Chronic Obstructive Pulmonary Disease with Frequent Exacerbator Phenotype: What is Different in these Patients?

Abstract

Background: Acute exacerbation events, which can develop during the natural course of chronic obstructive pulmonary disease (COPD) can lead to worsening quality of life, increased hospital costs, and higher rates of morbidity and mortality. In recent years, individuals at heightened risk of COPD exacerbations have been said to display a so-called "frequent exacerbator (FE)" phenotype, defined as having two or more exacerbation events (or ≥ 1 exacerbation with a hospitalization) within 1 year.

Materials and methods: We conducted a retrospective study involving 299 patients with COPD. Patients were divided into 2 groups as non-exacerbator phenotype (group-1, n=195) and FE phenotype (group-2, n=104).

Results: FE phenotype was identified in 35.1% of patients. There were no significant differences between these two phenotypes in terms of gender, smoking status, or leukocyte count. However, FEs were found to be older (p=0.04), with more frequent detection of emphysema (p=0.02) and lower eosinophil levels (p=0.02). FEs also demonstrated worse pulmonary function parameters.

Conclusion: COPD patients with the FE phenotype likely require a different treatment algorithm due to differing clinical features such as poorer respiratory function, lower eosinophil levels, and more frequent emphysema.

Keywords: COPD; Clinical characteristic; Frequent exacerbator; Hospitalization; Phenotype.

Figure 1.

Hospitalization and chronic obstructive pulmonary disease (COPD) exacerbation rates based on the (A) new Global Initiative for Chronic Obstructive Pulmonary Disease (GOLD) classification system and (B) GOLD 2007 classification

Figure 2.

Frequency of inhaled corticosteroid treatment based on phenotype in patients with (A) Global Initiative for Chronic Obstructive Pulmonary Disease (GOLD) stage II, III, or IV disease and (B) GOLD stage III or IV disease