Xiao X, et al. - In this retrospective analysis of COPD patients (≥ 18 years of age) on home oxygen who were hospitalized for COPD exacerbation, researchers determined the prevalence of atrial fibrillation (AF). They used the 2003 to 2014 Nationwide Inpatient Sample as well as multivariate-adjusted models to assess the link between AF and clinical factors, cost, length of stay, and hospital outcomes. Overall, 244,488 (18.2%) of 1,345,270 included patients had AF. An increase in AF prevalence was noted from 2003 to 2014 in hospital encounters with end-stage COPD. Factors related to increased odds of AF were advancing age, female sex, white race, high income, and large hospital size. Risk of in-hospital death, acute respiratory failure, invasive mechanical ventilation, noninvasive mechanical ventilation, acute kidney injury, sepsis, and stroke were predicted by the presence of AF. Increased cost and length of stay were also noted in association with AF.