Background Clopidogrel/aspirin antiplatelet therapy is routinely administered 7 to 10 days prior to pipeline aneurysm treatment. Our study assessed the safety and efficacy of a 600 mg loading dose of clopidogrel 24 hours before PED treatment.

Methods We performed a retrospective cohort study involving patients treated with pipeline from October 2010 to May 2016. They were divided into two groups: 39.7%(n=158) patients were dispensed a loading dose of 650 mg of aspirin plus at least 600 mg of clopidogrel 24 hours preceding PED deployment; 60.3%(n=240) received 81–325 mg of aspirin daily for 10 days with 75 mg of clopidogrel daily pre-procedurally. The mean follow-up was 15.8 months (SD=12.4 months). modified Rankin Scale (mRS) was registered before the discharge and at each follow-up visit. To control confounding we used multivariable logistic regression and propensity score conditioning.

Results Of 398 patients, the proportion of female patients was ≈16.5% (41/240) in both groups and shared the same mean of age ≈56.46 years. Similarly, ≈12.2% (mean=0.09; SD=0.30) had a subarachnoid hemorrhage. 92% (mean=0.29; SD=0.70) from the pre-treatment group and 85.7%(mean=0.44; SD=0.91) of the bolus group had a mRS&It=2. In a multivariate analysis, bolus did not affect the mRS score, p=0.24. 7 patients had a long-term recurrence: 2 (0.83%; mean=0.01; SD=0.10) from the pre-treatment group. In a multivariable logistic regression, bolus was not associated with a long-term recurrence rate (OR, 1.91; CI95%, 0.27–13.50; p=0.52) neither with thromboembolic accidents (OR, 0.99; CI 95%, 0.96–1.03; p=0.83) nor with hemorrhagic events (OR, 1.00; CI95%, 0.97–1.03; p=0.99). 3 patients were announced dead: (1) receiving bolus had an acute SAH. The mean mortality rate was parallel in both groups ≈0.25(SD=0.16). Bolus was not associated with mortality (OR, 1.11; CI95%, 0.26–4.65; p=0.89). The same associations were present in propensity score adjusted models.

Conclusion In a cohort receiving PED, 600 mg loading dose of clopidogrel should be safe and efficacious in those off the standard protocol or showing and It30% platelet inhibition before treatment.

Disclosures E. Atallah: None. K. Bekelis: None. S. Tjoumakaris: None. R. Rosenwasser: None. P. Jabbour: None.