Exacerbation and Cardiovascular Events in Eosinophilic Chronic Obstructive Pulmonary Disease

Background: Eosinophilia is often observed in patients with chronic obstructive pulmonary disease (COPD), but the influence of eosinophilia on the clinical outcomes of patients with COPD is unknown. This study aimed to evaluate the clinical characteristics of eosinophilic COPD (E-COPD) and define the effects of treatment with inhaled corticosteroids (ICS) on cardiovascular events in patients with E-COPD. Methods: We included 398 patients with COPD and classified them into two groups: E-COPD (blood eosinophil counts >300 cells/μL or >4%) and non-E-COPD. Patient characteristics and exacerbations between the two groups were compared and the effects of ICS on these variables were studied. Results: E-COPD patients (n = 196) experienced 4.49- and 6.13-time greater numbers of moderate and severe exacerbations, respectively, than non-E-COPD patients (n = 202). In the Cox proportional hazards analysis, higher eosinophil counts and lower pulmonary function values were significantly associated with moderate and severe exacerbations. Patients with E-COPD treated with ICS had fewer cardiovascular events than those treated without ICS (relative risk, 0.39; p = 0.011). Conclusion: These results suggest that eosinophilia may be associated with increased exacerbations of COPD and that treatment with ICS may be considered to reduce cardiovascular events in patients with E-COPD.