The Effect of Salicylate on Platelet Function in CKD (Chronic Kidney Disease) Patients Treated With Aranesp

Background: It is well known that treatment with EPO increases the risk of thrombotic complications in patients with chronic kidney disease, including cerebral thrombosis. The requited level of Hgb for sufficient treatment has therefore been set at a relatively low level (6.8-7.3 mM). One obvious potential cause of this problem is the increased thrombocytosis and platelet activation caused by EPO treatment. An old investigation has shown that low-dose acetyl salicylic acid (ASA) treatment can remove this effect. This investigation has not been performed using modern methods to investigate platelet function, and the possible prophylaxis of EPO-induced thrombosis has since received little interest. Investigators of current study therefore propose to repeat this investigation using advanced methods for assessing thrombocyte function, as a preliminary, exploratory investigation prior to a later randomized controlled study. Pre-treatment Washout (4 weeks, 6 weeks if treated with Mircera)) Patients who are not treated with ESA do not receive any treatment. Patients treated with ESA stop their treatment for 4 weeks. Patients treated with Mircera ® stop treatment for 6 weeks. Patients must not take ASA as an analgesic during the whole period of the project. At the end of the pre-treatment period, the Standard package (blood samples) is assessed. EPO Treatment (4 weeks) The patient is treated with darbepoetin alfa (Aranesp) in equipotent doses compared to previous therapy. After 2 weeks the Hgb is measured, and the EPO dosis adjusted if necessary at the discretion of the responsible physician. After 4 weeks, the Standard package is assessed. If the Hgb is \>8,0 mM or is rising rapidly (\>1,2mM per month), the EPO dose is reduced at the discretion of the responsible physician. EPO + ASA Treatment Aranesp treatment is supplemented with ASA (Hjertemagnyl ® 75 mg x 1 daily). After 4 weeks the Standard package is assessed. If the patient develops gastrointestinal symptoms (abdominal pain, nausea or heartburn), and is not already being treated with pantoprazole or other PPI (proton pump inhibitors), treatment is supplemented with pantoprazole 40 mg x 1 daily. ASA treatment withdrawal - e.g. in regard to surgery - results in discontinuation of participation in the study. Post-treatment Washout Both Aranesp and Hjertemagnyl treatment is stopped. After 4 weeks the Standard package and is assessed. Termination The indication for, and dose of ESA and ASA is prescribed at the discretion of the responsible physician.