ST-elevation myocardial infarction

Overview 
Theory 
Diagnosis 
Management 
Follow up 
Resources 

Please note that formulations/routes and doses may differ between drug names and brands, drug formularies, or locations. Treatment recommendations are specific to patient groups: see disclaimer

ACUTE

suspected or clinical diagnosis of STEMI (symptoms of myocardial ischaemia + ST elevation on ECG)

1st line – aspirin

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1st line –

aspirin

Give all patients with suspected STEMI a single loading dose of aspirin as soon as possible, unless they have aspirin hypersensitivity.[2][75]

Aspirin can be given orally (or via nasogastric tube if oral ingestion is not possible). An intravenous loading dose is used in some countries; however, this formulation is not available in the UK.

Check your local protocol or discuss the patient with a senior colleague if they have hypersensitivity to aspirin.

Start treatment for STEMI immediately after making a clinical working diagnosis - do not wait for cardiac troponin levels to confirm it.[2]

After the loading dose, continue with a lower maintenance dose of aspirin as part of ongoing dual antiplatelet therapy unless contraindicated.

Primary options

aspirin: 300 mg orally (chewed or dispersed in water) as a loading dose, followed by 75-100 mg once daily thereafter

Plus – assess eligibility for coronary reperfusion therapy

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Plus –

assess eligibility for coronary reperfusion therapy

Treatment recommended for ALL patients in selected patient group

Immediately assess the patient’s eligibility for coronary reperfusion therapy as soon as a clinical diagnosis of STEMI has been made.[2][75]

If eligible, take steps to ensure coronary reperfusion therapy (primary percutaneous coronary intervention or fibrinolysis) is delivered as quickly as possible. If not eligible, offer conservative medical management.[75]
Do not allow the patient’s age, ethnicity, or sex to influence your assessment of their suitability for reperfusion therapy.[75] Evidence suggests that women tend to receive reperfusion therapy less frequently and/or in a more delayed fashion than men, and are less likely to receive cardiac rehabilitations and secondary prevention medications.[2]

For most patients with STEMI, primary percutaneous coronary intervention (PCI) is the preferred reperfusion strategy provided it can be delivered within 120 minutes of the time when fibrinolysis could have been given.[2][75][81]

Multiple randomised controlled trials have shown that primary PCI has better outcomes (in terms of reducing mortality, reinfarction, or stroke) and less intracranial bleeding than fibrinolysis provided it can be delivered in a timely manner by an experienced team.[2][166][167][168][169][170][171]
However, fibrinolysis may be more appropriate when there is a lack of access to timely PCI.[2][75]

Practical tip

The European Society of Cardiology (ESC) acute coronary syndrome guideline lists the contraindications to fibrinolytic therapy as follows:[2]

Absolute contraindications
- History of intracranial haemorrhage or stroke of unknown origin at any time
- Ischaemic stroke in the last 6 months
- Central nervous system damage, neoplasm, or arteriovenous malformation
- Major trauma/surgery/head injury within the last 1 month
- Gastrointestinal bleeding within the last 1 month
- Bleeding disorder
- Aortic dissection
- Non-compressible punctures within the last 24 hours (e.g., liver biopsy, lumbar puncture)
Relative contraindications
- Transient ischaemic attack in the last 6 months
- Oral anticoagulant therapy
- Pregnancy or within 1 week postnatal
- Refractory hypertension (systolic BP >180 mmHg and/or diastolic BP >110 mmHg)
- Advanced liver disease
- Infective endocarditis
- Active peptic ulcer
- Prolonged or traumatic cardiopulmonary resuscitation.

If primary PCI is not available within 120 minutes but your patient has a contraindication to fibrinolysis:

Seek immediate advice from the interventional cardiology team
For a patient with an absolute contraindication to fibrinolysis, primary PCI will normally be the preferred management strategy despite the delay in accessing it.

Seek immediate specialist input from the interventional cardiology team.[2]

If you are managing the patient within a PCI-capable hospital, this team will be available on site. If not, call the interventional cardiology team at your designated PCI-capable hospital to discuss immediate transfer for coronary reperfusion therapy.
Also take the earliest opportunity to gain intravenous access and start continuous haemodynamic monitoring and pulse oximetry.[2]

Practical tip

When placing an intravenous cannula, avoid placing it in the right hand or right wrist area as the right radial artery is the usual route used to perform primary PCI.

Concurrent anticoagulation and dual antiplatelet therapy is given alongside coronary reperfusion, regardless of whether primary PCI or fibrinolysis is used. The benefits of reperfusion in reducing mortality and improving myocardial salvage decline rapidly with time.[2][75]

It is, therefore, vital to take every step possible to ensure the chosen reperfusion strategy (primary PCI or fibrinolysis) is delivered as quickly as possible.

Practical tip

Do not give anticoagulation therapy if the patient is likely to be eligible for primary PCI.[2][71]

This will be given by the interventional cardiology team in the cardiac catheterisation laboratory.

The ESC acute coronary syndrome guideline has set widely accepted maximum time-to-treatment targets as follows:[2]

Interval	Target
First medical contact to ECG and STEMI diagnosis	<10 minutes
STEMI diagnosis to primary PCI	<120 minutes If this time target cannot be met, consider fibrinolysis
STEMI diagnosis to primary PCI if the patient’s first medical contact is at a hospital	<60 minutes if the patient presents to or is in a PCI-capable hospital <90 minutes if the patient presents to or is in a non-PCI-capable hospital and needs transferring
STEMI diagnosis to administration of a bolus/infusion of a fibrinolytic drug (if primary PCI cannot be accessed within 120 minutes)	<10 minutes
Start of fibrinolysis to ECG assessment of its success or failure	60-90 minutes
If fibrinolysis is successful, time interval from starting fibrinolysis to early coronary angiography	2-24 hours

The most appropriate coronary reperfusion strategy will depend on:[2][71][74]

Duration of ischaemic symptoms
Persistence or resolution of ST-segment elevation on serial ECGs
Availability of timely access to primary PCI
- Whether a patient is first assessed in a PCI-capable or non-PCI-capable hospital
- Estimated transfer time from a non-PCI-capable to a PCI-capable hospital
Whether there was a pre-hospital STEMI diagnosis made by trained and fully equipped paramedic team who can administer initial pharmacotherapy
The quality and expertise of the regional network infrastructure in place for STEMI management.

