Antiplatelet Agents in patients undergoing non-cardiac surgery

Publication: 01/12/2007  
Next review: 30/12/2022  
Clinical Guideline
ID: 1186 
Approved By:  
Copyright© Leeds Teaching Hospitals NHS Trust 2021  


This Clinical Guideline is intended for use by healthcare professionals within Leeds unless otherwise stated.
For healthcare professionals in other trusts, please ensure that you consult relevant local and national guidance.

Antiplatelet agents in patients undergoing non-cardiac surgery

Patients with coronary artery disease are at a greater risk of major adverse cardiac events in the perioperative period. The use of antiplatelet agents reduces the risk of ischaemic events.

Patients at a higher risk of thrombotic events include those with:

  • Acute coronary syndrome within 12 months
  • Stroke or TIA within 1 month
  • Bare metal stent (BMS) within 1 month*1
  • First generation drug eluting stent (DES) within 12 months
  • New generation drug eluting stent (DES) within 6 months

Patients undergoing surgery within 6 months of percutaneous coronary intervention (PCI with angioplasty or stent) need to be discussed with cardiology.

It should be noted that antiplatelet agents also increase the risk of major bleeding during surgery.

Within this guideline there are different sections relating to medication, indication and procedure being undertaken. Please ensure to check the relevant sections to confirm guidance corroborates.

Back to top

Coronary stents

Stopping dual antiplatelet therapy (DAPT) prior to surgery is associated with an increased incidence of adverse cardiac events. Patients who have had recent percutaneous coronary intervention (PCI) with stenting are at particular risk. A PCI causes damage to the vessel wall and the area is prone to thrombosis - the use of DAPT is important in preventing this. In addition, surgery induces a hypercoagulable state and increases the risk of thrombosis.

Two types of stent are used – bare metal and drug eluting. The choice of stent depends on the calibre of vessel and length of diseased segment stented at PCI. Drug eluting stents (DES) are resurfaced with endothelium more slowly than bare metal stents therefore DAPT is maintained in these patients for a longer period.

The risk of thrombosis after PCI declines over time and depends on the type of stent used. In the initial period after PCI, the risk of adverse coronary events associated with surgery is very high and only urgent surgery should be performed in this time. If the planned surgery is within the high risk period following PCI then the risk of stopping therapy alongside to the risk of continuing therapy has to be taken on by the surgical team.

Defer purely elective surgery for:

  • 1 month after bare metal stent (BMS) insertion*1
  • 12 months after first generation drug eluting stent (DES) insertion
  • 6 months after new generation DES insertion

After this time antiplatelet therapy may be stopped for 7 days prior to operation. There is emerging evidence for withholding of antiplatelet agents between 1 and 6 months following new generation DES insertion, but the reliability of this evidence is to be validated. Therefore, cardiology should be contacted if within this time period and the patient is requiring surgery.

For those patients requiring more urgent surgery, stopping DAPT prior to surgery incurs an increased perioperative risk of cardiovascular complications. In these patients it is recommended that aspirin be continued wherever possible and DAPT be restarted as soon as possible after surgery. The decision to stop DAPT should only be taken after multidisciplinary discussion between pharmacy, cardiology and surgical teams. It is important to:

  • Determine the specific type of stent used
  • Assess the risk of bleeding associated with surgery if antiplatelet therapy is continued
  • Assess the risk of thrombotic complications if antiplatelet therapy is discontinued

See DAPT section below for more information and Appendix A for factors to consider preoperatively

Bridging therapy is not used for antiplatelets at LTHT even for patients at very high risk of thrombotic event (See Appendix A).

For those patients at high risk of thrombosis when stopping one of these agents prior to surgery, switching to aspirin 75mg daily for 7 days pre-operatively may be considered.

Back to top

Vascular indications

Patients taking antiplatelets for vascular indications should ideally not have their treatment interrupted.

For patients taking clopidogrel for vascular indications; this should be stopped and switched to aspirin 75mg once daily 7 days pre-operatively (this is a consensus based approach at Leeds Teaching Hospitals (LTH)).

The only potential exception to this is for patients who are admitted for very high bleed risk surgery as usually even aspirin needs to be stopped pre-operatively. In these cases there should be a discussion with the surgeon to confirm their preference as well as a discussion with the vascular surgeon to confirm it is appropriate to stop antiplatelets for 7 days pre-operatively.

