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.

Inclusion Criteria:

• Age > 18 years
• The patient was hospitalized in the cardiothoracic-vascular and respiratory intensive care unit of Amiens-Picardy University Hospital.
• Patient scheduled for on-pomp cardiac surgery [coronary artery bypass grafting, valve replacement, ascending aorta replacement, or combined surgery (valve and bypass grafting)].
• Introduction of norepinephrine post-surgery for the treatment of vasoplegic syndrome.
• On-pomp cardiac surgery in less than 48 hours.
• Hemodynamically stable patient with MAP > 65 mmHg for more than 4 hours on noradrenaline
• Monitoring of MAP with a radial or femoral arterial catheter
• Social security beneficiary
• Signature of the consent to participate in the study by the patient, preoperatively

Exclusion Criteria:

• Permanent arrhythmia (atrial fibrillation, flutter, or frequent atrial extrasystoles).
• Treatment with dobutamine, epinephrine, or vasopressin analog
• Patients with preoperative chronic end-stage renal failure require postoperative extra-renal purification.
• Pregnant woman
• The patient is dependent on an internal or external pacemaker.
• Hypothermia < 36°.
• Patient under mechanical circulatory assistance after cardiac surgery.
• Hemorrhagic shock
• Patient under guardianship or curators