Prognosis of COPD with Asthma-Like Features and ACO: Is the Prognosis of COPD and ACO Different?

Some patients with COPD have asthma-like features, such as significant bronchodilator reversibility, blood eosinophilia, and/or atopy, but they may not be clinically diagnosed with asthma. According to some proposed diagnostic criteria for ACO, a physician’s confirmed diagnosis of asthma or typical respiratory symptoms of asthma is not necessarily required for a diagnosis of ACO. As such, patients with COPD could be labeled as having ACO simply because of the presence of asthma-like features. This chapter summarizes the evidence for the prognosis of COPD with asthma-like features and ACO. The impact of asthma-like features or ACO on lung function declines, exacerbations, and mortality varied between studies. The interpretation of results from each study requires caution. Various factors should be considered when interpreting results, including the ACO diagnostic criteria, disease severity, sample size, and follow-up period. Such variations can affect ACO prognosis. The condition shows heterogeneous phenotypes, even among patients classified as having ACO.