Background and purposes Prophylactic antiplatelet medication is beneficial in decreasing thromboembolic complications during endovascular treatment for intracranial aneurysms. The efficacy may be limited by individual response variability to antiplatelet medication, especially clopidogrel. We compared the efficacy of two antiplatelet medications, low-dose prasugrel and clopidogrel, in patients undergoing endovascular treatment for intracranial aneurysms.

Patients and technique During the period between November 2014 and March 2015, 96 patients harboring 109 unruptured intracranial aneurysms underwent endovascular treatment in a single institution. Laboratory and clinical data from the prospectively maintained registry were utilized. Antiplatelet medication was given the day before endovascular treatment (prasugrel of 20 mg or 30 mg, clopidogrel of 300 mg). Response to the antiplatelet medication was measured by the VerifyNow system. Procedure-related complications were compared between the two groups.

Results There were no significant differences in the clinical baseline characteristics between the two groups, including the patients’ ages (low-dose prasugrel group vs. clopidogrel group, 57.2 ± 9.7 years vs. 53.8 ± 12.8 years; p = 0.1438) and the aneurysmal volumes (179 ± 887 mm3 vs. 128 ± 432 mm3; p = 0.7239). The BASE values were lower in the clopidogrel group (324.5 ± 37.1 vs. 307.9 ± 37.6; p = 0.0225). However, PRU values were lower (132.8 ± 76.7 vs. 243.9 ± 64.1; p < 0.0001) and% inhibition values were higher (59.3 ± 23.4% vs. 21.5 ± 16.5%) in the prasugrel group. There was no thromboembolic events but one procedural bleed in each group, respectively, with no clinical consequences.

Conclusion Our data demonstrated the superiority of the low-dose prasugrel premedication in terms of stronger suppression of the platelet reactivity. We may omit the antiplatelet response assay with the low-dose prasugrel premedication prior to the endovascular treatment of intracranial aneurysm patients.

Disclosures H. Kang: None. Y. Cho: None. M. Han: None. W. Cho: None. J. Kim: None.