Switching of Oral Anticoagulation Therapy After PCI in Patients With Atrial Fibrillation: The RE-DUAL PCI Trial Subanalysis. 
The aim of this study was to assess if prior oral anticoagulant agent (OAC) use modifies the lower bleeding risk observed with dabigatran dual therapy (dabigatran twice daily plus a P2Y12 inhibitor) versus warfarin triple therapy (warfarin plus a P2Y12 inhibitor plus aspirin) in patients with atrial fibrillation who underwent percutaneous coronary intervention (PCI).  In the RE-DUAL PCI (Randomized Evaluation of Dual Antithrombotic Therapy With Dabigatran Versus Triple Therapy With Warfarin in Patients With Nonvalvular Atrial Fibrillation Undergoing Percutaneous Coronary Intervention) trial, the primary outcome of major bleeding or clinically relevant nonmajor bleeding was lower with dabigatran dual therapy versus warfarin triple therapy in patients with atrial fibrillation who underwent PCI.  A total of 2,725 patients were randomized to dual therapy with dabigatran (110 or 150 mg twice daily) plus clopidogrel or ticagrelor or triple therapy with warfarin plus aspirin and clopidogrel or ticagrelor.  Subgroup analysis compared risk for major bleeding or clinically relevant nonmajor bleeding and a composite thromboembolic endpoint in patients with prior OAC use and in those who were OAC treatment naive.  Risk for major bleeding or clinically relevant nonmajor bleeding was reduced with both dabigatran dual therapies compared with warfarin triple therapy in both the prior OAC use group (hazard ratios: 0.58 [95% confidence interval (CI): 0.42 to 0.81] and 0.61 [95% CI: 0.41 to 0.92] with 110 and 150 mg dabigatran, respectively) and the OAC-naive group (hazard ratios: 0.49 [95% CI: 0.38 to 0.63] and 0.76 [95% CI: 0.59 to 0.97] with 110 and 150 mg dabigatran) (p for interaction = 0.42 and 0.37, 110 and 150 mg dabigatran, respectively).  The risk for thromboembolic events seemed similar with dabigatran dual therapy (both doses) and warfarin triple therapy across subgroups.  Bleeding risk was reduced with dabigatran dual therapy versus warfarin triple therapy in patients with atrial fibrillation after PCI, regardless of whether they were prior OAC users or OAC treatment naive.  These results suggest that it is also safe to switch patients on OAC pre-PCI to dabigatran dual therapy post-PCI.