Study objective: To examine the effect of fluticasone propionate, 250 μg/salmeterol, 50 μg combination (FSC 250/50) twice daily on lung hyperinflation and associated measures of exercise performance in patients with COPD.
Design: This was a randomized, double-blind, parallel-group study.
Patients: Eligible patients were ≥ 40 years old with a diagnosis of COPD, prealbuterol FEV1 < 70% of predicted, FEV1/FVC ratio ≤ 0.70, and functional residual capacity (FRC) ≥ 120% of predicted normal.
Interventions: Patients were randomized to FSC 250/50; salmeterol, 50 μg; or placebo twice daily for 8 weeks. Predose and postdose spirometry, plethysmography, and constant-load cycle cardiopulmonary exercise test evaluations were compared. The primary comparison was FSC 250/50 with placebo. The salmeterol group was included for exploratory comparisons with FSC 250/50.
Results: A total of 185 patients (mean baseline FEV1 of 41% predicted) were enrolled. At rest, FSC 250/50 significantly reduced postdose FRC and increased inspiratory capacity (IC) compared with placebo (differences of − 0.35 ± 0.12 L and 0.33 ± 0.06 L [mean ± SE], respectively, at week 8; p ≤ 0.003) and increased exercise endurance time (difference, 132 ± 45 s; p = 0.004). At a standardized time during exercise (isotime), FSC 250/50 increased postdose IC by 0.20 ± 0.05 L over placebo with associated improvements in tidal volume and minute ventilation (p < 0.05 vs placebo at week 8). Improvement in exercise time was significantly correlated with the increase in IC (r = 0.45, p < 0.001) but not FEV1 (r = 0.23, p = 0.08). Predose comparisons of FSC 250/50 with salmeterol and placebo favored FSC 250/50.
Conclusion: We conclude that FSC 250/50 decreases lung hyperinflation at rest and during exercise with an associated increase in exercise endurance time when compared with placebo.