In postoperative cardiac surgery under extracorporeal circulation, the patient may develop a vasoplegic syndrome, characterized by arterial hypotension (mean arterial pressure (MAP) \< 65 mmHg); a decrease in vascular resistance and a cardiac output that may be normal or increased, and increased postoperative mortality/ International recommendations recommend the prescription of noradrenaline as a first-line treatment to reduce morbidity and mortality. However, excess norepinephrine or duration of exposure is also deleterious. The Acumen IQ device (Edwards Lifesciences) allows the calculation of a predictive index of arterial hypotension episodes (predictive hypotension index, HPI). HPI could improve norepinephrine weaning by preventing episodes of arterial hypotension or detecting preload dependence, thus avoiding the transient increase in norepinephrine during hypotension. This is a single-center, prospective, open-label, randomized, controlled, 2-group, parallel, intention-to-treat study. The aim was to evaluate the superiority of a new decision algorithm, based on the HPI delivered by the Acumen IQ device, to reduce the duration of norepinephrine administration in post-cardiac surgery vasoplegic shock. The duration of the interventional protocol is 72 hours. To evaluate the clinical impact of the protocol, the time of the study will be 30 days. Several follow-up visits will be performed (end-of-protocol day, discharge day, and at D30 of inclusion) to collect clinical, biological, and HPI monitoring data.