What is the recommended dual antiplatelet therapy (DAPT) regimen for a patient with a history of acute coronary syndrome (ACS) or percutaneous coronary intervention (PCI) with coronary stent placement?

Recommended Dual Antiplatelet Therapy for ACS and PCI with Stent Placement

For patients with acute coronary syndrome or those undergoing PCI with coronary stent placement, initiate ticagrelor (180 mg loading dose, then 90 mg twice daily) plus aspirin (75-100 mg daily) for 12 months as first-line therapy, unless contraindications or excessive bleeding risk exist. 1

First-Line P2Y12 Inhibitor Selection Algorithm

Ticagrelor is the preferred agent for all ACS patients regardless of initial treatment strategy, including those pre-treated with clopidogrel (which should be discontinued when ticagrelor is commenced). 1

Alternative Options Based on Patient Characteristics:

• Prasugrel (60 mg loading dose, 10 mg daily) is recommended for P2Y12 inhibitor-naïve patients with NSTE-ACS or STEMI undergoing PCI, unless high bleeding risk or contraindications exist. 1

• Clopidogrel (600 mg loading dose, 75 mg daily) should be used when ticagrelor or prasugrel are contraindicated, specifically for patients with:

  • Prior intracranial hemorrhage 1
  • Indication for oral anticoagulation 1
  • History of prior stroke or TIA (prasugrel is absolutely contraindicated in this population per FDA labeling) 2

Critical Contraindications and Warnings

Prasugrel must never be used in patients with prior stroke or TIA due to increased risk of fatal and intracranial bleeding. 2 This is an FDA black box warning and represents a Class III: Harm recommendation. 1

Additional prasugrel considerations:

• Generally not recommended in patients ≥75 years (except high-risk situations with diabetes or prior MI) 2
• Consider dose reduction to 5 mg daily in patients <60 kg due to increased bleeding risk 2
• Contraindicated in active pathological bleeding 2

Standard Duration and Timing

The default duration is 12 months for all ACS patients who are not at high bleeding risk, regardless of ACS type, stent type, or completeness of revascularization. 1

Timing of Loading Dose:

• For NSTE-ACS patients: Administer loading dose once coronary anatomy is established, typically at time of PCI rather than upstream 2
• For STEMI patients presenting within 12 hours: Loading dose may be given at diagnosis, though most receive it at time of PCI 2
• For STEMI patients presenting >12 hours after symptom onset: Wait until coronary anatomy is established 2

Modified Duration Based on Bleeding Risk:

• Shortened duration (6 months) may be considered in patients with excessive bleeding risk (e.g., PRECISE-DAPT score ≥25) 1
• Shortened duration (3 months) followed by P2Y12 inhibitor monotherapy has shown favorable outcomes in recent trials, decreasing net adverse clinical events without impacting major adverse cardiovascular events 3
• Never discontinue DAPT within the first month after stent placement, even if bleeding concerns exist, as this dramatically increases stent thrombosis risk 1

Mandatory Bleeding Risk Mitigation Strategies

Every patient on DAPT must receive the following protective measures:

• Proton pump inhibitor (PPI) co-prescription for all patients to reduce gastrointestinal bleeding risk 1
• Low-dose aspirin (75-100 mg daily) when combined with P2Y12 inhibitors—higher doses increase bleeding without improving efficacy 1
• Radial over femoral access for coronary angiography and PCI when performed by an expert radial operator 1

Switching from Clopidogrel to Ticagrelor

In ACS patients previously on clopidogrel, switch to ticagrelor immediately by giving the 180 mg loading dose without waiting for clopidogrel washout, as ticagrelor demonstrates superior reduction in cardiovascular events. 1

Special Population: Triple Therapy (DAPT + Anticoagulation)

When oral anticoagulation is required, use clopidogrel as the P2Y12 inhibitor rather than ticagrelor or prasugrel due to significantly lower bleeding risk. 1 Discontinue aspirin 1-4 weeks after PCI and continue P2Y12 inhibitor with anticoagulation. 1

Aspirin Dosing Specifics

• With ticagrelor: Use 81 mg daily (American guidelines) or 75-100 mg daily (European guidelines) 1
• Never exceed 100 mg daily when using DAPT, as higher doses increase bleeding without additional benefit 1

Post-DAPT Transition Strategy

After completing 12 months of DAPT without bleeding complications:

• Transition to ticagrelor monotherapy (discontinue aspirin) ≥1 month after PCI in patients who tolerated DAPT 1
• This approach reduces bleeding risk while maintaining cardiovascular protection 1

Critical Pitfalls to Avoid

• Do not use clopidogrel as first-line therapy when ticagrelor or prasugrel are available and not contraindicated—this represents suboptimal care 1
• Do not administer prasugrel to patients with prior stroke/TIA—this is an absolute contraindication 2
• Do not omit PPI co-prescription—this simple intervention significantly reduces gastrointestinal bleeding 1
• Do not use aspirin doses >100 mg daily with DAPT—higher doses only increase bleeding 1
• Do not discontinue DAPT for elective non-cardiac surgery within the first month after stent placement 1