Warfarin superior to antiplatelet treatment for A Fib
Clinical QuestionWhat benefit does warfarin provide over antiplatelet therapy in patients with nonvalvular atrial fibrillation?
Bottom LineWarfarin treatment is more effective than antiplatelet treatment in preventing strokes and delaying mortality in patients with atrial fibrillation. The difference between the two approaches is greater for patients who have already had a stroke or transient ischemic attack (TIA). Using rough estimates, 1 stroke is prevented for every 40 patients (who have not had a previous stroke or TIA) treated with warfarin instead of placebo, or for every 14 patients who have had a previous event. One stroke is prevented for every 81 previous stroke or TIA patients treated with warfarin instead of antiplatelet therapy (primary prevention) or for every 24 patients who have had a previous event. (LOE = 1a)
ReferenceHart RG, Pearce LA, Aguilar MI. Meta-analysis: Antithrombotic therapy to prevent stroke in patients who have nonvalvular atrial fibrillation. Ann Intern Med 2007;146:857-867. [PMID:17577005]
Study DesignMeta-analysis (randomized controlled trials)
FundingSelf-funded or unfunded
SynopsisResearch continues to find the best approach to preventing stroke in patients with nonvalvular atrial fibrillation. The current study is an updated meta-analysis previously performed by the authors: 13 randomized studies enrolling an additional 18,000 patients have been conducted since 1999, including 4 trials that are ongoing or have not been published. The studies were identified by searching 2 databases, contacting investigators, and searching reference lists of identified studies. The new meta-analysis included 29 studies with a total 28,044 patients comparing anticoagulation and antiplatelet therapy with placebo or each other. The study results were not homogeneous and the researchers used a random effects model to better handle the heterogeneity. In patients receiving placebo, the stroke rate was 13% per year for patients who had a previous stroke or TIA, and 4.1% per year for those who had not had a previous event. Most patients in the studies had not experienced a previous event. As compared with antiplatelet therapy alone, warfarin decreased strokes by 37%, including when compared with the combination of clopidogrel and aspirin. In absolute terms, the rate of stroke was 0.7% less per year with warfarin than with aspirin for patients without a previous event and 7% less in patients with a previous TIA or stroke. The risk of intracranial hemorrhage was higher with warfarin, though the increase was small, only 0.2% per year. Overall mortality was 9% less with warfarin than with antiplatelet treatment (absolute rate difference = 0.5% per year).
Barry, Henry, et al., editors. "Warfarin Superior to Antiplatelet Treatment for a Fib." EE+ POEM Archive, John Wiley & Sons, 2019. Evidence Central, evidence.unboundmedicine.com/evidence/view/infoPOEMs/426592/all/Warfarin_superior_to_antiplatelet_treatment_for_A_Fib.
Warfarin superior to antiplatelet treatment for A Fib. In: Barry HH, Ebell MHM, Shaughnessy AFA, et al, eds. EE+ POEM Archive. John Wiley & Sons; 2019. https://evidence.unboundmedicine.com/evidence/view/infoPOEMs/426592/all/Warfarin_superior_to_antiplatelet_treatment_for_A_Fib. Accessed June 10, 2023.
Warfarin superior to antiplatelet treatment for A Fib. (2019). In Barry, H., Ebell, M. H., Shaughnessy, A. F., & Slawson, D. C. (Eds.), EE+ POEM Archive. John Wiley & Sons. https://evidence.unboundmedicine.com/evidence/view/infoPOEMs/426592/all/Warfarin_superior_to_antiplatelet_treatment_for_A_Fib
Warfarin Superior to Antiplatelet Treatment for a Fib [Internet]. In: Barry HH, Ebell MHM, Shaughnessy AFA, Slawson DCD, editors. EE+ POEM Archive. John Wiley & Sons; 2019. [cited 2023 June 10]. Available from: https://evidence.unboundmedicine.com/evidence/view/infoPOEMs/426592/all/Warfarin_superior_to_antiplatelet_treatment_for_A_Fib.
* Article titles in AMA citation format should be in sentence-case
TY - ELEC T1 - Warfarin superior to antiplatelet treatment for A Fib ID - 426592 ED - Barry,Henry, ED - Ebell,Mark H, ED - Shaughnessy,Allen F, ED - Slawson,David C, BT - EE+ POEM Archive UR - https://evidence.unboundmedicine.com/evidence/view/infoPOEMs/426592/all/Warfarin_superior_to_antiplatelet_treatment_for_A_Fib PB - John Wiley & Sons DB - Evidence Central DP - Unbound Medicine ER -