Characteristics of Patients With Asymptomatic Atrial Fibrillation and Ischemic Stroke-Insights From the GLORIA-AF Registry (Phase 2)

BackgroundAsymptomatic nonvalvular atrial fibrillation is often suspected in patients with cryptogenic stroke which constitute 20%-30% of ischemic strokes. Detection of atrial fibrillation (AF) and treatment with anticoagulation can reduce the risk of stroke. We sought to investigate the prevalence of asymptomatic atrial fibrillation (aAF) in patients with a history of stroke or an acute stroke on admission.MethodsFrom November 2011 until December 2014, 15,308 patients with a first episode of AF were enrolled in phase 2 of the international, prospective, multicenter global registry on long-term oral anticoagulation treatment in patients with AF (GLORIA-AF) Registry. For the present analysis, we focused on patients with aAF regarding the prevalence of stroke.ResultsOne third of patients (n = 4892, 32%) had aAF. Of these, 611 (12.5%) had a history of stroke or an acute stroke on admission. In contrast, 519 of 10,416 (5.0%) patients with symptomatic AF (sAF) had a history of stroke or an acute stroke on admission. Higher age, male gender, permanent AF, stroke, and the combination of stroke, TIA or systemic embolism were associated with a higher prevalence of aAF on admission. In a multivariable analysis, patients with aAF had a 2.3-fold (95% confidence interval (CI), 2.02-2.54) risk for stroke compared to patients with sAF. Other independent risk factors for stroke were a history of prior bleeding (odds ratio 1.62, 95% CI, 1.34-1.92), chronic kidney disease (1.38, 1.21-1.56), and diabetes mellitus (1.24, 1.10-1.41).ConclusionaAF is reported in about one third of patients with newly diagnosed AF and is associated with a 2.3-fold risk for stroke compared to sAF. Therefore, screening for aAF in high-risk patients might be appropriate to prevent further embolic cerebrovascular events.