AHA Wades Into Conversation Over Periprocedural Use of Non-Vitamin K Antagonist Oral Anticoagulants

As the number of US patients with nonvalvular atrial fibrillation being treated with non-vitamin K antagonist oral anticoagulants (NOACs) continues to grow, the American Heart Association (AHA) is adding its voice to the chorus of recommendations for patient management. The AHA’s new scientific statement, which comes 1 month after the American College of Cardiology (ACC) released a “decision pathway” targeting the same patient group, is positioned not as strict guidelines—no formal classes of recommendation/level of evidence are provided—but rather offers “practical suggestions” for providers who manage patients with bleeds or at risk for bleeding.

NOACs, initially shorthand for novel oral anticoagulants, “are no longer new or novel,” the statement’s lead author, Amish N. Raval, MD (University of Wisconsin, Madison), told TCTMD. “They are now widely used in clinical practice, yet there are very [few] practical guidance statements for their use in these sorts of settings.”

Highlights from the paper, published online February 7, 2017, ahead of print in Circulation, include a comprehensive comparison of the currently available drugs, protocols for NOAC reversal, and suggested pathways for NOAC bridging in the event that it is needed.

“A lot of these [things] are widely known but need to be solidified,” Raval said. For example, the paper suggests that routine therapeutic monitoring of the NOAC effect is not necessary anymore given the drugs’ predictability. “In most situations, the time of last drug ingestion combined with a recent assessment of creatinine clearance should enable appropriate clinical decision-making,” the authors write.

Next, Raval said, it is important to highlight the two patient populations to think about: those who are actively having life-threatening bleeding and those who are merely at risk for it. Given the limited options for NOAC antidotes—the only one approved for use in the United States is for dabigatran (Pradaxa, Boehringer Ingelheim)—and the complicated processes needed to treat these situations, hospitals that “manage patients on these drugs, especially those that have acute care or critical care type environments, should really develop [multidisciplinary] protocols that work for them,” he said. This “allows for more rapid responses and more algorithmic approaches.”

Concern Over Bridging

Last month, the ACC released an expert consensus decision pathway for the periprocedural management of patients with nonvalvular A-fib, complete with an accompanying smartphone app. The chair of that paper’s writing committee, John Doherty, MD (Thomas Jefferson University, Philadelphia, PA), told TCTMD that while the new AHA document is more of a “good, focused update,” it is “not as actionable” as a guidelines statement.

While praising the authors for their efforts, Doherty expressed unease with the amount of space Raval and colleagues dedicated to how to transition from one anticoagulant to another, a process known as bridging. “There are very few instances in which you have to bridge one of these novel agents with unfractionated heparin,” he said, adding that when readers see the emphasis placed on this, “it might lead to some bridging behavior which is perhaps more than it needs to be.”

Notably, the ACC guidelines document advised against transitioning from a NOAC to low-molecular-weight or unfractionated heparin, Doherty said. It’s likely that most clinicians who use NOACs “know who should get a bridge and who should not get a bridge, but the fact that there was a whole section devoted to it” might send the wrong message, he added.

In response, Raval said he understood Doherty’s point, but argued that the reason his team spent so much energy on describing how to properly bridge is because other papers have not. “It does happen infrequently, but it’s a common enough occurrence” to warrant thorough advice, he said. “We’ve put more time and effort in that only because that area is not as well addressed in prior statements, either by the European documents or elsewhere, and that's fundamentally why we wanted to put some more emphasis.”

Waiting for Antidotes

Looking to the future, Raval said more “concentrated” clinical trials are needed in this arena because much of the data his team used is “directly addressing questions that we were making some interpretations over. For example, a lot of times we were looking at secondary endpoints and post hoc analyses of other clinical trials, typically the large efficacy trials that led to the approval of these NOACs.”

Specifically, he would like to see studies that “point to the importance of really considering the consequences of these protocols that we have put together.”

Until then or until antidotes are approved in the US for drugs other than dabigatran, however, it’s unlikely that we will see any updates with regard to treatment protocols for patients on NOACs in the periprocedural setting, Raval predicted. “Then I think we can modify our reversal protocols to highlight those. But until we have those available, this is what we got.”