Study on Optimal Temperature During Cardiopulmonary Bypass (THERMIC-4)
THERMIC-4
Normothermic Versus Hypothermic Cardiopulmonary Bypass in Adult Cardiac Surgery: a Multicentre Feasibility Randomised Controlled Trial
2 other identifiers
interventional
100
1 country
11
Brief Summary
In order to perform heart surgery, a machine called cardiopulmonary bypass (CPB), or more commonly known as a heart-lung machine, is used to maintain the circulation of oxygenated blood needed by the rest of the body and its organs. Historically, when a patient is connected to CPB, their body is cooled below the normal body temperature. This is known as hypothermia. This is because scientific studies have previously shown that reduced body temperature lowers metabolism and therefore offers more protection to the brain and other organs due to the reduced oxygen requirement. The evidence supporting this practice, however, has been challenged throughout the history of cardiac surgery, with studies supporting that normothermia, or normal body temperature, is a safe alternative. Despite this, the practice of hypothermia has persisted. Published data from a survey of 139 cardiac surgeons in the United Kingdom showed that 84% still routinely employ hypothermic CPB during surgery. To assess whether normothermic or hypothermic CPB is safer, a clinical trial requiring a large sample size and high recruitment rates will be required. Therefore, the investigators aim to assess firstly the feasibility of trial recruitment and allocation adherence in this study. 100 adults across 10 different cardiac surgery centres in the United Kingdom will be recruited to a multicentre feasibility randomised controlled trial comparing normothermia (active comparator) against hypothermia (control comparator) during cardiopulmonary bypass in cardiac surgery. This study will also test the ability of the Cardiothoracic Interdisciplinary Research Network (CIRN), a trainee-led research collaborative, to collect pilot data on Major Adverse Cardiac and Cerebrovascular Events (MACCE) using a regulation-approved electronic application HealthBitⓇ. Participants will also be asked to complete quality of life surveys. The results of this study will subsequently inform a large, adequately powered randomised controlled trial for optimal temperature management during CPB.
Trial Health
Trial Health Score
Automated assessment based on enrollment pace, timeline, and geographic reach
participants targeted
Target at P50-P75 for not_applicable
Started May 2024
11 active sites
Health score is calculated from publicly available data and should be used for screening purposes only.
Trial Relationships
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Study Timeline
Key milestones and dates
First Submitted
Initial submission to the registry
July 2, 2023
CompletedFirst Posted
Study publicly available on registry
August 16, 2023
CompletedStudy Start
First participant enrolled
May 20, 2024
CompletedPrimary Completion
Last participant's last visit for primary outcome
November 1, 2025
CompletedStudy Completion
Last participant's last visit for all outcomes
February 1, 2026
CompletedApril 3, 2025
March 1, 2025
1.5 years
July 2, 2023
March 31, 2025
Conditions
Keywords
Outcome Measures
Primary Outcomes (2)
Total number of participants recruited over a 6 month period
The target recruitment rate is 1 participant per week per centre. The feasibility trial will be considered positive if 80% of target met, together with outcome 2.
6 months
Adherence rate to allocation
The feasibility trial will be considered positive if 74%\* of target adherence to trial allocation is met, together with outcome 1. \*74% is derived from 80% of target adherence of 92% as per Warm Heart Study
6 months
Secondary Outcomes (10)
Incidence of 6-week composite endpoint of Major Adverse Cardiac and Cerebrovascular Events (MACCE)
6 weeks
Incidence of deep sternal wound infection, with or without treatment
6 weeks
Incidence of all adverse events
6 weeks
Critical care length of stay
6 weeks
Post-operative length of stay
6 weeks
- +5 more secondary outcomes
Other Outcomes (3)
Data completeness
6 months
Attrition rate
6 months
User satisfaction of ResearchApp
6 months
Study Arms (2)
Hypothermic Cardiopulmonary Bypass
ACTIVE COMPARATORPatients allocated to this arm will undergo standard care for coronary artery bypass grafting and/or valve surgery with mild hypothermia during CPB.
Normothermic Cardiopulmonary Bypass
ACTIVE COMPARATORPatients allocated to this arm will undergo intervention care for coronary artery bypass grafting and/or valve surgery with normothermia hypothermia during CPB.
