Retrograde Autologous Priming for Reducing Blood Transfusions

(TheRAPy Trial)

Recruiting at 3 trial locations

Overseen By Jessica Spence

Age: Any Age

Sex: Any

Trial Phase: Academic

Sponsor: Population Health Research Institute

Disqualifiers: Complete <=200 cases, <95% agreement

No Placebo Group All trial participants will receive the active study treatment (no placebo)

Compensation: Varies

Number of Visits: Unknown

Duration: 12 periods of 4 weeks

4500 Participants Needed

Trial Summary

What is the purpose of this trial?

The TheRAPy vanguard trial is a multicentre, multiple period randomized, cluster crossover vanguard trial testing the feasibility of a full-scale trial to evaluate whether a centre-based policy of routine use of RAP versus a policy of crystalloid priming reduces RBC transfusion for patients undergoing cardiac surgery on cardiopulmonary bypass. It will also provide information about key parameters of the TheRAPy full-scale trial.

Will I have to stop taking my current medications?

The trial information does not specify whether you need to stop taking your current medications. It's best to consult with the trial coordinators or your doctor for guidance.

What data supports the effectiveness of the treatment Retrograde Autologous Priming for reducing blood transfusions?

Research shows that Retrograde Autologous Priming (RAP) can significantly reduce the number of patients needing blood transfusions during and after heart surgery, as well as the total amount of blood transfused during the hospital stay. ^{1 2 3 4 5}

How does the treatment Retrograde Autologous Priming differ from other treatments for reducing blood transfusions?

Retrograde Autologous Priming (RAP) is unique because it involves using the patient's own blood to prime the cardiopulmonary bypass system, which reduces the need for donor blood transfusions during cardiac surgery. This method minimizes haemodilution (dilution of blood), which is a common issue with standard priming methods that use acellular solutions. ^{1 2 4 6 7}

Research Team

Jessica Spence, MD, PhD

Principal Investigator

Population Health Research Institute

Eligibility Criteria

This trial is for patients undergoing cardiac surgery with cardiopulmonary bypass at hospitals that do more than 200 such surgeries a year. The entire cardiovascular team must agree to follow the assigned priming policy throughout the trial.

Inclusion Criteria

I am having heart surgery with cardiopulmonary bypass at a participating hospital.

My hospital performs over 200 adult heart surgeries yearly and agrees to follow the trial's blood management policy.

Exclusion Criteria

Complete 200 or fewer cardiac surgical cases

Less than 95% of their cardiovascular surgery group agrees to manage patients according to either of the two policies

Timeline

Screening

Participants are screened for eligibility to participate in the trial

2-4 weeks

Treatment

Participants undergo cardiac surgery with either retrograde autologous priming or crystalloid priming

12 periods of 4 weeks

Follow-up

Participants are monitored for transfusion requirements and adherence to policies up to 72 hours after surgery

1 week

Data Collection

Data is collected about critical parameters affecting the design and implementation of the full-scale trial

6 months

Treatment Details

Interventions

• Retrograde Autologous Priming

Trial Overview The study compares two methods of preparing the heart-lung machine used in surgery: retrograde autologous priming (RAP) and crystalloid priming, to see if RAP reduces the need for blood transfusions during cardiac surgery.

Participant Groups

Group I: Retrograde autologous priming Experimental Treatment 1 Intervention

sites implement retrograde autologous priming (RAP) during cardiac surgery

Group II: Crystalloid priming Experimental Treatment 1 Intervention

sites implement crystalloid priming use during cardiac surgery

Who Is Running the Clinical Trial?

Population Health Research Institute

Lead Sponsor

Trials

165

Recruited

717,000+

Findings from Research

Retrograde autologous priming of the cardiopulmonary bypass circuit significantly reduces the number of patients receiving intraoperative packed red blood transfusions and the total number of transfusions during hospital stays, based on a meta-analysis of six trials involving adult cardiac surgery.

While retrograde autologous priming shows promise in reducing overall transfusion needs, it does not significantly decrease the number of units transfused during the surgery itself, indicating that its benefits may be more pronounced in the overall hospital context rather than intraoperatively.

NCBI (Pubmed)

pubmed.ncbi.nlm.nih.gov

Retrograde autologous priming and allogeneic blood transfusions: a meta-analysis. Saczkowski, R., Bernier, PL., Tchervenkov, CI., et al.[2017]

Retrograde autologous priming (RAP) significantly reduces the need for intraoperative allogeneic red cell transfusions in cardiac surgery, with a pooled odds ratio of 0.34 from 18 studies involving 4,664 patients.

RAP also decreases the overall incidence of hospital-wide red cell transfusions without increasing the risk of adverse events like acute kidney injury or stroke, suggesting it is a safe and effective strategy for minimizing transfusions during cardiac surgery.

