Three-month treatment response and exacerbation in chronic obstructive pulmonary disease

Serial blood eosinophils and clinical outcome in patients with chronic obstructive pulmonary disease

BACKGROUND

Blood eosinophils have been suggested as a potential biomarker in chronic obstructive pulmonary disease (COPD), and their stability over time has been investigated in a few studies. However, the association between the stability of blood eosinophils and long-term clinical outcomes in COPD patients has yet to be fully elucidated. This study aimed to evaluate the stability of blood eosinophils and its association with clinical outcomes in COPD patients.

METHODS

In total, 299 COPD patients from the Korean Obstructive Lung Disease cohort with at least two blood eosinophil measurements were included. Patients were stratified according to a cut-off of 300 cells/μL, and the association between eosinophil changes and all-cause mortality was analysed. The annual decline in forced expiratory volume in 1 s (FEV1), serial changes in St George's Respiratory Questionnaire score (SGRQ), and exacerbations during follow-up were compared among eosinophil groups.

RESULTS

Patients were stratified into three groups according to the blood eosinophil cut-off: persistently < 300 cells/μL (PL; n = 175), variable (V; n = 68), and persistently ≥300 cells/μL (PH; n = 56). There were no significant differences in baseline characteristics (age, sex, smoking, body mass index, use of inhaled corticosteroids, exacerbations in the previous year, FEV1 (L or % predicted), or emphysema score) among the groups. During a median follow-up of 6.0 years, the PH group had a better survival rate than the PL group (adjusted mortality rate ratio, 0.29; 95% confidence interval, 0.09-0.97; P = 0.045). The PH group also showed improved symptoms and impact domains of SGRQ score compared to the PL group. No difference was found in annual FEV1 decline or exacerbations during follow-up among the groups.

CONCLUSIONS

Patients with persistently high blood eosinophils had a better survival rate than those with persistently low blood eosinophils. Serial follow-up of blood eosinophils could help to predict outcomes in COPD patients.

Effect of Indacaterol on Cough and Phlegm in Chronic Obstructive Pulmonary Disease Patients: A Meta-Analysis of Five Randomized Controlled Trials

We investigated the effects of indacaterol on cough and phlegm in patients with stable chronic obstructive pulmonary disease (COPD). We performed a meta-analysis with five randomized controlled trials (RCTs) of indacaterol in stable COPD patients. The symptom severity was defined using the St. George's Respiratory Questionnaire (SGRQ). We analyzed patients treated with 150 µg (n = 945) and 300 µg (n = 832) out of 3,325 patients who completed the SGRQ from five RCTs. After a 12-week treatment of 150 µg indacaterol, cough improvement was reported in 36.5% (316/866) of patients treated with indacaterol vs. 32.2% (259/804) patients treated with placebo (Relative Ratio [RR], 1.13; 95% confidence interval [CI], 0.99-1.29). Phlegm improvement was reported in 31.0% (247/798) of patients treated with indacaterol vs. 30.6% (225/736) of patients treated with placebo (RR, 1.01; 95% CI, 0.87-1.18). Dyspnea improvement was reported in 39.5% (324/820) of patients treated with indacaterol vs. 31.5% (237/753) patients treated with placebo (RR, 1.33; 95% CI, 1.03-1.71; P = 0.001, I(2) = 55.1%). Only dyspnea improvement was significant compared to placebo even at the 300 µg indacaterol dose. Compared to placebo, a 12-week treatment of the long-acting beta-agonist, indacaterol might not have a significant effect on cough or phlegm in stable COPD.