CLS: Cardiac Imaging Flashcards
True or false. CTCA has a low NPV?
False. it has a high NPV of >90%
True or false, CTCA has a high sensitivity and specificity
True
Describe the PPV for CTCA.
It is not that high. this means that if we pick up on a lesion, we cannot tell how bad it is.
What are the indications for CTCA?
- Follow up from other investigations (eg exercise, perfusion or stress echo)
- intermediate pre-test probability for CAD. Chest pain, ECG uninterpretable or unable to exercise
- Acute chest pain however no ECG changes and serial enzymes negative
What is one of the main limitations of CTCA?
calcified plaques can give a “calcium blooming artefact” looking like obstruction.
What is the “triple rule out” for CTCA?
- Coronary artery disease
- Aortic dissection
- Acute pulmonary embolism
What are the 3 types of coronary plaques?
soft, mixed, calcified
How is the calcium score obtained?
CT looks at density of all calcified plaques in coronary arteries to develop total coronary calcium score.
Indication for calcium scoring
asymptomatic patients aged 45-75 with intermediate cardiovascular risk (10-20%). (at least 2 framingham risk factors)
When to not use calcium scoring?
o At very low risk (<5% absolute 10 year risk); or
o High risk (>20% absolute 10 year risk) as testing is unlikely to alter the recommended management.
o Symptomatic or previously documented CAD
What are the cut offs for calcium score?
o Low risk (CAC 1-100) <10%
o Intermediate risk (CAC 100-400): 10-20%
o Moderately high risk (CAC 101-400 & 75th centile), 15-20%
o High risk (CAC >400)- >20%
What is the management based on Calcium score results?
o Very low –> no treatment
o Low –> healthy diet
o Moderate –> aspirin + statin
o High –> aspirin + statin. Aim LDL <2.0 mmol. Consider additional investigation
