ACUTE CORONARY SYNDROME

Recognition

Definition

• “The term 'acute coronary syndromes' (ACS) encompasses a range of conditions including unstable angina, Non-ST-Segment-Elevation Myocardial Infarction (NSTEMI) and ST-Segment-Elevation Myocardial Infarction (STEMI) that are due to a sudden reduction of blood flow to the heart. This is usually caused by a blood clot that forms on a patch on atheroma within a coronary artery.” (NICE).

STEMI

• “STEMI occurs when a coronary artery or one of the smaller branches that supplies blood to the heart becomes suddenly blocked by a blood clot, causing the heart muscle supplied by the artery to die” (NICE).

NSTEMI and Unstable angina

• “In unstable angina and NSTEMI the blood clot causes a reduced blood flow, but not a total blockage so the heart muscle supplied by the affected artery does not die.” (NICE).

Risk Factors

• Increasing age
• Male sex
• Established coronary artery disease
• Family history of ischaemic heart disease
• Smoking
• Hypertension
• Diabetes mellitus
• Hyperlipidaemia
• Obesity
• Sedentary lifestyle

History

If possible, ascertain if patient has:

• Previous admissions with chest pain or cardiac conditions
• Been diagnosed with a cardiac condition
• Has a history of diabetes – as these patients are at a higher risk of a silent Myocardial Infarction (MI)
• Been taking medication for a cardiac condition
• Had any operations on their heart
• Any allergies

General symptoms

• Shortness of breath (dyspnoea)
• Cyanosis
• Palpitations
• Clammy
• Sweaty
• Nausea
• Impending sense of doom
• Chest pain
• Tight, heavy, crushing, radiating to the jaw or left arm
• Lasting longer than 15 minutes

General Signs

• Dyspnoea
• Pale
• Raised jugular venous pressure (JVP)
• Hypotensive
• Tachycardic

Initial Assessment and Investigations

• ABCDE assessment
• Sit patient up if able to tolerate. This may improve the patients breathing but must be done with knowledge of the patient’s blood pressure and appreciation of the effect this will have on the blood pressure
• Assess patient’s airway
• Monitor oxygen saturations and respiratory rate
• If patient is hypoxic give Oxygen (O₂) to achieve target saturations. Initially give 15 L/min via a reservoir mask if the patient is acutely unwell
• Target saturations:
• 94 - 98% for patients not at risk of hypercapnic respiratory failure
• 88 - 92% for patients at risk of hypercapnic respiratory failure due to conditions such as Chronic Obstructive Pulmonary Disease (COPD)
• Examine patient’s chest
• Listening for:
• Bibasal crepitations
• Cardiac wheeze chest
• Arterial blood gas (ABG) if concerned about patient’s ventilation
• Chest X-ray if concerned about patient’s ventilation. If the patient is unwell request a portable X-ray
• Obtain intravenous access by placing 2 large bore cannulae in the antecubital fossa. Take blood to check Full Blood Count (FBC), Urea and Electrolytes (U&Es), Calcium, Magnesium, Glucose, Troponin and Venous Blood Gas (VBG)
• Raised Troponin may be a sign of myocardial damage. It rises approximately 4 to 6 hours after injury and can remain high for approximately ten days. Refer to trust guidelines for clinically relevant result
• Check Capillary Refill Time (CRT) - hold for five seconds and refilling should occur in 3 seconds
• Assess pulse rate, rhythm and character
• Monitor heart rate and blood pressure
• Listen to patient’s heart sounds and assess if a murmur is present
• Look for raised Jugular Venous Pressure (JVP)
• Look for peripheral and sacral oedema
• Check urine output and consider catheterisation
• Intravenous (IV) fluids as required by clinical picture and balanced with patient’s risk of fluid overload. See more details in the “Circulation” Chapter in the “Response” Section under “Fluid Challenge”
• 12 Lead Electrocardiogram (ECG)
  • ECG changes
    • STEMI
      • New regional ST segment elevation
      • New Left bundle branch block (LBBB) and chest pain
    • NSTEMI
      • New regional ST segment depression
      • Deep T-wave inversion
    • Unstable angina
      • No specific ECG changes
• Call for senior help if not done already
• Consider cardiac monitoring
• Check pupils are equal and reactive
• Assess Glasgow Coma Scale or ACVPU using the NEWS2 chart
• Check patient’s temperature and blood sugar
• Examine patient’s abdomen and legs
• Consider venous thromboembolism prophylaxis- discuss with cardiology

Response

Management

STEMI

Immediate management

• Inform senior immediately
• Analgesia
• Titrate Morphine 2.5 - 10 mg slow IV bolus
• Nitrate
• Glyceryl Trinitrate if blood pressure > 90 mmHg systolic
• 500 microgram tablet sublingual
• 400 - 80 0microgram spray sublingual
• Repeat after 5 minutes if required
• Max 3 doses
• Aspirin
• 300 mg orally (unless contraindicated)
• Ticagrelor
• 180 mg orally (unless contraindicated)
• Low Molecular Weight Heparin (LMWH) subcutaneously as per local guidelines and following discussion with cardiologist

Referrals

• Discuss with senior member of the team
• Contact critical care outreach team
• Referral to cardiologist:
  • Primary Percutaneous Coronary Intervention (Primary PCI)
    • Patients should be offered primary PCI if:
      • They have presented within 12 hours of onset of pain
      • Primary PCI can be done within 120 minutes of the time when fibrinolysis could have been offered
    • In patients whom this does not apply consider thrombolysis (if no contraindications)
    • If patients are not at a hospital where Primary PCI is done they will need blue light transfer to a Primary PCI centre
• Consider referral to Intensive Care Unit (ICU) if:
• Failure to respond to medical management
• Patient requires ventilator support
• Patient requires blood pressure support
• Deterioration of blood gas following medical management

NSTEMI

Immediate management

• Inform senior immediately
• Analgesia
• Titrate Morphine 2.5 - 10 mg slow IV bolus
• Nitrate
• Glyceryl Trinitrate if blood pressure > 90mmHg systolic
• 500 microgram tablet sublingual
• 400 - 800 microgram spray sublingual
• Repeat after 5 minutes if required
• Max 3 doses
• Aspirin
• 300 mg orally (unless contraindicated)
• Ticagrelor
• 180 mg orally
• LMWH subcutaneously as per local guidelines

Referrals

• Discuss with senior member of the team
• Contact critical care outreach team
• Referral to cardiologist:
• Urgently if pain continues or dynamic ECG changes
• Consider referral to Intensive Care Unit (ICU) if:
• Failure to respond to medical management
• Patient requires ventilator support
• Patient requires blood pressure support
• Deterioration of blood gas following medical management

Future management

• Consider:
• Dual antiplatelet therapy (Aspirin and Ticagrelor)
• Angiotensin-Converting Enzyme (ACE) inhibitor
• Beta blocker
• Statin
• Lifestyle advice
• Cardiac rehabilitation