None listed
Conditions
Brief summary
Cardiopulmonary bypass (CPB) is a critical component of most open-heart surgeries, allowing surgeons to operate on a still and bloodless field. However, its use is associated with a range of potential complications. Conventional CPB circuits produce non-pulsatile continuous flow (CF), which is the most widely adopted perfusion mode in cardiac surgery. Although CF maintains systemic circulation during cardiac surgery, it lacks the natural pulsatility of normal cardiac output. Pulsatile flow (PF) has been proposed as an alternative perfusion strategy that more closely mimics the natural arterial pulse generated by the heart. This project will compare the clinical-effectiveness, cost-effectiveness, and safety of pulsatile versus continuous flow cardiopulmonary bypass perfusion strategies. It is hypothesised that PF will improve a hierarchical composite measure of early postoperative organ dysfunction and all-cause mortality, without safety concern, compared to CF cardiopulmonary bypass.
Interventions
The investigational intervention is pulsatile flow cardiopulmonary bypass (CPB), which is a clinically accepted perfusion strategy. A CPB pump will be configured to generate pulsatile blood flow, mimicking the natural pulsatility of the heart. Settings to include:
- Pulse frequency: 50/min.
- Pulse amplitude: 20% above mean arterial pressure.
- Flow reduction for diastole: 40% of baseline.
- Maximum circuit pressure: Less than or equal to 250 mmHg PF is maintained until the aortic cross-clamp is
The investigational intervention is pulsatile flow cardiopulmonary bypass (CPB), which is a clinically accepted perfusion strategy. A CPB pump will be configured to generate pulsatile blood flow, mimicking the natural pulsatility of the heart. Settings to include: - Pulse frequency: 50/min. - Pulse amplitude: 20% above mean arterial pressure. - Flow reduction for diastole: 40% of baseline. - Maximum circuit pressure: Less than or equal to 250 mmHg PF is maintained until the aortic cross-clamp is removed. These parameters are applied consistently across participants to ensure comparability, although minor real-time adjustments within the predefined safety range may be made by the perfusionist to maintain haemodynamic stability according to intraoperative arterial pressures. The pulsatile flow intervention will be applied for the duration of the aortic cross-clamp application during CPB. In line with standard intraoperative management, the anticipated duration of pulsatile flow is typically less than four hours. The intervention will be administered by experienced cardiac perfusionists, in collaboration with the cardiac surgeon and anaesthetist. Adherence to the intervention will be monitored through continuous perfusion device analytics and intraoperative data capture. All relevant CPB parameters, including frequency, amplitude, circuit pressures, and flow rates, will be automatically logged and cross-checked against the protocol via standardised case report forms. Site self-monitoring processes are in place to identify and address any deviations, with refresher training provided where required.
Sponsors
Wesley Research Institute
Study design
Allocation
Randomised controlled trial
Primary purpose
Treatment
Masking
Blinded (masking used) (Subject, Outcomes Assessor)
Eligibility
Sex/Gender
All
Age
45 Years to No maximum
Healthy volunteers
No
Inclusion criteria
Participants must meet ALL of the following criteria: • Age 45 years or older. • Undergoing complex cardiac surgery, including: o Elective, urgent, and emergent. o Multiple valve surgery. o Combined coronary artery bypass grafting with valve surgery. o Aortic root/ascending aorta/aortic arch surgeries. o Surgeries for congenital heart defects in adults. o Heart ± lung transplantation. o Ventricular assist device implantation. • EuroSCORE II predicted mortality risk exceeding 2%. • Willing and able to give informed consent and comply with trial procedures. • No strong indication or contraindication to either pulsatile or continuous flow CPB, as determined by the investigator and treating clinicians.
Exclusion criteria
Any of the following: • Life expectancy of < 1 year due to factors unrelated to cardiac surgery. • Pre-existing dialysis-dependent renal failure. • Pregnancy or breastfeeding. • Intra-aortic balloon pump or other mechanical circulatory support. • Any other significant condition that, in the investigator’s opinion, would either: o Place the patient at excessive risk due to trial participation, or o Confound trial outcomes (e.g., advanced liver disease, refractory sepsis). • Inability to provide informed consent.
Outcome results
None listed