Precision PCI Registry

Dual antiplatelet therapy (DAPT) with aspirin and a P2Y12 receptor inhibitor (clopidogrel, prasugrel, or ticagrelor) is the standard of care after percutaneous coronary intervention (PCI) to reduce the risk of atherothrombotic events. Prasugrel and ticagrelor are preferred over clopidogrel in patients with an acute coronary syndrome but are associated with greater bleeding risk. The cytochrome P450 (CYP)2C19 enzyme is essential for metabolism of clopidogrel (a prodrug) to its pharmacologically active form. Approximately 30% of the U.S. population carries a CYP2C19 loss-of-function (LOF) allele that reduces the bioactivation and effectiveness of clopidogrel, but not prasugrel or ticagrelor, after PCI.

Previous studies have demonstrated the feasibility and effectiveness of incorporating CYP2C19 genotyping into clinical care to guide DAPT, with prasugrel or ticagrelor prescribed in patients with a CYP2C19 LOF allele. However, the influence of key patient-specific factors on outcomes with genotype-guided DAPT (notably African ancestry, comorbidities that impact clopidogrel effectiveness, and genotypes beyond CYP2C19) has not been defined but is critical to understand in order to optimize the clinical impact of genotype-guided DAPT. Moreover, the impact on clinical outcomes of using CYP2C19 genotype to guide de-escalation from more potent agents (e.g., prasugrel or ticagrelor) to clopidogrel in patients without a LOF allele, which has become highly clinically relevant due to more frequent initial use of prasugrel or ticagrelor after acute coronary syndrome and PCI, has not been investigated in a diverse, real-world clinical setting.

The long-term goal of this line of research is to optimize a precision medicine DAPT strategy that improves outcomes after PCI. The investigators hypothesize that multiple clinical and genetic factors jointly contribute to the effectiveness and safety of CYP2C19 LOF allele-guided selection of DAPT after PCI in a real-world clinical setting. This hypothesis will be tested by conducting a multi-center, observational study of 1,500 patients with PCI and clinical CYP2C19 genetic testing.

Aim 1: Define the influence of African ancestry and other patient-specific factors on clinical outcomes with CYP2C19 genotype-guided DAPT after PCI in a real-world setting

Aim 2: Evaluate the safety and effectiveness of CYP2C19 genotype-guided de-escalation of DAPT following PCI in a real-world setting

Aim 3: Elucidate the effect(s) of genetic variants beyond CYP2C19 LOF alleles on platelet reactivity and clinical outcomes with clopidogrel after PCI

A total of 1500 patients will be enrolled. Their data will be added to an existing cohort of approximately 4500 patients to address these aims.

Baseline data from the PCI admission will include:

• PCI indication
• Angiographic and procedural features (e.g. location of PCI, stent type)
• CYP2C19 genotype
• Discharge diagnoses
• Medications on admission, during hospitalization, and at discharge
• Self-reported race
• Socioeconomic status (including education, income and occupation)
• Health insurance type

Follow-up Data:

Patient follow-up will occur at 1, 6, and 12 months after PCI or until DAPT discontinuation via telephone call and EHR review to assess for hospitalizations and medication changes.

Data Management:

Data will be stored electronically in a secured database that is only accessible to study investigators. Quality assurance procedures will include use of a data dictionary, data checks ensure compliance with predefined rules for data ranges and checks for missing data. Hospitalization records will be reviewed by independent cardiologists to verify atherothrombotic and bleeding events. Deaths will be assessed by query of the National Death Index (NDI) and North Carolina state death index.