1. Patients with atrial fibrillation are often treated with long-term oral anticoagulation, and may require interruption of their anticoagulation for elective surgeries or invasive procedures.
2. This study demonstrated that periprocedural bridging with dalteparin did not significantly reduce the risk of arterial thromboembolic disease when compared to placebo.
3. Patients treated with bridging dalteparin experienced significantly higher risk of major and minor bleeding.
Original Date of Publication: August 2015
Study Rundown: Patients with atrial fibrillation are at a higher risk of stroke, transient ischemic attack (TIA), and systemic embolism. An important aspect of managing patients with atrial fibrillation involves treating them with long-term oral anticoagulation to reduce this risk. There has long been uncertainty regarding the need for bridging anticoagulation in these patients when their oral anticoagulants are held in preparation for an elective surgery or invasive procedure. The Bridging Anticoagulation in Patients who Require Temporary Interruption of Warfarin Therapy for an Elective Invasive Procedure or Surgery (BRIDGE) trial sought to determine the effects of bridging with dalteparin in patients with atrial fibrillation. In summary, the study demonstrated that there were no significant differences in the rates of arterial embolism (i.e., stroke, TIA, systemic embolism) between those who received bridging therapy and those who did not. The rates of major and minor bleeding were significantly higher, however, in patients who did receive bridging therapy. Based on these findings, periprocedural bridging with low-molecular-weight heparin is not recommended.
One major limitation of the study was that few patients at high-risk of stroke were involved in the study (i.e., CHADS2 score of 5 or 6). Another important note is that patients with mechanical heart valves were not included in this trial. Eisai donated dalteparin to the study, but had no role in the design or conduct of the study, data analysis, or manuscript preparation.
Click to read the study in NEJM
In-Depth [randomized controlled trial]: This randomized trial was conducted at 108 sites in the United States and Canada. Patients were eligible for the trial if they were ≥18 years of age, had permanent or paroxysmal atrial fibrillation or flutter, were on warfarin therapy ≥3 months, were undergoing an elective operation or procedure requiring interruption of their warfarin, and had one of the CHADS2 risk factors (i.e., congestive heart failure, hypertension, age ≥75 years, diabetes mellitus, previous stroke/embolism). Exclusion criteria included having a mechanical heart valve, stroke/systemic embolism/TIA in the previous 12 weeks, major bleeding in the previous 6 weeks, creatinine clearance <30 mL/minute, platelet count <100×103/m3, or planned cardiac/intracranial/intraspinal surgery. Eligible patients were randomized in a 1:1 ratio to either bridging with dalteparin (100 IU/kg subcutaneously twice daily) or placebo from 3 days prior to the procedure until 24 hours prior, and then for 5-10 days after the procedure (i.e., until the INR was ≥2). The primary efficacy outcome was the rate of arterial thromboembolism (i.e., stroke, TIA, or systemic embolism), while the primary safety outcome was the rate of major bleeding at 30 days. Minor bleeding was a secondary safety outcome.
Outcomes were assessed for 1813 patients. Very few patients in either group had CHADS2 scores of 5 or 6 (2.7% in the no bridging group, 3.4% in the bridging group). There were no significant differences between the bridging and non-bridging groups in the risk of arterial thromboembolism at 30 days (0.4% vs. 0.3%, respectively; p = 0.01 for non-inferiority, p = 0.73 for superiority). The risk of major bleeding was significantly higher in the bridging group (3.2% vs. 1.3%; p = 0.005). Minor bleeding was also more frequently seen in the bridging group as compared with those on placebo (20.9% vs. 12.0%; p < 0.001).
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