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.
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 ¡Ý 50 % .
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 ¡À 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).
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 % .