Generally, patients who are prescribed dual antiplatelet therapy following vascular surgery stentings (carotid and lower limb) need to continue DAPT for 6 weeks to 3 months. For elective surgery avoid stopping DAPT within first 6 weeks and have a patient specific discussion with the relevant clinician if stenting less than 3 months ago.

Patients undergoing fistula surgery for dialysis can continue any single agent antiplatelet.

For interventional radiology procedures there is no need to stop aspirin and clopidogrel unless specifically stated in the guideline.

Back to top

Neurology Indications

For patients on antiplatelet treatment following a stroke or TIA the below is advised:

  • Aim for surgeries to be conducted one month after a stroke or TIA.
    • If the stroke or TIA was over one month ago then clopidogrel can be stopped and replaced for the duration of cessation with aspirin 75mg once daily (this is a consensus based approach at LTH).This applies whether the patient has had one or multiple stroke(s)/TIA(s).
      • Note aspirin may be inappropriate to use prior to very high bleed risk procedures, please see aspirin section of guideline.
    • If the surgeon does not want aspirin then clopidogrel should be stopped 7 days prior to procedure. The patient is to be counselled on the need for surgery and the small risk of perioperative stroke while they are off their antiplatelet medication.
  • If within one month of the stroke or TIA and surgery cannot be delayed please discuss the individual case as a MDT between the surgeon, anaesthetist and stroke physician
    • The stroke physician to contact is whoever is on for TIA OR whichever consultant last saw the patient (this may differ to the discharge letter).

Clopidogrel is to be recommenced as soon as deemed appropriate by the surgical team. Stop any aspirin that was commenced in place of clopidogrel prior to surgery.

Back to top


Perioperative continuation of antiplatelet agents may lead to an increase in bleeding complications. Use of low dose aspirin, and P2Y12 receptor antagonists such as clopidogrel, prasugrel and ticagrelor in patients undergoing non-cardiac surgery should be based on the risk of perioperative bleeding and the risk of thrombotic complications.

Back to top


Use of aspirin in the perioperative period should be based on individual assessment of cardiovascular morbidity and bleeding risks. Aspirin prevents myocardial infarction in patients with coronary artery disease. It was thought that the antiplatelet and anti-inflammatory effects of aspirin were probably cardioprotective in the perioperative period. The POISE 2 trial showed the administration of low dose aspirin did not reduce perioperative cardiac morbidity or mortality. Aspirin withdrawal did not increase these risks, but there was an association with an increased incidence of major bleeding where aspirin was continued. Patients who had undergone recent insertion of coronary stents were excluded from the study.
Aspirin should be discontinued if bleeding risk outweighs the potential cardiovascular benefits.

High dose aspirin (>150mg): consider reducing to lower dose for 7 days pre-operatively

Low dose aspirin (≤150mg): continue with none to be taken on day of surgery

Please note in patients undergoing spinal surgery or certain neurosurgical and ophthalmic operations (i.e. those with a very high bleed risk) it is recommended that aspirin is stopped for at least 7 days prior to surgery. Discuss with the surgical speciality if unsure.

Back to top

Restarting Aspirin

Aspirin should be continued post operatively unless stipulated otherwise by the surgical team. If it was stopped pre-operatively restart as soon as clinically appropriate.

Back to top

P2Y12 Receptor Antagonists (Clopidogrel, Prasugrel and Ticagrelor)

P2Y12 receptors can be blocked chemically reducing the overall effect of adenosine diphosphate on platelets, thus reducing coagulation. Currently in use are the oral agents clopidogrel, prasugrel, ticagrelor, and an intravenous agent cangrelor. These agents are commonly used in combination with aspirin.

Back to top

Dual Antiplatelet Therapy

Dual antiplatelet therapy (DAPT) is prescribed for a variety of cardiovascular indications. Patients on DAPT have an increased risk of surgical bleeding compared to patients taking aspirin alone. The literature on surgical bleeding in patients on DAPT is conflicting. The key issue is whether DAPT should be maintained or stopped prior to operation, therefore the perioperative anaesthetic management plan for patients taking DAPT will depend upon:

  1. Whether the patient is to undergo an elective or emergency surgery procedure
  2. Whether the patient would be placed at high risk of thrombotic events from withdrawal of DAPT even for a short time.
  3. Whether the patient is at high risk of bleeding if DAPT is continued perioperatively

The manufacturers of clopidogrel recommend stopping it 7 days before surgery or neuraxial blockade.

