Antiplatelet Therapy and Bleeding Outcomes With CYP2C19 Genotyping.

Area of Science:

• Cardiology
• Pharmacogenomics
• Clinical Research

Background:

• Antiplatelet therapy is crucial after percutaneous coronary intervention (PCI).
• The role of CYP2C19 genotyping in guiding antiplatelet therapy and its impact on bleeding risk in real-world settings remains under-investigated.
• P2Y12 inhibitors are commonly used post-PCI.

Purpose of the Study:

• To evaluate the impact of antiplatelet therapy, guided by CYP2C19 genotyping, on bleeding events in a real-world post-PCI population.
• To assess the association between different P2Y12 inhibitors and bleeding risk.
• To investigate the rates and predictors of antiplatelet de-escalation.

Main Methods:

• Prospective, single-center cohort study with 1-year follow-up.
• Included patients undergoing PCI, CYP2C19 genotyping, and P2Y12 inhibitor therapy.
• Primary outcome: time to first bleed (Bleeding Academic Research Consortium criteria). Secondary outcomes: major bleeding, antiplatelet switching.

Main Results:

• A high incidence of bleeding (33%) was observed post-PCI.
• Treatment with ticagrelor or prasugrel was associated with a significantly increased risk of any bleeding (aHR 2.04) and major bleeding compared to clopidogrel.
• This increased bleeding risk with potent agents was also observed in non-carriers of CYP2C19 no-function alleles.
• Antiplatelet de-escalation to clopidogrel occurred in 36% of patients on potent agents, more frequently after a bleed in non-carriers of no-function alleles.

Conclusions:

• Bleeding is a frequent complication in patients on antiplatelet therapy post-PCI.
• Potent P2Y12 inhibitors (ticagrelor, prasugrel) are linked to higher bleeding risks, particularly in individuals without CYP2C19 no-function alleles.
• Genotype-guided de-escalation of antiplatelet therapy warrants further investigation in prospective clinical trials.