clopidogrel resistance

INTRODUCTION: Antiplatelet premedication policy for patients scheduled for endovascular treatment of stent-assisted coiling has become routine practice to avoid thrombotic complications. However, clopidogrel resistance remains a serious clinical challenge in predicting and preventing thrombotic complications. Measuring platelet activity is still an uncertain method for predicting clinical outcome and pharmacogenetic testing has not yet been proven as useful and cost-effective in clinical practice. We aimed to compare CYP2C19 polymorphism and MDR1 variances with point-of-care aggregometry test results in clopidogrel premedicated patients with non-ruptured intracranial aneurysms who were scheduled for stent-assisted endovascular treatment. METHODS: We designed a prospective study for our patient cohort with planned elective endovascular treatment. All patients were premedicated for the endovascular intervention with oral dual antiagregation therapy. In selected patients we analysed and compared demographic data, localisation of the aneurysm, endovascular material used, results of genetic analysis, results of the ADPtests for clopidogrel, dosing regimen for clopidogrel and incidence of angiographic and/or clinical complications. We compared and statistically analysed correlation between pharmacogenetic findings, aggregometry results and complication rates. RESULTS: We did not find a correlation between pharmacogenetic finding and aggregometry results. However, there was a statisticaly significant correlation between pharmacogenetic polymorphism of CYP2C19 and complication rate and a trend showing correlation between MDR1 variations and aggregometry results. CONCLUSION: CYP2C19 polymorphism as well as transport MDR1 activity are, according to our results, parameters which could be helpful in predicting possible complications and choosing another therapeutic approach in certain patient groups.