Platelet Function Testing with a VerifyNow-Directed Personalized Antiplatelet Strategy and Associated Rates of Thromboembolic Complications After Pipeline Embolization for Complex Cerebral Aneurysms

Abstract

Background: VerifyNow-directed personalized antiplatelet therapy for aneurysm embolization with a Pipeline Embolization Device (PED) remains controversial. Evaluate thrombotic complications between patients who received VerifyNow-directed personalized antiplatelet therapy versus those who did not after PED flow diversion of complex cerebral aneurysms.

Methods: This was a retrospective cohort of consecutive patients undergoing flow diversion with PED at the Medical University of South Carolina between January 2012 and May 2018. Patients who received VerifyNow-directed personalized antiplatelet therapy were compared with those who received antiplatelet therapy without platelet function testing. Patients with a P2Y12 reaction unit (PRU) ≥194 were deemed to be clopidogrel hyporesponsive. The primary outcome is the rate of thrombotic complications, and the secondary outcomes are the rate of hemorrhagic and thrombotic complications stratified by PRU and high-risk clinical and procedure-related candidate predictors.

Results: Thrombotic complications were not different between patients managed with (n = 159) versus without (n = 110) VerifyNow (6.9% vs. 7.3%; P = 0.911). Hemorrhagic complications were also no different (3.1% vs. 4.5%; P = 0.550). PRU stratification revealed no difference in thrombotic or hemorrhagic complications (P = 0.488 and P = 0.136, respectively). The only significant predictors for thrombotic complications were the presence of diabetes (OR 2.9; P = 0.034), obesity (OR 5.1; P ≤ 0.001), fusiform aneurysm (OR 3.3; P = 0.023), posterior circulation implantation (OR 3.4; P = 0.016), and >1 PED implanted (OR 2.4; P = 0.046).

Conclusions: The role of VerifyNow and personalized antiplatelet therapy in patients undergoing flow diversion with PED to treat complex aneurysms did not demonstrate a benefit in reducing thrombotic complications.

Keywords: Aneurysm; Clopidogrel; Pipeline embolization device; Platelet function test; Responders; Thromboembolic; Ticagrelor.