Evaluation of Potential Racial Disparities in CYP2C19-Guided P2Y12 Inhibitor Prescribing After Percutaneous Coronary Intervention

Abstract

Black patients suffer worse outcomes after percutaneous coronary intervention (PCI) than White patients. Inequities in antiplatelet prescribing may contribute to this health disparity. We compared P2Y₁₂ inhibitor prescribing by race following CYP2C19 genotyping to guide antiplatelet therapy selection after PCI. Patients from 9 sites that performed clinical CYP2C19 genotyping after PCI were included. Alternative therapy (e.g., prasugrel or ticagrelor) was recommended for CYP2C19 no-function allele carriers, in whom clopidogrel is predicted to be less effective. The primary outcome was choice of P2Y₁₂ inhibitor (clopidogrel vs. alternative therapy) based on genotype. Of 3,342 patients included, 2,448 (73%) were White, and 659 (20%) were Black. More Black than White patients had a no-function allele (34.3% vs. 29.7%, P = 0.024). At hospital discharge following PCI, 44.2% of Black and 44.0% of White no-function allele carriers were prescribed alternative therapy. At the time of the last follow-up within 12 months, numerically fewer Black (51.8%) than White (56.7%) no-function allele carriers were prescribed alternative therapy (P = 0.190). However, the difference was not significant after accounting for other factors associated with P2Y₁₂ inhibitor selection (odds ratio 0.79, 95% confidence interval 0.58-1.08). Alternative therapy use did not differ between Black (14.3%) and White (16.7%) patients without a no-function allele (P = 0.232). Among real-world patients who received CYP2C19 testing after PCI, P2Y₁₂ inhibitor prescribing rates did not differ between Black and White patients. Our data suggest an absence of racial disparity in genotype-guided antiplatelet prescribing among patients receiving CYP2C19 testing.

Figure 1.. P2Y₁₂ inhibitor therapy at hospital discharge following PCI and at time of event or last follow-up stratified by race and CYP2C19 phenotype.

Data are shown for patients with a no-function allele (A) and without a no-function allele (B). Unadjusted p value shown. PCI, percutaneous coronary intervention; IM, intermediate metabolizer. NM, normal metabolizer; PM, poor metabolizers; RM, rapid metabolizer; UM, ultra-rapid metabolizer

Figure 2.. Logistic regression analysis of factors associated with alternative therapy versus clopidogrel use at the time of event or last follow-up in CYP2C19 intermediate and poor metabolizers.

The model includes variables that remained independently associated (p<0.05) with choice of P2Y₁₂ inhibitor therapy. The odds ratio and 95% confidence interval for each variable remaining in the model after stepwise selection are shown in Table S3.