The Effect of Inhaled Nitric Oxide on the Exercise Capacity of Patients with Advanced Interstitial Lung Disease: A Randomized Controlled Trial

Abstract

Abstract Purpose To assess the impact of inhaled nitric oxide (iNO) on the six-minute walk distance in patients with advanced interstitial lung disease Methods In a prospective, single-blinded, randomized, placebo-controlled trial, participants with advanced interstitial lung disease, underwent two separate six-minute walk tests: one with iNO and the other with a placebo. The primary outcome measured the difference in meters between the distances covered in the two tests. Secondary outcomes included oxygen saturation levels, distance-saturation product, and Borg dyspnea score. A predefined subgroup analysis was conducted for patients with pulmonary hypertension. Results Overall, 44 patients were included in the final analysis. The 6MWT distance was similar for iNO treatment and placebo, median 362 m (IQR 265–409) vs 371 m (IQR 250–407), respectively (p = 0.29). Subgroup analysis for patients with pulmonary hypertension showed no difference in 6MWTD with iNO and placebo, median 339 (256–402) vs 332 (238–403) for the iNO and placebo tests respectively (P = 0.50). Conclusion In patients with advanced interstitial lung disease, both with and without concurrent pulmonary hypertension, the administration of inhaled nitric oxide failed to elicit beneficial effects on the six-minute walk distance and oxygen saturation. The use of inhaled NO was found to be safe and did not lead to any serious side effects. (NCT03873298, MOH_2018-04-24_002331)