New-onset atrial fibrillation in patients with acute hypercapnic respiratory failure requiring noninvasive ventilation.

Introduction: Atrial fibrillation (AF) and COPD are the most common cardiac arrhythmia and chronic lung conditions worldwide. Exacerbations of COPD can be associated with acute hypercapnic respiratory failure (AHRF). It is unclear if new-onset AF (NOAF) during hospitalisation with AHRF influences long-term outcomes. Methods: We conducted a retrospective cohort study using TriNetX, a global federated health research network. Patients ≥18 years old and hospitalised with a known diagnosis of COPD and new AHRF requiring noninvasive ventilation (NIV) were divided into two cohorts based on the development of NOAF within 7 days of AHRF. After propensity score matching (1:1), there was a total of 14 213 patients in each group. Outcomes were recorded at 1 year from the index admission to hospital. The outcomes of interest were all-cause death, re-admission, stroke, myocardial infarction, composite embolic end-point (acquired absence of limb, acute vascular disorders of intestine, acute and critical limb ischaemia) and dementia. Results: At 12 months following hospitalisation with AHRF requiring NIV, patients who developed NOAF during their admission had a statistically higher rate of death (hazard ratio (HR) 1.26, 95% CI 1.21-1.32), re-admission (HR 1.07, 95% CI 1.04-1.10), stroke (HR 1.46, 95% CI 1.27-1.68), myocardial infarction (HR 1.41, 95% CI 1.31-1.51) and the composite embolic end-point (HR 1.35, 95% CI 1.22-1.51). There was no statistically significant difference in rates of dementia (HR 1.08, 95% CI 0.97-1.21). Conclusion: The development of NOAF in AHRF requiring NIV is associated with a higher risk of mortality, readmission, stroke, myocardial infarction and composite embolism at 1 year. NOAF functions an independent indicator of poor outcomes in such patients.