A study assessing the usefulness of measuring platelet function after cardiac surgery

ISRCTN ISRCTN43298975
DOI https://doi.org/10.1186/ISRCTN43298975
Secondary identifying numbers Protocol Version 3 (Date 3th Aug 2011) R&D number 10CARD16
Submission date
11/01/2014
Registration date
23/01/2014
Last edited
09/09/2015
Recruitment status
No longer recruiting
Overall study status
Completed
Condition category
Circulatory System
Prospectively registered
Protocol
Statistical analysis plan
Results
Individual participant data

Plain English summary of protocol

Background and study aims
Patients suffering from a type of heart disease called coronary artery disease (CAD) are treated with drugs like Aspirin and Clopidogrel. When they come for coronary artery bypass surgery (CABG) these medications are usually stopped a few days before surgery to reduce bleeding after the operation (postoperative bleeding). However, stopping the medications has some risks and hence it is often continued until the day of surgery. Patients who are still on medication are at an increased risk of postoperative bleeding. Transfusion of blood and blood products can have harmful effects and hence efforts should be made to minimize transfusion. There is a need to test for platelet dysfunction before platelet transfusion. Several platelet function tests have been reported to measure platelet dysfunction and find out if there is a need for platelet transfusion. However, none of these tests are suitable for routine clinical practice as they are laborious and time consuming. We aim to design a study to compare the accuracy of two tests, thromboelastography (TEG) and Multiplate® analyzer, and to determine their usefulness in prediction of postoperative blood loss and in guiding postoperative transfusion requirements (blood and platelets) and the need for surgical re-exploration.

Who can participate?
Patients referred for first time isolated CABG will be approached to take part in the study.

What does the study involve?
Group A will include patients who were on anti-platelet drugs till the day of surgery. Group B will include who stopped anti-platelet drugs at least 5 days before the operation. Blood was sampled for Multiplate® and TEG assessments immediately after inserting the arterial line (before the operation) and after protamine administration after cessation of cardiopulmonary bypass (after the operation). We will compare the two groups' post-surgery blood loss and need for transfusion of blood products after the operation. TEG and Multiplate® analyzer results will also be compared for the two groups. No additional clinical visits will be required for the purpose of the study.

What are the possible benefits and risks of participating?
There are no direct benefits to the patients enrolled in this study. It will improve our understanding of the effect of antiplatelet drugs and will compare the two tests: TEG and Multiplate®. The results of this study can be of potential benefit to future patients. Patients enrolled for the study will be treated according to routine during and after the operation. The only additional intervention will be blood sampling. The study itself will not cause any adverse event.

Where is the study run from?
The Heart and Lung Centre, Wolverhampton, UK.

When is the study starting and how long is it expected to run for?
The study started in November 2011 and ended in June 2013.

Who is the main contact?
Mr Pankaj Kumar Mishra FRCS CTh (pankaj.mishra@nhs.net; mishrapk_25@yahoo.com)
Mr Heyman Luckraz FRCS CTh (heyman.luckraz@nhs.net)
Dr Mohammed Fayaz FRCA

Contact information

Mr Heyman Luckraz
Scientific

Heart and Lung Center
Wednesfield Road
Wolverhampton
WV10 0QP
United Kingdom

Phone +44 (0)190 230 7999
Email heyman.luckraz@nhs.net

Study information

Study designProspective controlled double-blind single-centre trial
Primary study designObservational
Secondary study designCase-control study
Study setting(s)Hospital
Study typeScreening
Participant information sheet Not available in web format, please use the contact details below to request a patient information sheet
Scientific titleThe role of point-of-care assessment of platelet function in predicting postoperative bleeding and transfusion requirements after coronary artery bypass grafting (CABG)
Study objectivesObjective measurement of platelet function after cardiac surgery can be potentially useful in prediction of postoperative blood loss and in guiding postoperative transfusion requirements (blood and platelets) and the need for surgical re-exploration. The Multiplate® platelet analyser is better in this regard than standard thromboelastography (TEG).

