
Lammi, Matthew R.; Ghonim, Mohamed A.; Johnson, Jessica; D'Aquin, Johnny; Zamjahn, John B.; Pellett, Andy; Okpechi, Samuel C.; Romaine, Connie; Pyakurel, Kusma; Luu, Hahn H.; Shellito, Judd E.; Boulares, Hamid; and DeBoisblanc, Bennett P., "Acute Effect of Inhaled Iloprost on Exercise Dynamic Hyperinflation in COPD Patients: A Randomized Crossover Study" (2021). School of Medicine Faculty Publications. 115.