Guideline update issued on prevention of stroke in nonvalvular afib

The American Academy of Neurology recently issued a guideline update on preventing stroke in patients with nonvalvular atrial fibrillation (NVAF).

The guideline update reviewed the evidence published since 1998, when the Academy's last guideline on this topic was issued, and focused on how often various technologies identify previously undetected NVAF in patients with cryptogenic stroke, as well as which therapies including antithrombotic medications reduce stroke risk and severity and have the lowest risk of hemorrhage. The guideline panel based its practice recommendations on the strength of the evidence according to systematic review, principles of care, benefits and harms, costs, intervention availability, and patients' preferences.

The panel concluded that cardiac rhythm monitoring probably detects occult NVAF in patients who have recently had a cryptogenic stroke. In addition, it found that dabigatran, rivaroxaban and apixaban are probably at least as effective as warfarin for stroke prevention but confer a lower hemorrhage risk. Triflusal added to acenocoumarol appears to be more effective than acenocoumarol monotherapy in reducing risk for stroke, the panel noted. Clopidogrel plus aspirin, meanwhile, appears to be less effective than warfarin for stroke prevention with a lower intracranial bleeding risk; this combination also appears to reduce stroke risk more than aspirin alone but with a higher risk for major hemorrhage. Aspirin and apixaban have similar bleeding risk, but the latter appears to be more effective in reducing risk for stroke, the panel said.

Based on its findings, the panel recommended that clinicians choose one of the following regimens to reduce risk for stroke or subsequent stroke in patients with NVAF who are thought to require oral anticoagulants (Level B recommendation):

• warfarin, with a target international normalized ratio of 2.0 to 3.0;
• dabigatran, 150 mg twice daily (in patients with a creatinine clearance >30 mL/min);
• rivaroxaban, 15 mg/d (in patients with a creatinine clearance of 30 to 49 mL/min) or 20 mg/d;
• apixaban, 5 mg twice daily (in patients with a serum creatinine >1.5 and <2.5 mg/dL and body weight <60 kg or age ≥80 years or both); or
• triflusal, 500 mg, plus acenocoumarol, with a target international normalized ratio of 1.25 to 2.0 (for patients at moderate risk for stroke; this choice is mainly for those in developing countries).

The panel noted that clinicians might obtain outpatient cardiac rhythm studies in patients with cryptogenic stroke but no known NVAF in order to identify occult NVAF (Level C recommendation). In addition, the panel said, clinicians should prescribe dabigatran, rivaroxaban, or apixaban to patients with NVAF who require anticoagulant medication and have a high risk for intracranial bleeding (Level B recommendation).

Clinicians should offer oral anticoagulation routinely to NVAF patients older than 75 if they have no history of recent unprovoked bleeding or intracranial hemorrhage (Level B recommendation); oral anticoagulation can also be offered to NVAF patients with dementia or occasional falls, but patients or family members should be told that the risk-benefit ratio is not known in those whose dementia is moderate or severe or in those who fall very frequently, the panel said (Level B recommendation).

A summary of the guideline, which was published Feb. 24 by Neurology, is available online.