Perioperative Bridging Anticoagulation

Posted by • August 28th, 2015

Perioperative Bridging AnticoagulationIn this Original Article, a trial assigned patients with atrial fibrillation who required warfarin interruption for an elective procedure to either bridging anticoagulation or placebo. Forgoing bridging was noninferior to bridging for arterial thromboembolism and superior for major bleeding. A video summary is also available with the article on NEJM.org.

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. A randomized, double-blind, placebo-controlled trial by Douketis, et al. (the Bridging Anticoagulation in Patients who Require Temporary Interruption of Warfarin Therapy for an Elective Invasive Procedure or Surgery [BRIDGE] trial) hypothesized that forgoing bridging anticoagulation would be noninferior to bridging with low-molecular-weight heparin for the prevention of perioperative arterial thromboembolism and would be superior to bridging with respect to major bleeding.

Figure 1. BRIDGE Study Design.

Table 1. Baseline Characteristics of the Patients. 

Clinical Pearls

Do patients with atrial fibrillation who require interruption of their warfarin therapy for an elective operation have a worse outcome with respect to perioperative arterial thromboembolism if they forgo bridging anticoagulation?

In the Douketis study, 1884 patients were enrolled, with 950 assigned to receive no bridging therapy and 934 assigned to receive bridging therapy. The primary efficacy outcome was arterial thromboembolism at 30 days. In this study, a strategy of discontinuing warfarin treatment without the use of bridging anticoagulation was noninferior to the use of bridging anticoagulation for the prevention of arterial thromboembolism. At 30 days after the procedure, the incidence of arterial thromboembolism was 0.4% (four events among 918 patients) in the no-bridging group and 0.3% (three events among 895 patients) in the bridging group (mean between-group dif

ference, 0.1 percentage points; 95% confidence interval [CI], −0.6 to 0.8; P=0.01 for noninferiority; P=0.73 for superiority).

Table 2. Perioperative Anticoagulant Management.

How much greater is the risk of major bleeding with the use of bridging anticoagulation as compared to a strategy that discontinues perioperative warfarin treatment?

In the study by Douketis et al., bridging conferred a risk of major bleeding that was nearly triple the risk associated with no bridging. Major bleeding occurred in 1.3% of the patients (12 of 918) in the no-bridging group and in 3.2% (29 of 895) in the bridging group, which indicated that no bridging was superior to bridging with regard to major bleeding (relative risk, 0.41; 95% CI, 0.20 to 0.78; P=0.005).

Morning Report Questions

Q: Does a strategy forgoing bridging anticoagulation in this clinical setting increase the risk of myocardial infarction or venous thromboembolism?

A: In the Douketis study, there was no significant difference between the groups in the rates of acute myocardial infarction, deep-vein thrombosis, pulmonary embolism, or death.

Table 3. Study Outcomes.

Q: How generalizable are the findings of the Douketis study?

A: There are potential limitations of the BRIDGE trial. First, although it aimed to recruit a representative sample of patients with atrial fibrillation for whom bridging anticoagulation is normally considered, certain groups were underrepresented. Few patients had a CHADS2 score of 5 or 6, although the mean score of 2.3 is similar to that among patients with atrial fibrillation who were assessed in recent trials and patient registries, in which the mean scores were between 2.1 and 2.8. Patients undergoing major surgical procedures associated with high rates of arterial thromboembolism and bleeding (e.g., carotid endarterectomy, major cancer surgery, cardiac surgery, or neurosurgery) were not represented in the trial, although the procedures performed were representative of the most common interventions patients undergo during an interruption of therapeutic anticoagulation, the majority of which are low-risk procedures, such as colonoscopy or ambulatory surgery. In addition, the findings should not be applied to patients with mechanical heart valves, who were specifically not included in the trial.

Comments are closed.