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Updated: May 10, 2026
Microfluidics in Assessing Platelet Function
Published on: November 8, 2024
Platelet reactivity evaluated with the VASP assay following ticagrelor loading dose in acute coronary syndrome
Marc Laine1, Richard Toesca, Julie Berbis
1Département de cardiologie, Hôpital universitaire nord, Aix-Marseille Univ., Marseille, France.
Insights
Ticagrelor
Area of Science:
- Cardiology
- Pharmacology
- Interventional Cardiology
Background:
- Platelet reactivity (PR) inhibition post-P2Y12-ADP receptor antagonist loading dose (LD) impacts ischemic and bleeding risks after percutaneous coronary intervention (PCI) in acute coronary syndromes (ACS).
Purpose of the Study:
- To evaluate PR inhibition from a 180 mg ticagrelor LD.
- To determine the high on-treatment platelet reactivity (HTPR) rate in ACS patients undergoing PCI.
Main Methods:
- A multicenter prospective observational study included 115 ACS patients (STEMI, NSTEMI, unstable angina) undergoing PCI.
- Platelet reactivity (PR) was assessed using the VASP index within 24 hours after a 180 mg ticagrelor LD.
- High on-treatment platelet reactivity (HTPR) was defined as a VASP index ≥50%.
Main Results:
- The mean VASP index was 17±14%, with a HTPR rate of 3.5%.
- A significant proportion of patients (65.6%) showed a VASP index <16%.
- No baseline characteristics were associated with PR, and PR levels were similar across STEMI, NSTEMI, and unstable angina groups.
Conclusions:
- The 180 mg ticagrelor LD provides non-uniform PR inhibition in ACS patients.
- A low rate of HTPR (3.5%) was observed, but a high percentage of patients had low PR inhibition (VASP index <16%).
Background:
The level of platelet reactivity (PR) inhibition obtained after P2Y12-ADP receptor antagonist loading dose (LD) is associated with the ischemic and bleeding risk following percutaneous coronary intervention (PCI) in acute coronary syndromes (ACS).
Objective:
We aimed to evaluate the level of PR inhibition achieved by a 180 mg LD of ticagrelor and the rate of high on-treatment platelet reactivity (HTPR) in ACS patients undergoing PCI.
Methods:
We performed a multicentre prospective observational study enrolling ACS patients undergoing PCI. Patients were included if they were admitted for ST-elevation myocardial infarction or non ST-elevation ACS. To assess PR, a VASP index was measured at least 6 and within 24 hours following a 180 mg LD of ticagrelor. HTPR was defined as a VASP index ≥50%.
Results:
One hundred and fifteen patients were included: 31.3% of STEMI, 49.6% of NSTEMI and 19.1% of unstable angina. Following ticagrelor LD the mean VASP index was 17±14%. However the response to ticagrelor was not uniform with a small inter-individual variability: inter quartile range: 7.6-22.8% and a rate of HTPR of 3.5%. A high number of patients, 65.6%, had a VASP index <16%. None of the baseline characteristics of the study population was associated with PR. In addition, PR was similar in STEMI, NSTEMI and unstable angina (p=0.9).
Conclusion:
In ACS patients the level of PR inhibition achieved by a 180 mg loading dose of ticagrelor is not uniform and the rate of HTPR is 3.5%. A high proportion of patients exhibited a VASP index <16%.
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