Many patients who present with STEMI are already taking long-term oral anticoagulation for various indications.[2]

This is a relative contraindication for fibrinolysis.
For any such patient, choose a primary PCI strategy for coronary reperfusion therapy, regardless of the anticipated time to access this intervention.[2]

More info: Summary flowchart – choice of coronary reperfusion strategy

The flowchart below summarises the choice of coronary reperfusion strategy according to time since the patient’s symptom onset and the anticipated time to access primary PCI.[2][75]

[Figure caption and citation for the preceding image starts]: Selection of the most appropriate reperfusion strategy. PPCI, primary percutaneous coronary interventionCreated by the BMJ Knowledge Centre [Citation ends].

Plus – analgesia

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Plus –

analgesia

Treatment recommended for ALL patients in selected patient group

Give pain relief.[2][82]

Titrated intravenous opioids (e.g., morphine or diamorphine) are the most commonly used option for analgesia.
Pain relief is important not just for the comfort of the patient but also because it may reduce myocardial and microvascular damage due to reduction of heart rate, cardiac workload, and oxygen consumption.[2]

Primary options

morphine sulfate: 2.5 to 10 mg intravenously initially, followed by 2.5 to 10 mg if required (at a rate of 1-2 mg/minute)

diamorphine: 2.5 to 5 mg intravenously initially, followed by 1.25 to 5 mg if required (at a rate of 1-2 mg/minute)

Plus – anti-emetic

Consider – oxygen

Consider – intravenous nitrate

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Consider –

intravenous nitrate

Additional treatment recommended for SOME patients in selected patient group

Routine use of an intravenous nitrate in STEMI is not recommended as there is no evidence to support its benefits.[2]

In practice, a sublingual (or buccal) dose is often given after a STEMI diagnosis has been made (and sometimes before the patient arrives at hospital).

Practical tip

If your patient experiences a spontaneous resolution of ST-segment elevation, along with complete symptom relief, after taking glyceryl trinitrate, this is suggestive of coronary spasm with or without associated MI.[2]

Refer to cardiology.
Aim for early coronary angiography (within 24 hours).

Consider an intravenous nitrate if the patient has:[2][82]

Sustained hypertension
Clinical and/or radiographic evidence of congestive heart failure
Persistent chest pain (residual angina) despite administration of sublingual (or buccal) glyceryl trinitrate (which the patient may have received before arriving at hospital).

Titrate the rate of infusion according to the patient’s blood pressure and wider clinical response.

Do not give an intravenous nitrate when there is hypotension or right ventricular infarction.

Practical tip

Administration of intravenous nitrate should not delay transfer to the catheterisation laboratory.

An intravenous nitrate can be given in the catheterisation laboratory by the interventional cardiology team, if needed.
Recanalisation of the occluded infarct artery is the most effective way of relieving refractory chest pain so the priority is to get the patient to primary percutaneous coronary intervention as quickly as possible.

Primary options

glyceryl trinitrate: 15-20 micrograms/minute intravenous infusion initially, adjust dose according to response, maximum 400 micrograms/minute

isosorbide dinitrate: 2-10 mg/hour intravenous infusion initially, adjust dose according to response, maximum 20 mg/hour

<12 hours since symptom onset: primary PCI available within 120 minutes

Plus – primary PCI

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Plus –

primary PCI

Treatment recommended for ALL patients in selected patient group

Select primary percutaneous coronary intervention (PCI) as the preferred reperfusion strategy for any patient who had symptom onset <12 hours ago and has:[2][75][81][166][167][168][169][172]

Ongoing signs and symptoms of myocardial ischaemia, AND
Persistent (or increasing) ST-segment elevation on ECG.

Take steps to ensure that primary PCI will be delivered within 120 minutes of the time when fibrinolysis could have been given.[75][81]

Primary PCI involves immediate transfer to the catheterisation laboratory with the intention of opening the artery with stent placement. Drug-eluting stents are recommended by the European Society of Cardiology and the UK National Institute for Health and Care Excellence.[2][75] [ ] [ ]

Many hospitals have round-the-clock PCI capability. If yours does not, then arrange immediate transfer to your designated PCI-capable hospital.
If it is not possible to ensure primary PCI within 120 minutes, offer fibrinolysis (if not contraindicated).[75]
If your patient has STEMI with cardiogenic shock, seek urgent senior support. Coronary angiography ± primary PCI is indicated.[2][75]
If the patient’s coronary anatomy is unsuitable for PCI, or PCI fails, emergency coronary artery bypass graft ( CABG) is recommended.[2]
For more information on supportive management, see Shock.

Plus – P2Y12 inhibitor

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Plus –

P2Y12 inhibitor

Treatment recommended for ALL patients in selected patient group

Give any patient who will undergo primary percutaneous coronary intervention (PCI) dual antiplatelet therapy with a P2Y₁₂ inhibitor plus aspirin .[75]

After the initial aspirin loading dose, reduce the aspirin to a lower daily maintenance dose.
Check your local protocol when deciding which P2Y₁₂ inhibitor to use, the timing of this and the recommended initial loading and ongoing daily doses.

The UK National Institute for Health and Care Excellence (NICE) recommends the following for any patient undergoing PCI:[75]

Prasugrel, in combination with aspirin, if the patient is not already taking an oral anticoagulant
- For patients aged 75 years and older, the bleeding risk of using prasugrel needs to be weighed up against its effectiveness. If the bleeding risk from prasugrel is a concern in these patients, ticagrelor or clopidogrel may be used as alternatives.
Clopidogrel, in combination with aspirin, if the patient is already taking an oral anticoagulant.

The European Society of Cardiology guideline recommends prasugrel or ticagrelor (in combination with aspirin) for patients undergoing primary PCI. Prasugrel should be considered in preference to ticagrelor, but clopidogrel is only indicated when neither of these drugs is available or they are contraindicated.[2]

Cangrelor is a reversible intravenous P2Y₁₂ inhibitor that can be considered if the patient is unable to ingest an oral drug.[2] NICE has yet to make any recommendation on the use of cangrelor.

Always follow your local protocol for P2Y₁₂ inhibitor selection and timing.

