Intraoperative hypotension and blood pressure variability are associated with postoperative complications in surgical patients.

The investigators have developed a closed-loop vasopressor (CLV) controller that titrates norepinephrine to correct hypotension.

After having tested the system in a small cohort series of patients undergoing major surgeries, the investigators aimed to test the feasibility of the CLV controller in three high risk patients undergoing cardiac surgery

The investigators have recently developed an automated closed-loop vasopressor (CLV) controller to better titrate vasopressor (e.g:norepinephrine) to maintain MAP within a narrow range (±5mmHg of the chosen target).

The investigators published engineering, animal studies and recently described the feasibility of titration of norepinephrine in 20 patients undergoing major noncardiac procedures. This initial cohort human study showed the controller was able to keep patients within ± 5 mmHg of a target pressure for more than 90% of management time. Cardiac surgery represents unique challenges in MAP management as the manipulation of the heart itself, the use of cardiopulmonary bypass (CPB) and cardioplegia, and the pre-existing cardiac disease all increase the difficulty in maintaining a steady MAP throughout the surgical period.

In this case series the investigators describe three cardiac surgical procedures managed with the CLV system (one coronary artery bypass graft (CABG) procedure done under CPB; one robotic minimally invasive direct coronary artery bypass (MIDCAB) procedure (through a mini-thoracotomy), and one off-pump CABG) in order to assess its feasibility, efficiency and behavior in three high-risk patients before starting a randomized controlled trial.

Inclusion Criteria:

• Adult high risk patients undergoing cardiac surgery (robotic, off-pump and on pump cardiac surgery)

Exclusion Criteria:

• Atrial fibrillation