 Blood will be drawn immediately prior to percutaneous coronary intervention. In addition to routine haematological and biochemical parameters complete blood count, white cell count, platelet count, creatinine, urea, sodium, potassium, cholesterol, glucose, troponine I, creatinine phosphokinase, liver function tests and clotting screen one additional blood sample will be taken and separated into plasma and serum. Polymorphonuclear leukocytes will be used for measurements of DNA damage and repair proteins. 