Apixaban Plus Mono Versus Dual Antiplatelet Therapy in Acute Coronary Syndromes: Insights From the APPRAISE-2 Trial

Item does not contain fulltextBACKGROUND: Bleeding limits anticoagulant treatment in patients with acute coronary syndromes (ACS). OBJECTIVES: We investigated whether background concomitant antiplatelet therapy influences the effects of apixaban after ACS. METHODS: This study examined high-risk ACS patients who were treated with aspirin or aspirin plus clopidogrel and who were randomized to apixaban 5 mg twice daily or placebo. In a post-hoc analysis, we assessed whether the effect of apixaban on efficacy and safety outcomes varied by the concomitant antiplatelet regimen by using simple Cox modeling and marginal structural models with propensity scores and antiplatelet therapy as a time-dependent covariate. RESULTS: At baseline, of 7,364 patients, 16.3% (n = 1,202) were on aspirin alone, and 79.0% (n = 5,814) were on aspirin plus clopidogrel. A total of 19.2% (n = 1,415) switched antiplatelet therapy during follow-up. No differential effect of apixaban versus placebo was observed for the composite endpoint of cardiovascular death, myocardial infarction, and ischemic stroke in patients taking aspirin (12.21 per 100 patient-years vs. 13.21 per 100 patient-years; adjusted hazard ratio [HR]: 0.91; 95% confidence interval [CI]: 0.62 to 1.32) or aspirin plus clopidogrel (13.22 vs. 14.24; adjusted HR: 0.95; 95% CI: 0.78 to 1.14; pinteraction = 0.84). Compared with placebo, apixaban increased Thrombolysis In Myocardial Infarction major bleeding in patients taking aspirin (1.48 vs. 0.25; adjusted HR: 6.62; 95% CI: 0.75 to 51.73) and in patients taking aspirin plus clopidogrel (2.58 vs. 1.02; adjusted HR: 2.44; 95% CI: 1.34 to 4.45; pinteraction = 0.41). Similar results were obtained with marginal structural models and in patients treated with and without percutaneous coronary intervention. CONCLUSIONS: Post-ACS treatment with apixaban versus placebo showed no efficacy, but it increased bleeding regardless of concomitant therapy with aspirin alone or aspirin plus clopidogrel. (Apixaban for Prevention of Acute Ischemic Events 2 [APPRAISE-2]; NCT00831441)

Response to letter regarding article, "Efficacy and Safety of Apixaban Compared With Warfarin at Different Levels of Predicted International Normalized Ratio Control for Stroke Prevention in Atrial Fibrillation"

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Efficacy and safety of apixaban compared with warfarin at different levels of predicted international normalized ratio control for stroke prevention in atrial fibrillation

Background—In the Apixaban for Reduction in Stroke and Other Thromboembolic Events in Atrial Fibrillation (ARISTOTLE) trial, apixaban compared with warfarin reduced stroke and systemic embolism, major bleeding, and mortality. We evaluated treatment effects in relation to 2 predictions of time in therapeutic range (TTR).<p></p> Methods and Results—The trial randomized 18 201 patients with atrial fibrillation to apixaban 5 mg twice daily or warfarin for at least 12 months. For each patient, a center average TTR was estimated with the use of a linear mixed model on the basis of the real TTRs in its warfarin-treated patients, with a fixed effect for country and random effect for center. For each patient, an individual TTR was also predicted with the use of a linear mixed effects model including patient characteristics as well. Median center average TTR was 66% (interquartile limits, 61% and 71%). Rates of stroke or systemic embolism, major bleeding, and mortality were consistently lower with apixaban than with warfarin across center average TTR and individual TTR quartiles. In the lowest and highest center average TTR quartiles, hazard ratios for stroke or systemic embolism were 0.73 (95% confidence interval [CI], 0.53–1.00) and 0.88 (95% CI, 0.57–1.35) (Pinteraction=0.078), for mortality were 0.91 (95% CI, 0.74–1.13) and 0.91 (95% CI, 0.71–1.16) (Pinteraction=0.34), and for major bleeding were 0.50 (95% CI, 0.36–0.70) and 0.75 (95% CI, 0.58–0.97) (Pinteraction=0.095), respectively. Similar results were seen for quartiles of individual TTR.<p></p> Conclusions—The benefits of apixaban compared with warfarin for stroke or systemic embolism, bleeding, and mortality appear similar across the range of centers’ and patients’ predicted quality of international normalized ratio control.<p></p&gt