Background and purpose: The discrimination between paroxysmal and persistent atrial fibrillations (AF) has not been considered to guide secondary stroke prevention, because it remains unclear whether patients with persistent AF are at higher risk compared with paroxysmal AF, particularly in secondary prevention. We aimed to assess the differences in clinical outcomes between mostly anticoagulated patients with persistent vs. paroxysmal AF who had ischemic stroke or TIA.
Methods: Using interim data of 1192 nonvalvular AF (NVAF) patients with acute ischemic stroke or TIA who were registered in the SAMURAI-NVAF study (an ongoing prospective, multicenter, observational study) to determine choice of anticoagulantion therapy and clinical outcomes, we divided patients into those with paroxysmal AF and those with persistent AF. We compared clinical outcomes between the 2 groups.
Results: The median follow-up period was 1.0 year (IQR 0.3-2.0). Of the 1192 patients, 434 (191 women, 77.3±10.0 y.o.) and 758 (336, 77.9±9.9) were assigned to the paroxysmal AF group and persistent AF group, respectively. Of each group, 220 (50.7%) and 442 (58.3%) were anticoagulated with warfarin and 199 (45.9%) and 276 (36.4%) were so with non-vitamin K antagonist oral anticoagulant (NOAC) (p=0.004). As for primary outcomes, 30 (6.2%/person-year) and 78 (9.9) ischemic events, respectively [hazard ratio adjusted for sex, age, initial NIHSS, CHADS2 score, creatinine clearance, anticoagulation with warfarin (vs. NOAC) (HR) 0.65; 95% CI 0.42-0.98], and 18 (4.9%/person-year) and 31 (3.8) hemorrhagic events, respectively (HR 0.97, 0.52-1.75), occurred during follow-up. As for secondary outcomes, the person-year rate of ischemic stroke or TIA was 3.9% and 8.4%, respectively (HR 0.46, 0.27-0.76), that of intracranial hemorrhage was 1.6% and 1.7%, respectively (HR 0.97, 0.36-2.37), and that of death was 11.1% and 15.7%, respectively (HR 0.90, 0.64-1.26).
Conclusions: Among patients with prior ischemic stroke or TIA, those with persistent AF had a higher risk of ischemic events, and ischemic stroke or TIA compared with those with paroxysmal AF. The prevention of progress to persistent AF from paroxysmal AF may be beneficial for secondary prevention in patients with NVAF.