The American College of Cardiology and American Heart Association (ACC/AHA) recently released a guideline-focused update on dual antiplatelet therapy (DAPT) in patients with coronary artery disease (CAD).
The update was the result of analysis of 11 study findings (including SECURITY, EXCELLENT, RESET, OPTIMIZE, and the OPTIDUAL investigations).
All of these studies evaluated patients treated with coronary stent implantation (predominantly with drug-eluting stents [DES]) who were given either shorter or longer durations of DAPT as well as 1 large, randomized controlled trial of patients 1 to 3 years after myocardial infarction (MI) on the efficacy of DAPT compared with aspirin monotherapy.
The goal of the update was “to evaluate, update, harmonize, and when possible, simplify recommendations on the duration of DAPT.”
It is important to note that the recommendations for DAPT duration apply to newer-generation stents and generally speaking, only to patients not treated with oral anticoagulant therapy.
First, the guidelines recommend that shorter-duration DAPT can be considered for patients at a lower ischemic risk with high bleeding risk whereas longer-duration DAPT can be considered for patients with the inverse (higher ischemic risk, lower bleeding risk).
In addition, patients with non-ST segment elevation (NSTE) acute coronary syndrome (ACS) and STEMI now have similar recommendations because they, as the report stated, “both are part of the spectrum of acute coronary syndrome.”
More specifically, in patients with ACS (NSTE-ACS or STEMI) treated with DAPT after coronary stent implantation, “it is reasonable to use ticagrelor in preference to clopidogrel for maintenance P2Y12 inhibitor therapy” (class IIa recommendation). The same applies to NSTE-ACS patients treated with medical therapy alone.
For the patients treated with DAPT after stent implantation who are also not high-risk for bleeding complications and do not have a history of stroke or transient ischemic attack (TIA), “it is reasonable to choose prasugrel over clopidogrel for maintenance P2Y12 inhibitor therapy” (class IIa recommendation). The authors cautioned that patients with a prior history of stroke or TIA should not be treated with prasugrel (class III: harm).
The recommended daily dose of aspirin is 81 mg for patients treated with DAPT, bearing in mind that lower doses of aspirin are associated with lower bleeding complications.
In patients receiving triple therapy (aspirin, P2Y12 inhibitor, and oral anticoagulant), clinicians should assess ischemic and bleeding risks, keep triple therapy duration as short as possible, consider clopidogrel as the preferred P2Y12 inhibitor, use a low-dose of aspirin (≤100 mg/day), and note that proton pump inhibitors should be used in patients with a history of gastrointestinal (GI) bleeding and are reasonable to use in those patients with an increased risk of GI bleeding.
For those patients with stable ischemic heart disease who have been treated with percutaneous coronary intervention (PCI) using a bare metal stent (BMS) treated with DAPT, P2Y12 inhibitor therapy with clopidogrel should be given for a minimum of 1 month (class Ia recommendation). Whereas patients treated with a DES should be given P2Y12 inhibitor therapy with clopidogrel for at least 6 months (class I recommendation).
After BMS or DES implantation in patients with ACS (either NSTE-ACS or STEMI) treated with DAPT, P2Y12 inhibitor therapy—clopidogrel, prasugrel, or ticagrelor—should be given for at least 12 months (class I recommendation). As in the above, the recommended daily dose of aspirin is 81 mg.
Some class IIa recommendations for this patient population include: use of ticagrelor in preference to clopidogrel for P2Y12 inhibitor maintenance therapy and choosing prasugrel over clopidogrel in patients who are not at high bleeding risk and who do not have stroke or TIA history.
Separate recommendations are included for patients with STEMI who are treated with DAPT in conjunction with fibrinolytic therapy. Their P2Y12 inhibitory therapy (in the form of clopiodgrel) should be continued for a minimum of 14 days (class Ia recommendation) and ideally, at least 12 months.
In those patients who must subsequently undergo coronary artery bypass graft (CABG) surgery after stent implantation, P2Y12 inhibitor therapy should continue postoperatively so that DAPT continues until the completion of recommended duration of therapy. In patients with either NSTEM-ACS or STEMI-ACS treated with DAPT undergoing CABG, P2Y12 inhibitor therapy should continue after surgery to complete 12 months of DAPT therapy after ACS.
Finally, the report offers guidelines for the perioperative management regarding timing of elective noncardiac surgery in patients treated with PCI and DAPT, which includes the delay of surgery by 30 days after BMS implantation, and ideally, 6 months after DES implantation.
Levine GN, Bates ER, Bittle JA, et al; for the American College of Cardiology/American Heart Association Task Force on Clinical Practice Guidelines. 2016 ACC/AHA guideline focused updated 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.