Novel Oral Anticoagulant Based Versus Vitamin K Antagonist Based Double Therapy Among Stented Patients With Atrial Fibrillation: Insights From the PIONEER AF-PCI Trial.

BACKGROUND: Among stented patients with atrial fibrillation, double therapy with a novel oral anticoagulant plus single antiplatelet therapy (SAPT) reduces bleeding or cardiovascular rehospitalizations compared with a vitamin K antagonist (VKA) based triple therapy regimen. A recent study demonstrated that apixaban based double therapy reduced bleeding compared with VKA based double therapy. However, it remains unknown whether rivaroxaban based double therapy is superior to a VKA based double therapy. METHODS: Patient with stented atrial fibrillation (n=2124) were randomized to 3 groups: rivaroxaban 15 mg od plus a P2Y12 inhibitor (Group 1, n=709); rivaroxaban 2.5 mg bid plus dual antiplatelet therapy (DAPT; Group 2, n=709); and warfarin plus DAPT (Group 3, n=706). Before randomization, subjects were stratified according to a prespecified duration of DAPT (1, 6, or 12 months). After the prespecified DAPT duration, subjects in Group 2 were switched to rivaroxaban 15 mg plus low dose aspirin, and those in Group 3 were switched to VKA plus low dose aspirin. The Wei, Lin, and Weissfeld time to multiple events method was used to compare the occurrence of all bleeding and cardiovascular rehospitalizations among subjects on a novel oral anticoagulant versus VKA based double therapy. RESULTS: A total of 906 subjects were prespecified to a 1 or 6 months DAPT duration and received at least one dose of study drug. Twenty subjects (3.3%) assigned to novel oral anticoagulant+SAPT, and 15 (5.1%) subjects assigned to VKA+SAPT experienced multiple rehospitalizations. In total, 124 (20.3%) events occurred among subjects on novel oral anticoagulant+SAPT compared with 87 (29.6%) among subjects on VKA+SAPT (hazard ratio=0.65 [95% CI, 0.45-0.93], P=0.008). CONCLUSIONS: Among stented patients with atrial fibrillation, rivaroxaban plus SAPT was superior to warfarin plus SAPT in lowering total bleeding and cardiovascular rehospitalization. CLINICAL TRIAL REGISTRATION: URL: https://www.clinicaltrials.gov. Unique identifier: NCT01830543.

D-Dimer Levels and Effect of Rivaroxaban on Those Levels and Outcomes in Patients With Acute Coronary Syndrome (An ATLAS ACS-TIMI 46 Trial Substudy).

D-dimer has been used as both a diagnostic and prognostic biomarker in the assessment of patients with venous thromboembolism, but its prognostic value in the setting of arterial acute coronary syndromes (ACS) and the ability of pharmacotherapy to reduce D-dimer in ACS is less well characterized. It was hypothesized that elevated baseline D-dimer would be associated with poor clinical outcomes in ACS, and that Factor Xa inhibition with Rivaroxaban would reduce D-dimer acutely and chronically. The ATLAS ACS TIMI-46 trial assessed the safety and efficacy of rivaroxaban compared with placebo in ACS patients. A subset of subjects had a D-dimer measured at baseline (n = 1,834, 52.5%). A univariate and multivariable logistic regression assessed the relation between baseline D-dimer and a composite end point of cardiovascular death, myocardial infarction, or stroke through 6 months. The Wilcoxon rank sum test was used to compare change in D-dimer level between the treatment groups from baseline. Baseline D-dimer was associated with the composite efficacy outcome in a univariate logistic regression (odds ratio 1.15, 95% confidence interval 1.03 to 1.29, p = 0.015) and a multivariable logistic regression (odds ratio 1.13, 95% confidence interval 1.00 to 1.28, p = 0.048). Rivaroxaban administration lowered D-dimer levels compared wth placebo after administration of the first dose of study drug (p = 0.026), at day 30 (p < 0.001) and day 180 (p < 0.001). In conclusion, elevated baseline D-dimer was associated with an increased risk of the composite outcome within 6 months of the ACS event and administration of the Factor Xa inhibitor rivaroxaban was associated with lower D-dimer levels compared with placebo after the first dose, at day 30 and day 180.