Genetic-Guided Oral P2Y₁₂ Inhibitor Selection and Cumulative Ischemic Events After Percutaneous Coronary Intervention

Background: Genetic-guided P2Y₁₂ inhibitor selection has been proposed to reduce ischemic events by identifying CYP2C19 loss-of-function (LOF) carriers at increased risk with clopidogrel treatment after percutaneous coronary intervention (PCI). A prespecified analysis of TAILOR-PCI (Tailored Antiplatelet Therapy Following PCI) evaluated the effect of genetic-guided P2Y₁₂ inhibitor therapy on cumulative ischemic and bleeding events.

Objectives: Here, the authors detail a prespecified analysis of cumulative endpoints. The primary endpoint was cumulative incidence rate of ischemic events at 12 months. Cumulative incidence of major and minor bleeding was a secondary endpoint. Cox proportional hazards models as adapted by Wei, Lin, and Weissfeld were used to estimate the effect of this strategy on all observed events.

Methods: The TAILOR-PCI trial was a prospective trial including 5,302 post-PCI patients with acute and stable coronary artery disease (CAD) who were randomized to genetic-guided P2Y₁₂ inhibitor or conventional clopidogrel therapy. In the genetic-guided group, LOF carriers were prescribed ticagrelor, whereas noncarriers received clopidogrel. TAILOR-PCI's primary analysis was time to first event in LOF carriers.

Results: Among 5,276 patients (median age 62 years; 25% women; 82% acute CAD; 18% stable CAD), 1,849 were LOF carriers (903 genetic-guided; 946 conventional therapy). The cumulative primary endpoint was significantly reduced in the genetic-guided group compared with the conventional therapy (HR: 0.61; 95% CI: 0.41-0.89; P = 0.011) with no significant difference in cumulative incidence of major or minor bleeding (HR: 1.36; 95% CI: 0.67-2.76; P = 0.39).

Conclusions: Among CYP2C19 LOF carriers undergoing PCI, a genetic-guided strategy resulted in a statistically significant reduction in cumulative ischemic events without a significant difference in bleeding. (Tailored Antiplatelet Therapy Following PCI [TAILOR-PCI]; NCT01742117).