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

Objectives: 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. Methods: 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. Results: 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. Conclusions: This study shows the suitability of using genotyping to guide antiplatelet therapy in ischemic stroke patients in a clinical setting.