CXCL8 and heart failure: To learn more about the possible intrinsic regenerative response mechanisms to operative and/or ischemic stress, peripheral blood is analyzed at different points in time in the perioperative course for markers of angiogenesis (VEGF, FGF), inflammatory response (IL-6, IL-8, TNF-α), endothelial activation (sE-selectin), and heart failure (myoglobin).