Platelet function testing-guided antiplatelet dosing for elective flow diversion of internal carotid artery aneurysms

BACKGROUND: Under- or over-inhibition of platelet aggregation by antiplatelets may contribute to ischemic or hemorrhagic complications following flow diversion for intracranial aneurysms. We aimed to describe our institutional practice of adjusting antiplatelet doses based on periprocedural Multiplate Analyzer platelet function testing (PFT) to avoid under- or over-inhibition. METHODS: Patients with an internal carotid artery (ICA) aneurysm treated electively with flow diversion and with antiplatelet doses guided by PFT were included. Patients were classified as having either low-, standard-, or high-dose antiplatelets based on their discharge doses. The primary outcome was major ipsilateral stroke (National Institutes of Health Stroke Scale score (NIHSS) ≥4) or neurological death within 6 months. RESULTS: One hundred and nine (57.4±12.9 years, 94 (86.2%) female) patients met the inclusion criteria. Aspirin (range 25-100 mg/day) was used in 109 (100%), prasugrel (range 1.25-15 mg/day) in 74 (67.9%), clopidogrel (range 37.5-75 mg/day) in 33 (30.3%), and ticagrelor (range 90-180 mg/day) in 2 (1.8%) patients. Low-dose antiplatelets were used in 57 (52.3%), standard-dose in 50 (45.9%), and high-dose in 2 (1.8%) patients. Two (1.8%) patients met the primary outcome (one in each of the standard- and low-dose groups) and 4 (3.7%) patients had symptomatic neurological complications that did not meet the primary outcome. CONCLUSIONS: In a cohort managed with routine periprocedural PFT to avoid under- or over-inhibition of platelet function, low-dose antiplatelets were commonly prescribed, and a low complication rate was observed. These findings support further prospective evaluation of PFT-guided antiplatelet dosing.