Results During 36 months, 721 patients underwent CABG. Only patients older that 70 years-old with an acute coronary syndrome were included. High risk was defined as Euroscore I greater than 7. Exclusion criterias were Chronic Renal Failure, off-pump surgery and additional procedures. 85(12%) patients were selected for analysis. Mean Age was 75(70-87). 56(65.9%) were male and 29(34.1%) were female. Mean Euroscore I was 10(8-20). Mean EF was 46%(+/-11). Left-main coronary obstruction was present in 13(15%). Cardioplegic solution was administered randomly. HCS was administered to 40(47%) and HTK to 45(53%) patients. 30 days-Mortality occurred in 7(8.2%), 4 in HCS and 3 in HTK (p:0.551). Mean CPB time was 84min(42-110) and Cross-clamp time was 50min (24-65) with no difference between groups. Number of grafts performed were 3(1-5) Perioperative infarction occurred in 11(12%) patients, 5(7.9%) in HTK and 6(5.9%) in HCS (p:0.4), postoperative atrial fibrilation was present in 15(17.5%), 8 in HCS and 7 in HTK(p:0.4), Mean ICU time was 3days (1-5) for HTK and 5 for HCS (2-7). LOS was 4 for HTK and 6 days for HCS(p:0.2).