Genotype-Guided P2Y₁₂ Inhibitor Monotherapy Within 7 Days of Percutaneous Coronary Intervention in High Bleeding Risk Patients: The CHAMP Trial — A Pilot Study and Safety Assessment

Objective: To test the feasibility and safety of genotype guidance in the selection of P2Y₁₂ monotherapy within 1 week of percutaneous coronary interventions (PCIs) among patients with high bleeding risk (HBR). Patient and Methods: The study was a single-center, open-label, pilot trial. Patients (n=100) with HBR (as defined by an academic research consortium) after successful PCI received dual antiplatelet therapy with clopidogrel and aspirin. Following availability of cytochrome P450 2C19 (CYP2C19) genotype results (mean, 2.9 days), aspirin was discontinued. Normal, rapid, or ultrarapid CYP2C19 metabolizers continued clopidogrel monotherapy for 90 days whereas loss-of-function allele carriers switched to prasugrel or ticagrelor monotherapy. The primary safety endpoints were a composite of post-dismissal cardiac death/spontaneous myocardial infarction less than 30 days or stent thrombosis <90 days of discharge. The subjects also underwent post-dismissal assessment for BARC (Bleeding Academic Research Consortium) type 3 or 5 bleeding, all-cause death, any MI, and/or repeat revascularization up to 90 days. Results: There were 98 patients with complete data (median age, 76.5 years, 36% women; 49% acute coronary syndrome). Sixty-nine (70.4%) were normal, rapid, or ultrarapid metabolizers and continued clopidogrel monotherapy, and 29 (29.6%) were intermediate CYP2C19 metabolizers and received monotherapy with prasugrel (n=21) or ticagrelor (n=8). The mean duration of dual antiplatelet therapy was 5.1 days. During 90-day follow-up, no patient died, there was one possible stent thrombosis, and three patients on clopidogrel had Bleeding Academic Research Consortium type 3 bleeding events. Conclusion: Genotype-guided P2Y₁₂ inhibitor monotherapy within a week of PCI is feasible and likely safe in patients with HBR (CHAMP [Clopidogrel With High Bleeding Risk and Adverse Events With Monotherapy in Patients Undergoing Percutaneous Coronary Interventions]; NCT05223335).