Abstract Number: LBA20 Platelet Function Inhibition is superior with ticagrelor with a lower incidence of Intracerebral Hemorrhage

Abstract

Introduction The most common antiplatelet agents administered for neurovascular disease treatment and prevention are aspirin, clopidogrel, and ticagrelor. The utility of monitoring various platelet function assays (PFAs) in relation to neurovascular disease is unclear and variability exists in clinical practice. The aim of this study was to evaluate PFAs as a biomarker of the platelet inhibition in aspirin, clopidogrel, and ticagrelor in patients on antiplatelet agents for a broad range of neurovascular indications. Methods We conducted a retrospective chart review of prospectively collected data on patients who presented to our comprehensive stroke center and had PFAs drawn. PFAs utilized include Aspirin VerifyNow test, measured in aspirin resistance units (ARU) and Plavix VerifyNow test, measured in P2Y12 reaction units (PRU). Values less than 550 ARU are consistent with aspirin‐induced platelet inhibition. Similarly, values less than 197 PRU are indicative of platelet inhibition in clopidogrel or ticagrelor. Compliance and incidence of intracranial hemorrhage (ICH) were assessed. Social science statistics software was used for data analysis. Results From January to June 2022, a total of 297 patients had platelet function assays drawn for neurovascular indications. Average age was 69.96 (95% CI 68.31, 71.61). One hundred and eighty nine subjects were on aspirin. Mean ARU was 448.73 (95% CI 438.53, 458.93). One hundred twenty three subjects were on clopidogrel. Mean PRU for clopidogrel was 162.84 (95% CI 147.33, 178.35). Fifteen subjects were on ticagrelor. Mean PRU for ticagrelor was 73.27 (95% CI 34.62, 111.91). There was a significant difference in therapeutic efficacy between clopidogrel and ticagrelor in subjects who were compliant (n = 105 clopidogrel complaint; n = 14 ticagrelor complaint) (z‐score 3.63, p‐value 0.00028). There was a significant difference between incidence of ICH in subjects compliant and therapeutic on clopidogrel as compared to ticagrelor (n = 8 clopidogrel and ICH; n = 1 ticagrelor and ICH) (Fisher value = 0.0205). Conclusions Our study suggests that platelet inhibition of ticagrelor may be superior to that of clopidogrel with a lower incidence of intracranial hemorrhage as a complication of therapy. Significant limitations include the discrepancy in respective sample sizes. Larger, prospective studies are needed to validate our results.