Primary options

prasugrel: <75 years of age and body weight <60 kg: 60 mg orally as a loading dose, followed by 5 mg once daily thereafter; <75 years of age and body weight ≥60 kg: 60 mg orally as a loading dose, followed by 10 mg once daily thereafter; ≥75 years of age: 60 mg orally as a loading dose, followed by 5 mg once daily thereafter

clopidogrel: <75 years of age: 300-600 mg orally as a loading dose, followed by 75 mg once daily thereafter; ≥75 years of age: 75 mg orally once daily

The licensed loading dose in the UK is 300 mg. The ESC guideline recommends a higher loading dose of 600 mg for patients proceeding to PCI. While this higher dose is not licensed in the UK, it is widely used in practice.[2]

ticagrelor: 180 mg orally as a loading dose, followed by 90 mg twice daily thereafter

Plus – parenteral anticoagulation

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Plus –

parenteral anticoagulation

Treatment recommended for ALL patients in selected patient group

Anticoagulation is routinely given during primary percutaneous coronary intervention (PCI).

This will be started by the interventional cardiology team in the cardiac catheterisation laboratory.
- Therefore, do not start anticoagulation if your patient is likely to be eligible for primary PCI.

Unfractionated heparin is recommended first line for intravenous anticoagulation.[2][75] Alternatives include:

Bivalirudin (a direct thrombin inhibitor) for patients with a history of heparin-induced thrombocytopenia
Enoxaparin.

Fondaparinux is not recommended as an adjunctive anticoagulant during primary PCI.[2]

It was associated with catheter thrombosis at the time of primary PCI in the OASIS-6 trial.[188]

Routine post-procedural anticoagulation is not required after primary PCI unless there is a separate indication for it, for example:[2]

Full-dose anticoagulation:
- Atrial fibrillation
- Mechanical heart valve
- Left ventricular thrombus
Prophylactic-dose anticoagulation:
- Patients at high risk of venous thromboembolism
Consult local protocols for full- and prophylactic-dose regimens for these indications. The doses presented here are the doses used during primary PCI only.

Primary options

heparin: no glycoprotein IIb/IIIa inhibitor use planned: 70-100 units/kg intravenous bolus; glycoprotein IIb/IIIa inhibitor use planned: 50-70 units/kg intravenous bolus

enoxaparin: 0.5 mg/kg intravenous bolus

bivalirudin: 0.75 mg/kg intravenous bolus initially, followed by 1.75 mg/kg/hour intravenous infusion during procedure and for up to 4 hours after procedure, reduce to 0.25 mg/kg/hour for a further 4-12 hours if necessary

Consider – glycoprotein IIb/IIIa inhibitor

<12 hours since symptom onset: primary PCI NOT available within 120 minutes of the time when fibrinolysis could be given AND patient is eligible for fibrinolysis

Plus – fibrinolysis

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Plus –

fibrinolysis

Treatment recommended for ALL patients in selected patient group

Give fibrinolysis (unless contraindicated) if primary percutaneous coronary intervention (PCI) cannot be delivered within 120 minutes of the time when fibrinolysis could be given.[75][81]

Start anticoagulation at the same time as giving fibrinolysis and start dual antiplatelet therapy immediately afterwards.[2][71][75]

Check your local protocols regarding the choice of fibrinolytic drug.

The UK National Institute for Health and Care Excellence recommends a fibrin-specific drug such as alteplase or tenecteplase.[152] It also recommends streptokinase (a non-fibrin-specific drug) as an option in some patients.[152]
The European Society of Cardiology (ESC) guideline recommends the same fibrin-specific drugs plus reteplase (no longer available in the UK).[2] According to these guidelines, consider a half-dose of tenecteplase if the patient is aged 75 years or older.[2]
When choosing a fibrinolytic drug take account of:[152]
- Balancing the benefit and harm (e.g., stroke risk) of each drug for the individual patient
- The importance of avoiding giving streptokinase to a patient who has received it in the past (patients treated with streptokinase may develop antibodies that neutralise the drug if repeat treatment is given)
- Your local hospital protocol for reducing delays in the administration of thrombolysis.

To shorten the time to treatment, fibrinolysis can be administered as part of the pre-hospital management of STEMI.[2][152]

This may be part of the emergency care treatment pathway where geographical considerations mean the anticipated time to primary PCI will be >120 minutes.
In such cases, a bolus dose of tenecteplase ( or reteplase if available) is preferred for the sake of practicality as the other fibrinolytic drug options are administered by intravenous infusion.

If your patient is not already at a PCI-capable hospital, transfer them to one immediately after giving fibrinolysis.[2]

This is so that rescue PCI can be performed if fibrinolysis fails or angiography ± PCI can be arranged if fibrinolysis is effective.

If primary PCI cannot be delivered within 120 minutes of STEMI diagnosis, seek a specialist cardiology opinion to support your choice of reperfusion strategy.[2][71][153]

The greatest benefit of fibrinolysis is observed when given <2 hours after symptom onset. Its clinical efficacy diminishes as time from symptom onset increases.[72][154]
Therefore, the later the patient presents (particularly >2-3 hours), the more consideration should be given to transferring for primary PCI instead – discuss the options with cardiology.[2][74]

Practical tip

The ESC acute coronary syndrome guideline lists the contraindications to fibrinolytic therapy as follows:[2]

Absolute contraindications
- History of intracranial haemorrhage or stroke of unknown origin at any time
- Ischaemic stroke in the last 6 months
- Central nervous system damage, neoplasm, or arteriovenous malformation
- Major trauma/surgery/head injury within the last 1 month
- Gastrointestinal bleeding within the last 1 month
- Bleeding disorder
- Aortic dissection
- Non-compressible punctures within the last 24 hours (e.g., liver biopsy, lumbar puncture)
Relative contraindications
- Transient ischaemic attack in the last 6 months
- Oral anticoagulant therapy
- Pregnancy or within 1 week postnatal
- Refractory hypertension (systolic BP >180 mmHg and/or diastolic BP >110 mmHg)
- Advanced liver disease
- Infective endocarditis
- Active peptic ulcer
- Prolonged or traumatic cardiopulmonary resuscitation.

Evidence: Role of fibrinolysis in STEMI

Fibrinolytic therapy remains an important evidence-based intervention in settings where primary PCI cannot be offered in a timely manner.

