What dose of aspirin is given in acute coronary syndrome?

A single loading dose of 300 mg as soon as possible, unless there is clear evidence of allergy, in both STEMI and unstable angina or NSTEMI, according to NICE NG185. In NSTEMI aspirin is then continued indefinitely unless bleeding risk or hypersensitivity prevents it.

When is primary PCI chosen over fibrinolysis in STEMI?

NG185 says to offer primary PCI to patients presenting within 12 hours of symptom onset if it can be delivered within 120 minutes of the time fibrinolysis could have been given. If it cannot, fibrinolysis is offered with an antithrombin at the same time, and an ECG at 60 to 90 minutes checks whether reperfusion has succeeded.

What is the GRACE score used for in NSTEMI?

GRACE predicts 6-month mortality. NG185 says to use it once the diagnosis is made and aspirin and antithrombin have been given. Predicted mortality above 3.0 per cent means considering angiography within 72 hours; 3.0 per cent or less allows conservative management with angiography if ischaemia recurs. Clinical instability means immediate angiography regardless of score.

Which antithrombin is given in NSTEMI?

Fondaparinux, unless the patient has a high bleeding risk or is going for immediate angiography, according to NG185. Unfractionated heparin with monitoring is the alternative for significant renal impairment with a creatinine above 265 micromoles per litre, and is given in the cath lab for any PCI.

Should dual antiplatelet therapy be started for chest pain before the diagnosis?

No. NG185 says not to offer dual antiplatelet therapy to people with chest pain before a diagnosis of unstable angina or NSTEMI is made. Aspirin alone is given first; the second agent, prasugrel, ticagrelor or clopidogrel, is chosen once the diagnosis, bleeding risk and anticoagulant need are known.

Does every patient with an acute coronary syndrome need oxygen?

No. The BTS emergency oxygen guideline sets a target SpO2 of 94 to 98 per cent for most acutely ill patients and asks for oxygen to be titrated to that target rather than given liberally. A patient with normal saturations does not need supplemental oxygen for chest pain alone.

Acute Coronary Syndrome — CT1 Anaesthetics Interview Clinical Judgement Answer

Chest pain on the ward is an acute coronary syndrome until the ECG and troponin say otherwise, and NICE NG185 sets the response: aspirin 300 mg as soon as possible, an immediate decision about reperfusion if there is ST elevation, and antithrombin plus a GRACE score if there is not. The STEMI rule is 12 hours from symptom onset and 120 minutes to primary PCI; the NSTEMI rule is angiography within 72 hours if the predicted 6-month mortality is above 3 per cent. For a CT1 anaesthetics candidate the station is about the first ten minutes, the phone call to the cath lab, and the patient who arrests while you wait.

Key takeaways

NICE NG185 (November 2020) says to offer a single loading dose of 300 mg aspirin as soon as possible in both STEMI and unstable angina or NSTEMI, unless there is clear evidence of allergy.
For STEMI, assess eligibility for reperfusion immediately: primary PCI if the patient presents within 12 hours of symptom onset and PCI can be delivered within 120 minutes of the time fibrinolysis could have been given; otherwise fibrinolysis with an antithrombin at the same time.
After fibrinolysis, an ECG at 60 to 90 minutes; residual ST elevation means immediate angiography with follow-on PCI.
For NSTEMI or unstable angina, offer fondaparinux unless there is a high bleeding risk or immediate angiography is planned, and do not start dual antiplatelet therapy before the diagnosis is made.
Score 6-month mortality with GRACE once aspirin and antithrombin are given: immediate angiography if clinically unstable; angiography within 72 hours if predicted mortality is above 3.0 per cent; conservative management can be considered at 3.0 per cent or less.
Dual antiplatelet choice follows NG185: prasugrel or ticagrelor with aspirin unless the patient needs an oral anticoagulant, in which case clopidogrel; ticagrelor when PCI is not indicated.

How do you recognise an acute coronary syndrome on the ward?

You recognise an acute coronary syndrome from the history of central chest pain or its equivalents, a 12-lead ECG read within minutes of the pain, and a troponin, and you separate STEMI from NSTEMI and unstable angina on the ECG alone, because the STEMI pathway cannot wait for a blood result.

