Aspirin resistance in patients with impaired renal functions

Background: Cardiovascular diseases (CVD) are the leading cause of death in patients with chronic kidney diseases (CKD). Aspirin resistance (AR) worsens prognosis in CVD. Aim: The aim of this study was to detect AR prevalence in this patient group. Methods: The 203 patients (mean age 61.84 +/- 11.51 years, 128 [63.1%] male) with stable coronary artery disease included in the study were grouped into four study groups according to their estimated glomerular filtration rate (eGFR) values. Multiplate test was used to determine AR. Platelet aggregation results were presented as aggregation unit (AU) x min and values over 300 AU x min were accepted as AR. Results: 61 (30.04%) patients in the whole study population were found to have AR. Differences were detected between AR ratios and multiplate values of the patient groups (p=0.006 and p=0.002). AR ratio was highest in patient group 4 (eGFR < 30 mL/min/ 1.73 m(2)) and/or on chronic haemodialysis therapy, whereas there was little difference among the other three groups. In multivariate analysis, while AR status was independently related to female sex (OR=2.31, CI 1.14-4.65, p=0.019) and mean platelet volume (MPV) (OR=1.68, CI 1.21-2.33, p=0.002), multiplate test results were independently related to MPV (b=0.265, p < 0.0001) and eGFR (b=-0.165, p=0.025). Conclusions: The AR ratio was found to be high in severe CKD patients, especially haemodialysis patients, but not in mild and moderate CKD patients. This increased AR ratio in severe CKD patients may affect the prognosis in patients who already have an increased risk for cardiovascular complications.