On 01/04/2012 the following changes were made to the trial record:
1. The scientific title was changed from 'An observational pilot study assessing the usefulness of measuring platelet function after cardiac surgery' to 'The role of point-of-care assessment of platelet function in predicting postoperative bleeding and transfusion requirements after Coronary Artery Bypass Grafting (CABG)'
2. The study design was changed from 'Prospective controlled observational double-blind trial' to 'Prospective controlled double-blind single-centre trial'
3. The target number of participants was changed from 80 to 84
Ethics approval(s)NREC Committee Black Country, West Midlands, 05/07/2011, ref: 11/WM/0130
Health condition(s) or problem(s) studiedCoronary Artery Disease / Coronary Artery Bypass Graft / Antiplatelet medications
InterventionCurrent interventions as of 01/04/2014:
Group A (n=42) will include patients who were on anti-platelet drugs until the day of surgery. Group B (n=42) will include patients who stopped anti-platelet drugs at least 5 days pre-operatively.

Patients enrolled for the study will be treated according to institutional routine during the intraoperative and postoperative period. The only additional intervention will be blood sampling immediately after inserting the arterial line and after protamine administration after cessation of cardiopulmonary bypass. Anesthetists and surgeons will be blinded to the results of the Multiplate® measurements.

The TEG measurements will be used as per current practice to influence our decision making in terms of using blood products. Additional protamine or blood products will be given based on our clinical guidelines.

Previous interventions:
Control group of patients (Group A) who did not receive antiplatelet therapy or stopped antiplatelet therapy several days prior to CABG. Study group (Group B) will include patients who continued antiplatelet medications until the day of surgery.

Patients enrolled for the study will be treated according to institutional routine during the intraoperative and postoperative period. The only additional intervention will be blood sampling immediately after inserting the arterial line and after protamine administration after cessation of cardiopulmonary bypass. Anesthetists and surgeons will be blinded to the results of the Multiplate® measurements. The TEG measurements will be used as per current practice to influence our decision making in terms of using blood products.

Additional protamine or blood products will be given based on our clinical guidelines. Blood loss for the first 8 hours will be recorded. Use of blood products intraoperatively or postoperatively will be also recorded for the first 24 hours.
Intervention typeOther
Primary outcome measureCurrent primary outcome measures as of 01/04/2014:
The primary endpoint was to correlate excessive post-operative bleeding defined as blood loss in excess of 2.5 ml/kg/hr in the immediate 3 hours, with the presence of platelet dysfunction as assessed by Multiplate® and TEG.

Previous primary outcome measures:
The primary endpoint is to correlate excessive postoperative bleeding defined as a blood loss of 2.5 ml/kg/hr in the immediate 3 hours and the total bleeding within the first 8 hours post-surgery, with the presence of platelet dysfunction as measured by the Multiplate®.
Secondary outcome measuresCurrent secondary outcome measures as of 01/04/2014:
1. Transfusion requirements for blood and blood products
2. Overall blood loss within 8 hours of surgery
3. Postoperative complications
4. Intensive care unit (ICU) length of stay
5. Hospital length of stay

Previous secondary outcome measures:
1. Transfusion requirements for blood and blood products
2. Comparison of Multiplate® and TEG
3. Postoperative complications
4. ICU length of stay
5. Hospital length of stay
Overall study start date16/11/2011
Completion date12/06/2013

Eligibility

Participant type(s)Patient
Age groupAdult
Lower age limit18 Years
SexBoth
Target number of participants84
Key inclusion criteria1. Male and female patients aged 18 years and over
2. Patient who can give informed consent
3. Patients undergoing first time coronary artery bypass graft (CABG) using cardiopulmonary bypass
Key exclusion criteria1. Patients who are unable to consent
2. Patients less than 18 years old
3. Severe liver or renal dysfunction (Altered Liver Function Test, Creatinine >200)
4. Patients who are already part of another study
5. Patient with known bleeding diathesis
Date of first enrolment16/11/2011
Date of final enrolment12/06/2013

Locations

Countries of recruitment

  • England
  • United Kingdom

Study participating centre

Royal Wolverhampton NHS Trust
Wolverhampton
WV10 0QP
United Kingdom

Sponsor information

Wolverhampton Coronary Aftercare Support Group (UK)
Charity

Charitable Trust
Heart and Lung Centre
Wednesfield Road
Wolverhampton
WV10 0QP
United Kingdom

Funders

Funder type

Charity

Wolverhampton Coronary Aftercare Support Group (UK )

No information available

Results and Publications

Intention to publish date
Individual participant data (IPD) Intention to shareNo
IPD sharing plan summaryNot provided at time of registration
Publication and dissemination planNot provided at time of registration
IPD sharing plan

Study outputs

Output type Details Date created Date added Peer reviewed? Patient-facing?
Results article results 01/01/2015 Yes No