What is the recommended dual anti-platelet therapy (DAPT) regimen for a patient post percutaneous coronary intervention (PCI)?

Dual Antiplatelet Therapy Post-PCI

For patients undergoing PCI, initiate aspirin (75-100 mg daily) plus a P2Y12 inhibitor immediately, with ticagrelor (180 mg loading dose, then 90 mg twice daily) or prasugrel (60 mg loading dose, then 10 mg daily) strongly preferred over clopidogrel, and continue this dual antiplatelet therapy for at least 12 months in ACS patients or 6 months in stable CAD patients. 1, 2, 3

Optimal P2Y12 Inhibitor Selection

For ACS patients (STEMI, NSTEMI, unstable angina):

• First-line choice: Ticagrelor 180 mg loading dose, then 90 mg twice daily 1, 2, 3
• Alternative for PCI patients: Prasugrel 60 mg loading dose, then 10 mg daily (for P2Y12 inhibitor-naïve patients undergoing PCI) 2, 4
• Use clopidogrel only when: Ticagrelor or prasugrel are contraindicated, or patient requires oral anticoagulation 2, 3

For stable CAD patients:

• Clopidogrel 75 mg daily is acceptable as first-line 1
• Ticagrelor or prasugrel may be considered but have weaker recommendations (Class IIb) 1

Critical Contraindications to Prasugrel

Never use prasugrel in patients with: 4

• Prior stroke or TIA (any time in history) - this is an absolute contraindication
• Age ≥75 years (generally not recommended due to increased fatal bleeding risk)
• Body weight <60 kg (consider dose reduction to 5 mg daily if used)
• Active pathological bleeding

Ticagrelor has no stroke/TIA contraindication and is preferred in these patients. 2, 5

Standard DAPT Duration

ACS patients (regardless of stent type):

• Minimum duration: 12 months 1, 2, 3
• High bleeding risk patients: May shorten to 6 months 1
• Low bleeding risk, high ischemic risk: May extend beyond 12 months 1

Stable CAD patients:

• Standard duration: 6 months regardless of stent type (drug-eluting or bare-metal) 1
• High bleeding risk: May shorten to 1-3 months 1
• Extended duration (>12 months): May be reasonable in selected low-bleeding-risk patients 1

Shortened DAPT Strategy (De-escalation)

In selected patients, discontinue aspirin after 1-3 months and continue P2Y12 inhibitor monotherapy to reduce bleeding risk (Class IIa recommendation). 1

This strategy is reasonable for:

• Patients who have tolerated initial DAPT without bleeding complications 1
• Those at higher bleeding risk but lower ischemic risk 1
• Transition specifically to P2Y12 inhibitor monotherapy (not aspirin monotherapy) 1, 6, 7

Mandatory Bleeding Risk Mitigation

Every patient on DAPT must receive: 2, 3

1. Proton pump inhibitor (PPI) - Class I recommendation for all patients to reduce GI bleeding 1, 2, 3
2. Low-dose aspirin only - maintain 75-100 mg daily (never higher doses with DAPT) 2, 3, 4
3. Radial artery access - when PCI performed by experienced radial operator 1, 2, 3

Timing of P2Y12 Inhibitor Loading Dose

ACS patients:

• STEMI presenting within 12 hours: Give loading dose at time of diagnosis 4
• NSTEMI/unstable angina: May defer loading dose until coronary anatomy known (especially if CABG likely within days) 4
• STEMI presenting >12 hours after symptom onset: Give loading dose after coronary anatomy established 4

The FDA label for prasugrel specifically notes that in NSTEMI patients, no clear benefit was observed when loading dose was given before angiography compared to at time of PCI, but bleeding risk increased with early administration. 4

Perioperative Management

For non-cardiac surgery:

• Never discontinue DAPT within first month after stent placement - thrombotic risk is highest 3, 5
• Minimum delay: 1 month after any stent type (Class IIa) 1
• Preferred delay: 6 months after recent MI or high ischemic risk features 1
• Continue aspirin perioperatively if bleeding risk allows 2, 5

For CABG:

• Discontinue clopidogrel 5 days (preferably 7 days) before surgery 5, 4
• Discontinue ticagrelor 5 days before surgery 5
• Discontinue prasugrel at least 7 days before surgery 4
• Resume P2Y12 inhibitor after CABG to complete 12 months of DAPT 3, 5

Switching Between P2Y12 Inhibitors

From clopidogrel to ticagrelor in ACS patients:

• Give ticagrelor 180 mg loading dose immediately without waiting for clopidogrel washout 2
• Discontinue clopidogrel when ticagrelor is started 2
• This switch is recommended early after hospital admission 1, 2

Special Population: Triple Therapy (DAPT + Anticoagulation)

When oral anticoagulation is required:

• Prefer clopidogrel over ticagrelor due to significantly lower bleeding risk 2
• Discontinue aspirin 1-4 weeks after PCI and continue P2Y12 inhibitor (preferably clopidogrel) plus anticoagulant 2
• Duration of triple therapy should be minimized 1

Critical Pitfalls to Avoid

1. Never use clopidogrel as first-line in ACS patients when ticagrelor or prasugrel are available and not contraindicated - this represents suboptimal care 2, 3, 5

2. Never discontinue DAPT prematurely (especially within first month after stent) - dramatically increases risk of stent thrombosis, MI, and death 2, 3, 5

3. Never omit PPI prescription with DAPT - this simple intervention significantly reduces GI bleeding 2, 3, 5

4. Never give prasugrel to patients with prior stroke/TIA - this is contraindicated due to increased cerebrovascular bleeding risk 2, 3, 4

5. Never fail to resume P2Y12 inhibitor after CABG in ACS patients - must complete 12 months total DAPT duration 3, 5