JBS3 and NICE CG181 Summary

Here is a summary of the main points from the Joint British Society for prevention of cardiovascular disease guidelines (JBS3) and NICE CG181 - Cardiovascular Disease: risk assessment and reduction, including lipid modification

Q

Non HDL- Cholesterol - what is it and why is it being measured now?

A

Non HDL-cholesterol is the sum of all the cholesterol contained in lipoproteins which are known to contribute to atherosclerosis (narrowing of arteries).  Non HDL-cholesterol includes the cholesterol carried by low density lipoprotein (LDL-cholesterol) and very low density lipoprotein (VLDL-cholesterol).  It is thought to be a better risk predictor for cardiovascular disease compared to LDL-cholesterol alone, and is particularly beneficial for patients with type 2 diabetes.  It is also thought to be better for monitoring responses to treatments.   It can be calculated by a simple subtraction (total cholesterol minus HDL-cholesterol).  There is no need to fast for the test, and therefore it is more convenient for patients and clinicians alike.  LDL-cholesterol cannot be directly measured, requires a fasting test and is then calculated using a complicated equation.

Q

Do patients no longer need to fast for a cholesterol test?

A

Both NICE and JBS3 recommend measuring total cholesterol and HDL- cholesterol to achieve the best estimate of cardiovascular risk.  Because total cholesterol and HDL-cholesterol are largely unaffected by recent dietary intake they do not require a fasting test.  Non HDL- cholesterol can be calculated by a simple calculation: (Total cholesterol minus HDL- cholesterol).  Before starting lipid lowering medication, both guidelines recommend taking a full lipid profile which includes measuring triglycerides level. 

Q

What are the target levels for HDL- Cholesterol?

A

No target levels have been specified in the guidelines.  HEART UK’s lipid experts advise that ideally men should have an HDL-cholesterol of 1mmol/L or above, and women 1.2mmol/L or above.  The relationship between the level of HDL-cholesterol and coronary risk appears to level off at 1.6mmol/L and it is uncertain at present if increasing levels beyond this value is beneficial.  More research is required to clarify this.

Link to HEART UK’s HDL fact sheet

Q

When should a statin be offered to patients in primary prevention?

A

For the majority of people, cardiovascular disease risk is determined using a risk calculator called QRISK2 which estimates the percentage risk of an event over a 10 year period.  In England, people aged 40-84 should be invited to have a 10 year cardiovascular risk assessment (NHS Health Check) every 5 years. Prior to these new guidelines, the threshold for offering a statin was 20% risk over 10 years.  This has now been halved to 10% risk.

However, before offering cholesterol lowering medication to those whose risk is above the 10% threshold, improvements to diet and lifestyle and other modifiable risk factors should be tried first. People should then be offered the opportunity to have their risk assessed again after trying these  changes, at a time period decided between them and their health care professional.  QRISK2 can only provide an approximate value for cardiovascular risk so interpretation of the risk score should always reflect the clinician’s judgement.  Clinicians should also be aware of those factors that may predispose a person to premature cardiovascular risk, such as Familial Hypercholesterolaemia (FH)

Q

What do the guidelines say about lifetime risk vs 10% 10 year risk 

A

JBS3 Guidelines introduced a new concept of “lifetime risk”.  As age is a major determinant of CVD risk, the 10 year QRISK2 tool does not identify younger people who are at high lifetime risk and if left untreated will go on to develop premature CVD.  JBS3 argues that it is better to find these people at a younger age and intervene to delay the first CVD event.  Lifetime risk is a better way to identify these younger people, in particular women who have an increased lifetime event risk due to a high rate of elevated, modifiable risk factors such as smoking status, family history and deprivation

JBS3 has two important risk assessment tools:

Heart age tool: this assesses relative and absolute risk, calculated by estimating the age of someone of the same gender and ethnicity and within the same annual risk of events but with all other risk factors at optimal levels

Healthy years: represents “event free survival” and the age at which an individual might expect to have their first CVD event (with their current risk profile) using a visual tool to show how improvements in modifiable risk factors can result in a “gain in life years” through changes such as stopping smoking, lowering blood pressure or reducing cholesterol levels. 

Link to JBS3 Risk Calculator

Q

When should a risk calculator not be used?

A

NICE do not recommend the use of a risk calculator for people who are already at high risk of CVD. This includes anyone with existing CVD, type 1 diabetes, Chronic Kidney Disease (CKD), and those who may have an inherited high cholesterol such as familial hypercholesterolaemia (FH).  The JBS3 risk assessment tool can be used to highlight increased CVD risk and guide appropriate risk factor modification in those with CKD.  

