An 89-year-old female was referred to her local doctor with persistent chest pain. She was rushed to our hospital because acute coronary syndrome was suspected. Emergency catheterization revealed a severe stenosis in left main trunk. An intra-aortic balloon pump (IABP) was placed, and we planned urgent surgery. During off-pump coronary artery bypass grafting, mitral valve regurgitation due to systolic anterior motion (SAM) occurred, her hemodynamics remained unstable after the operation. We performed tapering of catecholamine, and gave intravenous fluids and use of β-blocker to her. But what most improved her hemodynamics was that we removed the IABP.