Dual Antiplatelet Therapy Guidelines Get an Update

The American College of Cardiology has updated its recommendations on dual antiplatelet therapy (DAPT) from the 2011 guidelines.¹

In this update, there are specific recommendations on antiplatelet choice and duration to help clinicians put new evidence into practice.

While some recommendations will not surprise those familiar with DAPT, pharmacists involved in the care of patients with coronary artery disease should key in on these recommendations.

Extending DAPT is a trade-off

When continuing DAPT beyond 12 months, there is a trade-off between continued major adverse cardiac events (MACE) prevention and bleeding.

In studies, patients who received up to 36 months of DAPT benefited from a 1% to 2% MACE reduction, but bleeding increased by 1%.¹

Although most data published has not tested change in mortality, the authors of this guideline said they believed that extended DAPT does not seem to result in increased mortality.

DAPT score

The DAPT score can help clinicians determine the benefits versus risks of continuing or stopping DAPT.

Patients score 1 point for the following: current cigarette smoker, diabetes, myocardial infarction (MI) at presentation, prior percutaneous coronary intervention (PCI) or MI, stent diameter <3mm, and paclitaxel-eluting stent.

Two points are scored if the patient has a history of heart failure or left ventricular ejection fraction of <30%, or saphenous vein graft PCI.

One point is deducted if the patient's age is 65 to 74 years, and 2 points are deducted if the patient is 75 years or older.

Patients with a DAPT score of 2 or greater may benefit from extended DAPT, and those with a score less than 2 may be at higher risk of bleeding complications.

Ticagrelor stands out

Ticagrelor is recommended as the preferred antiplatelet agent over clopidogrel in patients with acute coronary syndromes (ACS) after coronary stent implantation or non-ST elevation ACS managed with medical therapy alone.

If patients do not have a history of stroke or transient ischemic attack and are not at high risk for bleeding complications, prasugrel is preferred over clopidogrel.

6- and 12-month assessments

In patients with ACS following initiation of DAPT, in most circumstances, 12 months of therapy is recommended.

However, at 6 months after the initiation of DAPT, the patient should be re-evaluated for bleeding risk. If the risk of bleeding is deemed high (see DAPT score), the DAPT therapy should be capped at 6 months.

On the other hand, if patients are found to be at low risk of bleeding after 12 months of DAPT, it may be reasonable to continue DAPT if the patients are not at high risk of bleeding and no significant bleeding has occurred while on DAPT.

These guidelines provide better guidance than previous editions that left these decisions up to the prescribers' discretion with vague, at best, recommendations on duration and drug.

Certainly these will help those caring for these patients by providing a structured approach for each patient. The complete guidelines are available online at http://www.acc.org/dapt.

Reference:

1) 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; doi:10.1016/j.jacc.2016.03.513.