Several landmark studies demonstrated the benefits of fibrinolysis in patients with STEMI (prior to the advent of primary PCI).

The 1988 Second International Study of Infarct Survival (ISIS-2) proved that the benefits of aspirin and fibrinolytics (e.g. streptokinase) were additive and associated with improved 10-year survival following acute MI.[178]
The Fibrinolytic Therapy Trialists’ Collaborative Group (1994) demonstrated highly significant benefits in saving lives and helped to establish the time window when fibrinolytic therapy is most effective.[154]
- The study demonstrated highly significant absolute mortality reductions from fibrinolysis of about:
  - 30 per 1000 for those presenting within 0-6 hours of symptom onset
  - 20 per 1000 for those presenting 7-12 hours after symptom onset.
- There was a statistically uncertain benefit of about 10 per 1000 for those presenting at 13-18 hours (with more randomised evidence needed in this group to assess reliably the net effects of treatment).
The 1993 GUSTO trial compared different fibrinolysis strategies.[179][180]
- It demonstrated a benefit of 14% reduction in mortality (95% CI, 5.9% to 21.3%) for accelerated tissue plasminogen activator (t-PA) versus streptokinase (the standard fibrinolytic treatment at the time). Alteplase (recombinant t-PA) was used in the trial.
- The trial randomly assigned 41,021 patients with evolving acute MI to 4 different fibrinolytic strategies. The data for the primary end point of 30-day mortality for each treatment arm was as follows:
  - Streptokinase plus subcutaneous heparin = 7.2%
  - Streptokinase plus intravenous heparin = 7.4%
  - t-PA plus intravenous heparin = 6.3%
  - Streptokinase plus t-PA plus intravenous heparin = 7.0%.
- A significant excess of haemorrhagic strokes was observed for accelerated t-PA (P = 0.03) and for the combination strategy (P <0.001), as compared with streptokinase only.

The 2013 STREAM trial provided further support for fibrinolysis as an appropriate reperfusion strategy for STEMI when primary PCI cannot be delivered in a timely manner – especially if followed by routine early angiography ± PCI (a 'pharmaco-invasive strategy').[171]

The STREAM trial was conducted at a time when primary PCI was established as the standard of care for STEMI.
In the trial, 1892 STEMI patients presenting within 3 hours of symptom onset but unable to have primary PCI within 1 hour were randomly assigned to:
- Primary PCI or
- Pre-hospital bolus tenecteplase (with a half-dose used in patients ≥75 years) plus clopidogrel plus enoxaparin before transport to a PCI-capable hospital
  - Patients had emergency angiography if fibrinolysis failed
  - If fibrinolysis was successful, patients had routine angiography within 6-24 hours after randomisation.
There was no significant difference between the primary PCI and fibrinolysis groups in the primary composite end point of death, shock, congestive heart failure, or reinfarction within 30 days.
- More intracranial haemorrhages occurred in the fibrinolysis group.
The ESC guideline recommendation is that fibrinolysis should be given within 10 minutes of STEMI diagnosis.[2]

The extent to which the delay-to-PCI time diminishes the advantages of primary PCI over fibrinolysis has been widely debated and more research is needed.[2]

It is clear that if delay to treatment is similar, primary PCI is superior to fibrinolysis in reducing mortality, reinfarction, or stroke.[2]
- However, fibrinolysis can be administered expeditiously and the longer the delay to primary PCI, the lower the benefits over fibrinolysis. The exact cut-off point at which the delay to access PCI makes fibrinolysis the better reperfusion strategy is based on weak evidence.

Multivariate meta-analyses provide further evidence to support a pharmaco-invasive strategy, suggesting it is safer and more effective than facilitated PCI or fibrinolysis, where primary PCI is not available in a timely fashion.[181]

Primary options

tenecteplase: body weight <60 kg: 30 mg (6000 units) intravenous bolus as a single dose; body weight 60 to <70 kg: 35 mg (7000 units) intravenous bolus as a single dose; body weight 70 to <80 kg: 40 mg (8000 units) intravenous bolus as a single dose; body weight 80 to <90 kg: 45 mg (9000 units) intravenous bolus as a single dose; body weight ≥90 kg: 50 mg (10,000 units) intravenous bolus as a single dose

alteplase: accelerated regimen (if started within 6 hours of symptom onset): 15 mg intravenous bolus, followed by 0.75 mg/kg (maximum 50 mg/dose) intravenous infusion over 30 minutes, then 0.5 mg/kg (maximum 35 mg/dose) intravenous infusion over 60 minutes, maximum 100 mg total dose over 90 minutes; regular regimen (if started within 6-12 hours of symptom onset): 10 mg intravenous bolus, followed by 50 mg intravenous infusion over 60 minutes, then 10 mg intravenous infusion over 30 minutes for four infusions, maximum 100 mg total dose over 3 hours and maximum 1.5 mg/kg in patients with body weight <65 kg

The ESC guideline recommends the accelerated regimen as the preferred regimen.[2]

Secondary options

streptokinase: 1.5 million units intravenous infusion given over 30-60 minutes

Drug choice, dose and interactions may be affected by the patient's comorbidities. Check your local drug formulary.

Show drug information for a patient with no comorbidities

Primary options

tenecteplase

alteplase

Secondary options

streptokinase

Plus – parenteral anticoagulation

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Plus –

parenteral anticoagulation

Treatment recommended for ALL patients in selected patient group

Start anticoagulation at the same time as fibrinolysis.[2][71][75]

The choice of parenteral anticoagulation can be any one of:[2]

Enoxaparin – the European Society of Cardiology (ESC) guideline recommends this as the first-choice anticoagulant for patients undergoing fibrinolysis[2][189][190][191]
Unfractionated heparin – a weight-adjusted intravenous bolus followed by an intravenous infusion, recommended by ESC when enoxaparin is not available
Fondaparinux (only if streptokinase is used for fibrinolysis) – an intravenous dose initially, followed by the first subcutaneous dose given 24 hours later.[192]

Ensure anticoagulation for any patient undergoing fibrinolysis continues:[2][71]

Up to the point of coronary revascularisation with percutaneous coronary intervention (if performed), or
For the duration of hospital stay to a maximum of 8 days in total if revascularisation is not performed.[2]

