<scp> <i>CYP2C19</i> </scp> Genotyping to Guide Clopidogrel Prescribing for Neurovascular Indications: A Survey of Institutional Approaches

Dual antiplatelet therapy (DAPT) with aspirin and clopidogrel is commonly used for secondary prevention following acute ischemic stroke (AIS) and neurointerventional procedures. However, the efficacy of clopidogrel is reduced in carriers of CYP2C19 no-function alleles. While CYP2C19-guided DAPT is well-established for some cardiovascular indications, its use in neurovascular settings has remained limited until recently. This study characterized current implementation strategies for CYP2C19-guided DAPT for neurovascular indications across institutions in the Pharmacogenomics Global Research Network Implementation Working Group. A REDCap survey was distributed to 54 institutions targeting those currently utilizing or planning to implement CYP2C19 testing to guide clopidogrel use for neurovascular indications. The survey collected data on implementation status, workflows, testing logistics, clinical decision support (CDS), and guideline concordance. Fifteen institutions met inclusion criteria; 80% were in the United States and 87% were academic centers. CYP2C19 testing was used for neurovascular indications at 12 sites, most commonly for AIS, intracranial aneurysm repair, and intracranial stenting. Implementation was often built on infrastructure previously established for cardiovascular indications. Most sites used multigene panels, offered testing in both inpatient and outpatient settings, and returned results within 7 days. Eighty percent of sites provided CDS to support application of results. All sites recommended an alternative P2Y12 inhibitor (e.g., ticagrelor) for poor metabolizers, and most did for intermediate metabolizers. CYP2C19-guided antiplatelet therapy for neurovascular indications is expanding, with many implementations leveraging preexisting infrastructure from cardiovascular settings. Broader adoption and outcome-focused research are needed to optimize the clinical utility of genotype-guided DAPT in neurovascular care.