Do novel oral anticoagulants safely prevent stroke in patients with nonvalvular A-fib?

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Yes. Dabigatran, rivaroxaban, and apixaban are safe and effective compared with warfarin for preventing stroke in patients with nonvalvular atrial fibrillation. These novel oral anticoagulants (NOACs) are noninferior in reducing the number of strokes and systemic emboli and in lowering all-cause mortality while not increasing major bleeding complications and hemorrhagic events (strength of recommendation: A, consistent meta-analyses of randomized controlled trials [RCTs]).

Evidence summary

A 2014 meta-analysis of 4 RCTs including 71,683 patients with nonvalvular atrial fibrillation evaluated the NOACs dabigatran, rivaroxaban, apixaban, and edoxaban, for efficacy and safety compared with warfarin.1 The RCTs analyzed 42,411 patients receiving NOACs and 29,272 patients receiving warfarin. All trials were designed to show noninferiority. Selection criteria for RCTs included all phase 3 trials of available NOACs (edoxaban isn’t available in the United States). Median follow-up was 1.8 to 2.8 years.

Pooled data demonstrated that NOACs were noninferior to warfarin in preventing stroke or systemic embolism (relative risk [RR]=0.81; 95% confidence interval [CI], 0.73-0.91; number needed to treat [NNT]=147). The main benefit was derived from the relatively large decrease in the rate of hemorrhagic stroke (RR=0.49; 95% CI, 0.38-0.64; NNT=97) compared with warfarin. All-cause mortality was lower with NOACs as well (RR=0.90; 95% CI, 0.85-0.95; NNT=128).

A significant increase in gastrointestinal bleeding occurred with NOACs compared with warfarin (RR=1.3; 95% CI, 1.1-1.6; number needed to harm=185), but NOACs were associated with a decrease in intracranial hemorrhage similar to the reduction in hemorrhagic stroke (RR=0.48; 95% CI, 0.39-0.59; NNT=132).

Evidence-based answers from the Family Physicians Inquiries Network

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