Samuel Z. Goldhaber, MD


June 04, 2015

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Hello. This is Dr Sam Goldhaber from the Clot Blog at on Medscape, recording from the American College of Cardiology Scientific Sessions in San Diego.

The topic of this Clot Blog is "London Bridge Is Falling Down." We're going to discuss the recently published ORBIT-AF Registry,[1] which looked at bridging.

ORBIT-AF is a real-world registry of patients with atrial fibrillation. Of more than 7000 patients who were followed, about 2200 had to interrupt their anticoagulation for various procedures, such as colonoscopy, or for surgery.

There has been a traditional approach of stopping warfarin for 4 days prior to an operation, covering the patients with low-molecular-weight heparin as a bridge into surgery, and then stopping the low-molecular-weight heparin at the time of surgery. The idea is that this would permit the warfarin to be metabolized and at the same time would prevent perioperative thrombosis, such as myocardial infarction (MI) and stroke.

I have to say that bridging seems to have been gradually falling out of favor, certainly in North America. What we find in the ORBIT-AF study is that more than 2000 patients had interruption of their anticoagulation for about 2800 various procedures that were done in the course of the study. Believe it or not, there was actually no reduction whatsoever in the myocardial infarction, stroke, and other thrombosis rates in patients who were given the bridging protocols, whereas patients who were not bridged, who simply stopped the anticoagulation, had fewer MIs and strokes. This didn't necessarily reach a statistically significant difference after various adjustments were made for patient characteristics, but what happened for sure is that with the bridging strategy there was far more major bleeding—about three times as much major bleeding with bridging compared with no bridging.

It appears that what already is starting to happen in practice is being backed up by this large observational registry, ORBIT-AF. So far—when we actually step back and look at various observational studies that have been done on bridging—there is no evidence that bridging will reduce stroke, MI, or other thrombotic complications preoperatively. And there is a great deal of evidence to suggest that bridging will increase major bleeding complications.

In our personal practice we rarely bridge our patients. We will, of course, bridge them if they have mechanical mitral valves or if they had some sort of thrombotic episode within the 3 months prior to surgery. And there are other exceptional circumstances; we might consider bridging if a patient has antiphospholipid antibody syndrome. But for the most part, we simply have the patient hold their warfarin or hold their novel oral anticoagulant. It seems that this recently published study backs up what is happening in common practice.

This is Dr Sam Goldhaber, signing off for the Clot Blog.


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