SNOWMASS, COLO. – The 2017 American College of Cardiology Expert Consensus Decision Pathway for Periprocedural Management of Anticoagulation in Patients with Nonvalvular Atrial Fibrillation is a dense, 28-page document filled with multicolored flow charts and six separate management algorithms. But this complex scheme is no substitute for practical clinical judgment and individualized decision making, N.A. Mark Estes, MD, said at the Annual Cardiovascular Conference at Snowmass.
“I spent the last 2 weeks trying to understand this document. It’s very well thought out and uses the best available evidence, but the evidence is very limited. I applaud the ACC for getting this information together, but since the evidence is really lacking, I think one really has to rely on practical considerations of individualized risk and benefit,” said Dr. Estes, professor of medicine at Tufts University in Boston.The decision pathway attempts to guide physicians in making decisions about whether and how to interrupt anticoagulation or bridge with a parenteral agent such as low-molecular-weight heparin, and how to restart oral anticoagulation post-procedure (J Am Coll Cardiol. 2017 Jan 5; doi: 10.1016/j.jacc.2016.11.024).
The document defies concise summary. Dr. Estes chose instead to describe the approach he uses in clinical decision-making regarding anticoagulation in patients with atrial fibrillation undergoing invasive procedures. He relies upon three elements: stroke risk as assessed by CHA2DS2-VASc score; bleeding risk using the HAS-BLED score; and the inherent bleeding risk of the procedure itself.
“An important thing to remember is, any procedure done along the spinal cord or intracranially carries an extremely high risk of bleeding,” the cardiologist noted by way of example.
If a patient with atrial fibrillation has a CHA2DS2-VASc score of 2 or less, he doesn’t offer bridging regardless of the HAS-BLED score. If the stroke risk is high as defined by a CHA2DS2-VASc score of 7 or more, and the patient’s bleeding risk isn’t high, meaning the HAS-BLED score is less than 3, he seriously considers bridging, provided that the patient’s oral anticoagulant is warfarin.
“I don’t think at this point we should be bridging with the DOACs [the direct oral anticoagulants dabigatran, rivaroxaban, apixaban, and edoxaban]. All the available data on bridging with the DOACs indicates that it results in a high risk of bleeding with no reduction in risk of stroke,” Dr. Estes said.
The “vast majority” of patients with atrial fibrillation facing surgery have a CHA2DS2-VASc score of 3-7 and thus fall into a category where individualized consideration of the risks and benefits of bridging rules. The large, randomized, double-blind BRIDGE trial speaks to this population. In this study of atrial fibrillation patients on warfarin prior to their procedure, bridging with low-molecular-weight heparin resulted in an increased risk of major bleeding with no reduction in stroke risk compared with a temporary halt of warfarin with no bridging (N Engl J Med. 2015 Aug 27;373[9]:823-33).
“This is a no-brainer,” Dr. Estes said. “When you bridge, your patients bleed more, and you don’t reduce strokes.”
The real challenge is the type of patient who falls into what he called “the dilemma zone,” with a CHA2DS2-VASc score of 7 or more and a HAS-BLED score of 3 or higher, meaning they are at very high risk for both stroke and bleeding.
“I have a discussion with those patients. I usually do not bridge. I’m biased because of having done a lot more harm than good in bridging,” the cardiologist said.
Dr. Estes reported serving as a consultant to Boston Scientific, Medtronic, and St. Jude Medical.