The ward patient is often atypical: post-operative, diabetic, elderly, or sedated, presenting with breathlessness, hypotension, a new arrhythmia or confusion rather than crushing pain. A good answer says the ECG is done for any of those, not only for pain.

NG185 asks for a resting 12-lead ECG looking particularly for dynamic or unstable patterns of ischaemia, and a formal risk assessment as soon as the diagnosis of NSTEMI or unstable angina is made.

In practice, the differential is the part the panel probes. Aortic dissection, pulmonary embolism, pneumothorax and oesophageal rupture all present as chest pain, and two of them are made worse by the antithrombotic you are about to give.

What is the A to E and first-hour management of an acute coronary syndrome?

The first hour of an acute coronary syndrome is A to E with continuous monitoring and a defibrillator at hand, aspirin 300 mg, oxygen only to target, analgesia, and the reperfusion decision made in parallel with the cardiology call.

Airway, breathing and circulation

Oxygen titrated to an SpO2 of 94 to 98 per cent as the BTS emergency oxygen guideline sets, rather than given to everyone by reflex.
Continuous ECG monitoring with defibrillator pads on if there is ST elevation or arrhythmia, because ventricular fibrillation in the first hour is the death you can prevent.
A 12-lead ECG immediately and repeated if the pain changes, plus intravenous access, bloods including troponin, renal function and clotting.
Blood pressure in both arms and pulses if dissection is possible, before any antithrombin.

Drugs in the first hour

Aspirin 300 mg as a single loading dose as soon as possible, unless clearly allergic, in every acute coronary syndrome (NG185).
For STEMI, the reperfusion decision now: primary PCI or fibrinolysis, with an antithrombin given at the same time as any fibrinolytic.
For NSTEMI or unstable angina, fondaparinux unless there is a high bleeding risk or immediate angiography is planned; unfractionated heparin instead if creatinine is above 265 micromoles per litre.
Analgesia and an antiemetic, and treatment of any arrhythmia or heart failure alongside.

What are the NG185 time thresholds for STEMI, and what is GRACE for NSTEMI?

The NG185 thresholds for STEMI are 12 hours and 120 minutes: primary PCI is offered to patients presenting within 12 hours of symptom onset if it can be delivered within 120 minutes of the time fibrinolysis could have been given, and fibrinolysis is offered if it cannot. For NSTEMI, GRACE predicts 6-month mortality and sets the timing of angiography.

According to NG185, coronary reperfusion should be assessed immediately, irrespective of age, ethnicity or sex, and delivered as quickly as possible. After fibrinolysis an ECG at 60 to 90 minutes tells you whether it worked; residual ST elevation means immediate angiography.

For NSTEMI and unstable angina, NG185 says to use an established score predicting 6-month mortality, for example GRACE, as soon as the diagnosis is made and aspirin and antithrombin have been given. Immediate angiography is offered if the patient is clinically unstable.

The threshold is 3.0 per cent predicted 6-month mortality. Above it, NG185 says to consider angiography with follow-on PCI within 72 hours of first admission if there are no contraindications. At or below it, conservative management can be considered, with angiography if ischaemia recurs or is shown on testing.

What is the definitive management of an acute coronary syndrome?

Definitive management of an acute coronary syndrome is reperfusion for STEMI, angiography timed by risk for NSTEMI, dual antiplatelet therapy chosen by bleeding risk and anticoagulant need, a drug-eluting stent if stenting is indicated, and secondary prevention started before discharge.

Antiplatelet choices under NG185

STEMI having primary PCI: prasugrel with aspirin if not on an oral anticoagulant, with a bleeding-risk judgement at age 75 and over where ticagrelor or clopidogrel are alternatives; clopidogrel with aspirin if already anticoagulated.
STEMI not treated with PCI: ticagrelor with aspirin unless bleeding risk is high, in which case clopidogrel or aspirin alone.
NSTEMI having angiography: prasugrel or ticagrelor with aspirin if no indication for ongoing anticoagulation, prasugrel only once the anatomy is defined and PCI intended; clopidogrel if anticoagulation is needed.
NSTEMI when PCI is not indicated: ticagrelor with aspirin unless bleeding risk is high.

