Refractory cardiogenic shock may lead to the emergent implantation of an ECMO (ExtraCorporeal Membrane Oxygenation). Previous recent guidelines recommend the use of IABP (Intra-Aortic Balloon Pump) in this situation. Up to now, it still remains a debate whether the combination of both these devices may be usefull. The purpose of this study was to determine the impact of an IABP combined to the ECMO on the basis of general hemodynamic parameters and microcirculation. This monocentric prospective study included all patients hospitalized for refractory cardiogenic shock treated with ECMO and IABP between November 2010 and October 2011 in our Intensive Care Unit at la Pitié-Salpêtrière hospital, Paris, France. General hemodynamic status was assessed using clinical parameters, echocardiography and pulmonary capillary catheter. Microcirculation was evaluated using orthogonal polarized spectroscopy and tissue oxygen saturation in muscle (InSpectra®) as well as in brain (Equanox®). We included 12 consecutive patients aged of 57,3±14,4 yo (75% men). IABP was associated with lower systolic pulomary arterial pressure (23,4±9,4 mmHg vs 28,5±10,5 mmHg, p<0,05), lower mean pulmonary arterial pressure (18,8±7,8 mmHg vs 23,7±0,9 mmHg, p<0,01), lower pulmonary capillary wedge pressure (14,9±7,7 mmHg vs 19,3±9,6 mmHg, p<0,01) and higher left ventricular filling (LV) pressure (E/A ratio at 1,3±0,4 vs 2,0±0,9, p=0,04). IABP significantly reduced LV dimensions (End-diastolic LV diameter 51,8±13,6 mm vs 54,2±13,4 mm, p<0,001 and End-systolic LV diameter 49,6±13,7 mm vs 50,8±13,1 mm, p<0,05). However, no statistical improvement of the microcirculation was observed on the basis of muscular and brain oxymetry. In refractory cardiogenic shock requiring ECMO, the association with an IABP could reduce the incidence of acute pulmonary edema by recreating a pulsatile blood flow but does not significantly improve micro-circulation.