Liberal versus restrictive transfusion strategy for cardiac surgery

Liberal versus restrictive transfusion strategy for cardiac surgery


TRICS IV trial: Transfusion Requirements in Cardiac Surgery

The TRICS IV trial is designed to determine whether a liberal transfusion strategy is superior to a restrictive strategy in cardiac patients < 65 years. TRICS IV will incorporate an innovative pragmatic Bayesian design to include patients recruited to TRICS III in its sample size estimation and analysis. It will also include the option of physiologic triggers for transfusion, in addition to the above Hb based thresholds. As for TRICS III, this study is being led by Professor David Mazer’s group from Canada with Canadian Institutes of Health Research (CIHR) funding and will involve an international collaboration. We have secured National Health and Medical Research Council MRFF International Collaborative Trials funding of $A870k for the Australian arm of this study, which will include a local iron availability sub-study. We plan to recruit 500 adult cardiac surgical patients (Euroscore 1 ≥ 6) through multiple Australian sites over three years. Those involved with TRICS III will find the trial conduct and management very familiar.

Please email Professor David Scott if you are interested in being involved, with your contact details and any questions.

Principal investigators

Dr David Mazer, St. Michael’s Hospital (Toronto, ON, Canada)

Professor David A. Scott  (The University of Melbourne and St Vincent's Hospital, Melbourne)

Trial manager

Bhavita Patel, TRICS IV Trial Coordinator, Department of Critical Care, University of Melbourne


The TRICS-IV trial continues to progress well with over 600 participants recruited from 37 sites globally. We are continuing to drive recruitment in Australia and continue our significant contribution to this internationally led trial. To date, we have randomised 95 participants and have 13 active sites. We have recently implemented some funding changes and are planning amendments to our protocol that aim to streamline the data collection process for all of our participating sites. We are looking forward to increasing our recruitment in 2024.


The Transfusion Requirements in Cardiac Surgery trial (TRICS III) was published in 2017 and along with a subsequent meta-analysis, established non-inferiority of a restrictive red blood cell  transfusion strategy in high-risk cardiac surgery patients (trigger Hb < 75 g/L) versus a liberal strategy (Hb < 95 g/L intraoperatively and ICU, and < 85 g/L on a non-ICU ward). The primary outcome was a composite outcome including death, myocardial infarction, stroke, or new renal failure.  An unexpected finding in the planned subgroup analysis was that the liberal strategy appeared to be superior to the restrictive strategy in patients ≤75 years of age [odds ratio 1.32 (95% confidence interval (1.07−1.64) P=0.001)]. The interaction was robust in a series of sensitivity analyses according to decades of age (P = 0.004), with age as a continuous variable with restricted cubic splines (P = 0.006), and after adjustment for all the variables used to define subgroups (P = 0.002), with an inflection point at which the differences became manifest was found at around age 65 years.

Trial summary

Study summary
An international, multi-centre, randomised controlled trial to assess transfusion thresholds in younger patients undergoing cardiac surgery.

Study design
Multi-centre open-label randomised controlled trial (RCT) of a restrictive versus liberal transfusion strategy in higher risk patients ≤65 years of age having cardiac surgery on cardiopulmonary bypass, using a superiority trial design.

A higher haemoglobin (Hb) concentration for red blood cell (RBC) transfusion (liberal transfusion strategy) will be superior to a restrictive strategy in terms of vital organ function (heart, brain and kidney) and mortality 6 months after cardiac surgery.

Sample size
1440 patients.

Study duration
Three years.


MRFF ICTC Grant $869,565 (2021-2024)


Prof David Scott
Prof Alistair Royse
Dr Raymond Hu
Prof John Fraser
Prof Cyril David Mazer
Dr Nadine Shehata
Prof Paul Bannon
Prof James Isbister


St Vincent's Hospital, Melbourne
St. Michael’s Hospital (Toronto, ON, Canada)
Australian and New Zealand College of Anaesthetists Clinical Trials Network (ANZCA CTN)

Trial registration Identifier: NCT04754022

Hepcidin and Iron Storage Sub-Study ACTRN identifier: 12621000952842p

Participating hospitals

Australian hospitals
Gold Coast University Hospital
Flinders Medical Centre
Royal Melbourne Hospital
St Vincent's Hospital Melbourne
Austin Health
The Alfred

How to get involved

For further information about this study, please contact the TRICS-IV Project Manager, Bhavita Patel by email.

For more information

Last updated 14:53 4.04.2024