Summary of evidence-based guideline update: prevention of stroke in nonvalvular atrial fibrillation: report of the Guideline Development Subcommittee of the American Academy of Neurology

Abstract

Objective: To update the 1998 American Academy of Neurology practice parameter on stroke prevention in nonvalvular atrial fibrillation (NVAF). How often do various technologies identify previously undetected NVAF? Which therapies reduce ischemic stroke risk with the least risk of hemorrhage, including intracranial hemorrhage? The complete guideline on which this summary is based is available as an online data supplement to this article.

Methods: Systematic literature review; modified Delphi process recommendation formulation.

Major conclusions: In patients with recent cryptogenic stroke, cardiac rhythm monitoring probably detects occult NVAF. In patients with NVAF, dabigatran, rivaroxaban, and apixaban are probably at least as effective as warfarin in preventing stroke and have a lower risk of intracranial hemorrhage. Triflusal plus acenocoumarol is likely more effective than acenocoumarol alone in reducing stroke risk. Clopidogrel plus aspirin is probably less effective than warfarin in preventing stroke and has a lower risk of intracranial bleeding. Clopidogrel plus aspirin as compared with aspirin alone probably reduces stroke risk but increases the risk of major hemorrhage. Apixaban is likely more effective than aspirin for decreasing stroke risk and has a bleeding risk similar to that of aspirin.

Major recommendations: Clinicians might obtain outpatient cardiac rhythm studies in patients with cryptogenic stroke to identify patients with occult NVAF (Level C) and should routinely offer anticoagulation to patients with NVAF and a history of TIA/stroke (Level B). Specific patient considerations will inform anticoagulant selection in patients with NVAF judged to need anticoagulation.

Figure 1. Proportion of patients with ischemic stroke identified with nonvalvular atrial fibrillation, by study

Studies sorted by monitoring duration. CI = confidence interval; ELR = event loop recorder; HM = Holter monitoring; inptTele = continuous inpatient telemetry; MCOT = mobile cardiac outpatient telemetry; phoneEKG = outpatient transtelephonic EKG monitoring; sEKG = serial EKG; sELR = serial event loop recordings.

Figure 2. Relative risk reductions of various outcomes in patients with nonvalvular atrial fibrillation receiving various antithrombotic regimens as compared with warfarin or its derivatives

Acenocoum = acenocoumarol; ASA = acetylsalicylic acid; CI = confidence interval.