In the catheter laboratory and after

NG185 says to give systemic unfractionated heparin in the cath lab to NSTEMI patients undergoing PCI whether or not they have had fondaparinux, and to use a drug-eluting stent where stenting is indicated. Patients stable after successful fibrinolysis are considered for angiography during the same admission.

That said, the station rarely reaches the stent. It stays on the ward, where your job is the aspirin, the ECG, the antithrombin decision and the call.

When do you escalate an acute coronary syndrome, and who do you call?

You escalate an acute coronary syndrome at the first ECG, and the calls are to the medical registrar and the on-call cardiologist or primary PCI centre for any ST elevation, because the 120-minute clock starts at the moment fibrinolysis could have been given, not when the ambulance arrives.

For NSTEMI the calls are for instability. NG185 says immediate angiography if the clinical condition is unstable, which means ongoing pain, dynamic ECG changes, arrhythmia, heart failure or shock. Say those words rather than 'if they get worse'.

As the anaesthetic CT1 you are called for the arrest, the cardiogenic shock and the transfer. A patient going to a primary PCI centre by ambulance with pads on needs an escort who can manage an arrest en route, and a good answer says you would clarify who that is before the trolley moves.

The other escalation is the one you resist. A surgeon who wants to proceed with a list on a patient with new ST changes needs to hear that the case is off until cardiology has seen them, and that is a conversation you have with your consultant beside you.

What is the human-factors and reflective-practice angle in acute coronary syndrome?

The human-factors angle in acute coronary syndrome is time: every step from pain to reperfusion has a clock, and the delays come from ECGs waiting for a machine, from an atypical patient nobody suspected, and from a phone call made in the wrong order.

A good answer says you make the cardiology call while the aspirin is being given, not after, and that you read the ECG yourself rather than waiting for a report.

Reflective practice wants a real event. Most candidates have a post-operative patient whose chest pain was called indigestion, or an arrest in which the pads went on late. Describe what you learned, and what you now do when a nurse tells you a patient is 'a bit sweaty'.

Working under pressure is the arrest with a cardiology team on the phone and a cath lab being opened. Show that you can run the algorithm, hand over cleanly, and travel with the patient if that is what the team needs.

What are the common mistakes candidates make with acute coronary syndrome?

The commonest mistake with acute coronary syndrome at interview is quoting a 300 mg aspirin dose without saying when, or starting dual antiplatelet therapy before the diagnosis is made, which NG185 specifically says not to do in chest pain.

Giving high-flow oxygen by reflex. The BTS target is 94 to 98 per cent, titrated.
Getting the STEMI timing wrong: 12 hours from symptom onset, 120 minutes from when fibrinolysis could have been given.
Forgetting the antithrombin with fibrinolysis, or giving fondaparinux to a patient going for immediate angiography.
Quoting a GRACE threshold other than 3.0 per cent predicted 6-month mortality, or forgetting the 72-hour window.
Not putting defibrillator pads on a STEMI patient and not staying with them.
Treating chest pain as cardiac without asking about the tearing pain, the unequal pulses, the recent surgery and the swollen leg.

How this comes up at the CT1 anaesthetics interview

Acute coronary syndrome comes up at the CT1 anaesthetics interview as post-operative chest pain, a peri-arrest patient or a pre-operative ECG in the clinical judgement station, which ANRO marks on clinical judgement and decision making, reflective practice and working under pressure.

Clinical judgement is the ECG and the first-hour drugs. Decision making is STEMI or not, PCI or fibrinolysis, and postponing a list. Reflective practice is the atypical presentation you missed once. Working under pressure is the arrest and the transfer.

The panel commonly adds a surgeon who wants to proceed. The anaestheticinterview bank's 340 questions include that turn, and its AI-marked spoken practice scores whether you name the cardiology conversation and your consultant.

Acute Coronary Syndrome and Chest Pain