THERMIC-3
Research type
Research Study
Full title
Intermittent Antegrade Warm Blood versus Cold Blood Cardioplegia in Children Undergoing Open Heart Surgery: A Randomised Controlled Trial (THERMIC-3)
IRAS ID
211278
Contact name
Serban Stoica
Contact email
Sponsor organisation
University Hospitals Bristol NHS Trust
ISRCTN Number
ISRCTN13467772
Duration of Study in the UK
2 years, 6 months, 1 days
Research summary
Research Summary
Congenital heart disease is not uncommon and morbidity following cardiac surgery in children remains significant. Surgical repair of congenital heart defects usually requires the heart to be stopped using a cold solution containing potassium (cardioplegia) which protects the heart and keeps it still when operating. We have previously shown that cold cardioplegia solutions may have deleterious effects on the recovery of the heart after surgery in adults. However, very little is known about the effects of using warm cardioplegia solutions in children. Therefore, we will assign children undergoing open heart surgery by chance to one of two groups, using either warm or cold cardioplegia solutions to stop and protect the heart. Clinical and biochemical measures of recovery and complications following surgery will be compared between the two groups.
A sub-study will also look at methods for measuring core body temperature monitoring in children undergoing cardiac surgery with cardiopulmonary bypass. Temperature monitoring is an essential and a universally measured sign in the management of critically ill children. Rectal temperature monitoring is currently the most commonly used method for estimation of the core body temperature in ill children. Multiple studies in adults and children have questioned the accuracy of rectal temperature monitoring when compared to pulmonary artery or urinary catheter monitoring. However, these studies are limited by small numbers. The sub study is a proof of concept study, which will compare measurements of core body temperature obtained using a temperature sensing urinary catheter and a rectal temperature probe and other temperature measuring devices such as axillary, oral, aural and oesophageal probes.
Summary of Results
What was this study about?
During heart surgery in children, surgeons temporarily stop the heart and protect it using a special solution called ‘cardioplegia’. The Thermic-3 study compared two commonly used approaches:- Cold blood cardioplegia (4-6oC)
- Warm blood cardioplegia (34 oC or above)Both cardioplegia temperatures have been used in children, but they had not been directly compared with each other in children, to find out which is better. The Thermic-3 study wanted to find out whether warm blood cardioplegia provided better protection for the heart during and after surgery.
Who took part?
The study included 97 children undergoing congenital heart surgery at Bristol Royal Hospital for Children. Participants were randomly assigned to receive either warm blood cardioplegia (49 children) or cold blood cardioplegia (48 children).The main measure was cardiac troponin T (cTnT), which is released when heart muscle is damaged. Lower levels indicate better protection of the heart. A range of other clinical outcomes were also looked at during the study (e.g. time spent in intensive care, complications, kidney function and other blood test results).
What were the results?
Children who received warm blood cardioplegia had similar troponin levels to those who received cold blood cardioplegia, suggesting that both methods protected the heart equally well.A range of other clinical outcomes such as blood gas, blood test and kidney function results were similar between the two groups.
However, children in the warm blood cardioplegia group had on average a longer stay in intensive care and experienced more complications. These complications were probably related to surgical factors and technical issues, rather than the temperature of the cardioplegia.
Overall, the Thermic-3 study showed that warm blood cardioplegia is safe and can be used successfully in children undergoing heart surgery However, it did not improve protection of the heart more than cold blood cardioplegia.
REC name
London - Central Research Ethics Committee
REC reference
18/LO/0205
Date of REC Opinion
7 Mar 2018
REC opinion
Favourable Opinion