Effects of Aging on Clinical Outcomes in Patients Receiving Genotype-guided P2Y12 Inhibitor Selection After Percutaneous Coronary Intervention

Study Objective: To compare the clinical effectiveness of genotype-guided P2Y12 inhibitor selection following PCI in older patients (≥70 years) and younger patients (<70 years).

Design And Setting: Single-center, retrospective, cohort study. Risk of major adverse cardiovascular or cerebrovascular events (MACCE), defined as stent thrombosis, ischemic stroke, transient ischemic attack, non-fatal acute coronary syndrome, or cardiovascular death during 12 months after PCI, was compared across genotype and antiplatelet therapy groups by proportional hazards regression in patients ≥70 years and <70 years.

Patients: 1,469 patients who underwent PCI and had CYP2C19 genotype testing at a single academic medical center.

Measurements And Main Results: The study population was comprised of 402 (27.4%) ≥70 years (older group) and 1067 (72.6%) <70 years (younger group). Alternative P2Y12 inhibitors (prasugrel or ticagrelor) were used less often in the older group than the younger group in patients with a CYP2C19 no function allele (55% vs. 67%; p = 0.02) and in patients without a no function allele (10% vs. 35%, p < 0.001). For patients treated with clopidogrel, MACCE was significantly higher in no function allele carriers compared to those without a no function allele in the older group (19.2% vs. 12.7%; adjusted HR 2.32; 95% CI 1.07-5.05; p = 0.03) and the younger group (17.4% vs. 10.4%; adjusted HR 2.01; 95% CI 1.17-3.46; p = 0.01). In patients without a no function allele, MACCE risk was similar with clopidogrel compared to prasugrel or ticagrelor in the older group (adjusted HR 0.99; 95% CI 0.44-2.21; p = 0.98) and the younger group (adjusted HR 1.12; 95% CI 0.72-1.74; p = 0.61).

Conclusion: This study suggests important clinical benefits of CYP2C19 genotype-guided antiplatelet therapy after PCI in both younger and older patients.