Mar 29, 2016 | Debabrata Mukherjee, MD, FACC

A 76-year-old- male with past history of smoking and a prior myocardial infarction (MI) two years ago for which he was treated medically presents for evaluation. He now has stable angina despite optimal guideline-directed medical management, which interferes with his ability to play golf. Stress test reveals moderate to large size anterolateral ischemia and coronary angiography reveals an 80% mid-LAD stenosis. He undergoes PCI with a 3.0 X 15 mm Xience stent. Based on current guidelines and the recently developed DAPT score, optimal duration of DAPT for this gentleman would be

  • At least 6 months of DAPT with clopidogrel
  • At least 6 months of DAPT with clopidogrel, prasugrel or ticagrelor
  • At least 12 months of DAPT with clopidogrel
  • Prolonged DAPT therapy beyond 12 months

The correct answer is (a), at least 6 months of DAPT with clopidogrel based on the 2016 ACC/AHA guideline focused update on duration of dual antiplatelet therapy in patients with coronary artery disease.1 Clopidogrel is the only P2Y12 inhibitor approved for SIHD so answer (b) is incorrect. The 2016 guideline has shortened the duration of DAPT from 12 months to 6 months so answer (c) is incorrect. Finally the gentleman has a low DAPT score (<2) and his bleeding risks outweigh potential ischemic benefits and prolonged DAPT would not be recommended. DAPT longer than 12 months is recommended for those with a DAPT score ≥ 2. A score of ≥2 is associated with a favorable benefit/risk ratio for prolonged DAPT while a score of <2 is associated with an unfavorable benefit/risk ratio.

Clinical and Procedural Factors Associated With Increased Ischemic Risk (Including Stent Thrombosis) or Increased Bleeding Risk

Increased Ischemic Risk/Risk of Stent Thrombosis
(may favor longer-duration DAPT)

Increased Bleeding Risk
(may favor shorter-duration DAPT)

Increased ischemic risk

  • Advanced age
  • ACS presentation
  • Multiple prior MIs
  • Extensive CAD
  • Diabetes mellitus
  • CKD

Increased risk of stent thrombosis

  • ACS presentation
  • Diabetes mellitus
  • Left ventricular ejection fraction <40%
  • First-generation drug-eluting stent
  • Stent undersizing
  • Stent underdeployment
  • Small stent diameter
  • Greater stent length
  • Bifurcation stents
  • In-stent restenosis
  • History of prior bleeding
  • Oral anticoagulant therapy
  • Female sex
  • Advanced age
  • Low body weight
  • CKD
  • Diabetes mellitus
  • Anemia
  • Chronic steroid or NSAID therapy

ACS indicates acute coronary syndrome; CAD, coronary artery disease; CKD, chronic kidney disease; DAPT, dual antiplatelet therapy; MI, myocardial infarction; and NSAID, nonsteroidal anti-inflammatory drug.

Factors Used to Calculate a “DAPT Score”



Age ≥75 y


Age 65 to <75 y


Age <65 y


Current cigarette smoker


Diabetes mellitus


MI at presentation


Prior PCI or prior MI


Stent diameter <3 mm


Paclitaxel-eluting stent


CHF or LVEF <30%


Saphenous vein graft PCI


A score of ≥2 is associated with a favorable benefit/risk ratio for prolonged DAPT while a score of <2 is associated with an unfavorable benefit/risk ratio. CHF indicates congestive heart failure; DAPT, dual antiplatelet therapy; LVEF, left ventricular ejection fraction; MI, myocardial infarction; and PCI, percutaneous coronary intervention.

Adapted with permission from Yeh RW, Secemsky E, Kereiakes DJ, et al. Development and validation of a prediction rule for benefit and harm of dual antiplatelet therapy beyond one year after percutaneous coronary intervention: an analysis from the randomized Dual Antiplatelet Therapy Study. JAMA. March 2016. In Press1).


  1. Levine GN, Bittl JA, Brindis RG, et al. 2016 ACC/AHA Guideline Focused Update on Duration of Dual Antiplatelet Therapy in Patients With Coronary Artery Disease. J Am Coll Cardiol 2016; doi=10.1016/j.jacc.2016.03.513.