Efficacy and Safety of Rivaroxaban Versus Aspirin in Embolic Stroke of Undetermined Source and Carotid Atherosclerosis.

Background and Purpose- The sources of emboli in patients with embolic stroke of undetermined source (ESUS) are multiple and may not respond uniformly to anticoagulation. In this exploratory subgroup analysis of patients with carotid atherosclerosis in the NAVIGATE (New Approach Rivaroxaban Inhibition of Factor Xa in a Global Trial Versus ASA to Prevent Embolism)-ESUS trial, we assessed whether the treatment effect in this subgroup is consistent with the overall trial population and investigated the association of carotid atherosclerosis with recurrent ischemic stroke. Methods- Carotid atherosclerosis was analyzed either as the presence of mild (ie, 20%-49%) atherosclerotic stenosis or, separately, as the presence of carotid plaque. Primary efficacy outcome was ischemic stroke recurrence. Safety outcomes were major bleeding and symptomatic intracerebral bleeding. Results- Carotid plaque was present in 40% of participants and mild carotid stenosis in 11%. There was no significant difference in ischemic stroke recurrence between rivaroxaban- and aspirin-treated patients among 490 patients with carotid stenosis (5.0 versus 5.9/100 patient-years, respectively, hazard ratio [HR], 0.85; 95% CI, 0.39-1.87; P for interaction of treatment effect with patients without carotid stenosis 0.78) and among 2905 patients with carotid plaques (5.9 versus 4.9/100 patient-years, respectively, HR, 1.20; 95% CI, 0.86-1.68; P for interaction of treatment effect with patients without carotid stenosis 0.2). Among patients with carotid plaque, major bleeding was more frequent in rivaroxaban-treated patients compared with aspirin-treated (2.0 versus 0.5/100 patient-years, HR, 3.75; 95% CI, 1.63-8.65). Patients with carotid stenosis had similar rate of ischemic stroke recurrence compared with those without (5.4 versus 4.9/100 patient-years, respectively, HR, 1.11; 95% CI, 0.73-1.69), but there was a strong trend of higher rate of ischemic stroke recurrence in patients with carotid plaque compared with those without (5.4 versus 4.3/100 patient-years, respectively, HR, 1.23; 95% CI, 0.99-1.54). Conclusions- In ESUS patients with carotid atherosclerosis, we found no difference in efficacy between rivaroxaban and aspirin for prevention of recurrent stroke, but aspirin was safer, consistent with the overall trial results. Carotid plaque was much more often present ipsilateral to the qualifying ischemic stroke than contralateral, supporting an important etiological role of nonstenotic carotid disease in ESUS. Clinical Trial Registration- URL: https://www.clinicaltrials.gov. Unique identifier: NCT02313909.

Real-World Setting Comparison of Nonvitamin-K Antagonist Oral Anticoagulants Versus Vitamin-K Antagonists for Stroke Prevention in Atrial Fibrillation: A Systematic Review and Meta-Analysis.

BACKGROUND AND PURPOSE: Evidence from the real-world setting complements evidence coming from randomized controlled trials. We aimed to summarize all available evidence from high-quality real-world observational studies about efficacy and safety of nonvitamin-K oral anticoagulants compared with vitamin-K antagonists in patients with atrial fibrillation. METHODS: We searched PubMed and Web of Science until January 7, 2017 for observational nationwide or health insurance databases reporting matched or adjusted results comparing nonvitamin-K oral anticoagulants versus vitamin-K antagonists in patients with atrial fibrillation. Outcomes assessed included ischemic stroke, ischemic stroke or systemic embolism, any stroke or systemic embolism, myocardial infarction, intracranial hemorrhage, major hemorrhage, gastrointestinal hemorrhage, and death. RESULTS: In 28 included studies of dabigatran, rivaroxaban, and apixaban compared with vitamin-K antagonists, all 3 nonvitamin-K oral anticoagulants were associated with a large reduction of intracranial hemorrhage (apixaban hazard ratio [HR], 0.45; 95% confidence interval [CI], 0.31-0.63; dabigatran HR, 0.42; 95% CI, 0.37-0.49; rivaroxaban HR, 0.64; 95% CI, 0.47-0.86); similar rates of ischemic stroke and ischemic stroke or systemic embolism (apixaban HR, 1.05; 95% CI, 0.75-1.19 and HR, 1.08; 95% CI, 0.95-1.22 / dabigatran HR, 0.96; 95% CI, 0.80-1.16 and HR, 1.17; 95% CI, 0.92-1.50 / rivaroxaban HR, 0.89; 95% CI, 0.76-1.04 and HR, 0.73; 95% CI, 0.52-1.04, respectively); apixaban and dabigatran with lower mortality (HR, 0.65; 95% CI, 0.56-0.75 and HR, 0.63; 95% CI, 0.53-0.75, respectively); apixaban with fewer gastrointestinal (HR, 0.63; 95% CI, 0.42-0.95) and major hemorrhages (HR, 0.55; 95% CI, 0.48-0.63); dabigatran and rivaroxaban with more gastrointestinal hemorrhages (HR, 1.20; 95% CI, 1.06-1.36 and HR, 1.24; 95% CI, 1.08-1.41, respectively); dabigatran and rivaroxaban with similar rate of myocardial infarction (HR, 0.96; 95% CI, 0.77-1.21 and HR, 1.02; 95% CI, 0.54-1.89, respectively). CONCLUSIONS: This meta-analysis confirms the main findings of the randomized controlled trials of dabigatran, rivaroxaban, and apixaban in the real-world setting and, hence, strengthens their validity.