Updated US Guidelines Lower DAPT Duration From 12 to 6 Months in Stable Patients Receiving DES

Updated US guidelines now support prescribing 6 months—not 12 months—of dual antiplatelet therapy (DAPT) after DES implantation for patients with stable ischemic heart disease. Additionally, a new guideline writing style, introduced by the American College of Cardiology (ACC) and American Heart Association, more clearly differentiates the levels of evidence used to shape each recommendation.

“The theme of the whole document is to shorten the length of dual antiplatelet therapy,” writing committee member Eric Bates, MD (University of Michigan, Ann Arbor), told TCTMD. Specifically, therapy for at least 6 months is given a class I recommendation in stable patients, with class IIb caveats that physicians can prescribe for longer in patients at low bleeding risk and shorter in patients at high bleeding risk. These new “symmetrical” guidelines should hopefully appease physicians on both sides of the DAPT duration debate, he explained.

Both the DAPT Study and PEGASUS TIMI-54 showed a decreased risk of ischemic events with long-term therapy—perhaps even longer than 12 months—but a potentially higher risk of bleeding. The DAPT Score, introduced at the 2015 American Heart Association meeting and published today in the JAMA, was developed with the goal of singling out patients who may or may not benefit from extended thienopyridine therapy. On the other hand, European guidelines have supported a shorter course of DAPT in stable patients receiving DES since 2014, and many physicians in the United States have been calling for parallel guidelines.

Resolving confusion associated with prior discrepancies in varying society DAPT recommendations, this focused update—published today in the Journal of the American College of Cardiology—will update six previously published guidelines. “That’s a step forward because the other guidelines did have some conflict in wording and even recommendations as different committees sat down,” Bates said.

What Else is New?

Bates highlighted several other updates, among them a class I recommendation for all patients receiving DAPT to be prescribed 81 mg of aspirin. Also ticagrelor and prasugrel are now recommended as a class IIa indication over clopidogrel.

In patients with NSTE ACS or STEMI, however, the 12-month recommendation still holds. Again, there is room for physician judgement. “You can go longer as a IIb recommendation or you can go only 6 months with a IIb recommendation,” Bates added.

He also pointed to the recommendation for handling DAPT in the period prior to noncardiac surgery, which states that patients should wait 30 days and 6 months after receiving a BMS or DES, respectively. “Increasing evidence [suggests] that drug-eluting stents have better outcomes than bare-metal stents across almost all indications now with the newer-generation stents and a lower risk for stent thrombosis,” he explained. “So this I think gives support for stopping at 3 months if the patient can wait that long just to get the better stent result as long as they are at low risk for an ischemic complication.”

Lastly, as a formatting update, Bates explained that the writing committee members made a conscious effort to show how they came to each recommendation. While class III recommendations were split into “no benefit” and “harm” 3 years ago, he said now level B evidence is marked as based on randomized or nonrandomized data and level C evidence is marked as based on data or expert opinion. “It’s a new step forward in trying to define for the reader the level of evidence that was used to make the recommendation,” he said, adding that this feature allows for greater transparency.

‘Long Overdue’

This update “conforms with the European guidelines” and is “long-overdue,” said Sorin Brener, MD (New York Methodist Hospital, Brooklyn, NY), who reviewed the new document for TCTMD. “We know that probably even less than [6 months] is ok, but I think that 6 months is a very good compromise,” he said, adding that the previously held 12-month recommendation was somewhat arbitrary.

However, Brener said he would have liked to have seen more guidance on how to determine the best patients for prolonged therapy. The DAPT Score is appropriate for some, but it “relies heavily on angiographic issues or on procedural issues, which I think excludes the patients who did not have a stent and are treated for MI with medical therapy,” he explained. “So you cannot use the DAPT Score in those patients, because all those categories that involve the actual procedure would be irrelevant.”

Other constraints, such as chronic kidney disease, should also be included in this evaluation, Brener said.

But as for the new methodology of the evidence references, Brener was enthusiastic. He described it as “excellent,” noting, “It is very important to understand that there is level B and there is level B, and even more importantly, there is level C and there is level C.”

Source:

• Levine GN, Bates ER, Bittl JA, et al. 2016 ACC/AHA guideline focused update on duration of dual antiplatelet therapy in patients with coronary artery disease: a report of the American College of Cardiology/American Heart Association task force on clinical practice guidelines. J Am Coll Cardiol. 2016;Epub ahead of print.

Related Stories:

• Long-Term DAPT with Ticagrelor Reduces Ischemic Risk, Ups Bleeding in MI Patients
• Despite New Findings, Optimal DAPT Duration Still Up in the Air
• DAPT Study Shows Benefit of Long-Term Treatment After DES Implantation