025: Impact of initial clinical presentation on clopidogrel low response: is there any intra-individual variability over time?

Abstract

Clopidogrel low response correlates with poor prognosis after percutaneous coronary intervention (PCI). It is today clearly demonstrated that there is a large inter-individual variability in clopidogrel response. Some authors also suggest intra-individual variability over time. We assessed the impact of initial clinical presentation on clopidogrel low response. In this prospective study, clopidogrel response was assessed in 100 patients following PCI: 50 presented with acute coronary syndrome (ACS group) and 50 patients with stable coronary disease were matched 1 to 1 on age, sex, BMI and diabetes (stable group). All patients were tested between 18h and 24h after a 600mg clopidogrel loading dose using the test of VerifyNow-P2Y12 (results expressed as PRU). Patients under chronic clopidogrel therapy or treated with GpIIb-IIIa inhibitors were excluded. The mean age was 61±12 in each group. Altogether, 28% patients were diabetics in each group and the mean BMI was 27.6±5.6 and 27.9±5.9 in the ACS group and stable group, respectively (p=ns). The mean PRU values were 159±94 and 197±80 in the ACS group and stable group, respectively (p=0.033). By multivariate analysis, “ACS group” was significantly associated with higher PRU value (p=0.018) (see Table). The present study suggests - firstly - that initial clinical presentation (especially ACS) is a strong predictor of clopidogrel low response - and secondly - an intra-individual variability over time. These results are in accordance with recent trials showing a benefit of increased antiplatelet therapy in ACS patients. Table – Predictors of clopidogrel low response. Categorical Variables Continuous Variables Univariate analysis Multivariate analysis mean PRU Correlation r p p Clinical Présentation Stable group 159 0,033 0,018 ACS group 197 Age 0,283 0,004 0,076 Sex Male 202 0,068 0,207 Female 167 BMI 0,215 0,033 0,026 Tabac No 155 0,005 0,536 Yes 205 Diabetes No 205 0,060 0,684 Yes 167 Renal failure No 174 0,182 0,775 Yes 216 PPI No 202 0,075 0,418 Yes 167