Whole Blood Platelet Aggregation in Chronic Kidney Disease Patients on Aspirin Study

Higher coronary in-stent thromboses and bleeding complications on anti-platelet agents are more common in Chronic Kidney Disease vs. non-Chronic Kidney Disease patients. Poor inhibition of platelet aggregation by anti-platelet agents predicts future cardiovascular events. Clinical practice guidelines are ambiguous about the use of these agents in Chronic Kidney Disease due to lack of controlled studies. The investigators hypothesize that patients with Chronic Kidney Disease compared with non-Chronic Kidney Disease have reduced platelet aggregation and poor platelet inhibitory response to aspirin. The aims are to 1) define the range of whole blood platelet aggregation in stages 3-5 Chronic Kidney Disease patients; 2) investigate whether patients with stages 4-5 Chronic Kidney Disease vs. non-Chronic Kidney Disease have lower platelet aggregation or impaired von Willebrand Factor activity; and 3) compare inhibition of platelet aggregation from baseline after 2 weeks of aspirin therapy and another 2 weeks of clopidogrel therapy added to aspirin in Chronic Kidney Disease vs. non-Chronic Kidney Disease patients. Accomplishing these aims will provide pilot data to power future studies of targeted anti-platelet agent treatments in Chronic Kidney Disease in order to improve cardiovascular outcomes.