What are the primary and secondary recommendations for antiplatelet therapy (DAPT) in patients receiving a drug-eluting stent?

Dual Antiplatelet Therapy (DAPT) for Drug-Eluting Stents

For patients with drug-eluting stents (DES), the standard DAPT duration is 6 months for stable coronary artery disease and 12 months for acute coronary syndrome, consisting of low-dose aspirin plus a P2Y12 inhibitor (clopidogrel, ticagrelor, or prasugrel). 1

Primary DAPT Recommendations

Standard Duration Based on Clinical Presentation

• Stable Coronary Artery Disease with DES: 6 months of DAPT (Class I, Level B) 1
• Acute Coronary Syndrome (ACS) with DES: 12 months of DAPT regardless of stent type (Class I, Level B) 1, 2
• Bare-Metal Stent (BMS): 1 month of DAPT (Class I, Level A) 1

DAPT Components

• Aspirin: Low-dose (75-100 mg daily) continued indefinitely 1
• P2Y12 inhibitor: Clopidogrel, ticagrelor, or prasugrel 1
  • For ACS patients, ticagrelor or prasugrel is preferred over clopidogrel if no contraindications exist (Class IIa, Level B) 1, 2

Secondary DAPT Recommendations (Duration Adjustments)

Extended Duration

• For patients with low bleeding risk but high thrombotic risk, DAPT may be extended beyond the standard duration up to 30 months (Class IIb, Level A) 1
• Extended DAPT (>12 months) decreases myocardial infarction (OR: 0.67) and stent thrombosis (OR: 0.45) but increases major hemorrhage (OR: 1.58) 1, 3

Shortened Duration

• For patients with high bleeding risk and stable CAD who have received a DES, 3 months of DAPT may be considered (Class IIa, Level B) 1
• Short-term DAPT followed by P2Y12 inhibitor monotherapy reduces major bleeding compared to 12-month DAPT 3

Special Considerations

Loading Dose Administration

• For prasugrel, a 60 mg loading dose is administered, followed by 10 mg daily maintenance dose 4
• In clinical trials, the loading dose was administered:
  • After coronary anatomy was established in UA/NSTEMI patients
  • At the time of diagnosis in STEMI patients presenting within 12 hours of symptom onset 4

Weight-Based Dosing

• For patients weighing <60 kg on prasugrel, consider lowering maintenance dose to 5 mg due to increased bleeding risk 4

Management During Surgical Procedures

• For patients requiring surgery during the DAPT period:
  • Continue aspirin if possible 1
  • Temporarily discontinue P2Y12 inhibitor for 5-7 days before surgery 1, 2
  • Resume treatment as soon as possible after surgery 1

Risk Stratification

• Use both DAPT and PRECISE-DAPT scores to assess the risk/benefit of prolonging DAPT 2
• For endoscopic procedures:
  • Low-risk procedures: Omit morning dose of anticoagulants on procedure day 2
  • High-risk procedures: Last dose of anticoagulants at least 48h before procedure 2

Important Warnings and Precautions

• Never prematurely discontinue DAPT without consulting the patient's cardiologist, as this significantly increases stent thrombosis risk 1
• Discontinuation of therapy has been associated with a hazard ratio of 161 for death and MI 2
• Stent thrombosis risk increases after 5 days without antiplatelet therapy 2
• For patients on DAPT with GI bleeding, do not withhold both antiplatelet agents due to high risk of stent thrombosis 2
• In patients with drug-eluting coronary stents and GI bleeding, early resumption of P2Y12 receptor inhibitor is recommended, preferably within 5 days after endoscopic hemostasis 2

Comparative Efficacy of Different Durations

• Short-term (3-6 months) DAPT compared to 12 months shows:

  • No significant difference in stent thrombosis, myocardial infarction, stroke, revascularization, or mortality 5
  • Significant reduction in total bleeding risk (RR 0.61,95% CI 0.43-0.87) 5

• Extended-term (>12 months) DAPT compared to 12 months shows:

  • Reduced risk of myocardial infarction (RR 0.68,95% CI 0.54-0.87) 3
  • Higher risk of major bleeding 3
  • In ACS patients specifically, reduced risk of MI without significant increase in bleeding 3

The optimal DAPT strategy should balance thrombotic and bleeding risks, with newer-generation DES generally allowing for shorter DAPT durations with improved safety compared to first-generation DES 6.