FROM 2015 ISTH CONGRESS
TORONTO (FRONTLINE MEDICAL NEWS) – Forgoing bridging anticoagulation in patients with atrial fibrillation (AF) is noninferior to perioperative bridging with low-molecular-weight heparin for the prevention of arterial thromboembolism and decreases the risk of major bleeding.
Those results emerged from trial data presented at the International Society on Thrombosis and Haemostasis congress and published simultaneously in the New England Journal of Medicine . Study investigator Dr. Thomas Ortel, chief of the division of hematology at Duke University Medical Center, Durham, N.C., discussed results of the BRIDGE (Effectiveness of Bridging Anticoagulation for Surgery) trial, which evaluated the safety and efficacy of bridging anticoagulant therapy.
Bridging anticoagulation is frequently used in patients taking chronic oral anticoagulant therapy who need their anticoagulation transiently held for an operation or invasive procedure. The need for bridging anticoagulation never has been shown definitively, however, Dr. Ortel said in an interview.
“This is the first prospective, randomized, placebo-controlled, double-blind clinical trial to investigate the role of bridging anticoagulant therapy in patients with AF on chronic anticoagulation with warfarin who need the anticoagulant therapy held for an elective operation or invasive procedure,” he said.
Dr. Ortel and his coauthors evaluated 1,884 patients in the trial, which compared bridging and no bridging in patients with nonvalvular/valvular AF or atrial flutter who required warfarin interruption for elective surgery. The median age was 72.7 years, and 73% of patients were male. A total of 336 patients had a history of stroke or transient ischemic attack.
After stopping warfarin 5 days before the procedure, study participants received dalteparin 100 IU/kg (934 patients) or matching placebo (950 patients) for 3 days before and 5-9 days after the procedure. Dalteparin/placebo was resumed 12-24 hours after minor surgery and 48-72 hours after major surgery.
Warfarin was resumed 24 hours or less after the procedure. Follow-up lasted 30 ± 7 days after the procedure. Primary outcomes were arterial thromboembolism and major bleeding. Secondary outcomes were minor bleeding, death, myocardial infarction, and venous thromboembolism.
Protocol adherence occurred in 81% of patients before the procedure, and in 94.5% of patients post procedure.
The incidence of arterial thromboembolism was 0.4% in the no-bridging group, compared with 0.3% in the bridging group (95% confidence interval, –0.6 to 0.8; P = .01 for noninferiority). The incidence of major bleeding was 1.3% in the no-bridging group and 3.2% in the bridging group (relative risk, 0.41; 95% CI, 0.20-0.78; P = .005 for superiority).
“Current practice guidelines provide weak and inconsistent recommendations concerning the need for bridging anticoagulation,” Dr. Ortel said. “This study provides the highest level of evidence to support a strong recommendation concerning the role of bridging in this patient population.”
It is estimated that approximately one in six warfarin-treated patients with AF will need anticoagulation transiently held for an elective operation or invasive procedure each year, making this a common clinical scenario for providers, Dr. Ortel said. Knowing the findings from the BRIDGE trial will help guide clinicians in making decisions when this situation arises in their patients, he concluded.
“With the introduction of the direct oral anticoagulants, we will now need to develop periprocedural approaches to manage patients on a variety of different agents,” he said. “Warfarin continues to be extensively used in many of these patients, however, and the BRIDGE trial will contribute to improved management for these individuals.”
In response to an audience member’s question about which patients should receive bridging anticoagulation, Dr. Ortel said that “right now, our data would suggest that for AF patients, we don’t need to bridge.”
“I can’t say that, necessarily, for prosthetic heart valves or for venous thromboembolism. I think some of the recommendations that you’ve seen in the guidelines where people try to stratify this by how recently they had thromboembolism or by what type of heart valve they have – those might be the higher-risk patients to consider. But that’s all based on existing guidelines and no prospective data, so I feel comfortable telling you who you don’t need to bridge in, but I’m not going to tell you who you should,” he added.
The BRIDGE Trial was sponsored by the National Heart, Lung, and Blood Institute. Dr. Ortel disclosed grant/research support from Eisai Co. Ltd and Pfizer Inc.