Primary options

enoxaparin: <75 years of age: 30 mg intravenous bolus, followed by 1 mg/kg subcutaneously every 12 hours until revascularisation or hospital discharge for up to 8 days, maximum 100 mg/dose for each of the first 2 subcutaneous doses; ≥75 years of age: 0.75 mg/kg subcutaneously every 12 hours until revascularisation or hospital discharge for up to 8 days, maximum 75 mg/dose for each of the first 2 subcutaneous doses

heparin: 60 units/kg (maximum 4000 units) intravenous bolus, followed by 12 units/kg/hour (maximum 1000 units/hour) intravenous infusion for 24-48 hours; adjust dose according to aPTT

Secondary options

fondaparinux: 2.5 mg intravenously once daily on the first day, followed by 2.5 mg subcutaneously once daily for up to 8 days (or hospital discharge if sooner)

Plus – P2Y12 inhibitor

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Plus –

P2Y12 inhibitor

Treatment recommended for ALL patients in selected patient group

Give the patient dual antiplatelet therapy with a P2Y₁₂ inhibitor plus aspirin immediately after giving fibrinolysis.[75]

After the initial aspirin loading dose, reduce the aspirin to a lower daily maintenance dose.
Check your local protocol when deciding which P2Y₁₂ inhibitor to use, the timing of this and the recommended initial loading and ongoing daily doses.

The UK National Institute for Health and Care Excellence recommends the following:[75]

Ticagrelor, in combination with aspirin, unless the patient has a high bleeding risk
Clopidogrel, in combination with aspirin, or aspirin alone for patients with a high bleeding risk.

The European Society of Cardiology guideline recommends clopidogrel (in combination with aspirin) as the preferred agent.[2]

Primary options

ticagrelor: 180 mg orally as a loading dose, followed by 90 mg twice daily thereafter

clopidogrel: <75 years of age: 300 mg orally as a loading dose, followed by 75 mg once daily thereafter; ≥75 years of age: 75 mg orally once daily

Plus – angiography with or without PCI

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Plus –

angiography with or without PCI

Treatment recommended for ALL patients in selected patient group

Use an ECG 60-90 minutes after administering fibrinolysis to assess whether it has been successful.[2][75]

If fibrinolysis has failed (<50% ST-segment resolution at 60-90 minutes), offer immediate coronary angiography, with follow-on percutaneous coronary intervention (PCI) if indicated.[2][75] Do not repeat fibrinolytic therapy.[2][75]

If the patient has recurrent myocardial ischaemia after fibrinolysis, seek immediate specialist advice from cardiology. PCI may be indicated.[75]

If fibrinolysis is successful, consider angiography during the same hospital admission for patients who are clinically stable.[75]

The European Society of Cardiology (ESC) guidelines recommend arranging angiography ± PCI of the infarct-related artery within 2-24 hours.[2]
Several randomised trials and two meta-analyses have shown that early routine angiography (with PCI if needed) after fibrinolysis reduces the rate of reinfarction and recurrent ischaemia compared with a watchful waiting strategy. The benefits of early routine PCI following fibrinolysis were seen across patient subgroups and without any increased risk of adverse events such as stroke or major bleeding.[173][174][175]

The ESC guideline recommends immediate rescue PCI if, at any time following fibrinolysis, the patient develops haemodynamic or electrical instability, worsening ischaemia, or persistent chest pain.[2]

Emergency angiography ± PCI is recommended if, at any time following fibrinolysis, the patient has:

Heart failure or cardiogenic shock[2]
Recurrent ischaemia or evidence of re-occlusion after initially successful fibrinolysis.[2][176][177]

<12 hours since symptom onset: primary PCI NOT available within 120 minutes AND patient has absolute contraindication to fibrinolysis

Plus – consult interventional cardiology team to discuss primary PCI

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Plus –

consult interventional cardiology team to discuss primary PCI

Treatment recommended for ALL patients in selected patient group

If primary percutaneous coronary intervention (PCI) is not available within 120 minutes but your patient has a contraindication to fibrinolysis:

Seek immediate advice from the interventional cardiology team
For a patient with an absolute contraindication to fibrinolysis, primary PCI will normally be the preferred management strategy despite the delay in accessing it.

Practical tip

The European Society of Cardiology acute coronary syndrome guideline lists the contraindications to fibrinolytic therapy as follows:[2]

Absolute contraindications
- History of intracranial haemorrhage or stroke of unknown origin at any time
- Ischaemic stroke in the last 6 months
- Central nervous system damage, neoplasm, or arteriovenous malformation
- Major trauma/surgery/head injury within the last 1 month
- Gastrointestinal bleeding within the last 1 month
- Bleeding disorder
- Aortic dissection
- Non-compressible punctures within the last 24 hours (e.g., liver biopsy, lumbar puncture)
Relative contraindications
- Transient ischaemic attack in the last 6 months
- Oral anticoagulant therapy
- Pregnancy or within 1 week postnatal
- Refractory hypertension (systolic BP >180 mmHg and/or diastolic BP >110 mmHg)
- Advanced liver disease
- Infective endocarditis
- Active peptic ulcer
- Prolonged or traumatic cardiopulmonary resuscitation.

If primary PCI is undertaken, the interventional cardiology team will start parenteral anticoagulation in the catheterisation laboratory.

Arrange echocardiography assessment of left ventricular ejection fraction for all STEMI patients.[75]

Plus – P2Y12 inhibitor

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Plus –

P2Y12 inhibitor

Treatment recommended for ALL patients in selected patient group

Give the patient dual antiplatelet therapy with a P2Y₁₂ inhibitor plus aspirin .[75]

After the initial aspirin loading dose, reduce the aspirin to a lower daily maintenance dose.
Check your local protocol when deciding which P2Y₁₂ inhibitor to use, the timing of this and the recommended initial loading and ongoing daily doses.

