Evaluation of the BRAINDEX Brain Monitor in Cardiac Surgery, Interventional Comparative Study

Inclusion Criteria: * Patient, male or female, over 18 years of age * Patient scheduled for cardiac surgery with programmed extracorporeal circulation (ECC) * Patient with no history of scalp injury or or skin diseases * Patient with an Euroscore 2 of less than 7%. * Patient affiliated or entitled to a social assurance Exclusion Criteria: * Weight under 40 kg * Frontal surface too small to allow application of SctO2, BIS electrodes on the same hemifront * Patient with severe, unbalanced hypertension * Measurement of systolic blood pressure (SBP) \> 180 mm Hg and/or diastolic blood pressure (DBP) \> 110 mm Hg * Patients undergoing emergency surgery * Patient with chronic renal failure, with glomerular filtration \< 30 ml/min/1.73m², or requiring renal transplantation or requiring renal transplantation * Patient with left ventricular ejection fraction \< 40% * Patient with a history of ischemic stroke * Patients with preoperative sepsis * Patient requiring noradrenaline infusion noradrenaline infusion in the 24 hours prior to surgery * Patient with preoperative uni or bilateral carotid stenosis bilateral carotid stenosis \> 50%. * Protected patient: adult under guardianship, curatorship or legal protection, deprived of liberty by judicial or administrative decision. * Pregnant, parturient or breast-feeding women. * Patients hospitalized without consent.