NCBI (Pubmed)

pubmed.ncbi.nlm.nih.gov

Retrograde Autologous Priming in Cardiac Surgery: Results From a Systematic Review and Meta-analysis. Hensley, NB., Gyi, R., Zorrilla-Vaca, A., et al.[2021]

In a study of 559 cardiac surgery patients, retrograde autologous priming (RAP) did not increase the risk of in-hospital mortality compared to a group that did not use RAP, indicating its safety as a blood conservation technique.

The use of RAP was associated with a significantly lower incidence of postoperative cardiac arrest (1 patient in the RAP group vs. 9 in the no-RAP group), suggesting a potential benefit in improving postoperative outcomes.

NCBI (Pubmed)

pubmed.ncbi.nlm.nih.gov

Retrograde autologous priming of the cardiopulmonary bypass circuit: safety and impact on postoperative outcomes. Murphy, GS., Szokol, JW., Nitsun, M., et al.[2006]

In a study of 201 patients undergoing coronary artery bypass grafting (CABG), retrograde autologous priming (RAP) did not significantly reduce the need for packed red cell (PRC) or blood product transfusions during surgery, indicating that RAP may not be effective in minimizing transfusion requirements.

Factors such as CPB time, preoperative hemoglobin levels, and creatinine clearance were found to be more significant predictors of blood product transfusion than the use of RAP, suggesting that other clinical parameters play a more critical role in transfusion needs.

NCBI (Pubmed)

pubmed.ncbi.nlm.nih.gov

The effect of retrograde autologous priming on intraoperative blood product transfusion in coronary artery bypass grafting. Nanjappa, A., Gill, J., Sadat, U., et al.[2015]

In a study of 545 cardiac surgical patients over 24 months, using retrograde autologous priming (RAP) during cardiopulmonary bypass did not significantly reduce the need for blood transfusions, with only a small, statistically insignificant decrease in patients receiving packed red blood cells (44% with RAP vs. 51% without).

Overall, the use of RAP as a blood conservation strategy did not demonstrate a clinically important benefit in reducing blood product use during cardiac surgeries, as no significant differences were found in the total units of packed red blood cells, platelets, or fresh frozen plasma transfused.

NCBI (Pubmed)

pubmed.ncbi.nlm.nih.gov

The failure of retrograde autologous priming of the cardiopulmonary bypass circuit to reduce blood use after cardiac surgical procedures. Murphy, GS., Szokol, JW., Nitsun, M., et al.[2019]

In a study of 100 patients undergoing coronary artery bypass grafting, retrograde autologous priming (RAP) significantly reduced the prime volume of the cardiopulmonary bypass system from 1,627 mL to 782 mL, leading to less haemodilution.

Patients in the RAP group experienced a higher lowest hematocrit level (26%) and a significantly lower rate of packed red blood cell transfusions (6%) compared to the NON-RAP group (26%), indicating that RAP is effective in minimizing blood loss during surgery.

NCBI (Pubmed)

pubmed.ncbi.nlm.nih.gov

Retrograde autologous priming reduces transfusion requirements in coronary artery bypass surgery. Severdija, EE., Heijmans, JH., Theunissen, M., et al.[2022]

In a study of 753 patients undergoing cardiac surgery, retrograde autologous priming (RAP) significantly reduced haemodilution and the need for blood transfusions, with a nadir haematocrit of 26.8% in the RAP group compared to 25.8% in controls.

RAP was associated with a lower transfusion frequency (26.1% vs 33.3%) and was found to be an effective strategy for minimizing transfusion rates during cardiopulmonary bypass, especially when the RAP volume was tailored to individual patient characteristics.

NCBI (Pubmed)

pubmed.ncbi.nlm.nih.gov

The effect of retrograde autologous priming volume on haemodilution and transfusion requirements during cardiac surgery. Vandewiele, K., Bové, T., De Somer, FM., et al.[2021]

References

1. England pubmed.ncbi.nlm.nih.gov

Retrograde autologous priming and allogeneic blood transfusions: a meta-analysis. [2017]

2. United States pubmed.ncbi.nlm.nih.gov

Retrograde Autologous Priming in Cardiac Surgery: Results From a Systematic Review and Meta-analysis. [2021]

3. United States pubmed.ncbi.nlm.nih.gov

Retrograde autologous priming of the cardiopulmonary bypass circuit: safety and impact on postoperative outcomes. [2006]

4. England pubmed.ncbi.nlm.nih.gov

The effect of retrograde autologous priming on intraoperative blood product transfusion in coronary artery bypass grafting. [2015]

5. United States pubmed.ncbi.nlm.nih.gov

The failure of retrograde autologous priming of the cardiopulmonary bypass circuit to reduce blood use after cardiac surgical procedures. [2019]

6. England pubmed.ncbi.nlm.nih.gov

Retrograde autologous priming reduces transfusion requirements in coronary artery bypass surgery. [2022]

7. England pubmed.ncbi.nlm.nih.gov

The effect of retrograde autologous priming volume on haemodilution and transfusion requirements during cardiac surgery. [2021]