The UK National Institute for Health and Care Excellence (NICE) recommends the following:[75]

If the patient is eligible for primary percutaneous coronary intervention (PCI):
- Prasugrel, in combination with aspirin, if they are not already taking an oral anticoagulant
  - For patients aged 75 years and older, the bleeding risk of using prasugrel needs to be weighed up against its effectiveness. If the bleeding risk from prasugrel is a concern in these patients, ticagrelor or clopidogrel may be used as alternatives.
- Clopidogrel, in combination with aspirin, if they are taking an oral anticoagulant.
If the patient is not having primary PCI:
- Ticagrelor, in combination with aspirin, unless the patient has a high bleeding risk
- Clopidogrel, in combination with aspirin, or aspirin alone, for patients with a high bleeding risk.

Cangrelor is a reversible intravenous P2Y₁₂ inhibitor that can be considered if the patient is unable to ingest an oral drug.[2] NICE has yet to make any recommendation on the use of cangrelor.

Always follow your local protocol for P2Y₁₂ inhibitor selection and timing.

Primary options

clopidogrel: <75 years of age: 300-600 mg orally as a loading dose, followed by 75 mg once daily thereafter; ≥75 years of age: 75 mg orally once daily

ticagrelor: 180 mg orally as a loading dose, followed by 90 mg twice daily thereafter

>12 hours since symptom onset: with ongoing evidence of myocardial ischaemia (symptoms and/or signs on ECG)

Plus – primary PCI

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Plus –

primary PCI

Treatment recommended for ALL patients in selected patient group

Seek immediate specialist advice from cardiology to discuss management options for any STEMI patient who presents >12 hours after symptom onset.

Coronary angiography ± primary percutaneous coronary intervention (PCI) is recommended if there is:
- Evidence of continuing myocardial ischaemia or cardiogenic shock[75]
- Haemodynamic instability or life-threatening arrhythmias.[2]

If your patient has ongoing ischaemic symptoms suggestive of MI but no ongoing ST-segment elevation on the ECG, primary PCI should be considered if one or more of the following is present:[2]

Cardiogenic shock or haemodynamic instability
Acute heart failure presumed secondary to ongoing myocardial ischaemia
Recurrent or refractory chest pain despite medical treatment
Cardiac arrest or life-threatening arrhythmia
Signs and symptoms suggestive of mechanical complications of acute MI
Recurrent dynamic ST-segment or T-wave changes, especially intermittent ST-segment elevation.

Plus – P2Y12 inhibitor

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Plus –

P2Y12 inhibitor

Treatment recommended for ALL patients in selected patient group

Give any patient who will undergo primary percutaneous coronary intervention (PCI) dual antiplatelet therapy with a P2Y₁₂ inhibitor plus aspirin .[75]

After the initial aspirin loading dose, reduce the aspirin to a lower daily maintenance dose.
Check your local protocol when deciding which P2Y₁₂ inhibitor to use, the timing of this and the recommended initial loading and ongoing daily doses.

The UK National Institute for Health and Care Excellence (NICE) recommends the following for any patient undergoing PCI:[75]

Prasugrel, in combination with aspirin, if they are not already taking an oral anticoagulant
- For patients aged 75 years and older, the bleeding risk of using prasugrel needs to be weighed up against its effectiveness. If the bleeding risk from prasugrel is a concern in these patients, ticagrelor or clopidogrel may be used as alternatives.
Clopidogrel, in combination with aspirin, if the patient is taking an oral anticoagulant.

The European Society of Cardiology recommends prasugrel or ticagrelor (in combination with aspirin) for patients undergoing primary PCI. Prasugrel should be considered in preference to ticagrelor, but clopidogrel is only indicated when neither of these drugs is available or they are contraindicated.[2]

Cangrelor is a reversible intravenous P2Y₁₂ inhibitor that can be considered if the patient is unable to ingest an oral drug.[2] NICE has yet to make any recommendation on the use of cangrelor.

Always follow your local protocol for P2Y₁₂ inhibitor selection and timing.

Primary options

clopidogrel: <75 years of age: 300-600 mg orally as a loading dose, followed by 75 mg once daily thereafter; ≥75 years of age: 75 mg orally once daily

ticagrelor: 180 mg orally as a loading dose, followed by 90 mg twice daily thereafter

Plus – parenteral anticoagulation

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Plus –

parenteral anticoagulation

Treatment recommended for ALL patients in selected patient group

Anticoagulation is routinely given during primary percutaneous coronary intervention (PCI).

This will be started by the interventional cardiology team in the cardiac catheterisation laboratory.
- Therefore, do not start anticoagulation if your patient is likely to be eligible for primary PCI.

Unfractionated heparin is recommended first line for intravenous anticoagulation.[2][75] Alternatives include:

Bivalirudin (a direct thrombin inhibitor) for patients with a history of heparin-induced thrombocytopenia
Enoxaparin.

Fondaparinux is not recommended as an adjunctive anticoagulant during primary PCI.[2]

It was associated with catheter thrombosis at the time of primary PCI in the OASIS-6 trial.[188]

Routine post-procedural anticoagulation is not required after primary PCI unless there is a separate indication for it, for example:[2]

Full-dose anticoagulation:
- Atrial fibrillation
- Mechanical heart valve
- Left ventricular thrombus
Prophylactic-dose anticoagulation:
- Patients at high risk of venous thromboembolism
Consult local protocols for full- and prophylactic-dose regimens for these indications. The doses presented here are the doses used during primary PCI only.

Primary options

heparin: no glycoprotein IIb/IIIa inhibitor use planned: 70-100 units/kg intravenous bolus; glycoprotein IIb/IIIa inhibitor use planned: 50-70 units/kg intravenous bolus

enoxaparin: 0.5 mg/kg intravenous bolus

Consider – glycoprotein IIb/IIIa inhibitor

>12 hours since symptom onset: no ongoing evidence of myocardial ischaemia (no symptoms and/or signs on ECG)

Plus – seek immediate cardiology advice to discuss management options

Plus – P2Y12 inhibitor

Back

Plus –

P2Y12 inhibitor

Treatment recommended for ALL patients in selected patient group

Give the patient dual antiplatelet therapy with a P2Y₁₂ inhibitor plus aspirin .[75]

After the initial aspirin loading dose, reduce the aspirin to a lower daily maintenance dose.
Check your local protocol when deciding which P2Y₁₂ inhibitor to use, the timing of this and the recommended initial loading and ongoing daily doses.

