Secondary Prevention of Coronary Heart Disease and Stroke - Antiplatelet Guideline

The following patients should have antiplatelet therapy for life (unless they develop an indication for anticoagulation):

Aspirin oral 75mg once daily (dispersible tablet) is the agent of choice (but see separate guidance here for stroke and TIA). Enteric coated aspirin does not reduce gastrointestinal (GI) symptoms. Only if aspirin is contraindicated or the side effects are intolerable (see section below 'Contraindications to aspirin') should clopidogrel oral 75mg once daily be used instead.

Caution with all antiplatelets - ideally blood pressure should be under control (<150/90mmHg) prior to commencing any antiplatelet agent, and certainly systolic <180mmHg.

Combination antiplatelet regimens

Table 1 – Dual antiplatelet therapy (DAPT) regimens

Indication Drug regimens and duration
Thrombotic stroke (also see additional 'Notes' below)
Stable thrombotic stroke or TIA See Secondary Prevention of Stroke and TIA guideline
Peripheral arterial disease
Carotid endarterectomy, carotid artery stenting, peripheral vascular disease or multi-vascular disease As advised by specialist services
ST elevation MI
Usually treated with Primary PCI

Aspirin oral 75mg once daily indefinitely

AND prasugrel oral 10mg once daily (commenced by interventional centre post-PCI)* for 6 months

or clopidogrel oral 75mg once daily (if previous TIA/CVA, at high risk of bleeding (i.e. anaemia or GI bleed), receiving concurrent anticoagulation, severe hepatic impairment or awaiting thrombolysis) for 6 months

*For patients aged ≥75years or <60kg: prasugrel 5mg once daily may be used at consultant cardiologist discretion
Medical management (e.g. late presentation STEMI, not suitable for coronary intervention)

Aspirin oral 75mg once daily indefinitely

AND clopidogrel oral 75mg once daily for 1 month
Non-ST elevation ACS
Medical management +/- PCI

Aspirin oral 75mg once daily indefinitely

AND clopidogrel oral 75mg once daily (if previous TIA/CVA, at high risk of bleeding (i.e. anaemia or GI bleed), receiving concurrent anticoagulation, severe hepatic impairment or awaiting thrombolysis) for 6 months

or prasugrel oral 10mg once daily (commenced by interventional centre post-PCI)* for 6 months

*For patients aged ≥75years or <60kg: prasugrel 5mg once daily may be used at consultant cardiologist discretion
Elective PCI in stable coronary artery disease

Drug-eluting stent

Balloon angioplasty

Aspirin oral 75mg once daily indefinitely

AND clopidogrel oral 75mg once daily for 6 months

Notes

  • If treated at an interventional centre, the duration of DAPT should be as advised by interventional cardiologist.
  • Where there is increased risk of bleeding or a contraindication or intolerance to prasugrel, clopidogrel may be used in combination with aspirin.
  • The duration of dual antiplatelet therapy (DAPT) may be extended at the discretion of the interventional cardiologist depending on the extent of disease. Conversely, shorter durations of DAPT may be used in patients at a higher risk of bleeding.
  • DAPT should be continued for the specified duration, thereafter reverting to lifelong aspirin monotherapy.
  • Coronary artery stents: Do not discontinue DAPT sooner than the recommended durations in Table 1 without prior discussion with the patient's interventional cardiologist. If an invasive procedure is required, and cannot be delayed till end of the DAPT duration, consult the patient's interventional cardiologist/local cardiologist for individual action plan. See guideline on perioperative management of patients on anticoagulants and antiplatelets on AthenA.
  • The duration of dual antiplatelet therapy should be clearly stated on the discharge prescription (if possible a STOP DATE should be included).
  • Antiplatelet agents are not recommended for thrombo-embolic prophylaxis in patients with atrial fibrillation alone, and are not a substitute for oral anticoagulants.

Combination anticoagulants (including warfarin and direct acting oral anticoagulants (DOACs)) with antiplatelet agents

This combination is associated with a significantly higher major haemorrhage complication rate than either agent alone, without offering any proven benefit in reducing ischaemic or thromboembolic events (except in patients with metallic prosthetic heart valves).

Patients on an anticoagulant who develop an indication for an antiplatelet agent (e.g. thrombotic stroke, ACS)

Seek specialist advice

Low thrombosis risk patients (e.g. atrial fibrillation (AF), deep vein thrombosis (DVT) >3 months previously) who develop an indication for dual antiplatelet therapy (e.g. AF patient requiring coronary stent) should stop the anticoagulant or receive triple therapy for as short a time as possible. 

High thrombosis risk patients (e.g. mechanical valves, recent venous thromboembolism) developing an ACS, require specialist advice and should be considered for triple therapy. Duration dependent on individual case basis.

Patients on antiplatelet agents who develop an indication for anticoagulant therapy (e.g. AF, DVT)

In patients with stable vascular disease, on a single antiplatelet agent, this agent should be discontinued for the duration of the anticoagulant therapy.

In patients with unstable vascular disease (e.g. recent ACS or stent) receiving dual antiplatelet therapy, the anticoagulant therapy should be commenced cautiously with close monitoring. Clopidogrel should be used in preference to prasugrel in the context of triple therapy.

It is accepted that some high thrombotic risk patients, with low inherent bleeding risk, may merit short-term triple therapy, however each case should be considered individually with a full risk:benefit assessment.

ACS patients currently on antiplatelet therapy

  • On aspirin monotherapy – add clopidogrel oral 75mg once daily
  • On clopidogrel monotherapy due to aspirin GI intolerance:
    • Add aspirin oral 75mg once daily in combination with a PPI (lansoprazole)
  • On clopidogrel monotherapy due to previous TIA / CVA:
    • Add aspirin oral 75mg once daily
    • Stop aspirin after dual antiplatelet therapy course is complete.
  • On aspirin and clopidogrel after previous ACS admission – continue and consider referral for further coronary intervention

Primary prevention

Routine antiplatelet therapy is not recommended for primary prevention of cardiovascular disease (including in type 2 diabetes). If aspirin 75mg once daily is deemed necessary based on an individual patient basis, the balance of risks and benefits should be considered (e.g. the risk of GI bleeding is higher in those who are frail, with co-morbidities and in those treated with other drugs, such as NSAIDs).

Contraindications to aspirin

These are rare, but include aspirin allergy (aspirin-induced angioedema, asthma or skin rash).

Relative contraindications for all antiplatelet agents (only prescribe on expert advice):

  • Recent GI bleed
  • Proven active peptic ulcer disease
  • Breast feeding
  • Haemophilia or other bleeding disorder

GI symptoms and use of aspirin

  • In patients with a history of bleeding peptic ulcer disease the combination of aspirin + PPI is safer than clopidogrel alone (for secondary prevention).
  • In patients developing GI symptoms after starting aspirin follow the algorithm below.

Patients developing GI symptoms after starting aspirin

Consider other contributory factors e.g.:
  • Excess alcohol intake
  • NSAID use (these may be OTC and not prescribed)
↓

If GI symptoms persist despite modification of contributory factors:

  • Add treatment dose PPI (see Management of Dyspepsia - N.B. use lansoprazole if patient concomitantly on clopidogrel)
  • Enteric coated aspirin does not reduce GI symptoms – not recommended.
↓

Patient complying and GI symptoms still persist?

(This will be a rare event)
↓

Change to clopidogrel oral 75mg once daily (secondary prevention only) and stop PPI.
Guideline reviewed October 2023
Page updated October 2023



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