The objective of the study is to examine whether the use of low-dose aspirin (75-100 mg / day) reduces the risk of cardiovascular disease in patients with chronic kidney disease (stage 3 or 4).

Hypothesis: The low-dose aspirin reduces cardiovascular risk in patients with chronic kidney disease without increasing the risk of bleeding

Inclusion Criteria:

• sign informed consent
• males 45-79 years or females 55-79 years. -Stage 3 or 4 CKD (estimated GFR by MDRD abbreviated, between 15 and 60 ml / min/1.73 m2) -

Exclusion Criteria:

• a previous cardiovascular event: cardiac arrhythmias, cardiac arrest, angina or acute myocardial infarction, stroke, carotid stenosis of more than 50%, peripheral vascular arteriopathy documented
• hospitalization for any cause in the last three months prior to inclusion in the study allergy of acetyl-salicylic acid
• coagulopathy from any cause
• thrombocytopenia <150,000 platelets
• liver disease from any cause
• Infection by hepatitis B virus, hepatitis C or HIV
• immunosuppressive treatment within 12 weeks before inclusion in the study
• Major bleeding events including gastrointestinal bleeding and brain hemorrhage.
• hemoglobinopathies (eg sickle cell disease or thalassemia of any kind)
• active malignancy (except non-melanoma skin cancer). May be included in the study patients with malignant neoplasia who have remained disease-free for at least the previous 5 years.
• uncontrolled inflammatory disease or symptomatic (eg rheumatoid arthritis, lupus, Chrom disease or bowel inflammatory disease)
• hemolysis
• treatment with oral anticoagulation and / or antiplatelet therapy prior.
• poorly controlled hypertension (> 160/90 mm Hg) -pregnancy or breast-
• women of childbearing potential not using effective contraception.