genetic polymorphism and incidence of in-stent restenosis in patients on clopidogrel: a matched case-control study.

OBJECTIVES

The cytochrome P450 2C19 () genetic polymorphism is associated with reduced clopidogrel bioactivation, increasing the risk of atherothrombotic complications after percutaneous coronary intervention (PCI). In-stent restenosis (ISR) is a complication that limits the long-term prognosis of PCI. The aim was to investigate the association between presence of the allele and ISR within one-year after PCI in patients prescribed dual antiplatelet therapy with aspirin and clopidogrel.

METHODS

Sixty patients with angiographically-confirmed drug eluting stent (DES)-ISR within 12 months post-PCI when on DAPT with aspirin and clopidogrel were retrospectively identified (Cases). Another 60 patients with no documented ISR post-PCI in the study period (Controls) were case-matched for age, gender, ethnicity, diabetes mellitus and estimated glomerular filtration rate value, and were invited for genotyping. The association between presence of the allele and ISR was analysed using the Fisher's exact test and binary logistic regression.

RESULTS

Twenty-six (43.3%) cases and 5 (8.3%) controls were carriers of one or two alleles. As to non-carrier status of the allele, 34 (56.7%) cases and 55 (91.7%) controls were identified. The association between carrier status and DES-ISR within one-year post-PCI was statistically significant (p<0.001) in both the univariate and multivariate analysis.

CONCLUSIONS

The proportion of patients who were carriers of one or two alleles who presented with DES-ISR within one-year post-PCI while on clopidogrel was significantly higher compared to patients with no documented ISR.