Prevalence of CYP2C19∗2 carriers in Saudi ischemic stroke patients and the suitability of using genotyping to guide antiplatelet therapy in a university hospital setup

To mitigate the incidence of recurrent stroke in patients, dual antiplatelet therapy comprising aspirin and clopidogrel is usually administered. Clopidogrel is a prodrug and its bioactivation is catalyzed by cytochrome P450 (CYP)2C19. The main objective of this work was to determine the prevalence of CYP2C19∗2 carriers in Saudi ischemic stroke patients and assess the suitability of using genotyping to guide antiplatelet therapy in a university hospital setup. This prospective (2018-2019) study was conducted on 256 patients (age 61 ± 12.5) clinically diagnosed with ischemic stroke who were genotyped using Spartan RX CYP2C19 assay. From the total patient group (256), upon admission, 210 patients were prescribed either aspirin, clopidogrel or dual antiplatelet therapy. Of the 27 patients with the CYP2C19∗2 allele who were prescribed clopidogrel (18) or dual antiplatelet therapy (9), only 21 patients could be followed up for a period of six months post stroke event, in addition to 21 age- and sex-matched patients with the normal allele. The CYP2C19∗2 allele carriers had a statistically significant increased risk of recurrent stroke compared to patients carrying the normal allele. This study shows the suitability of using genotyping to guide antiplatelet therapy in ischemic stroke patients in a clinical setting.