Prevalence and predictors of high-on treatment platelet reactivity with ticagrelor in ACS patients undergoing stent implantation

Background: Residual high-on treatment platelet reactivity (HRPR) predicts outcomes and major cardiovascular events. Ticagrelor has provided pharmacological and clinical evidence of more predictable and more potent antiplatelet effect as compared to clopidogrel. However, so far, few data have investigated the prevalence and predictors of HRPR in unselected patients treated with ticagrelor, that is therefore the aim of the current study. Methods and results: Our population is represented by 195 patients undergoing coronary stenting for ACS and receiving ASA and ticagrelor. Platelet function was assessed by multiplate impedance aggregometry (MEA) between 1 and 3 months after stenting. Main clinical features and biochemistry parameters were collected. HRPR for ticagrelor was defined for aggregation > 417 AUC after MEA-ADP stimulation. A total of 26 patients, (13.3%), displayed HRPR with ticagrelor. Older age (≥. 70 years, p = 0.002), hypertension (= 0.02) previous myocardial infarction (= 0.04), therapy with nitrates and beta-blockers (= 0.02), diuretics (= 0.03) and fasting glycaemia (= 0.05) were associated to HRPR with ticagrelor. By multivariate analysis, age ≥ 70 years (OR [95%CI] = 4.6[1.55-13.8], p = 0.006), concomitant therapy with beta-blockers (OR [95%CI] = 3.2[1.06-9.6], p = 0.04) and platelets count (OR[95%CI] = 1.0007 [1-1.016], p = 0.05) were identified as independent predictors of HRPR with ticagrelor. Conclusion: The present study firstly demonstrates that the occurrence of HRPR in patients treated with ticagrelor is not so futile, as it was observed in 13% of patients treated with ticagrelor. Older age, beta-blockers administration and platelets count are independent predictors of HRPR with ticagrelor.