Background Proper platelet inhibition is essential for prevention of thromboembolic complications in patients undergoing stent placement.

Objective The aim of this study was to analyze the impact of VerifyNow® assay (VNA) on the management of periprocedural antiplatelet therapy in cerebrovascular stenting.

Design/Methods Consecutive patients were retrospectively categorized in three groups: elective (Clopidogrel+aspirin (C+A)≥7 days), urgent (C+A for 12–72 h including clopidogrel bolus), and emergent (no previous C+A, intra-procedural abciximab and postprocedural C+A) stenting groups. Clopidogrel resistance (CR) and hypersensitivity (CH) were defined as <20% and >80% platelet inhibition measured by VNA, respectively.

Results A total of 72 consecutive patients undergoing cerebrovascular stenting were included in the analysis. Twenty-three patients (age 64±14; 65% male) underwent elective stenting to treat symptomatic atherosclerotic lesions. The rates of CR and CH were 26% and 13%, respectively. Three of the six CR patients were treated with abciximab to achieve platelet inhibition. In one of the patients with CH (96% inhibition), stenting procedure was aborted. There were no hemorrhagic or ischemic complications. Twenty patients (age 60±12; male, 75%) underwent urgent stenting to treat symptomatic atherosclerotic lesions (n=18), medically refractory carotid dissection (n=1), and carotid pseudoaneurysm due to a gunshot wound (n=1). The rates of CR and CH were 60% (12/20) and 5% (1/20), respectively. Nine of the twelve CR patients were treated with abciximab to achieve an average 42%±14% platelet inhibition (range, 22%–52%). There were two hemorrhagic (gastrointestinal bleeding and spontaneous intracranial hemorrhage) with no ischemic events in the CR group. The patient with CH had a spontaneous fatal ICH in the unaffected cerebral hemisphere. Twenty-nine patients (age, 65±15; male, 50%) underwent emergent stenting all presenting with acute ischemic stroke. None of these patients were on chronic outpatient C+A therapy. Two received boluses of Clopidogrel before the procedure. The remaining patients received intra-procedural intravenous abciximab (3–13 mg) to achieve 29%–94% platelet inhibition. There was one intracranial and one systemic hemorrhage with no ischemic events.

Conclusions Our results suggest the applicability of VNA in assuring adequate platelet inhibition. Future studies are needed to manage CR and CH optimally to prevent thrombosis or hemorrhage.

Competing interests A Noorian: None. R Gupta: Concentric Medical, Codman Neurovascular, CoAxia, and Rapid Medical. K Wyatt Chester: None. J Faggard: None. R Gershon: None. R Nogueira: Concentric Medical, ev3 Neurovascular, CoAxia, and Rapid Medical.