, according to results of an updated comparative effectiveness review.
Dabigatran (Pradaxa), by contrast, has shown reductions in stroke events but a similar rate of bleeding events compared to warfarin, according to the report from the Duke Evidence-based Practice Center, Durham, N.C.
Rivaroxaban (Xarelto), meanwhile, is “similar in both benefits and harms with warfarin” in evidence to date, investigators wrote in the report, which was prepared for the Agency for Healthcare Research and Quality (AHRQ) and the Patient-Centered Outcomes Research Institute (PCORI).
Finally, edoxaban (Savaysa) is “most likely similar” to warfarin with respect to preventing stroke or systemic embolism, with less risk for major bleeding and hemorrhagic stroke, investigators wrote in a summary of their findings on the AHRQ website.
“Effectiveness of these direct oral anticoagulants as compared to one another however is limited by the lack of randomized studies directly comparing their safety and effectiveness,” concluded investigators, led by Gillian D. Sanders, PhD, of Duke University.
The 612-page report details a systematic review based on 320 articles representing 185 unique studies. The review was designed to update a 2013 AHRQ report that evaluated evidence not only for treatment options to prevent stroke in patients with atrial fibrillation, but also for tools used to predict risk of stroke or bleeding.
In the 2013 report, investigators concluded that the newer anticoagulants showed “early promise” in reducing stroke and bleeding events compared with warfarin.
That earlier report said that CHA2 and CHA2DS2-VASc had the best evidence to support prediction of stroke events, while HAS-BLED provided the best discrimination of bleeding risk.
The updated report adds the ABC stroke risk score as a tool that, along with CHADS2 and CHA2DS2-VASc, has the “best evidence” predicting thromboembolic risk, authors said.
Imaging tools, on the other hand, still need more evidence supporting their use to predict thromboembolic risk, Dr. Sanders and colleagues said in their report.
The literature review, which covered the January 2000 through February 2018, turned up 61 studies relevant to predicting thromboembolic risk, 38 on bleeding risk, and 117 on preventing thromboembolic events with anticoagulation therapies, antiplatelet therapies, or procedures.
Direct oral anticoagulants were evaluated in randomized clinical trials that were “often very large, of good quality, and considered definitive in the field,” Dr. Sanders and colleagues wrote in their report.
However, these trials were constrained to comparing direct oral anticoagulants with warfarin or aspirin, and have not involved head-to-head comparison among the newer agents, they added.
“Based on these trials though, clinical leaders and professional societies have determined that these newer agents are better than the prior lone treatment of warfarin in terms of stroke prevention, side effects, and risk of bleeding,” they said in the published report.
SOURCE: Sanders GD, et al. 2018 Oct 30. AHRQ Publication No. 18(19)-EHC018-EF.
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