The manufacturers of prasugrel recommend stopping 7 days before surgery.

The manufacturers of ticagrelor recommend stopping 5 days prior to surgery; this can sometimes be reduced to stopping 3 days prior to procedure. Stopping 3 days prior to procedure is to be discussed with the patient’s surgical team.

Back to top

DAPT and Neuraxial Block

Neuraxial block is considered high risk in patients with abnormalities of coagulation. The American Society of Regional Anaesthesia, the European Society of Anaesthesiology and the Association of Anaesthetists of Great Britain and Ireland currently recommend that the interval between discontinuation of DAPT and use of epidural or spinal anaesthesia is 7 days for clopidogrel and prasugrel, and 5 days for ticagrelor. Before this time there is probably an increased risk of haematoma formation during invasive anaesthetic procedures, especially neuraxial techniques where the consequences of haematoma formation can lead to serious neurological injury.

Back to top

Acute Surgery

Patients who require emergency or very urgent surgery cannot be delayed to allow time for the effects of DAPT to recover fully. A suitable anaesthetic plan must be chosen. The benefits and risks of different techniques must be analysed as far as is possible according to current evidence and discussed with the patient. Such discussions must be clearly documented in the medical notes.

The decision to delay urgent surgery for antiplatelet therapy to “wear off” will rarely be appropriate and must be made at consultant level by surgeon and anaesthetist. In such patients e.g. elderly with fractured neck of femur, the risks of surgical delay for 7 days are likely to outweigh the risks of proceeding. A decision on the timing of surgery should be made by senior surgical and anaesthetic personnel.

Where emergency surgery is performed in a patient taking antiplatelet agents, platelet function tests and/or thromboeslastography may be considered but have variable accuracy. If the patient bleeds excessively, platelet transfusion may be considered. When feasible and appropriate stop antiplatelet therapy 24hours or more before urgent surgery as this may improve the response to platelet transfusion. Consider the use of antifibrinolytic agents such as tranexamic acid.

Back to top

Restarting DAPT

When DAPT has been stopped prior to surgery it should be restarted again as soon as is practical and safe after surgery. The precise timing should be discussed between the surgical and anaesthetic team. If there is a high risk of postoperative bleeding, restarting DAPT should be delayed until safe to do so. If an epidural catheter is in situ the restarting of DAPT must be discussed with the acute pain team prior to initiation of therapy.

Back to top

Appendix A - Assessing surgical and haemorrhagic risk

What is the precise nature of the planned operation and anaesthetic, and the possible complications?

How high is the perceived haemorrhagic risk?

Are there any other individual haemorrhagic risk factors such as:
Impaired renal function?
Advanced age (>75 years)
Low body weight (<60kg)

What are the consequences of excessive bleeding?

Are there any possible alternatives to surgical treatment?

Assessing thrombotic risk

When was the stent inserted?

What type of stent does the patient have?

How many stents were inserted and where are they located?

What antiplatelet regimen is being followed and what duration of therapy has been recommended?

Does the patient suffer from other associated risk factors for stent thrombosis?


Record: 1186


To assist medical, pharmacy and nursing staff in the perioperative management of patients taking antiplatelet agents.


Give guidance in the perioperative management of antiplatelet agents.

Identify groups of patients at high risk of complications if antiplatelet agents are stopped.

