Clinical Biochemistry - GP

For details about lipid metabolism, types of lipid and atherosclerosis see the student section. This section is concerned with the practicalities of primary and secondary prevention of cardiovascular disease (CVD).

Primary prevention

Primary prevention describes the measures used to try and reduce a person's risk of a cardiovascular event.

1. Check non fasting lipid profile

2. Check total cholesterol : HDL ratio

3. Together with knowing the patient's gender, age, smoking status and blood pressure, use primary prevention charts (or computer based risk program eg QRISK)to determine the 10yr CVD risk.

4. If the 10yr CVD risk is > 20% then consider statin treatment - usually simvastatin 40mg od (always warn about possible risk of muscle aching with statins and ask patient to stop the drug if this occurs and see a doctor). Note also -

If the total cholesterol result is > 7.5 mmol/L then Familial Hypercholesterolaemia (FH) should be considered. Ask about a family history of CVD, get lipid results from other family members if possible, check for physical signs of FH (in particular tendon xanthomata as well as xanthelasmata).

Exclude possible secondary causes of hypercholesterolaemia by checking U+E, glucose, LFT, TFT, CK, FBC. The CK is important as it serves as a baseline value to check against prior to any statin treatment.

If elevated triglycerides repeat the lipid profile in the fasting state. If the triglycerides remain elevated in the fasting sample then treatment of the triglycerides in primary prevention only required if possible risk of acute pancreatitis (may occur when triglycerides > 20 mmol/L). The elevated triglycerides may indicate an underlying pathology though eg diabetes or impaired fasting glycaemia, obesity, excessive alcohol intake, Familial Combined Hyperlipideamia (FCH).

5. Treatment should aim to get the cholesterol below 5 mmol/L. Consider the use of a more potent statin eg atorvastatin and possible use of combination therapy (eg statin/ezetimibe or statin/fibrate) to achieve this.

Discuss / refer to Dr Rob Lord if required.

To continue to 'secondary prevention' click here