Paige Nickelsen, PharmD,
Sarasota Memorial Hospital
Sarasota, Florida
Disclosure information not submitted.
Ron Neyens, PharmD
Clinical Pharmacy Specialist
MUSC Health of Medical University of South Carolina, United States
Disclosure information not submitted.
Title: Clopidogrel Hyperresponsiveness and Associated Complications Following Pipeline Embolization
INTRODUCTION: Antiplatelet therapy is recommended in patients for aneurysm embolization with a Pipeline Embolization Device (PED) to prevent thromboembolic complications. Given the multiplicity of platelet function testing (PFT) presenting variable degrees of associated specificity and sensitivity, a lack of defined criteria for hyperresponsiveness, and an absence for the procedure in which to care for these complex cases; the controversy remains. We hypothesize hemorrhagic complications to be more prevalent in patients who are hyperresponders to clopidogrel directed by VerifyNow antiplatelet therapy versus those who are normal responders to clopidogrel following PED flow diversion of complex cerebral aneurysms.
Methods: This is a retrospective study of a neuroendovascular database that was prospectively maintained, which included consecutive patients who underwent flow diversion of intracranial aneurysms with PED implantation at an academic medical center between September 2015 and July 2020. Patients with a VerifyNow-directed personalized antiplatelet therapy were evaluated over the first 6 months post PED implantation. Patients with a P2Y12 reaction unit (PRU) ≤ 60 were deemed to be clopidogrel hyperresponsive. The primary outcomes are the incidence of clopidogrel hyperresponsiveness and the rate of hemorrhagic complications between clopidogrel hyperresponders (PRU ≤ 60) and normal responders (PRU 61-194).
Results: The incidence of clopidogrel hyperresponders was fewer compared to normal responders (32% vs. 68%). Primary outcomes demonstrated 6% (n = 3) of patients being clopidogrel hyperresponsive and developing a thromboembolic complication, however not lending to differences in patients who were normal responders (p = 0.9). There were no hemorrhagic complications observed in patients who were clopidogrel hyperresponders, with all five hemorrhages occurring in those with a normal response (p = 0.12).
Conclusions: This study offers further evidence that patients may demonstrate variability in clopidogrel responsiveness after PED implantation. The role of VerifyNow-directed antiplatelet monitoring may have no significance in preventing hemorrhagic complications after PED implantation.