Implementing CYP2C19 Pharmacogenetic Testing for Personalized Antiplatelet Therapy: Findings From the QPGx-CARES...

CYP2C19 loss-of-function (LoF) alleles are associated with increased cardiovascular risk in clopidogrel-treated percutaneous coronary intervention (PCI) patients. Despite the guidelines recommendation for newer P2Y12 inhibitors, clopidogrel remains widely prescribed. The study the potential impact and feasibility of implementing pharmacogenetics (PGx) testing to guide antiplatelet therapy and develop strategies for its clinical integration to improve patient management.

A pilot study following a prospective cohort design was conducted within the largest community healthcare provider in Qatar using point-of-care (POC) CYP2C19 genotyping in tailoring antiplatelet therapy for PCI patients. Eligible patients underwent CYP2C19 genotyping, and P2Y12 inhibitor prescriptions were adjusted based on genetic results. The study measured antiplatelet prescribing patterns and identified clinically significant gene-drug interactions.

Out of 376 patients tested, 283 patients received PGx-guided recommendations for anti-platelet therapy. Actionable CYP2C19 alleles were detected in 22% of those patients, prompting a change in drug therapy. PGx-guided recommendations were adopted at a rate of 80%, and CYP2C19 genotyping was a significant predictor of antiplatelet therapy adjustments. A sub-analysis of the cost impact revealed an estimated reduction of 300 QR (82.41 $) per patient annually for ACS patients who underwent PCI with stent placement.

This real-world study highlights the feasibility and clinical impact of CYP2C19 genotyping in guiding antiplatelet therapy for ACS and PCI patients, supporting broader PGx testing implementation in routine cardiovascular care.

HMC-IRB Registration: IRB-HMC-2021-011, IRB-MoPH Assurance: IRB-A-HMC-2019-0014. ISRCTN registration: ISRCTN15110009, https://www.isrctn.com/ISRCTN15110009.