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Revised U.S. A fib guidelines revamp anticoagulation


 

The first update to U.S. medical-society guidelines for managing atrial fibrillation since 2014 raised the threshold for starting anticoagulant therapy in women, pegged the direct-acting oral anticoagulants (DOACs) as preferred over warfarin, and introduced for the first time weight loss as an important intervention tool for treating patients with an atrial arrhythmia.

Dr. Hugh Calkins, professor of medicine, Johns Hopkins Medicine, Baltimore Mitchel L. Zoler/MDedge News

Dr. Hugh Calkins

On January 28, the American College of Cardiology, American Heart Association, and Heart Rhythm Society posted online a 2019 focused update (Circulation. 2019 Jan 28. doi: 10.1161/CIR.0000000000000665) to the 2014 atrial fibrillation (AF) management guidelines that the groups had previously published (J Am Coll Cardiol. 2014 Dec 2;64[21]:2246-80).

Perhaps the two most important changes, as well as the two that lead off the new document, were a pair of class I recommendations on using oral anticoagulation in AF patients.

One of these updates reset the threshold for initiating oral anticoagulant therapy in women from 2 points on the CHA2DS2-VASc scale to 3 points, while leaving the threshold for men unchanged at 2 points. This brought U.S. guidelines in line with European guidelines, set by the European Society of Cardiology in 2016 (Eur Heart J. 2016 Oct 7;37[38]:2893-962). It will now also mean that, because of the way the CHA2DS2-VASc score is calculated, women with AF who are at least 65 years old will no longer automatically get flagged as needing oral anticoagulant therapy.

“This is a really important shift. It’s recognition that female sex is not as important a risk factor [for AF-associated stroke] as once was thought,” commented Hugh Calkins, MD, professor of medicine at Johns Hopkins Medicine in Baltimore and a member of the panel that wrote the update. “This will change the number of women with AF who go on anticoagulation,” predicted Dr. Calkins, who directs the cardiac arrhythmia service at his center. “We have been struggling with the notion that all women 65 or older with AF had to be on an anticoagulant. Now a clinician has more leeway. In general, patients with AF remain underanticoagulated, but this clarifies practice and brings us in line with the European guidelines.”

The second important change to the anticoagulation recommendations was to specify the DOACs as recommended over warfarin in AF patients eligible for oral anticoagulation and without moderate to severe mitral stenosis or a mechanical heart valve, which also matches the 2016 European guidelines and updates the prior, 2014, U.S. guidelines, which didn’t even mention DOACs.

Prescribing a DOAC preferentially to AF patients has already become routine among electrophysiologists, but possibly not as routine among primary care physicians, so this change has the potential to shift practice, said Dr. Calkins. But the higher price for DOACs, compared with warfarin, can pose problems. “The cost of DOACs remains an issue that can be a serious limitation to some patients,” said Craig T. January, MD, professor of medicine at the University of Wisconsin in Madison and chair of the guideline-writing panel. He also bemoaned the absence of head-to-head comparisons of individual DOACs that could inform selecting among apixaban, dabigatran, edoxaban, and rivaroxaban.

Another notable change in the 2019 update was inclusion for the first time of weight loss as a recommended intervention, along with other risk factor modification, an addition that Dr. Calkins called “long overdue.”

Dr. Vivek Reddy, professor of medicine, Mount Sinai Hospital, New York Mitchel L. Zoler/MDedge News

Dr. Vivek Reddy

“This is a new recommendation, and it will potentially be important,” said Dr. January, although the guidelines do not spell out how aggressive clinicians should be about having patients achieve weight loss, how much loss patients should achieve, or how they should do it. “There are a lot of observational data and basic science data suggesting the importance of weight loss. Most electrophysiologists already address weight loss. The problem is how to get patients to do it,” commented Vivek Reddy, MD, professor of medicine and director of cardiac arrhythmia services at Mount Sinai Hospital in New York.

Dr. Reddy expressed surprise over two other features of the updated guidelines. For the first time, the guidelines now address percutaneous left atrial appendage (LAA) occlusion and say: “Percutaneous LAA occlusion may be considered in patients with AF at increased risk of stroke who have contraindications to long-term anticoagulation.” The guidelines’ text acknowledges that this runs counter to the Food and Drug Administration labeling for the Watchman LAA occlusion device, which restricts the device to patients “deemed suitable for long-term warfarin (mirroring the inclusion criteria for enrollment in the clinical trials) but had an appropriate rationale to seek a nonpharmacological alternative to warfarin.”

“We do not take a position on the FDA’s” actions, Dr. January said in an interview.

“The ACC, AHA, and HRS guidelines should reflect what the FDA decided,” Dr. Reddy said in an interview. “I’m a little surprised the guidelines said that anticoagulation had to be contraindicated.

The 2019 update also added a class IIb, “may be reasonable” recommendation for catheter ablation of AF in patients with heart failure with reduced ejection fraction.

“I think a IIb recommendation is unfair; I think it should be a IIa recommendation because there have been positive results from two large, randomized, multicenter trials – CASTLE-AF [Catheter Ablation vs. Standard Conventional Treatment in Patients With LV Dysfunction and AF; N Engl J Med. 2018 Feb 1;378(5):417-27] and AATAC [Ablation vs Amiodarone for Treatment of AFib in Patients With CHF and an ICD; Circulation. 2016 Apr 26;133(7):1637-44], as well as positive results from several smaller randomized studies,” Dr. Reddy said. “I’m really surprised” that the recommendation was not stronger.

Dr. Calkins has been a consultant to Abbott, Altathera, AtriCare, Boehringer-Ingelheim, King, Medtronic, and St. Jude and has received research funding from Boehringer-Ingelheim, Boston Scientific, and St. Jude. Dr. January had no disclosures. Dr. Reddy has been a consultant to, received research funding from, or has an equity interest in more than three dozen companies.

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