- Among patients with minor stroke or transient ischemic attack (TIA), ticagrelor (Brilinta) plus aspirin was superior to clopidogrel (Plavix) plus aspirin in reducing high platelet reactivity and, among those with large-artery atherosclerosis, recurrent stroke risk.
Why this matters
- Main metabolic enzyme differs for ticagrelor (CYP3A4), clopidogrel (CYP2C19).
- Unknown whether differential efficacy, safety in acute coronary syndromes applies to stroke.
- 90-day high platelet reactivity less common with ticagrelor-aspirin vs clopidogrel-aspirin:
- In trial population (12.5% vs 29.7%; risk ratio, 0.40; P<.001>
- In subgroup carrying CYP2C19 loss-of-function alleles (10.8% vs 35.4%; risk ratio, 0.31; P<.001>
- Similar in trial population (6.3% vs 8.8%; HR, 0.70; P=.20),
- Lower with ticagrelor-aspirin in subgroup with large-artery atherosclerosis (6.0% vs 13.1%; HR, 0.45; P=.04).
- Chinese phase 2 randomized controlled trial: 675 patients with minor stroke or TIA (PRINCE trial).
- Randomization: open-label ticagrelor vs clopidogrel, plus aspirin within 24 hours of symptom onset.
- Main outcome: high platelet reactivity.
- Funding: Ministry of Science and Technology of People’s Republic of China; others. AstraZeneca (study drugs).
- High platelet reactivity a surrogate.
- Underpowered for clinical events.
- Lack of blinding.