Warfarin discontinuation ‘unnecessary’ for pacemaker surgery
medwireNews: Warfarin should not be discontinued in favor of heparin before pacemaker or implantable cardioverter-defibrillator (ICD) surgery in patients with a moderate-to-high risk for thromboembolism, the Bruise Control trial investigators recommend.
Just 3.5% of the 343 patients randomly assigned to continue their oral anticoagulation therapy during cardiac device surgery developed a clinically significant device-pocket hematoma compared with 16.0% of the 338 patients who began heparin bridging therapy 3 days in advance, report David Birnie (University of Ottawa Heart Institute, Ontario, Canada) and co-workers.
Warfarin continuation was also associated with a significantly lower need for hematoma-related hospitalization (1.2 vs 4.7%), hematoma-related halt to anticoagulation (3.2 vs 14.2%), and the need for hematoma evacuation (0.6 vs 2.7%) compared with bridging therapy.
Noting that patients with hematoma experienced greater pain and poorer quality of life than those without the complication, the researchers say: "These results suggest that continuation of warfarin during pacemaker or ICD surgery may be preferable to bridging therapy with heparin, at least for patients like those enrolled in our trial."
All patients had a 5% or greater predicted annual risk for thromboembolism. The rate of events was comparable between the treatment groups; one case of stroke and one case of transient ischemic attack in the continuing warfarin group, while the heparin bridging group had one case of cardiac tamponade and one myocardial infarction.
Commenting in a press release, author Vidal Essebag (McGill University Health Center, Montreal, Quebec, Canada) noted that the reduced risk for hematoma with warfarin continuation may seem "counterintuitive."
"One explanation that has been proposed is the concept of an 'anticoagulant stress test.' That is, if patients undergo surgery while fully anticoagulated, any excessive bleeding will be detectable and appropriately managed while the wound is still open," he hypothesized.
"In contrast, when surgery is performed with heparin bridging, such bleeding may remain latent, and appear only when full anticoagulation is resumed postoperatively."
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By Lynda Williams, Senior medwireNews Reporter