Serum levels of CK-MB and Hs-cTn will be measured at induction of anaesthesia (after placement of the arterial line), upon arrival at the intensive care unit (ICU), as well as every 3 hours for 12 hours, then every 6 hours the following 12 hours and a last sample is taken 48 hours after surgery. Samples are analysed at the department of Clinical Biochemistry of our institution with the Elecsys Troponin T hs immuno-assay. Lower limit of quantification being 0,14 Nano gram/L (company data).