Effects of Tiotropium on airway remodeling in patients with early stage COPD accessed by EB-OCT

ZQ. Zhou*^a (Dr), SY. Li^a (Prof), NS. Zhong^a (Prof)

^a The 1st affiliated hospital of Guangzhou medical university, Guangzhou institute of respiratory health., Guangzhou, CHINA

* zhou.ziqing@foxmail.com

Background: It’s still not clear whether use of long-acting bronchodilators be beneficial in early-stage COPD patients to decelerate airway remodeling. We aim to investigate the effects of Tiotropium on airway remodeling in GOLD I COPD patients. Method: We enrolled 71 patients with GOLD I COPD who were randomize divided into 3 groups. Patients in Group 1 (n=24) received Tiotropium 18μg once daily and SABA as need (T+S) during 24 months treatment period. Patients in Group 2 (n=24) received T+S during the first 12 month, and SABA as needed from the 12 to 24 months. Patients in Group 3 (n=23) receive SABA as needed during the 24 months treatment period. EB-OCT was performed to access airway remodeling at month 0, 12, 24. Pulmonary function test was performed every 3 months. Results: Baseline characteristics and baseline airway parameter access by EB-OCT were similar among three groups (All P>0.05). Tiotropium resulted in a significantly larger airway inner luminal area (Ai) than baseline in medium-sized (7.31±3.91mm2 v.s. 10.06±4.66mm2, P<0.01) and small airway (2.47±1.27mm2 v.s. 3.42±1.68mm2, P<0.01) at month 24 in Group 1. Tiotropium use from baseline through 12 months did not lead to a significantly larger Ai at month 24 in Group 2. EB-OCT image showed a decrease in Ai in medium-sized (7.14±3.88mm2 v.s. 6.64±3.10mm2, P<0.05) and small airway (2.54±1.67mm2 v.s. 2.29±0.98mm2, P<0.05) at month 24. From month 12 through month 24, the annual reduction of Ai in medium-sized and small airway in Group 1 was significant slower than that in Group 2 and 3. The decline in lung function in Group 1 trends to be the slowest among three groups. Conclusion: Tiotropium resulted in a significantly improvement in airway remodeling at month 24. Continuous using tiotropium decelerate the annual reduction of Ai in medium-sized and small airway.

Disclosure of funding source(s): none