Background: The purpose of this study was to verify the association between immediate post-procedural thromboembolic infarction and antiplatelet drug resistance after endovascular coil embolization for unruptured intracranial aneurysm.
Method: This study included 338 aneurysm cases between October 2012 and March 2015. All patients received post-procedural MRI within 48 hours after endovascular coil embolization. Antiplatelet drug resistance was checked a day before the procedure using the VerifyNow system. Abnormal antiplatelet response was defined as more than 550 aspirin response units (ARU) and more than 240 P2Y12 receptor reaction units (PRU). Also, we explored the optimal cutoff values of ARU and PRU. The primary outcome was radiologic infarction based on post-procedural MRI.
Results: Among 338 unruptured intracranial aneurysms, 32 (9.5%) and 105 (31.1%) had abnormal ARU and PRU values, respectively. Radiologic infarction was associated with old age (≥65, adjusted odds ratio (OR)1.777, 95% confidence interval (CI) 1.080-2.925) only with defined abnormal antiplatelet response (ARU≥550, PRU≥240). PRU values in the top 10th percentile (>294) were associated with radiologic infarction (p=0.003, OR 4.8, 95% CI 1.708-13.492). Using this cutoff value, age (OR 2.287, 95% CI 1.282-4.079), PRU (>294, OR 3.431 95% CI 1.528-7.706), and hyperlipidemia (OR 2.046 95% CI 1.041-4.020) were associated with radiologic infarction in multivariate analysis.
Conclusions: Radiologic infarction after coiling for unruptured aneurysm was closely associated with age. Only very high PRU values (>294) predicted post-procedural infarction. Further controlled studies are needed to determine precise cutoff values which could provide information regarding the optimal antiplatelet regimen for aneurysm coiling.