Platelet function in major vascular surgery
Research type
Research Study
Full title
PLatelet fUnction in patients undergoinG major, non-cardiac, vascular Surgery (PLUGS) – a prospective cohort study.
IRAS ID
302883
Contact name
Akshay Shah
Contact email
Sponsor organisation
University of Oxford / Research Governance, Ethics and Assurance
Duration of Study in the UK
1 years, 2 months, 1 days
Research summary
Research summary
WHY:
Many patients who require major operations of the blood vessels (vascular surgery) are taking antiplatelet medications. These drugs stop the dangerous blood clots from forming but can also cause bleeding. On the day of surgery, patients may require an epidural for pain relief. An epidural is an injection in your back that blocks the nerves carrying pain from the area being operated on. It is generally a safe procedure which provides excellent pain relief. One rare risk is bleeding into the injection site, which can have potentially devastating complications such as paralysis. Bleeding into the epidural injection site is estimated to occur in 1 in every 150,000 cases. The risk is thought to be higher in patients who are on antiplatelet medications and therefore guidelines recommend stopping some antiplatelet medications for between 5 and 7 days before an epidural injection. However, this is not based on high-quality research and stopping these medications, even for a brief period, can result in patients being at higher risk of stroke or heart attack.However, little is known about how individual people respond to these medications. Some research suggests that antiplatelet medications may not work in a third of patients. Epidural analgesia may be a suitable option for these patients. Expert committees have called for more research on identifying these patients.
WHAT:
The aim of our study is to better understand the true effects that antiplatelet medication has on circulating platelets in the blood. We will use novel methods of analysing platelet function.WHO and WHERE:
We will aim to recruit 80 patients at the John Radcliffe Hospital, Oxford. Recruited patients be split into the following groups: (i) aspirin alone, (ii) clopidogrel alone or (iii) dual antiplatelet therapy (aspirin and clopidogrel) and (iv) those who are not on any antiplatelet therapy ('control' group).Summary of results
Platelets are cells that help blood to clot. This process may become abnormal and the clots formed by platelets may block off important blood vessels, resulting in strokes and heart attacks. This is more common in patients who are older and who have high blood pressure or diabetes. As a result, many of these patients are prescribed antiplatelet medications, such as aspirin and clopidogrel. These drugs prevent formation of dangerous blood clots but may increase the risk of bleeding when a person undergoes an operation.However, little is known about how individual people respond to these medications. Some research suggests that antiplatelet medications may not work in a third of patients. Expert committees have called for more research on identifying these patients.
The aim of our study was to better understand the true effects that antiplatelet medication has on circulating platelets in the blood. We used novel methods of analysing platelet function. We recruited 80 patient participants across four study groups who are scheduled to undergo major vascular surgery at the John Radcliffe Hospital, Oxford.
We found that up to three-quarters of patients taking these medication have a degree of 'resistance' to them, which means they may not be working effectively. Furthermore, stopping these medications before major surgery had no impact on the function of circulating platelets.
This study has given us important information to design a much larger study involving larger numbers of patients across the UK. In addition, we also want to know if people in whom these medications do not work experience more heart attacks or blood clots.
REC name
West Midlands - Solihull Research Ethics Committee
REC reference
21/WM/0254
Date of REC Opinion
20 Dec 2021
REC opinion
Further Information Favourable Opinion