Q

What dose and which statin should be prescribed?

A

A cholesterol lowering medication such as a statin is recommended for those who have established CVD or are at increased risk of developing CVD i.e. diabetes, CKD, FH, and for primary prevention where there is an increased 10 year risk/high lifetime risk estimated by QRISK2/JBS3 risk calculator, where lifestyle modifications have been tried and have been insufficient or inappropriate. 

Statins should be started after an informed discussion about the benefits and risks between the health care professional and patient.  Before commencing statin treatment it is important for secondary causes and co-morbidities to be assessed, such as thyroid function, renal and liver function, Hba1c/fasting glucose for diabetes, smoking status and alcohol consumption.

Primary prevention: NICE recommend Atorvastatin 20mg as the statin and dose of choice.  The aim is to achieve a greater than 40% reduction in non HDL- cholesterol.   Atorvastatin 20mg is expected to achieve a 40% reduction in LDL- C.

Secondary prevention: NICE recommend Atorvastatin 80mg for people who have established CVD. Lower doses should be used if there is any potential for a drug interaction, high risk of side effects or patient preference.  A dose of Atorvastatin 80mg is expected to achieve at least a 55% reduction in LDL-cholesterol.   JBS3 recommend statins for those who have had an ischaemic stroke (after 2 weeks) but statins should be avoided in those with a history of haemorrhagic stroke, particularly if they have poorly controlled blood pressure.

For those with CKD, Atorvastatin 20mg is recommended for primary and secondary prevention.  CKD may also provide a pattern of raised triglycerides and reduced HDL-cholesterol levels.  Discussion with a renal specialist may be indicated for advice regarding doses.

Type 1 Diabetes: Atorvastatin 20mg should be considered for primary prevention of CVD in all adults with type 1 diabetes, due to their increased risk of CVD, especially in those over the age of 40, those who have had diabetes for more than 10 years, who have established neuropathy or have other CVD risk factors. 

Type 2 Diabetes: NICE recommend Atorvastatin 20mg should be used for those with a 10% or greater 10 year risk of developing CVD (using QRISK2).  JBS3 advocate use of statins in those above 40 years irrespective of lipid values and for those with existing CVD.

Q

How are  people who are already taking a statin affected by the guideline changes?

A

For those already treated and stable on a lower dose or different statin, NICE suggest that health care professionals should discuss the likely benefits and potential risks of changing/increasing statin doses on a routine medical review with their patients, to see if any change is needed or would be beneficial to the individual.

Q

How often should cholesterol be tested (and what other blood tests might be needed)

A

Primary prevention: people over the age of 40 should have their CVD risk reviewed on an “ongoing” basis and should be given the opportunity to have their risk assessed again after making any lifestyle changes. If their risk score is at a level where intervention is recommended but they decline the offer of treatment, they should be advised that their risk should be reassessed again in the future.  JBS3 recommend that CVD assessment should occur at least every 5 years.  For those people who fall below the 10 year treatment threshold, additional information about them can be gained using the JBS3 risk assessment “lifetime risk” as explained earlier.

For those who have started a statin:    A non fasting total cholesterol, HDL-cholesterol and non HDL-cholesterol should be measured after 3 months of starting a statin.  The aim is for a 40% or more reduction in non HDL-cholesterol (the reduction expected with a dose of Atorvastatin 20mg). 

If this has not been achieved, health care professionals should discuss possible reasons for this with their patients, including the time they take their medication, whether or not they are taking their medication, plus any diet and lifestyle changes that have been made.  They may consider increasing the dose of the statin  (if started on a dose below 80mg) and should use their clinical judgement especially for those who have co-morbidities/multi-pharmacy etc.   

Once people are established on an effective maintenance dose, an annual review is recommended which may include a non fasting total cholesterol,  HDL-cholesterol and non HDL-cholesterol.    Liver function tests should be taken before starting a statin, then measured within 3 months of starting treatment and again after 1 year.  It should not be measured after this unless clinically indicated.  A baseline CK measurement can also be taken.

JBS3 state that statins will lower non HDL-cholesterol and LDL-cholesterol by about the same amount.  Non HDL-cholesterol should be lowered to <2.5mmol/L which is the equivalent of a reduction in LDL-cholesterol of <1.8mmol/L

Q

What is the general advice for those who are unable to tolerate recommended statin doses?