Interventions
Mild hypothermia (between 32 - 35 °C) during cardiopulmonary bypass
Normothermia (active maintenance of temperature between 36.5 °C to 37.5°C; no active cooling below 36.5 °C) during cardiopulmonary bypass
Eligibility Criteria
You may qualify if:
- Participants may enter the trial if all of the following apply
- Adult patients (≥ 18 years) scheduled for coronary artery bypass surgery and/or valve replacement/ repair, either in the elective or urgent setting.
- European System for Cardiac Operative Risk Evaluation (EuroSCORE) II of 2 or higher.
- Able to understand and communicate to provide informed consent.
- Able to read and understand the English language.
You may not qualify if:
- Participants may not enter the trial if any of the following apply:
- Patients undergoing coronary artery bypass surgery in combination with other procedures including cardiac or vascular procedures that require deep hypothermic arrest.
- Patients undergoing emergency or salvage surgery.
- Patients undergoing off-pump cardiac surgery.
- Patients who are participating in another interventional trial.
- Unable to provide informed consent.
Contact the study team to confirm eligibility.
Sponsors & Collaborators
- University of Leicesterlead
- NHS National Waiting Times Centre Boardcollaborator
- Sheffield Teaching Hospitals NHS Foundation Trustcollaborator
- Oxford University Hospitals NHS Trustcollaborator
- Hull University Teaching Hospitals NHS Trustcollaborator
- University Hospitals Bristol and Weston NHS Foundation Trustcollaborator
- University Hospitals, Leicestercollaborator
- Royal Brompton & Harefield NHS Foundation Trustcollaborator
- King's College Hospital NHS Trustcollaborator
- University Hospital Plymouth NHS Trustcollaborator
Study Sites (11)
Glenfield Hospital, University Hospitals of Leicester NHS Trust
Leicester, Leicestershire, LE3 9QP, United Kingdom
Blackpool Victoria Hospital, Blackpool Teaching Hospitals NHS Foundation Trust
Blackpool, FY3 8NR, United Kingdom
University Hospitals Bristol and Weston NHS Foundation Trust
Bristol, BS1 3NU, United Kingdom
Castle Hill Hospital, Hull University Teaching Hospitals NHS Trust
Cottingham, HU16 5JQ, United Kingdom
Golden Jubilee National Hospital, NHS Golden Jubilee
Glasgow, G81 4DY, United Kingdom
King's College Hospital, King's College Hospital NHS Foundation Trust
London, SE5 9RS, United Kingdom
Royal Brompton Hospital, Guy's and St Thomas' NHS Foundation Trust
London, SW3 6NP, United Kingdom
Harefield Hospital, Guy's and St Thomas' NHS Foundation Trust
London, UB9 6JH, United Kingdom
John Radcliffe Hospital, Oxford University Hospitals NHS Foundation Trust
Oxford, OX3 9DU, United Kingdom
Derriford Hospital, Plymouth University Hospitals NHS Trust
Plymouth, PL6 8DH, United Kingdom
Northern General Hospital, Sheffield Teaching Hospitals NHS Foundation Trust
Sheffield, S5 7AU, United Kingdom
MeSH Terms
Conditions
Condition Hierarchy (Ancestors)
Central Study Contacts
Study Design
- Study Type
- interventional
- Phase
- not applicable
- Allocation
- RANDOMIZED
- Masking
- NONE
- Purpose
- TREATMENT
- Intervention Model
- PARALLEL
- Sponsor Type
- OTHER
- Responsible Party
- SPONSOR
Study Record Dates
First Submitted
July 2, 2023
First Posted
August 16, 2023
Study Start
May 20, 2024
Primary Completion
November 1, 2025
Study Completion
February 1, 2026
Last Updated
April 3, 2025
Record last verified: 2025-03
Data Sharing
- IPD Sharing
- Will share
- Shared Documents
- STUDY PROTOCOL, CSR
- Time Frame
- The investigators will retain the fully anonymised dataset indefinitely. The duration for which this will be shared will be determined on a case-by-case basis and defined in a Data Sharing Agreement.
- Access Criteria
- Requests must be from studies with appropriate ethics approval in place.
Fully anonymised individual participant data can be made available on request for future studies with ethics approval.