The pharmacodynamic response to aspirin varies significantly between individuals. Insufficient antiplatelet effects of aspirin are associated with increased risk of ischemic events. Chronic kidney disease (CKD) is suggested to affect the pharmacodynamic response to antiplatelet medication. High on-treatment platelet reactivity (HTPR) to clopidogrel has been reported to partially account for the enhanced risk of death and cardiovascular events in CKD patients.Objective:
To investigate the antiplatelet effects of aspirin in patients with CKD.Methods:
We conducted a cross-sectional study in 116 patients on permanent aspirin medication. The pharmacodynamic response to aspirin was determined by arachidonic acid-induced thromboxane formation.Results:
HTPR to aspirin was more frequent in patients with impaired renal function (47% vs. 22%; odds ratio, 3.16; 95% confidence interval [CI], 1.34–7.41; P = 0.008). The pharmacodynamic response to aspirin was impaired in patients with moderate/severe CKD (92; interquartile range [IQR], 282 ng mL−1) as compared to patients with normal/mildly reduced renal function (36; IQR, 100 ng mL−1; difference in medians, 57; CI, 5–110 ng mL−1; P = 0.013). Bivariate Pearson analysis showed residual thromboxane formation to be correlated with glomerular filtration rate (R = −0.303; R2 = 0.092; P = 0.001). Patients with CKD were older and more frequently female. Multivariate linear regression analysis revealed that the correlation was independent of age (R = −0.314; R2 = 0.082; P = 0.002) and gender (R = −0.305; R2 = 0.077; P = 0.006).Conclusion:
Renal function is correlated with pharmacodynamic response to aspirin. Patients with CKD have an increased risk of impaired antiplatelet effects of aspirin. Larger trials are needed to assess the clinical impact of this finding and investigate the optimal antithrombotic regimen in CKD patients.