Anti-platelet drug resistance in the prediction of thromboembolic complications after neurointervention

J Korean Neurosurg Soc. 2010 Oct;48(4):319-24. doi: 10.3340/jkns.2010.48.4.319. Epub 2010 Oct 30.

Abstract

Objective: The aim of this study was to analyze the correlation between thromboembolic complications and antiplatelet drugs before and after neurointervention.

Methods: Blood samples and radiographic data of patients who received a neurointervention (coil embolization, stent placement or both) were collected prospectively. Rapid platelet function assay-aspirin (RPFA-ASA) was used to calculate aspirin resistance in aspirin reaction units (ARU). For clopidogrel resistance, a P2Y12 assay was used to analyze the percentage of platelet inhibition. ARU > 550 and platelet inhibition < 40% were defined as aspirin and clopidogrel resistance, respectively.

Results: Both aspirin and clopidogrel oral pills were administered in fifty-three patients before and after neurointerventional procedures. The mean resistance values of all patients were 484 ARU and < 39%. Ten (17.0%) of 53 patients showed resistance to aspirin with an average of 597 ARU, and 33 (62.3%) of 53 patients showed resistance to clopidogrel with an average of < 26%. Ten patients demonstrated resistance to both drugs, 5 of which suffered a thromboembolic complication after neurointervention (mean values : 640 ARU and platelet inhibition < 23%). Diabetic patients and patients with hypercholesterolemia displayed mean aspirin resistances of 513.7 and 501.8 ARU, and mean clopidogrel resistances of < 33.8% and < 40.7%, respectively.

Conclusion: Identifying individuals with poor platelet inhibition using standard regimens is of great clinical importance and may help prevent cerebral ischemic events in the future. Neurointerventional research should focus on ideal doses, timing, choices, safety, and reliable measurements of antiplatelet drug therapy, as well as confirming the clinical relevance of aggregometry in cerebrovascular patients.

Keywords: Aspirin; Clopidogrel; Neurointervention; Resistance.