Screening for Familial Hypercholesterolaemia

Patients who may have Familial Hypercholesterolmaemia (FH) can be identified in the following searches in the CDRC Quality > Lipids 

Search Name	Search Returns	Action
? 2.0 Case Finding – Consider screening for familial hypercholesterolamia	Patients who have a significant chance of familial hypercholesterolaemia	Screen for FH – see below
? 2.01 Case Finding – Consider screening for familial hypercholesterolamia (also eligible for IFF FH referral)	Patients in 2.0 who are also appear in the IIF CVD04 ‘consider for FH assessment’ denominator	Screen for FH – see below
? 2.02 Case Finding – Consider screening for familial hypercholesterolamia – highest risk patients	Patients in 2.0 who are at highest risk of FH – for areas with limited resources – concentrate on these patients	Screen for FH – see below
? 2.1 Case Finding – Eligible for IFF FH referral but FH less likely	Patients who appear in the IIF CVD04 ‘consider for FH assessment’ denominator, who are less likely to have FH	Screen for FH – see below, but likely to have a secondary cause of hyperlipidaemia
? 2.2 Case Finding –  Code for FH but not genetic code – consider need for genetic testing	Patients with a code suggesting FH e.g. Possible FH who don’t have a definitive FH code	Review record and consider: Adding definitive code if appropriate Referral for genetic testing Removal of code if incorrect – e.g. secondary hyperlipidaemia

Patients are identified using a combination of tools – NICE guidance, estimated Dutch Lipid Clinic Network scores and estimated Welsh FH Score with adjustment for high triglyceride levels. 

Two pages of the Lipids Details Template will help with screening 

• Aetiology page – page showing information about possible causes of hyperlipidaemia, especially, secondary causes – Aetiology of Abnormal Lipids 
• FH Screening page – calculate the Dutch Lipid Clinic Network Score.  Local referrals protocols vary, but patients with a DLCNS >=6 are usually referred to a lipid clinic to consider FH genetic testing. 

The central panel shows relevant information from the record and the buttons on the left allow this information to be expanded. 

Record the following if not already recorded: 

• Family history of CVD and/or hyperlipidaemia 
• Family history of tendinous xanthomata 
• History of tendinous xanthomata 
• History of arcus 

Then use this information to calculate a Dutch Lipid Clinic Network Score. 

Consider secondary causes of hyperlipidaemia such as uncontrolled diabetes mellitus, untreated hypothyroidism, chronic renal failure, nephrotic syndrome, cholestasis, hypopituitarism, anorexia, obesity, anticonvulsants, antipsychotics, steroids, cyclosporin, anti-retrovirals, retinoids.  Some of these issues will be shown in the panel towards the bottom of the template.  

Use the bottom boxes to record referral to or consultation in lipid clinics (recent or historic) 

Calculating the highest LDL-cholesterol 

It can be difficult to find a pre-treatment LDL-cholesterol in some patients who have been on lipid lowering therapy for many years.  The Lipids Results button will show all previous lipid results to help with this. 

The LDL-C can be estimated using Friedewald equation: 

• LDL-C = non-HDL-C minus (triglycerides / 2.2).   
• This formula is not valid if the triglyceride level is >=4.5.  In addition the DLCNS is not valid if the lipid values are associated with a triglyceride level >2.3.   

In the example below the pre-treatment non-HDL can be estimated by subtracting the HDL (estimated at around 1, looking at subsequent values) from the total cholesterol, e.g. 8.2-1 = 7.2  

Then estimating that the pre-treatment triglyceride level was around 3, LDLC= 7.2-3/2.2 = ~5.8 

This patient’s lipid profile is highly suggestive of metabolic syndrome rather than FH, with low HDL-C, raised TGs and a BMI of >35.