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.