A

The NICE guidelines recommend treating a person with the maximum tolerated dose of statin.  If the patient is unable to take a high intensity statin, any statin at any dose will reduce CVD risk.  Patients should be encouraged to report any side effects they experience to their health care professional, who should discuss the following strategies: stopping the statin and trying again when symptoms resolve to see if they are related to the statin; reducing the dose of the statin; changing the statin to a lower intensity group.  If 3 different statins have been tried without success, patients should then be referred to see a lipid specialist in a lipid clinic, whose advice can also be sought by telephone.

Q

When should patients be referred to see a lipid specialist?

A

Patients should be referred to see a specialist in lipids for the following reasons:

-If they have unsuccessfully tried 3 different statins;

-if non HDL-cholesterol concentration is more than 7.5mmol/L or total cholesterol is more than 9mmol/L (even in the absence of a first degree family history of premature cardiovascular disease). 

-Urgent specialist review is recommended for people who’s triglyceride concentrations are more than 20mmol/L, and for those who’s triglyceride level still remains above 10mmol/L after repeated testing and review of secondary causes. 

-Clinicians should also seek specialist advice for treatment options for those at high risk of CVD such as those with CKD, type 1 diabetes, type 2 diabetes or genetic dyslipidaemias such as FH

Q

What other medications are available to lower cholesterol?

A

Both NICE Guidance and JBS3 do not recommend the routine prescription, or combination of medications such as fibrates, resins/bile acid sequestrant, omega 3 supplements and nicotinic acid for primary and secondary prevention of CVD.  Co-enzyme Q10 and Vitamin D are currently not recommended for those who have problems taking statins such as muscle symptoms in order to  increase adherence to treatment.  These medications should only be under specialist prescription and supervision.

Use of medications such as PCSK9 inhibitors and cholesterol absorption inhibitors, such as Ezetimibe are currently being reviewed by NICE

Q

What are the current recommendations for triglycerides?

A

NICE and JBS3 do not make a specific recommended level for triglycerides.  HEART UK's lipid specialists recommend a fasting triglyceride level should be 2mmol/L or less and  a non fasting triglyceride should be less than 4mmol/.   However, NICE gives advice regarding those with elevated levels as below:

Patients with triglyceride levels of above 20mmol/L should be referred to a specialist for urgent review.
Patients with triglyceride levels between 10 and 20mmol/L should have a repeat fasting test after an interval of 5 days – 2 weeks and be reviewed for secondary causes.  They should be referred to a specialist if their levels remain elevated. 
For patients with a triglyceride concentration between 4.5 and 9.9 mmol/L, health care professionals are advised that CVD risk may be underestimated by risk assessment tools. 

Q

What are the current recommendations for the total cholesterol /HDL - cholesterol ratio

A

There is no recommendation from NICE or JBS3 regarding the ratio which is calculated by dividing total cholesterol by HDL cholesterol.  This is the value required for the QRISK2 calculator.

Q

What are the recommendations for Familial Hypercholesterolaemia (FH)

A

Familial Hypercholesterolaemia (FH)  is the subject of its own NICE Guideline (CG71) and should be considered if there is a total cholesterol of more than 7.5mmol/L and a family history of premature cardiovascular disease.  Clinical findings, lipid profile and family history should be used to judge the likelihood of an inherited condition rather than the use of strict lipid cut off.   In the UK the Simon Broome criteria and the Dutch Lipid Clinic criteria are used to classify patients into “definite FH”, “probable FH” and “possible FH”.   Where FH is suspected, a fasting sample to enable LDL-cholesterol estimation may be required.  People suspected of having FH should be referred to a lipid specialist for confirmation of the diagnosis , genetic testing (where available) and family cascade screening.  The NICE Guideline for FH recommends a reduction of LDL-cholesterol of at least 50% from baseline.

Link to Simon Broome Diagnostic Criteria and Dutch Lipid Clinic Criteria

Q

What age should cholesterol treatment be stopped?

A

NICE stipulate that the QRISK 2 risk assessment tool can be used to assess CVD risk for primary prevention in people up to and including those aged 84.  People aged 85 and over are thought to be at increased risk of CVD because of their age alone, particularly those who have additional risk factors such as smoking, high blood pressure or raised cholesterol.  Atorvastatin 20mg is currently recommended for consideration in this group of people as statins may be of benefit in reducing their risk of non- fatal heart attack.  Health care professionals should discuss this with their older patients and take into consideration factors that may make such treatment inappropriate (i.e. benefits from lifestyle modification, interaction with other medications, and the general health of the patient).