Abstract 125: Atrial Fibrillation Known Before Stroke or Detected After Stroke Shares Similar Risk of Ischemic Stroke Recurrence and Death

Abstract

Objective: To compare the risk of 1-year ischemic stroke recurrence and death between atrial fibrillation (AF) diagnosed after stroke (AFDAS), AF known before stroke (KAF) and sinus rhythm (SR). Methods: From June 2012 to January 2013, 19 604 patients with acute ischemic stroke were admitted to 219 urban hospitals voluntarily participating in the China National Stroke Registry II. Based on heart rhythm assessed during admission, we classified patients as AFDAS, KAF, or SR. We explored the relationship between heart rhythm groups and 1-year ischemic stroke recurrence and death by using Cox regression adjusted for multiple covariates. Considering death is the competing risk of stroke recurrence, we used the competing-risks analysis of Fine and Gray to assess the association between heart rhythm and stroke recurrence. Results: Among 19604 ischemic stroke patients, 17727 had SR, 495 AFDAS, and 1382 KAF. At 1 year, 54 (10.9%) patients with AFDAS, 182 (13.2%) with KAF, and 1008 (5.7%) with SR had recurrent ischemic strokes (p< 0.0001). The mortality was 22.0% in patients with AFDAS , 22.1% in patients with KAF, and 7.0% in patients with SR (p< 0.0001). AFDAS-related ischemic stroke recurrence adjusted risk was higher than that of SR (hazard ratio 1.48 [95% confidence interval 1.19, 1.85]; p = 0.0005) but not different from that of KAF (hazard ratio 1.09 [95% confidence interval 0.85, 1.40]; p = 0.51). The adjusted risk of 1-year death for AFDAS was also higher than that of SR (hazard ratio 1.60 [95% confidence interval 1.29, 2.00]; p <0.0001) and not different from that of KAF (hazard ratio 1.09 [95% confidence interval 0.85, 1.40]; p = 0.49). Conclusions: The higher 1-year ischemic stroke recurrence and mortality between AFDAS and SR together with the lack of difference between AFDAS and KAF suggest the similar potential risk of AFDAS.