Leiden-Alloimmunisation-Likelihood (LAL) trial: alloimmunisation after pre-storage filtered, post-storage filtered and buffy-coat-depleted blood transfusion in cardiac surgery patients

INTERVENTION: Use of by filtration leukocyte reduced blood transfusions versus use of buffy‐coat depleted blood transfusions (=1990's standard in NL). CONDITION: Blood transfusions in cardiac surgery ; Surgery ; Blood transfusions PRIMARY OUTCOME: Anti‐Human Leukocyte Antigen (HLA) antibody formation (tested by LCT) and anti‐erythrocyte antibody formation (tested in 3 cell panel, with PEG). Samples for analyses are collected before surgery, on day 7 post‐surgery, 3 ‐ 10 weeks post‐surgery and 20 ‐ 30 weeks post‐surgery. SECONDARY OUTCOME: 1. Post‐operative infections; 2. Hospital stay; 3. Intensive Care Unit (ICU)‐stay; 4. Mortality; 5. Costs‐effect‐analyses; 6. In combination with other Randomised Controlled Trials (RCTs), that have randomised between these same two blood products: long term effects on the incidence of autoimmune diseases and malignancies INCLUSION CRITERIA: Patients planned for open heart surgery: Coronary Artery Bypass Graft (CABG), heart valve surgery or the combination of both.