Implementation and clinical outcomes of pharmacogenetic CYP2C19 testing for clopidogrel therapy in real-world clinical practice.

Type of funding sources: None.

BACKGROUNDCYP2C19 loss-of-function (LOF) polymorphisms are associated with adverse ischaemic events after PCI. The use of a point-of-care assay (POC) to routinely genotype patients immediately post PCI could rapidly identify patients at risk of adverse cardiac outcomes. PURPOSE To investigate the incidence of CYP2C19 polymorphisms (*2, *17) and 30-day MACE in patients presenting to catheter laboratory for PCI (See table 1).METHODS We performed a single centre prospective analysis of patients presenting to a cardiac catheterisation laboratory for percutaneous coronary intervention. Participants underwent prospective rapid point-of-care genotyping of CYP2C19 major alleles (2*,17*), using the SpartanRx PCR device via buccal swab sample. All patients provided written consent. RESULTS:A total of 120 tests were performed, 51 patients were normal allele carriers (*1), 31 patients were carriers of LOF alleles (*2) and 38 patients were carriers of gain of function alleles (*17). All tests results returned in one hour. Rate of dyslipidaemia was significantly different between three groups (55% vs. 63% vs. 36%; p = 0.050). A numerically higher proportion of LOF allele carriers received clopidogrel prior to undergoing pharmacogenetic testing but this was not statistically significant (52% vs. 35% vs. 34%; p = 0.09). Two cases of MACE at 30 day follow up occurred in the loss-of-function group. Both cases received clopidogrel.CONCLUSIONSWe have demonstrated that a rapid POC of CYP2C19 testing can take place in a real-world setting. Our incidence rate of LOF carriers is concordant with international published literature. We found 52% of LOF carriers were commenced on clopidogrel therapy prior to genetic analysis.

Comparison of CPY2C19 Metabolisers