Unstable angina (A&E)

Question 1

Define unstable angina.

Answer 1

Myocardial ischaemia at rest or on minimal exertion in the absence of acute cardiomyocyte injury/necrosis

Question 2

What is unstable angina characterised by? (4)

Answer 2

• prolonged angina at rest (>20min)
• OR new onset of severe angina
• OR angina that is increasing in frequency, duration or lower in threshold
• OR angina that occurs after a recent episode of MI

Question 3

What are the clinical features of unstable angina? (6)

Answer 3

• chest pain (that comes on randomly)
• sweating
• dyspnoea
• syncope
• epigastric pain
• back pain

Question 4

What are some risk factors for unstable angina? (9)

Answer 4

• diabetes
• hyperlipidaemia
• hypertension
• metabolic syndrome
• obesity
• renal impairment
• PVD
• advanced age
• smoking

Question 5

What are the first-line investigations for unstable angina? (4)

Answer 5

• ECG
• high-sensitivity troponin
• CXR
• FBC

Question 6

What do we see on ECG in unstable angina?

Answer 6

Typically normal - but sometimes pathological changes:

• ST depression (worse prognosis)
• transient ST elevation
• T-wave changes

Question 7

What is troponin like in unstable angina?

Answer 7

Not elevated - no dynamic elevation above 99th percentile

Question 8

Why do we do CXR in unstable angina?

Answer 8

• other causes of acute chest pain e.g. pneumothorax or widened mediastinum in aortic dissection
• complications of ACS e.g. pulmonary oedema due to HF

Question 9

What might FBC show in unstable angina? (3)

Answer 9

• normal
• thrombocytopenia
• anaemia

Question 10

What are some differential diagnoses for unstable angina? (11)

Answer 10

• stable angina
• NSTEMI
• STEMI
• congestive heart failure
• chest wall pain
• pericarditis
• myocarditis
• aortic dissection
• pulmonary embolism
• pleuritis
• pneumothorax

Question 11

How do we diagnose unstable angina? (3)

Answer 11

Suspect unstable angina based on:

• presence of symptoms (suggestive of myocardial ischaemia)
• ECG findings - no STEMI, may be normal or ST depression, transient STE or T-wave inversion
• no elevation of troponin

Question 12

What is the first-line treatment for unstable angina?

Answer 12

Aspirin - 300mg (continue indefinitely) + Fondaparinux (antithrombin - if no immediate PCI planned)

Question 13

What treatments do we consider in unstable angina?

Answer 13

• aspirin + fondaparinux
• GTN
• morphine
• anti-emetic
• clopidogrel (P2Y12 inhibitor)
• anticoagulation
• referral for invasive coronary angiography
• manage hyperglycaemia

Question 14

What score do we calculate in unstable angina and what do we do following this?

Answer 14

GRACE (estimated 6 month mortality)

• low-risk (<3%) = ticagrelor + aspirin
• intermediate/high-risk (>3%) = angiography with follow-up PCI if indicated + ticagrelor

Question 15

How do we manage unstable angina post-stabilisation? (5)

Answer 15

• start/increase anti-anginal medications: beta-blocker (bisoprolol) OR non-dihydropyridine CCB (verapamil)
• GTN
• continue dual antiplatelet therapy
• consider: ACEi/ARB, statin, eplerenone/spironolactone
• CVD risk factor management

Question 16

What does NICE recommend as first-line diagnostic investigation for unstable angina?

Answer 16

If clinical assessment reveals typical/atypical angina –> CT coronary angiography (also done if non-anginal chest pain with resting ECG ST-T/Q changes)

• contraindicated in renal impairment
• appropriate 2nd-line functional imaging e.g. stress echo, MRI or myocardial perfusion scan with SPECT

Question 17

What are some complications of unstable angina? (3)

Answer 17

• congestive heart failure
• ventricular arrhythmias
• Rx complications - bleeding, thrombocytopenia

Question 18

Describe the prognosis of unstable angina.

Answer 18

Overall mortality for NSTEMI/unstable angina is 4.8% over 6 months