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Original article (peer-reviewed)

Journal PloS one
Volume (Issue) 7(12)
Page(s) 52248 - 52248
Title of proceedings PloS one
DOI 10.1371/journal.pone.0052248


BACKGROUND Inhaled iloprost potentially improves hemodynamics and gas exchange in patients with chronic obstructive pulmonary disease (COPD) and secondary pulmonary hypertension (PH). OBJECTIVES To evaluate acute effects of aerosolized iloprost in patients with COPD-associated PH. METHODS A randomized, double blind, crossover study was conducted in 16 COPD patients with invasively confirmed PH in a single tertiary care center. Each patient received a single dose of 10 µg iloprost (low dose), 20 µg iloprost (high dose) and placebo during distinct study-visits. The primary end-point of the study was exercise capacity as assessed by the six minute walking distance. RESULTS Both iloprost doses failed to improve six-minute walking distance (p = 0.36). Low dose iloprost (estimated difference of the means -1.0%, p = 0.035) as well as high dose iloprost (-2.2%, p<0.001) significantly impaired oxygenation at rest. Peak oxygen consumption and carbon dioxide production differed significantly over the three study days (p = 0.002 and p = 0.003, accordingly). As compared to placebo, low dose iloprost was associated with reduced peak oxygen consumption (-76 ml/min, p = 0.002), elevated partial pressure of carbon dioxide (0.27 kPa, p = 0.040) and impaired ventilation during exercise (-3.0l/min, p<0.001). CONCLUSIONS Improvement of the exercise capacity after iloprost inhalation in patients with COPD-associated mild to moderate PH is very unlikely. TRIAL REGISTRATION ISRCTN61661881.