Haemo-autologous Antegrade Repriming (HAR) as Minimum Impact Perfusion Strategy for Cardiopulmonary Bypass

Study Overview
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Brief Summary
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Haemo-autologous Antegrade Repriming (HAR) is a procedure based in the combination of evidence proven measures designed to reduce the haemodilution caused by establishing the cardiopulmonary bypass (CPB) during cardiac surgery. This clinical trial aims to determinate, in one hand, the benefits related to HAR in terms of transfusion, ICU stay, ventilation time, early mortality and complications. In the other hand analyzes the gaseous microemboli (GME) load, comparing the oxygenators venting technology´s efficiency in treatment and control group, and its relation with patient´s neurocognitive status.

Detailed Description
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HAR is a repriming technique based in Retrograde Autologous Priming (RAP), that has been implemented by recently recommended measures in terms of reducing blood transfusions. The expected clinical benefits are related to hemodilution´s reduction up to only 300ml. The extracorporeal circuit has been reduced to 3/8 inch diameter in both lines, reducing the surface up to 1000ml of dynamic priming. Vacuum assisted venous drainage (VAVD) allows to empty the venous line after priming and deairing, facilitating the venous flow for CPB initiation. The antegrade repriming eliminates the maximum amount of crystalloid contained in the circuit, displacing it to a collector bag, by using autologous blood sequestered from the arterial line to the hardshell reservoir. HAR reduces the CPB hemodilution related to priming from 1500 to 300 ml preventing the usual sudden haemoglobin level reduction occured during every extracorporeal techinque´s establishment. Our mission is to analyze if HAR can be validated as a safe and effective tool to improve clinical outcomes in cardiac surgery procedures under extracorporeal circulation

Official Title
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Haemo-autologous Antegrade Repriming (HAR) Clinical Trial for Validation as Minimum Impact Perfusion Strategy in Cardiopulmonary Bypass

Conditions
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Anemia, Cognitive; Disorder, Due to General Medical Condition, Embolism, Air, Transfusion, Cardiac Disease, Extracorporeal Circulation; Complications, Valve Anomalies

Intervention / Treatment
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* Procedure: HAR


Participation Criteria
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Eligibility Criteria
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Inclusion Criteria: - All patients purposed to undergo elective cardiopulmonary bypass for cardiac valve surgery or other pathologies requiring to open heart chambers. Exclusion Criteria: Urgency and emergency Heart transplantations Severe cognitive affection Active sepsis Previous anemia Early re-intervention Pre-Op extracorporeal membrane oxygenation (ECMO) support Hemodynamic unstability during HAR Any clinical condition that may force protocol deviation

Ages Eligible for Study
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Minimum Age: 50 Years
Maximum Age: 99 Years

Sexes Eligible for Study
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All

Accepts Healthy Volunteers
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No

Study Plan
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How is the study designed?
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Design Details

Primary Purpose: Treatment
Allocation: Randomized
Intervention Model: Parallel Assignment
Interventional Model Description: In a preliminary phase, patients are randomly assigned to 4 branches, regarding to two conditions: oxygenator´s deairing type and HAR exposure. This phase is designed as pilot study with 100 patients in order to determine precisely the sample size needed depending on the observed effects. If there are no clinical differences between oxygenators behaviour, during the second stage, sample will be only divided in 2 groups due to HAR exposure.
Masking: Quadruple


Arms and Interventions

| Participant Group/Arm | Intervention/Treatment |
| --- | --- |
| Experimental: HAR group<br>Treated group is exposed to an haematic antegrade autologous repriming of the MiECC CLass IV circuit, reducing the haemodilution related to CPB initiation to a fix amount of 300ml | Procedure: HAR<br>* HAR, the 6 steps procedure that results in 300ml of haemodilution. Step 0: Circuit is primed with 1000ml of crystalloid solution. Step 1: Venous line content is drained to the reservoir. Step 2: arterial srystalloid priming is displaced to the reservoir retrogradely by autologous blood. Step 3: Crystalloid priming is discarded to the collector bag. Step 4: An amount of 300ml of arterial blood is sequestered to the reservoir avoiding the mixture. Step 5: The centrifugal pump and the oxygenator are reprimed with autologous blood displacing the priming and GME to the collector bag. Step 6: CPB is initiated with a low haemodilution of 300ml. Available at: https://zenodo.org/record/4276132#.X7K8AchKgRk<br>* Other names: Extracorporeal circuit repriming;|
| No Intervention: Control Group<br>Control group is not exposed to HAR. The extracorporeal circuit is a MiECC primed with 1000ml of Isofundin (crystalloid balanced solution) as an standard circuit | |

What is the study measuring?
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Primary Outcome Measures

| Outcome Measure | Measure Description | Time Frame |
| --- | --- | --- |
| Transfusion | Blood product consumption during patients hospital stay | 1 year | 
| ICU stay | Length of stay at Intensive Care Unit. (days) | 1 year | 
| Ventilation time | Hours under mechanical ventilation after surgery | 1 year | 
| Complications | Incidence of neurological, respiratory, urinary, cardiologic complications and multiorganic failure | 1 year | 
| Mortality | Incidence of death during hospital stay | 1 year | 

Secondary Outcome Measures

| Outcome Measure | Measure Description | Time Frame |
| --- | --- | --- |
| Emboli number | Number of total gaseous microemboli delivered by the extracorporeal system to the patient | 1 year | 
| Emboli Volume | Volume of total gaseous microemboli delivered by the extracorporeal system to the patient | 1 year | 
| Emotional regulation | Evolution of Emotional regulation test results, comparing the variation with the amount of embolic events detected during the extracorporeal procedure. (4-6 months) | 6 months after surgery | 
| Visual work memory variation and emboli | Evolution of Visuospatial working memory test results, comparing the variation of the basal status and short term measurements (4-6 months after surgery) with the amount of detected emboli delivered to the patient through the heart-lung machine´s circuit. | 6 months after surgery | 
| Executive functions and emboli | Analysis of the clock drawing test variation, comparing basal and short term (4-6 months after surgery) measurements, and the expected relation with the emboli detected during the extracorporeal technique | 6 months after surgery | 
| Visual memory and cognitive status evaluation and emboli | Analysis of the variation of cognitive functions using picture tests(comparing basal status and short term evaluation results (4-6 months after surgery) and the amount of emboli delivered to the patient during the cardiopulmonary bypass | 6 months after surgery | 

 Terms related to the study
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Keywords Provided by Centre Hospitalier Valida
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Retrograde autologous priming, RAP, HAR, cardiopulmonary bypass, Extracorporeal circulation, Gaseous microemboli, perfusion