Clinical condition:

Patients taking antiplatelet agents

Target patient group: All patients taking antiplatelet agents
Target professional group(s): Secondary Care Doctors
Secondary Care Nurses
Adapted from:

Evidence base


  1. Baigent C, Blackwell L, Collins R, et al. Aspirin in the primary and secondary prevention of vascular disease: collaborative meta-analysis of individual participant data from randomised trials. Lancet 2009; 373: 1849–60
  2. Fleisher LA, Fleischmann KE, Auerbach AD, et al. 2014 ACC/AHA Guideline on perioperative cardiovascular evaluation and management of patients undergoing noncardiac surgery: executive summary. Journal of the American College of Cardiology 2014; 64: 2373-2405
  3. Valgimigli M, Bueno H, et al. 2017. The Task Force for dual antiplatelet therapy in coronary artery disease of the European Society of Cardiology (ESC) and of the European Association for Cardio-Thoracic Surgery (EACTS). 2017 ESC focused update on dual antiplatelet therapy in coronary artery disease developed in collaboration with EACTS. European Heart Journal. 2018; 39:213-254
  4. Wong SSC, Irwin MG. Peri-operative cardiac protection for non-cardiac surgery. Anaesthesia 2016; 71 (Suppl.1): 29-39
  5. Devereaux PJ, Mrkobrada M, Sessler DI, et al. Aspirin in patients undergoing non-cardiac surgery. New England Journal of Medicine 2014; 370: 1494–503
  6. Kristensen SD, Knuuti J, Saraste A, et al. 2014 ESC/ESA Guidelines on non-cardiac surgery: cardiovascular assessment and management. European Heart Journal 2014; 35: 2383–2431
  7. Rossini R, Musumeci G, Visconti LO et al. Perioperative management of antiplatelet therapy in patients with coronary artery stents undergoing cardiac and non-cardiac surgery: a consensus document from the Italian cardiological, surgical and anaesthesiological societies. EuroIntervention. 2014; 10:38-46
  8. Horlocker T, Wedel D, Rowlingson J et al. Regional Anaesthesia in the patient receiving antithrombotic or thrombolytic therapy: American Society of Regional Anaesthesia and Pain Medicine evidence-based guidelines. Regional Anesthesia and Pain Medicine 2010; 35: 64 – 101
  9. Gogarten W, Vandermeulen E, Van Aken H, et al. Regional anaesthesia and antithrombotic agents: recommendations of the European Society of Anaesthesiology. European Journal of Anaesthesiology 2010; 27: 999–1015
  10. Harrop-Griffiths W, Cook T, Gill H, et al. Regional anaesthesia and patients with abnormalities of coagulation. Anaesthesia 2013; 68: 966-972
  11. Kam P, Nethery C, The thienopyridine derivatives, pharmacology and clinical developments. Anaesthesia 2003; 58: 28-35
  12. Koenig-Oberhuber V, Filipovic M. New antiplatelet drugs and new oral anticoagulants. British Journal of Anaesthesia 2016; 117 (S2): ii74–ii84
  13. Summary of Product Characteristics – Plavix® (clopidogrel). SANOFI. Accessed via 23/082021 [date of revision of the text May 2021]
  14. Summary of Product Characteristics – Brilique® (ticagrelor) 90mg film coated tablets. AstraZeneca UK Limited. Accessed via 10/07/2021 [date of revision of the text May 2021]
  15. Summary of Product Characteristics – Efient® (prasugrel) 10mg film-coated tablets. Daiichi Sanyko UK Limited. Accessed via 18/05/2021 [date of revision of the text December 2021]

Document history

LHP version 5.0

Related information

Appendix A

Assessing patients on antiplatelet agents with coronary stents

Assessing surgical and haemorrhagic risk
What is the precise nature of the planned operation and anaesthetic, and the possible complications?
How high is the perceived haemorrhagic risk?
Are there any other individual haemorrhagic risk factors?
What are the consequences of excessive bleeding?
How necessary is the surgery?
What is the urgency of the surgery—can the surgery be delayed?
Are there any possible alternatives to surgical treatment?

Assessing thrombotic risk
When was the stent inserted?
What type of stent does the patient have?
How many stents were inserted and where are they located?
Was the revascularization complete?
Is there a history of stent thrombosis previously?
What antiplatelet regimen is being followed and what duration of therapy has been recommended?
Does the patient suffer from other associated risk factors for stent thrombosis including:
    Renal impairment?
    Low cardiac ejection fraction?
    Are there any other individual thrombotic risk factors?

Back to top

Equity and Diversity

The Leeds Teaching Hospitals NHS Trust is committed to ensuring that the way that we provide services and the way we recruit and treat staff reflects individual needs, promotes equality and does not discriminate unfairly against any particular individual or group.