Abstract
The chronic airflow limitation characteristic of COPD is caused by a mixture of small airway disease (obstructive bronchiolitis) and parenchymal destruction (emphysema), the relative contributions of which vary from person to person.
Aim of this study was to evaluate, at the time of the first specialist evaluation, the differences in lung and cardiac function and HRCT extent of emphysema in patients with a spirometric diagnosis of COPD but different initial clinical presentation (chronic bronchitis [CB] versus dyspnea [Dy]). 45 consecutive patients referred to our outpatients service by their GP were divided according to their main first symptom (chronic bronchitis or dyspnea).Patients with Dy had an obviously higher dyspnea score vs those with CB (MRC 2.9±0.9 vs 2.3±0.6, p=0.02) and produced much less sputum (p<0.001). The severity of obstruction was similar in the two groups (FEV1 31±11% predicted in both groups, p=0.89; FEV1/VC 26±6% vs 27±7%, respectively for Dy and CB, p= 0.62). The CB had worse arterial blood gases (PaO2 62±12 vs 69±10 mmHg, p=003; PaCO2 50±7 ±vs 45±7 mmHg, p=0.02) and showed a higher proportion of pulmonary artery diameter >29 mm (a surrogate sign of pulmonary hypertension) 18/24 vs 8/21 pts, p=0.02). Dy group had larger CT emphysema extension score (35±16 vs 27±13%, even if this difference did not reach statistical significance, p=0.06). In conclusion we have shown differences between the two COPD phenothypes with similar airflow limitation, with CB patients showing worst ABGS and indirect signs of pulmonary hypertension, while Dy group was characterized by a higher degree of emphysema.
- © 2011 ERS
