Platelet Function in Minimal Extracorporeal Circulation in CABG (ECCTEG)
Cardiac surgery with extracorporeal circulation (ECC) triggers platelets. Minimal extracorporeal circulation system (minimal-ECC) has several advantages compared with conventional ECC amongst less platelet activation. Platelet function can be analysed with thromboelastography (TEG) and multiple electrode aggregometry (MEA).
The use of minimal ECC leads to less platelet dysfunction compared with conventional ECC in coronary artery bypass grafting (CABG) analysed with TEG and MEA
Single center, prospective, randomized, pilot study
20 patients undergoing CABG using minimal ECC. Patients continued the use of acetylsalicylic acid and discontinued the use of clopidogrel minimal 5 days preoperative.
20 patients undergoing CABG using conventional ECC. Patients continued the use of acetylsalicylic acid and discontinued the use of clopidogrel minimal 5 days preoperative.
Group 1: CABG using minimal ECC Group 2: CABG using conventional ECC
Main study parameters/endpoints:
- Results of TEG and MEA, see detailed description
- Per operative blood loss and total blood loss 24 hours after CABG
- Total amount of transfused platelet units during CABG and 24 hours after CABG
|Thrombocytopathy||Device: Mini extracorporeal circulation Device: Conventional extracorporeal circulation|
|Study Design:||Allocation: Randomized
Intervention Model: Parallel Assignment
Masking: Double Blind (Participant, Care Provider, Investigator)
Primary Purpose: Treatment
|Official Title:||Platelet Function in Minimal Extracorporeal Circulation Versus Conventional Extracorporeal Circulation in Coronary Artery Bypass Grafting|
- Platelet function [ Time Frame: Post-cardiopulmonary bypass ]Change in thrombocyte function is measured directly after Protamine and three hours after operation. This change is correlated to the reference preoperatively.
- Perioperative blood loss [ Time Frame: 24 hours ]
- Amount of platelet or fresh frozen plasma transfusion [ Time Frame: 24 hours ]
|Study Start Date:||April 2013|
|Study Completion Date:||December 2013|
|Primary Completion Date:||October 2013 (Final data collection date for primary outcome measure)|
Experimental: Mini extracorporeal circulation
Patients undergoing coronary artery bypass surgery on minimal extracorporeal circulation
Device: Mini extracorporeal circulation
Minimal-ECC versus conventional ECC circuits minimise foreign surface-blood interaction and are heparinized from tip to tip. The tubing length has been shortened to decrease crystalloid prime. Cardiotomy suction is minimised, which leads to less fibrinolysis. An active air-removal device is added to the closed circuit.
The use of minimal ECC has already shown a significant reduction of the systemic inflammatory reaction and less peroperative transfusion of blood products.
Other Name: Mini- ECC: ECC.O Oxygenator
Active Comparator: Conventional extracorporeal circulation
Patients undergoing coronary artery bypass surgery on conventional extracorporeal circulation
Device: Conventional extracorporeal circulation
Other Name: Conventional ECC: D903 Avant Oxygenator
Platelet function test
Thromboelastography (TEG) TEG is a test which provides information on the complete haemostasis. Also fibrinolysis can be measured. The strength of the clot can be measured. This provides information about platelet concentration, -function and platelet-fibrin interaction. It is measured in a medium with added heparinase, an enzyme that degrades heparin,, which makes TEG measurement possible during ECC. The results from the TEG will be displayed graphically and numerically. The letter R (reaction time) represents the time before the clot formation starts. This time is predominately dependent on coagulation factors and inhibitors such as heparin. The velocity at which the clot is then formed is displayed as the letter K (time between 2 mm en 20 mm amplitude in the thromboelastogram). The firmness of the clot is the maximum amplitude in the thromboelastogram (MA) and is dependent on the amount and function of the thrombocytes, fibrinogen concentration and factor XIII concentration of the sample. Fibrinolysis will be visualised in the parameter that displays the velocity of dissolving the clot (LY30= fibrinolysis 30 minutes after MA).
In case of a severe coagulation factor independency or use of heparin, the R parameter will be elongated. In severe thrombocytopathy, thrombocytopenia or a low fibrinogen concentration the graphic will show a lowered MA. In hyperfibrinolysis the LY30 will be elongated.
Multiple electrode Aggregometry (MEA) MEA is a technique to test platelet function in whole blood based on classical impedance aggregometry. The use of whole blood makes centrifugation redundant. The use of agonist ADP, arachidonic acid, collagen and TRAP provides information about platelet aggregation, and simultaneously provides specific information of the routes inhibited by clopidogrel and acetylsalicylic acid.
MEA calculates three parameters. The most important parameter, the area under the curve (AUC), reflexes the overall platelet activity . The area under the curve is influenced by the total height of the aggregation curve as well as by its slope. The other parameters are the height of the curve that describes the aggregation. The maximum slope of the curve describes the reflex velocity.
Results TEG and MEA contain:
- TEG angle
- TEG K
- TEG LY 30
- TEG MA
- TEG R
- MEA adenosine diphosphate (ADP)
- MEA arachidonic acid
- MEA collagen
- MEA thrombin receptor activating peptide (TRAP)
Please refer to this study by its ClinicalTrials.gov identifier: NCT01935245
|Catharina hospital Eindhoven|
|Eindhoven, Brabant, Netherlands, 5623 EJ|
|Principal Investigator:||Ingeborg HF Herold, MD||Catharina hospital Eindhoven, The Netherlands|