In this trial, patients with atrial fibrillation who required warfarin interruption for an elective procedure were assigned to either bridging anticoagulation or placebo. Forgoing bridging was noninferior to bridging for arterial thromboembolism and superior for major bleeding. For patients with atrial fibrillation who are receiving warfarin and require an elective operation or other elective invasive procedure, the need for bridging anticoagulation during perioperative interruption of warfarin treatment has long been uncertain. 1 – 3 Each year, this common clinical scenario affects approximately one in six warfarin-treated patients with atrial fibrillation. 4 , 5 Warfarin treatment is typically stopped 5 days before an elective procedure to allow its anticoagulant effect to wane; it is resumed after the procedure, when hemostasis is secured, at which point 5 to 10 days of treatment is required to attain therapeutic anticoagulation. 6 , 7 During the interruption of . . .