Mic Mac: Micro- and Macrocirculatory Assessment During Cardiac Surgery in Patients at Risk of Vasoplegic Syndrome: A Prospective Study.

In 2019, 45,236 cardiovascular surgical procedures were performed in France. Despite improved surgical and anesthetic management, cardiovascular surgery continues to be associated with a high mortality rate, with an estimated in-hospital death rate of 5.8%. One of the major complications associated with the patient's condition and the complexity of the surgery is post-extracorporeal circulation vasoplegia syndrome, the incidence of which is estimated at between 5 and 44%. It is associated with a high mortality rate of around 40%. This vasoplegia results in arterial hypotension and organ damage, culminating in multivisceral failure and death. This phenomenon remains poorly understood, as it is extremely complex and multifactorial (vasodilation by pathological nitric oxide production, role of neprilysin, depletion of endogenous catecholamines, alteration of the autonomic nervous system). At present, the only treatments available to manage vasoplegic syndrome are symptomatic. This vasoplegia is the consequence of alterations in microreactivity, leading to a loss of hemodynamic coherence between the macrocirculation and the microcirculation.

The aim of this work is to identify the metabolic pathways responsible for the alterations in vasoreactivity that lead to this loss of hemodynamic coherence, manifesting as hypotension at preserved cardiac output and complicating organ failure.

The investigators will select patients at risk of vasoplegic syndrome after extracorporeal circulation. A detailed assessment of their microcirculatory and macrocirculatory function, combined with blood and urine biomarker assays reflecting circulatory status at the time of sampling, will be carried out before the start of surgery, at the various key stages of cardiovascular surgery, then immediately post-operatively, at 12 hours, 24 hours, and 50 hours from the end of surgery. The monitoring of these parameters, whether or not associated with the appearance of a vasoplegic syndrome following extracorporeal circulation, will enable the investigators to better characterize the elements undergoing modification, and thus to better target the markers and metabolic pathways involved in vasoplegic syndrome, which in turn will enable the proposal of targeted curative or even preventive therapies.

Inclusion criteria

Have at least 3 point of the following risk factors for post-body circulation vasoplegic syndrome:

• Acute or chronic heart failure with left ventricular ejection fraction< 40% (1 pt)
• Complex cardiac surgery ( 2 pts)
• Cardiovascular risk factors with a EuroSCORE> 4% (1 pt)
• Chronic Kidney Disease Stage 4
• Type 2 Diabetes Mellitus
• Pre-operative heparin treatment
• Hypothyroidism
• Anti-hypertensive treatments including an ACE inhibitor, an angiotensin II receptor antagonist, a beta-blocker or Sacubitril

Exclusion criteria

• Heart transplantation
• Pre-operative hemodynamic instability
• Pregnant women
• Age <18
• Pre-existing sepsis
• Extracorporeal circulation support
• Heartmate/Impella/Carmat patient
• Hypothalamo-hypophyseal pathologies
• Adrenal insufficiency
• Anuric patient
• Guardianship/ curatorship
• Lack of social security coverage
• Opposition to clinical research by patients or their families