Cardiac Biomarkers in the Diagnosis of Ischaemic Heart Disease

Question 1

What are the most important cardiac markers

Answer 1

Troponin and BNP

Question 2

What is troponin

Answer 2

It is uniquely expressed by the heart. It is involved in muscle contraction as it is attached to the protein tropomyosin and lies in actin filaments. Troponin is where the binding site for myosin on actin is.

Question 3

What are the three types of troponin

Answer 3

I, C and T

Question 4

What are the indications of increased levels of troponin

Answer 4

Increased risk of future cardiac events occurring.

Question 5

What are the indications if you have both decreased cholesterol and troponin levels

Answer 5

Reduced risk of future cardiac events.

Question 6

What are the indications if you have reduced cholesterol but troponin levels are the same

Answer 6

There is no change in the risk of future cardiac events.

Question 7

What are the main drugs used in the treatment of heart disease

Answer 7

Statins

Question 8

What are the risk factors for cardiovascular disease

Answer 8

• age
• gender
• smoking status
• high systolic blood pressure
• high total cholesterol
• low HDL cholesterol
• diabetes

Question 9

What is high sensitivity C-reactive protein a biomarker for

Answer 9

Oxidative stress and inflammation

Question 10

At what level does C-reactive protein indicate a high risk of CVD

Answer 10

More than 3mg/L.

Question 11

What is C-reactive protein

Answer 11

An acute phase protein produced by the liver and adipose tissue.

Question 12

What is the role of C-reactive protein

Answer 12

It assists in complement binding in the immune response and phagocytosis of damaged cells.

Question 13

What is the role of C-reactive protein in atheroma formation

Answer 13

It is present in atherosclerotic lesions. it binds to LDL and assists macrophage uptake as well as enhancing local inflammation.

Question 14

What are the possible causes of chest pain

Answer 14

MI, angina, pericarditis, pneumothorax, pulmonary embolism, gastric reflux, peptic ulcer disease, muscular or skeletal pain.

Question 15

What type of cell is troponin released from

Answer 15

Cardiac troponins are released into the bloodstream from ischaemic cardiomyocytes.

Question 16

What are the advantages of using cardiac troponin in diagnosis of acute MI

Answer 16

• it can detect smaller changes - it is more sensitive
• it is more specific to MI
• It remains elevated fro up to 2 weeks after an MI

Question 17

What is type 1 MI

Answer 17

Spontaneous MI related to ischaemia due to a primary coronary event such a blockage of an artery.

Question 18

What is type 2 MI

Answer 18

Mi secondary to ischaemia due to either increased oxygen demand or decreased oxygen supply (imbalance in supply and demand)

Question 19

What is type 3 MI

Answer 19

Sudden unexpected cardiac death often with symptoms suggestive of myocardial ischaemia

Question 20

What is type 4 MI

Answer 20

MI associated with PCI/stent thrombosis

Question 21

What is type 5 MI

Answer 21

MI associated with CABG

Question 22

What are the differences in troponin levels normally in men and women

Answer 22

Men naturally have higher cardiac troponin than women.

Question 23

What is the normal concentration of troponin for a man

Answer 23

Below 34 ng/L

Question 24

What is the normal concentration of troponin for a woman

Answer 24

Below 16 ng/L

Question 25

What would be the issue if the troponin threshold for diagnosis of MI was the same for men and women

Answer 25

Less women within an abnormal range would be diagnosed with MI and so would not be treated, putting them at a huge disadvantage.

Question 26

At what level of troponin can you definitely say the person has not had an MI and they can be sent home

Answer 26

Below 5 ng/L

Question 27

What happens if the troponin level is above 5 ng/L

Answer 27

Another test is carried out after three hours to check troponin levels again before a diagnosis is made.

Question 28

What stimulates the secretion of natriuretic peptides

Answer 28

Ventricular stretch due to increased blood volume and wall tension.

Question 29

How is BNP produced

Answer 29

Prohormone is released in response to ventricular stretch and is cleaved to produce BNP.

Question 30

What is the role of BNP

Answer 30

To regulate blood pressure, blood volume and sodium balance.

Question 31

Where is ANP produced

Answer 31

The atria

Question 32

Where is BNP produced

Answer 32

The brain and the ventricles

Question 33

Where is CNP produced

Answer 33

The vascular endothelium

Question 34

What level of BNP indicates heart failure

Answer 34

High

Question 35

What investigation does BNP reduce the need to carry out

Answer 35

ECHO