Platelet function in patients undergoing major, non-cardiac, vascular surgery

Not Applicable

Completed

• Conditions: Participants scheduled to undergo elective, major non-cardiac, vascular surgery; Surgery

• Registration Number: ISRCTN11959105
• Lead Sponsor: niversity of Oxford

Brief Summary

Not available

Detailed Description

Not available

Study Timeline

• Results First Posted: 1900-01-01
• Study Start: 2022-04-14
• Study Completion: 2023-06-30
• Last Update Posted: 26 September 2023

Recruitment & Eligibility

• Status: Completed
• Sex: All
• Target Recruitment: 80

Inclusion Criteria

1. Participant is willing and able to give informed consent for participation in the study
2. Aged 18 years or above
3. Scheduled to undergo major non-cardiac vascular surgery (including, but not restricted to, abdominal aortic aneurysm (open or endovascular), carotid endarterectomy, lower limb arterial revascularisation)
4. For participants taking antiplatelet therapy: (i) aspirin alone, (ii) clopidogrel alone or (iii) dual antiplatelet therapy groups, at least 7 days of prescribed antiplatelet therapy prior to study recruitment. Patients who are on other antiplatelet therapy, but from the same therapeutic class as either aspirin or clopidogrel, will be allocated to that particular group.
5. Participants in the control group (iv) should not have been on any antiplatelet therapy

Exclusion Criteria

1. Congenital/inherited bleeding disorders
2. Haemodialysis-dependent chronic kidney disease
3. Enrolled into a study where an intervention may affect platelet function – this would be discussed on a case-by-case basis between the study Chief Investigators

Study & Design

• Study Type: Observational
• Study Design: Not specified

Primary Outcome Measures

Name	Time	Method
<br> 1. Percentage of patients with antiplatelet drug resistance at initial presentation to the Pre-operative Assessment Clinic and on the morning of surgery. For aspirin group (i), drug resistance will be defined as an arachidonic acid (AA)-induced platelet-fibrin clot strength (MAAA) >47 mm plus an AA-induced platelet inhibition rate < 50%. For P2Y12 inhibitors (clopidogrel) group (ii), drug resistance will be defined as an adenosine diphosphate (ADP)-induced platelet-fibrin clot strength (MAADP) >47 mm plus an ADP-induced platelet inhibition rate < 50%<br> 2. Percentage of patients with platelet inhibition measured using the TEG6S assay on the morning of surgery<br>

Secondary Outcome Measures

Name	Time	Method
<br> 1. Proportion of patients who self-report as being compliant with antiplatelet medications preoperatively. Compliance will be defined as taking >80% of prescribed doses as prescribed.<br> 2. Peri-operative blood loss, changes in haemoglobin concentration and transfusion requirements measured using routine healthcare records in the first 24 hours in the first 24 hours<br> 3. Return to theatre for bleeding in the first 24 hours and/or graft/stent thrombosis measured using routine healthcare records in the first 24 hours<br> 4. Peri-operative thrombotic events measured using routine healthcare records within 30 days of surgery<br> 5. Bleeding complications associated with regional anaesthesia measured using routine healthcare records at 30 days<br> 6. Days-alive-and-out-of-hospital at 30 days (DAOH-30) measured using routine healthcare records<br>