Unstable angina

Question 1

What is the defintion of unstable angina?

Answer 1

• Ischaemic symptoms suggestive of ACS with no elevation in troponin +/- ECG changes
• Initially treated as a NSTEMI until troponin result is known.

Question 2

(4)

What is the criteria for a diagnosis?

Answer 2

• Ischaemia at rest or minimal exertion in the absence of acute cardiomyocyte injury/necrosis
• > 20 min of angina at rest
• New onset of severe angina
• Angina increasing in frequency, duration or lower in threshold of activity
• Angina following recent MI

Question 3

What is the pathophysiology?

Answer 3

• Coronary artery narrowing caused by thrombus on disrupted atherosclerotic plaque
• Non occlusive of vessel however restricts blood supply causing transient ischaemia

Question 4

What is the investigation of CP onset <3 hours?

Answer 4

1. Do an immediate troponin at 0 hours
2. If patient presented > 1 hour after CP onset –> repeat 1 hour troponin

Question 5

What is the management if GRACE SCORE indicates moderate/high risk?

Answer 5

1. 300mg Asprin
2. Angiogram +- coronary angiogram in 72 hours

Question 6

What is the management if GRACE SCORE indicates low risk?

Answer 6

Dual anti platelet therapy + elective angiogram

Question 7

What is the most common complication?

Answer 7

Bleeding is main complication

Question 8

What are the ECG findings?

Answer 8

no evidence of ST elevation MI

• may show ST regression, transient ST elevation or T wave inversion } non specific of ischaemia

Question 9

What will troponin results show>

Answer 9

• No dynamic elevation of troponin
• Will be low - below 99th percentile

Question 10

Troponin very low at 0 hours and CP onset > 3 hours
- Interpret?

Answer 10

1. NSTEMI is ruled out
2. Consider if they have ongoing chest pain or recent worsening cp on exertion
   - if so, Unstable angina

Question 11

Troponin very low at 0 hours and CP onset < 3 hours and patient presented >1 hours after CP started
- Interpret?

Answer 11

1. Unable to r/o NSTEMI yet
2. Repeat troponin at 1 hour
   - If still low and patient presented > 1 hours after CP
   - R/O NSTEMI

Question 12

What is the mainstay of management?

Answer 12

Optimise anti anginal drugs

Question 13

If moderate rise in O hour troponin or patient presented <1 hour after CP onset?

Answer 13

1. Measure toponin at 1 hour
2. Measure troponin at 3 hours
   - If no dynamic change - consider unstable angina