The HO-1 induction will be assessed in a clinical trial by myocardial biopsy prior to and after aortic cross clamping in subjects with or without preceding heme arginate treatment in two different dosages. The HO-1 expression will also be measured in the clinical trials in peripheral blood mononuclear cells. As additional outcome, levels of myoglobin, creatine-kinase and troponin T and reactive oxygen species will be measured in plasma according to standard laboratory procedures.