The UK National Institute for Health and Care Excellence (NICE) recommends the following:[75]

If the patient is eligible for primary percutaneous coronary intervention (PCI):
- Prasugrel, in combination with aspirin, if they are not already taking an oral anticoagulant
  - For patients aged 75 years and older, the bleeding risk of using prasugrel needs to be weighed up against its effectiveness. If the bleeding risk from prasugrel is a concern in these patients, ticagrelor or clopidogrel may be used as alternatives.
- Clopidogrel, in combination with aspirin, if the patient is taking an oral anticoagulant.
If the patient is not having primary PCI:
- Ticagrelor, in combination with aspirin, unless the patient has a high bleeding risk
- Clopidogrel, in combination with aspirin, or aspirin alone, for patients with a high bleeding risk.

The European Society of Cardiology guideline recommends clopidogrel (in combination with aspirin) as the preferred agent.[2]

Primary options

clopidogrel: <75 years of age: 300-600 mg orally as a loading dose, followed by 75 mg once daily thereafter; ≥75 years of age: 75 mg orally once daily

ticagrelor: 180 mg orally as a loading dose, followed by 90 mg twice daily thereafter

ONGOING

post-STEMI

1st line – continue dual antiplatelet therapy

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1st line –

continue dual antiplatelet therapy

Ensure all patients are given dual antiplatelet therapy with aspirin and a P2Y₁₂ inhibitor (while taking into account any contraindications; seek specialist advice if the patient has a separate indication for anticoagulation. See more info panel below).[75]

Continue the P2Y₁₂ inhibitor used in the acute phase for up to 12 months (unless contraindicated).[75] The National Institute for Health and Care Excellence (NICE) in the UK recommends:[75]

For patients who had undergone percutaneous coronary intervention (PCI):
- Prasugrel in those not taking an oral anticoagulant. However, follow your local protocol. At present, many hospitals in the UK use ticagrelor rather than prasugrel in these patients. This new guidance by NICE will require a change in current practice in the UK. Consider ticagrelor or clopidogrel in patients aged 75 years or older if the bleeding risk from prasugrel is a concern
- Clopidogrel in those taking an oral anticoagulant.
For patients who had fibrinolysis:
- Ticagrelor unless the patient has a high bleeding risk
- Clopidogrel or aspirin alone if the patient has a high bleeding risk.

The European Society of Cardiology recommends 12 months of dual antiplatelet therapy as the default strategy, although alternate regimes can be considered in certain circumstances depending on bleeding and ischaemic risks:[2][195]

Single antiplatelet therapy (preferably with a P2Y₁₂ receptor inhibitor, e.g., ticagrelor) for patients who are event-free after 3-6 months of dual antiplatelet therapy and who are not high ischaemic risk[196][197][198][199][200][201]
Aspirin or P2Y₁₂ receptor inhibitor monotherapy after 1 month of dual antiplatelet therapy in patients with high bleeding risk.[202]

De-escalation of antiplatelet therapy in the first 30 days is not recommended. However, beyond 30 days after an acute coronary syndrome, de-escalation of P2Y₁₂ receptor inhibitor therapy may be considered as an alternative strategy in those at high bleeding risk.[2] Theoretically, by identifying patients who are unlikely to have a response to clopidogrel by genetic/platelet function testing, there is potential for personalised antiplatelet therapy.[203] However, it is unclear whether de-escalation guided by platelet function testing or genetic testing improves clinical management and outcomes, and such a strategy based on platelet function testing or genetic testing should be prospectively tested in patients who may benefit from de-escalating antithrombotic therapy.[2]

Continue aspirin indefinitely unless the patient has hypersensitivity.

Practical tip

Evidence on the selection and duration of antiplatelet therapy following coronary revascularisation is evolving rapidly, with studies showing potential benefits from different strategies.[204][205]

In the UK, you should check the patient’s clinical report for an individualised plan written by the interventional cardiology team. This should specify what antiplatelet therapy is advised for long-term management, based on current evidence, individual patient factors, and the specific interventions undertaken for each patient.

More info: Antiplatelet therapy for patients with a separate indication for anticoagulation

Seek specialist advice when deciding the duration and type (dual or single) of antiplatelet therapy in the 12 months after STEMI for patients with a separate indication for anticoagulation (e.g., in patients with ongoing atrial fibrillation).

The National Institute for Health and Care Excellence (NICE) in the UK recommends taking account of all of the following when deciding about the duration and type (dual or single) of antiplatelet therapy in patients with a separate indication for anticoagulation:[75]

Bleeding risk
Thromboembolic risk
Cardiovascular risk
Patient's wishes.

Be aware that long-term continuation of aspirin, clopidogrel, and oral anticoagulation (triple therapy) significantly increases bleeding risk.

For patients already on anticoagulation who had PCI:[75]

Continue anticoagulation and clopidogrel for up to 12 months
If the patient is taking a direct oral anticoagulant, adjust the dose according to bleeding risk, thromboembolic risk, and cardiovascular risk.

For patients with a new indication for anticoagulation who had PCI:[75]

Offer clopidogrel (to replace prasugrel or ticagrelor) for up to 12 months and an oral anticoagulant licensed for the indication, which best matches the patient's bleeding risk, thromboembolic risk, cardiovascular risk, and wishes.

For patients already on anticoagulation, or those with a new indication, who did not have PCI:[75]

Continue anticoagulation and, unless there is a high risk of bleeding, consider continuing aspirin (or clopidogrel for patients with contraindication for aspirin) for up to 12 months.

