Background and Purpose Flow diverters such as the Pipeline Embolization Device (PED) are relatively thrombogenic with a greater than 50% incidence of peri-procedural ischemic lesions despite dual antiplatelet therapy. Platelet function testing (PFT) has been used to ensure adequate platelet inactivation peri-procedurally, however, the relationship between level of platelet inhibition and rate of total thromboembolic complications remains inconclusive.

Methods Pre-procedural blood samples from PED patients pretreated for 7-10 days with dual anti-platelet therapy were assayed with the VerifyNow platelet function assay for P2Y12 reactivity (PRU) on the day of the procedure in 94 consecutive patients. Procedural ischemic lesions were detected by diffusion-weighted magnetic resonance imaging (DW-MRI) performed at 24 hours post-procedure. Logistic regression and area under curve (AUC) characteristic were generated, with optimal PFT threshold determined by maximizing Youden’s J statistic.

Results Forty-two of a total 94 PED consecutive procedures (44.7%) showed post-procedural ischemic lesions on DWI with two transiently symptomatic. The rate of hemorrhagic complications was zero. Baseline clinical, procedural, and radiographic parameters were similar between groups. P2Y12 reactivity was higher in ischemic patients (PRU 106.8 vs. 55.1, p<0.0001), and PRU was found to be a statistical predictor of ischemic lesion number and total surface area, with an increase in ten PRU increasing the odds of a DWI-positive lesion by seventeen percent (OR 1.017, CI 1.008-1.026) and AUC=0.74. The optimal PRU threshold was determined to be 100.5 (sensitivity 54.8%, specificity 82.7%), which is much lower than the generally accepted PRU threshold of 194.

Conclusions These results are the first to highlight the relationship between P2Y12 antagonism and DWI+ burden. Our findings confirm the important role of pre-procedural platelet function testing and post-procedural DW-MRI and lend support to the utility of the PRU assay for determining optimal reduction of PED-related peri-procedural ischemic events.

Disclosures C. Cebulla: None. S. Burke: None. A. Malek: 2; C; CereVasc Inc. 4; C; CereVasc Inc.