Tracheo-bronchial collapsibility (TBc) has been detected at computed tomography (CT) in Chronic Obstructive Pulmonary Disease (COPD). TBc is considered a local response to inflammatory agents not closely related to the obstructive functional pattern and to lung attenuation values at CT. We hypothesize however that TBc could influence symptoms and daily performance in patients with COPD. The purpose of our study was to investigate whether TBc is related to dyspnoea, exercise capacity and clinical phenotypes in patients with COPD.
Thirty-six patients (mean age 68±8, mean FEV1% 60±24) underwent clinical examination, lung function test, 6 minutes Walking Test and inspiratory-expiratory CT.TBc was measured by an automated software and correlated with MRC and Borg dyspnoea scales and with walked distance. Moreover we compared TBc in patients with predominant chronic bronchitis (CB) and predominant emphysema (E) phenotypes according to the rule available at www.clipcopd.com.
No significant relationship was found between TBc and MRC (r=-0.24, p=0.15), Borg scale (r=-0.12, p=0.48),walked distance (r=0.17, p=0.33). TBc was significantly higher in patients with CB phenotype (p=0.02, Fig. 1).
Patients with a predominant CB phenotype show a high level of TBc supporting the idea that the same inflammatory process could involve both trachea and bronchial tree. Dyspnoea and exercise capacity are global indexes of COPD that are not related to TBc.