Nitric Oxide-mediated Cardioprotection During Cardiac Surgery With Cardiopulmonary Bypass (NOinCPB)

This prospective randomized study elucidates the effects of exogenous nitric oxide delivered to the extracorporeal circulation circuit for cardioprotection against ischemia-reperfusion injury during coronary artery bypass graft surgery with cardiopulmonary bypass.

The aim of this study is to investigate the effects of exogenous nitric oxide (NO) delivered to the extracorporeal circulation circuit for cardioprotection against ischemia-reperfusion injury during coronary artery bypass graft surgery (CABG) with cardiopulmonary bypass (CPB). A total of 60 patients with ischemic heart disease referred for CABG with CPB are included in prospective randomized study. Patients are randomized to receive standard treatment or surgery based on modified CPB protocol. According to modified protocol, 40-ppm NO is supplied to the CPB circuit during CABG. The primary endpoints are changes in cardiac troponin I (cTnI) levels at 6, 24, and 48 hours after surgery compared with baseline. The secondary end points are the changes in the levels of creatine kinase-muscle/brain (CK-MB) compared with baseline and vasoactive inotropic score (VIS) at 6, 24, and 48 hours. NO supplied to the CPB circuit exertes cardioprotective effect. Changes in cTnI, CK-MB, and VIS are considered indictors of the presence or absence of cardioprotective action of NO supplied to the CPB circuit.

Coronary Artery Disease, Coronary Artery Bypass, Cardiopulmonary Bypass, Nitric Oxide, Reperfusion Injury, Myocardial

Cardioprotection, Ischemia-reperfusion injury, Nitric oxide, Cardiopulmonary bypass, Coronary artery bypass grafting

Patients of this group receive treatment with exogenous gaseous nitric oxide supplied directly to the oxygenator in the cardiopulmonary bypass circuit during coronary artery bypass grafting for coronary artery disease.

Patients of this group receive sham-treatment without supplying nitric oxide to the cardiopulmonary bypass circuit during coronary artery bypass grafting for coronary artery disease. Considering dilution of nitric oxide at a high ratio of 1 to 25,000 in the gas mixture of the cardiopulmonary bypass circuit (CPB), no addition of any inert gas to the CPB circuit is required in sham-treatment group.

40 ppm of exogenous gaseous nitric oxide is supplied directly to the oxygenator in the cardiopulmonary bypass circuit during coronary artery bypass grafting.

Changes in the plasma level of cTnI (ng/mL) relative to the baseline value are measured at 6, 24, and 48 hours after surgery.

Changes in the plasma level of CK-MB (U/L) relative to the baseline value are measured at 6, 24, and 48 hours after surgery.

Vasoactive inotropic score (VIS) is assessed at 6, 24, and 48 hours after surgery. VIS is calculated as follows: (dobutamine μg/kg/min × 1 + dopamine μg/kg/min × 1 + milrinone μg/kg/min × 10) + 100 × (adrenalin μg/kg/min + noradrenaline μg/kg/min + vasopressin μg/kg/min).

Inclusion Criteria: Coronary artery disease requiring coronary artery bypass grafting with the cardiopulmonary bypass. Exclusion Criteria: Non-elective surgery, age over 70 years, left ventricular ejection fraction less than 35%, history of myocardial infarction within three months prior to surgery, chronic atrial fibrillation, diabetes mellitus, and the elevated levels of cardiac specific markers within 12 h prior to the intervention.

Deidentified individual participant data (text, tables, figures, and appendices), underlying the results of the trial, will be shared with researchers to achieve the aims in the approved proposal.

Proposals may be submitted up to 36 months following publication of the results of the trial. After 36 months, the data will be available in the Center's data ware house but without investigator support other than deposited metadata.

Information regarding submitting proposals and accessing data may be requested from the principal investigator by e-mail.