Are aspirin and ticagrelor indicated only for non‑ST‑segment‑elevation myocardial infarction (NSTEMI) and not for ST‑segment‑elevation myocardial infarction (STEMI)?

Aspirin and Ticagrelor Are Indicated for BOTH NSTEMI and STEMI

I need to correct this misunderstanding: Dual antiplatelet therapy with aspirin and ticagrelor (or prasugrel) is recommended for BOTH STEMI and NSTEMI, not just NSTEMI. 1

Evidence for Use in STEMI

The 2017 ESC STEMI guidelines explicitly state that DAPT in the form of aspirin plus ticagrelor or prasugrel (or clopidogrel if the others are unavailable or contraindicated) is recommended for 12 months after PCI in STEMI patients (Class I, Level A recommendation). 1

• Aspirin at 75-100 mg daily is indicated for all STEMI patients 1
• The combination is recommended regardless of whether patients undergo primary PCI or receive fibrinolytic therapy 1
• When fibrinolysis is used, clopidogrel is specifically indicated in addition to aspirin (Class I, Level A) 1

Evidence for Use in NSTEMI

The 2012 ACC/AHA guidelines similarly recommend dual antiplatelet therapy for NSTEMI patients:

• Aspirin should be prescribed indefinitely, and clopidogrel (75 mg daily) or ticagrelor (90 mg twice daily) should be prescribed for up to 12 months in medically managed NSTEMI patients (Class I, Level B) 1
• For NSTEMI patients receiving stents, aspirin should be continued indefinitely, and a P2Y12 inhibitor (clopidogrel, prasugrel, or ticagrelor) should be given for at least 12 months 1

The PLATO Trial Evidence

The confusion may stem from subgroup analyses, but the PLATO trial—which established ticagrelor's superiority—included ALL types of acute coronary syndromes, not just NSTEMI:

• Ticagrelor showed consistent benefits across most subgroups, with no significant interaction between treatment effect and type of ACS 1
• Benefits appeared in both NSTEMI patients (11.4% vs 13.9% event rate; HR 0.83) and were evident regardless of ACS type 1
• The trial was designed as an "all-comer" study for patients with UA/NSTEMI, including both invasively and medically managed patients 1

Key Dosing Considerations

The aspirin dose matters significantly with ticagrelor:

• Aspirin maintenance doses >100 mg daily decrease ticagrelor's effectiveness (FDA Boxed Warning) 1
• The recommended aspirin maintenance dose with ticagrelor is 81 mg daily 1
• This aspirin-dose effect was consistent across geographic regions and explained much of the regional variation in PLATO outcomes 1

Practical Application

For STEMI: Start aspirin immediately (oral or IV) plus ticagrelor 180 mg loading dose (or prasugrel 60 mg after angiography if anatomy known), then maintain ticagrelor 90 mg twice daily for 12 months 1

For NSTEMI: Same regimen—aspirin plus ticagrelor or prasugrel for 12 months, with the choice depending on bleeding risk and whether coronary anatomy is known 1, 2, 3