Clinical analysis of chronic obstructive pulmonary disease phenotypes classified using high-resolution computed tomography

Objective and background: The present study was performed to clarify the clinical characteristics of patients with COPD classified into phenotypes according to the dominancy of emphysema and the presence of bronchial wall thickening (BWT) evaluated by chest high-resolution CT. Methods A total of 172 patients with stable COPD (FEV1 < 80%) were examined by chest high-resolution CT. Emphysematous changes and BWT were evaluated visually, and COPD patients were classified into three phenotypes: absence of emphysema, with little emphysema with or without BWT (A phenotype), emphysema without BWT (E phenotype) and emphysema with BWT phenotype (M phenotype). The clinical characteristics were compared among the three phenotypes. Results The A phenotype showed a higher prevalence of those who had never smoked and patients with wheezing both on exertion and at rest, higher values of BMI and diffusing capacity for carbon mononide (DLCO), milder lung hyperinflation, and greater reversibility of airflow limitation responsive to beta(2)-agonist as compared with the E phenotype. The M phenotype showed a higher prevalence of patients complaining of a large amount of sputum, productive cough and wheezing, higher rate of exacerbation or hospitalization and greater reversibility of airflow limitation responsive to beta(2)-agonist as compared with the E phenotype. Conclusions These findings suggest that the morphological phenotypes of COPD show several clinical characteristics and different responsiveness to bronchodilators.