Anesthesia, Coronary Artery Disease
Conditions
Keywords
Coronary artery disease, Transesophageal Echocardiography (TEE), Hyperoxia, Strain, Myocardial Deformation, Anaesthesia, CABG, Normoxaemia
Brief summary
The purpose of this study is to investigate the impact of supraphysiologic oxygen (hyperoxia) on myocardial function in anaesthetized patients with coronary artery disease.
Detailed description
Up to 106 patients with coronary artery disease undergoing elective coronary artery bypass graft (CABG) surgery will be recruited to undergo this single visit study. In the timeframe shortly after the induction of anaesthesia and prior to the start of surgery, myocardial strain as a marker of cardiac function will be measured by transesophageal echocardiography (TEE). Echocardiography measurements will be acquired at two different oxygen states for each patient. The fraction of inspired oxygen (FiO2) will be adjusted to reach a normoxaemic state (FiO2=0.3) and a hyperoxic state (FiO2=0.8). Patients will be randomized to which oxygen level is investigated first. Thereafter, the study intervention is completed and anaesthesia and surgery will be performed as planned by the treating team. Echocardiography images will be analyzed in a blinded manner for cardiac function and systolic and diastolic strain parameters. The results will help anaesthesiologists to better weigh risks and benefits when selecting an inspired oxygen fraction in such patients, and will help to evaluate hyperoxia as a risk factor for myocardial injury.
Interventions
DRUGOxygen
Two FIO2 settings during stable general anaesthesia resulting in normoxaemic and hyperoxic arterial oxygen partial pressures.
Sponsors
Insel Gruppe AG, University Hospital Bern
Study design
Allocation
RANDOMIZED
Intervention model
CROSSOVER
Primary purpose
OTHER
Masking
SINGLE (Outcomes Assessor)
Masking description
TEE images will be coded and analysed in batches at a later date by a blinded reader
Eligibility
Sex/Gender
ALL
Age
18 Years to No maximum
Healthy volunteers
No
Inclusion criteria
* Elective CABG surgery (with or without other cardiac surgery) * Ability to give and sign informed consent * Age \>18 years.
Exclusion criteria
* Absolute contraindication for TEE * Emergency surgery, including but not limited to patients with instable CAD: ST- and Non-ST-elevation myocardial infarction (STEMI, NSTEMI) and instable angina (instable AP) * Atrial fibrillation or significant arrhythmia * Pacemaker, CRT, left bundle branch block * Severe-grade valvular disease * Pericardial disease * Previous cardiac or thoracic aortic surgery * Previous chest radiation therapy or cardiotoxic or bleomycin chemotherapy * Severe pulmonary hypertension, cor-pulmonale, or right ventricular dysfunction, i.e., where high FIO2 might reduce pulmonary vascular resistance and right ventricular afterload * Patients where study explanation and informed consent cannot been performed/obtained at the latest on the day before scheduled surgery * Females of child-bearing potential
Design outcomes
Primary
| Measure | Time frame | Description |
|---|---|---|
| Difference in myocardial peak strain between oxygen levels | Through study completion, within 1hour post-induction | Percent (%), a measure of systolic function (shortening and thickening) of the myocardium |
Secondary
| Measure | Time frame | Description |
|---|---|---|
| Difference in myocardial strain rate between oxygen levels | Through study completion, within 1hour post-induction | Change in strain over time (/second) |
| Difference in myocardial strain rate ratio between oxygen levels | Through study completion, within 1hour post-induction | Change in E/A ratio |
| Difference in myocardial displacement between oxygen levels | Through study completion, within 1hour post-induction | Millimeters (mm) |
| Difference in myocardial time to peak displacement between oxygen levels | Through study completion, within 1hour post-induction | Milliseconds (ms) |
| Difference in myocardial velocities between oxygen levels | Through study completion, within 1hour post-induction | Change in displacement over time (millimeters/second) |
| Difference in myocardial time to peak strain between oxygen levels | Through study completion, within 1hour post-induction | Milliseconds (ms) |
| Difference in peak twist | Through study completion, within 1hour post-induction | Degrees (°) |
| Difference in peak torsion | Through study completion, within 1hour post-induction | Degrees/centimeter (°/cm) |
| Difference in ejection fraction (EF) | Through study completion, within 1hour post-induction | Percent (%) |
| Difference in chamber volumes | Through study completion, within 1hour post-induction | Millilitres (ml) |
| Difference in myocardial velocity ratio between oxygen levels | Through study completion, within 1hour post-induction | Change in E/A ratio |
Countries
Switzerland
Outcome results
None listed