[W5] Clinical Biochem of Heart Disease

Question 1

What are the three types of Acute Coronary Syndrome?

Answer 1

STEMI, NSTEMI, Unstable Angina

Question 2

What is the gold-standard biomarker for myocardial infarction?

Answer 2

Cardiac troponins (TnT, TnI)

Question 3

How soon after MI do cardiac troponins rise?

Answer 3

2–3 hours

Question 4

What is the diagnostic threshold for high-sensitivity troponin assays?

Answer 4

The 99th percentile of a healthy population

Question 5

What condition shows a stable, elevated troponin without MI?

Answer 5

Chronic myocardial injury (e.g. COPD, CKD)

Question 6

What triggers BNP and NT-proBNP release?

Answer 6

Ventricular wall stretch

Question 7

Which natriuretic peptide is more stable and preferred by NICE?

Answer 7

NT-proBNP

Question 8

What NT-proBNP level rules out HF?

Answer 8

<400 ng/L

Question 9

What NT-proBNP level warrants urgent Echo within 2 weeks?

Answer 9

> 2000 ng/L

Question 10

What are some non-HF causes of raised NT-proBNP?

Answer 10

Renal disease, age, sepsis, pulmonary embolism

Question 11

What can falsely raise troponin levels?

Answer 11

Macro-troponin, heterophilic antibodies (HAMA)

Question 12

What can cause a false negative in troponin assays?

Answer 12

Biotin interference

Question 13

Are cTnI and cTnT results interchangeable?

Answer 13

No – different assays and standardisation issues

Question 14

How is MI diagnosed with hs-troponin?

Answer 14

Dynamic rise/fall above 99th percentile + ischaemia symptoms

Question 15

Why is serial sampling used for hs-troponin?

Answer 15

To detect dynamic change confirming acute injury