Do not routinely offer prasugrel or ticagrelor in combination with anticoagulation in patients with a separate indication for anticoagulation.[75]

Primary options

aspirin: 75-100 mg once daily thereafter

-- AND --

prasugrel: <75 years of age and body weight <60 kg: 5 mg orally once daily; <75 years of age and body weight ≥60 kg: 10 mg orally once daily; ≥75 years of age: 5 mg orally once daily

ticagrelor: 90 mg orally twice daily

clopidogrel: 75 mg orally once daily

Secondary options

clopidogrel: 75 mg orally once daily

Plus – start or continue beta-blocker or non-dihydropyridine calcium-channel blocker

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Plus –

start or continue beta-blocker or non-dihydropyridine calcium-channel blocker

Treatment recommended for ALL patients in selected patient group

Ensure all patients are given a beta-blocker (while taking into account any contraindications).[75]

Start this as soon as the patient is haemodynamically stable.[75]
Continue the beta-blocker for at least 12 months if the patient does not have reduced left ventricular ejection fraction (LVEF).[75][206]

Continue the beta-blocker indefinitely if the patient has reduced LVEF.[75]

Do not routinely give calcium-channel blockers after STEMI.[75]

Consider a non-dihydropyridine calcium-channel blocker, such as verapamil, in a patient without pulmonary congestion or reduced LVEF who has a contraindication to beta-blockers (or when these need to be discontinued).[75]

Do not offer nicorandil (a potassium-channel activator) after STEMI.[75]

Primary options

bisoprolol: 1.25 mg orally once daily initially for 1 week, increase gradually according to response, maximum 10 mg/day

carvedilol: 3.125 mg orally twice daily initially, increase gradually according to response, maximum 50 mg/day (body weight <85 kg) or 100 mg/day (body weight >85 kg)

Secondary options

verapamil: 240 mg orally (modified-release) in the morning and 120 mg in the evening; or 120 mg orally (modified-release) three times daily

Plus – start or continue ACE inhibitor or angiotensin-II receptor antagonist

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Plus –

start or continue ACE inhibitor or angiotensin-II receptor antagonist

Treatment recommended for ALL patients in selected patient group

Ensure all patients are given an ACE inhibitor (while taking into account any contraindications).

Start this as soon as the patient is haemodynamically stable and continue it indefinitely. Complete upwards dose titration within 4-6 weeks of hospital discharge.[75]
Offer an angiotensin-II receptor antagonist as an alternative if the patient is intolerant to an ACE inhibitor.[75]
Measure renal function, serum electrolytes, and blood pressure before starting an ACE inhibitor or angiotensin-II receptor antagonist.[75] In practice, if the patient has abnormal renal function or blood pressure, start with a low dose and titrate this carefully with close monitoring.

Primary options

enalapril: 2.5 mg orally once daily initially, increase gradually according to response, usual dose 10-20 mg twice daily, maximum 40 mg/day

ramipril: 2.5 mg orally twice daily for 3 days, increase gradually according to response, maximum 10 mg/day

lisinopril: 2.5 to 5 mg orally once daily initially, increase gradually according to response, maximum 10 mg/day

Secondary options

valsartan: 20 mg orally twice daily initially, increase gradually according to response, maximum 320 mg/day

losartan: 12.5 mg orally once daily initially, increase gradually according to response, maximum 150 mg/day

candesartan: 4 mg orally once daily initially, increase gradually according to response, maximum 32 mg/day

Plus – statin

Consider – ezetimibe

Consider – proprotein convertase subtilisin/kexin type 9 (PCSK9) inhibitor

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Consider –

proprotein convertase subtilisin/kexin type 9 (PCSK9) inhibitor

Additional treatment recommended for SOME patients in selected patient group

A PCSK9 inhibitor monoclonal antibody may be added to statin and ezetimibe therapy if LDL-cholesterol targets are not achieved despite maximal statin and ezetimibe therapy.[2][63][210][211][212] Treatment can be started during acute coronary syndrome admission or at outpatient follow-up 4-6 weeks later.

Primary options

evolocumab: 140 mg subcutaneously every 2 weeks; or 420 mg subcutaneously once monthly

alirocumab: 75-150 mg subcutaneously every 2 weeks; or 300 mg subcutaneously every 4 weeks

Consider – aldosterone antagonist

Consider – sodium-glucose co-transporter-2 (SGLT2) inhibitor

Plus – cardiac rehabilitation

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ST-elevation myocardial infarction

Treatment algorithm

suspected or clinical diagnosis of STEMI (symptoms of myocardial ischaemia + ST elevation on ECG)

aspirin

Primary options

These drug options and doses relate to a patient with no comorbidities.

Primary options

Drug choice, dose and interactions may be affected by the patient's comorbidities. Check your local drug formulary.

Primary options

assess eligibility for coronary reperfusion therapy

Practical tip

Practical tip

Practical tip

More info: Summary flowchart – choice of coronary reperfusion strategy

analgesia

Primary options

These drug options and doses relate to a patient with no comorbidities.

Primary options

Drug choice, dose and interactions may be affected by the patient's comorbidities. Check your local drug formulary.

Primary options

anti-emetic

Primary options

These drug options and doses relate to a patient with no comorbidities.

Primary options

Drug choice, dose and interactions may be affected by the patient's comorbidities. Check your local drug formulary.

Primary options

oxygen

intravenous nitrate

Practical tip

Practical tip

Primary options

These drug options and doses relate to a patient with no comorbidities.

Primary options

Drug choice, dose and interactions may be affected by the patient's comorbidities. Check your local drug formulary.

Primary options

<12 hours since symptom onset: primary PCI available within 120 minutes

primary PCI

P2Y12 inhibitor

Primary options

These drug options and doses relate to a patient with no comorbidities.

Primary options

Drug choice, dose and interactions may be affected by the patient's comorbidities. Check your local drug formulary.

Primary options

parenteral anticoagulation

Primary options

These drug options and doses relate to a patient with no comorbidities.

Primary options

Drug choice, dose and interactions may be affected by the patient's comorbidities. Check your local drug formulary.

Primary options

glycoprotein IIb/IIIa inhibitor

Primary options

These drug options and doses relate to a patient with no comorbidities.

Primary options

Drug choice, dose and interactions may be affected by the patient's comorbidities. Check your local drug formulary.

Primary options

<12 hours since symptom onset: primary PCI NOT available within 120 minutes of the time when fibrinolysis could be given AND patient is eligible for fibrinolysis

fibrinolysis

Practical tip

Evidence: Role of fibrinolysis in STEMI

Primary options

Secondary options

These drug options and doses relate to a patient with no comorbidities.

Primary options

Secondary options

Drug choice, dose and interactions may be affected by the patient's comorbidities. Check your local drug formulary.

Primary options

Secondary options

parenteral anticoagulation

Primary options

Secondary options

These drug options and doses relate to a patient with no comorbidities.

Primary options

Secondary options

Drug choice, dose and interactions may be affected by the patient's comorbidities. Check your local drug formulary.

Primary options

Secondary options

P2Y12 inhibitor

Primary options

These drug options and doses relate to a patient with no comorbidities.

Primary options