Is there any difference in mortality rates of atrial fibrillation detected before or after ischemic stroke?

Background and purpose - Atrial fibrillation diagnosed after stroke (AFDAS) is a new term used for AF resulting from autonomic dysregulation. It is associated with a lower stroke recurrence compared to patients with known AF before a stroke (KAF). The aim of the study was to explore the characteristics and mortality rates in AFDAS patients. Methods - 134 ischemic stroke patients (66.1 +/- 14.2 years old, n=73 male) were consecutively included in the study. While patients who had known AF with anticoagulant therapy were grouped as KAF, patients with newly documented AF rhythm (either by daily ECG or ambulatory ECG monitor- ing) were classified as AFDAS. All patients were followed for 1 year to obtain all-cause mortality, cardiac mortality, and neurogenic mortality. Results - Of the 134 stroke patients, AF was detected newly in 38 patients and grouped as AFDAS. KAF patients had higher CHA2DS2VASc scores, hs-CRP and NT-proBNP levels, and more insular cortex involvement than the SR group. During the one-year follow-up, 35 stroke patients died. The mortality rate was significantly higher in patients with KAF (12/22; 54.5%) while the mortality rates were similar between AFDAS patients (11/38; 28.9%) and patients with sinus rhythm (SR) (12/74; 16.2%). KAF was an independent predictor when adjusted by age, sex, CHA2DS2VASc and NIHSS scores, and insular cortex involvement. While AFDAS had increased the mortality risk compared to SR, the difference was not significant in univariable and multivariable models. Conclusion - AFDAS patients have similar CHA2DS2VASc scores and mortality rates to patients with SR, which implies that AFDAS might be a relatively benign form of AF.