The Effect of Continued Mechanical Ventilation on the Occurrence of Myocardial Ischemia (VENTMICS-II)

The Effect of Continued Mechanical Ventilation on the Occurrence of Myocardial Ischemia in Patients Undergoing Totally Endoscopic Coronary Artery Bypass Grafting

The goal of this study is to examine the influence of mechanical ventilation on the occurrence of myocardial ischemia in patients undergoing endo-CABG.

Coronary artery bypass grafting (CABG) surgery is one of the main treatment options for patients suffering from coronary artery disease, a condition characterized by a build-up of cholesterol in the coronary arteries of the heart that affects 126 million people worldwide each year. During this procedure, cardiopulmonary bypass (CPB) takes over the function of the heart and lungs. In recent years, there has been a huge focus on reducing surgical trauma in this procedure, leading to the emergence of minimally invasive cardiac surgery (MICS) such as endoscopic CABG (endo-CABG). In these techniques, peripheral CPB with femoral arterial cannulation is the most commonly used strategy. However, the use of retrograde arterial perfusion is not without risk. It can cause that the upper part of the body only receives deoxygenated blood. The effect on the heart is not yet fully known. The hypoxemia could cause myocardial ischemia and this could damage the heart muscle cells. It is reported in the literature that establishing adequate ventilation from the initiation of CPB to cardiac arrest can resolve this phenomenon. This approach was investigated in a recently performed double-blinded, randomized, controlled pilot study (n=10) of our research group. However, a larger randomized controlled trial was needed. Therefore, this research aims to investigate the effect of continued mechanical ventilation on the occurrence of myocardial ischemia in patients undergoing endo-CABG.

Cardiac surgery, Minimally invasive cardiac surgery, Endoscopic coronary artery bypass grafting, Harlequin syndrome, Ventilation

Ventilation is discontinued after going on CPB and lungs are exposed to atmospheric pressure. Blood will be drawn: At baseline: before general anaesthesia, after start of CPB, after clamping the aorta, before unclamping the aorta, after the operation, 5 h after clamping the aorta, 12 hours after clamping the aorta, and 24 hours after aortic clamping

Ventilation is continued from going on CPB until clamping of the ascending aorta. Blood will be drawn: At baseline: before general anaesthesia, after start of CPB, after clamping the aorta, before unclamping the aorta, after the operation, 5 h after clamping the aorta, 12 hours after clamping the aorta, and 24 hours after aortic clamping

Ventilation is continued from going on CPB until clamping of the ascending aorta with tidal volume 3ml/kg ideal body weight, Fraction of inspired oxygen (FiO2) 50%, respiratory rate 5/min and Inspiratory:Expiratory (I/E) ratio 1/2.

Cardiac troponin T is represented in ng/L. If the value of cTn-T exceeds 14 ng/L, then cTn-T is able to detect myocardial ischemia at the predefined time points.

The influence of continued mechanical ventilation on the release of creatine kinase-myocardial band (CK-MB)

Creatine kinase-myocardial (CK-MB) band is represented in µg/L. If the value of CK-MB exceeds 6.2 µg/L, then CK-MB is able to detect myocardial ischemia at the predefined time points.

The influence of continued mechanical ventilation on the release of heart-type fatty acid-binding protein (hFABP)

Heart-type fatty acid-binding protein (hFABP) is represented in ng/L. If the value of hFABP exceeds 6 ng/L, then hFABP is able to detect myocardial ischemia at the predefined time points.

superoxide dismutase 1 and 2 (SOD1, SOD2), nuclear factor erythroid 2-related factor 2 (Nrf2), catalase (CAT), glutathione peroxidase (GPx), NADPH oxidase 2 and 4 (NOX2, NOX4), heme oxygenase-1 (HO-1), NAD(P)H quinone oxidoreductase 1 (NQO-1)) will be studied to determine the redox balance.

Neurological complications include cerebrovascular accident (CVA), transient ischemic attack (TIA), delirium, epilepsy

Graft failure describes total graft occlusion that prevents blood flow through the graft to the revascularized part of the heart.

Inclusion Criteria: Patients older than 18 years old Patients undergoing their first elective endo-CABG procedure using peripheral cannulation for CPB Patients who are able to give their informed consent Patients who speak Dutch or French Exclusion Criteria: Patients participating in another clinical trial Patients taking corticosteroids Patients with an ejection fraction < 25% Patients with lung diseases (chronic obstructive pulmonary disease (COPD), asthma) Patients where groin cannulation is not possible