Abstract TP167: Unanticipated Platelet Function Fluctuations Occur During The First 8 Hours After Neurointerventional Procedures In Patients Receiving Dual Anti-platelet Therapy

Abstract

Antiplatelet agents are administered before and after neuroendovascular surgery to minimize implant-associated thromboembolic events. Dual antiplatelet therapy (DAPT) uses aspirin plus P2Y12 receptor inhibitors: clopidogrel, ticagrelor, or prasugrel. Effects are quantified in P2Y12 reactivity units (PRU) and aspirin reactivity units (ARU) by the point-of-care assay, Accumetrics VerifyNow. We hypothesized that intraoperative events such as anesthesia may affect platelet inhibition, increasing the risk of unanticipated ischemic events in the early postoperative period. This retrospective study was approved by the institutional review board. 50 patients who underwent Verify Now testing preoperatively and within 12 hours postoperatively after placement of cervical or intracranial stents at a single institution (January 1, 2018 - May 25, 2021) were included. PRU values > 194 and ARU values > 550 were considered subtherapeutic. Anesthetic agents, heparin dosage, clopidogrel responsiveness, platelet count, liver function, procedure type and length, NIH stroke scale scores, and demographics were compared to perioperative platelet inhibition values. Our results indicate that P2Y12 inhibition is likely affected by intraoperative events. Approximately 25% of patients exhibited marginal (170-193) or subtherapeutic (> 194) PRU values during the first 8 hours following neuroendovascular procedures. The greatest variation occurred in the ticagrelor group (PRU median change 84) and was more likely to occur with reduced doses of both ticagrelor and clopidogrel. A single prasugrel patient (clopidogrel non-responder) exhibited the greatest absolute change (PRU 156 -> 316). ARU variations were less pronounced suggesting that perioperative aspirin platelet inhibition is more resilient. In conclusion, patients undergoing elective neuroendovascular procedures may be at risk for thromboembolic ischemic complications during the first 8 hours postoperatively due to shifts in P2Y12 mediated platelet inhibition. ARU values were less effected, supporting the use of DAPT as an ongoing clinical standard of care.