Which antiplatelet agent, ticagrelor or prasugrel, is preferred for acute coronary syndrome?

Antiplatelet Selection in Acute Coronary Syndrome

Both prasugrel and ticagrelor are superior to clopidogrel and should be used preferentially in ACS patients undergoing PCI, with prasugrel showing a slight edge in patients with NSTE-ACS proceeding to PCI, while ticagrelor remains the preferred option for medically managed patients and those with prior stroke/TIA. 1

Primary Recommendations by Clinical Scenario

For STEMI Managed with Primary PCI

• Prasugrel or ticagrelor should be administered to reduce major adverse cardiovascular events (MACE) and stent thrombosis 1
• Both agents carry Class I, Level B-R recommendations with equal standing 1
• Clopidogrel is only recommended when prasugrel or ticagrelor are unavailable, cannot be tolerated, or are contraindicated 1

For NSTE-ACS Undergoing PCI

• Prasugrel should be considered in preference to ticagrelor for NSTE-ACS patients who proceed to PCI (Class IIa, Level B) 1
• This recommendation is based on the 2020 ESC guidelines showing prasugrel's superiority in this specific population 1
• The 2025 ACC/AHA guidelines give both agents Class I recommendations but note prasugrel or ticagrelor should be used over clopidogrel 1

For NSTE-ACS Managed Medically (Without Revascularization)

• Ticagrelor is recommended to reduce MACE in patients managed without planned invasive evaluation 1
• Prasugrel is not recommended in medically managed ACS patients 1
• This represents a clear distinction where ticagrelor has proven efficacy that prasugrel lacks 1

Critical Contraindications and Dose Adjustments

Absolute Contraindications for Prasugrel

• Prior stroke or TIA - prasugrel should not be administered due to worse net clinical outcomes and increased intracranial hemorrhage risk 1, 2
• Active pathological bleeding 2

High-Risk Populations Requiring Caution with Prasugrel

• Age ≥75 years: Generally not recommended except in high-risk situations (diabetes or prior MI) where benefit may outweigh increased fatal and intracranial bleeding risk 2
• Body weight <60 kg: Consider lowering maintenance dose to 5 mg daily (though this dose hasn't been prospectively studied) 1, 2
• No net benefit observed in patients ≥75 years or <60 kg in TRITON-TIMI 38 1

Ticagrelor-Specific Considerations

• Causes dyspnea in approximately 10-15% of patients, though rarely severe enough to require discontinuation 1
• Must be used with low-dose aspirin (75-100 mg daily) - higher aspirin doses reduce ticagrelor's effectiveness 1
• Requires twice-daily dosing, which may affect compliance 1

Dosing Regimens

Prasugrel

• Loading dose: 60 mg orally 1
• Maintenance: 10 mg daily (standard dose) 1
• Maintenance: 5 mg daily for patients ≥75 years or <60 kg 1

Ticagrelor

• Loading dose: 180 mg orally 1
• Maintenance: 90 mg twice daily 1

Evidence from Recent Studies

ISAR-REACT 5 Trial (2019)

The most rigorous head-to-head comparison showed prasugrel superiority over ticagrelor in ACS patients planned for invasive evaluation 3:

• Primary endpoint (death, MI, or stroke at 1 year): 6.9% prasugrel vs 9.3% ticagrelor (HR 1.36,95% CI 1.09-1.70, p=0.006) 3
• MI: 3.0% prasugrel vs 4.8% ticagrelor 3
• Definite stent thrombosis: 0.6% prasugrel vs 1.1% ticagrelor 3
• Major bleeding: No significant difference (4.8% vs 5.4%, p=0.46) 3

Real-World Evidence (2024)

A large German cohort study emulating ISAR-REACT 5 confirmed these findings in routine care 4:

• Primary composite endpoint: 7.5% prasugrel vs 9.2% ticagrelor (HR 1.24,95% CI 1.12-1.37) 4
• Particularly beneficial in STEMI patients: 6.8% prasugrel vs 9.3% ticagrelor 4

Polish Registry (2025)

Among 381,278 ACS patients, both prasugrel and ticagrelor reduced mortality compared to clopidogrel, with ticagrelor showing superior net clinical outcomes over prasugrel 5

Timing of Administration

NSTE-ACS

• Do not routinely pre-treat with P2Y12 inhibitors before coronary anatomy is known when early invasive management is planned 1
• The ACCOAST trial demonstrated prasugrel pre-treatment increased bleeding without ischemic benefit 1
• May consider upstream treatment with clopidogrel or ticagrelor if angiography timing anticipated >24 hours (Class IIb) 1

STEMI

• Prasugrel or ticagrelor should be administered at time of primary PCI 1
• In STEMI presenting within 12 hours, loading dose typically given at diagnosis or PCI 2

Bleeding Risk Mitigation

Mandatory Co-Interventions

• Proton pump inhibitor recommended in combination with DAPT to reduce gastrointestinal bleeding 1
• Maintain aspirin dose at 75-100 mg daily (never exceed 100 mg with ticagrelor) 1

Duration Considerations

• Standard DAPT duration: 12 months unless excessive bleeding risk 1
• In patients who tolerate ticagrelor, transition to ticagrelor monotherapy at 1 month post-PCI is recommended to reduce bleeding 1
• For patients requiring anticoagulation, discontinue aspirin at 1-4 weeks post-PCI, continue P2Y12 inhibitor (preferably clopidogrel) 1

Common Pitfalls to Avoid

• Never use prasugrel in patients with prior stroke/TIA - this is an absolute contraindication with proven harm 1, 2
• Don't exceed 100 mg aspirin daily with ticagrelor - higher doses negate ticagrelor's benefit 1
• Avoid prasugrel pre-treatment in NSTE-ACS before knowing coronary anatomy - increases bleeding without benefit 1
• Don't start prasugrel in patients likely to need urgent CABG - requires 7-day washout period 2
• Don't use prasugrel for medically managed ACS - no evidence of benefit, only studied in PCI patients 1