Dr Rubin Minhas outlines key features from the guideline for modification of blood lipids, and the vital role of primary care in prevention of cardiovascular disease

The ground-breaking cardiovascular policy document, the National Service Framework for Coronary Heart Disease (NSF-CHD), was published in March 2000.1 In the intervening 8 years there has been much progress in advancing cardiovascular policy. In its Technology Appraisal on Statins for the prevention of cardiovascular events, published in 2006, NICE lowered the threshold for intervention with statins from a 30% risk of a cardiac event over 10 years, to a 20% cardiovascular risk over 10 years.2

Subsequent guidelines from NICE have updated information first presented in the NSF-CHD, particularly in relation to secondary prevention following myocardial infarction,3 and further revised guidance is provided in the new NICE guideline on Lipid modification: cardiovascular risk assessment and the modification of blood lipids for the primary and secondary prevention of cardiovascular disease.4,5

This new guideline emphasises the requirement for a partnership with patients and the importance of their understanding of concepts of risk and preventive care. Communication with patients remains important in relation to drug treatment.

As well as making recommendations on identifying patients at risk, the guideline has advice on the use of lipid-lowering drugs in primary prevention and for those patients who have already had a cardiovascular event. This is not considered in isolation but in the context of appropriate lifestyle advice.4

Identification of high-risk patients

The NSF-CHD recommended that a systematic approach should be used to identify people at high risk of cardiovascular disease (CVD) based initially on those patients with a diagnosis of hypertension, hypercholesterolaemia, and diabetes. The new NICE guideline recommends identification of people aged 40–74 years who are likely to be at high risk, by prioritising them based on an estimate of their CVD risk before a full formal assessment.4

The guideline recommends that CVD risk should be estimated using risk factors already recorded in primary care electronic medical records, for example age, sex, and smoking status. Computer software has been developed by clinical systems operators to facilitate this process.

The identification of people using prior risk is more effective and efficient than singling them out using individual risk factors. Opportunistic assessment of people who are not identified as being at risk of CVD should not be the main strategy used in primary care to assess future risk.4

Interpreting risk scoring

All CVD risk-estimation tools can only give an approximate assessment of CVD risk, and informed clinical judgement should always be used when interpreting them. For risk estimation the guideline recommends the use of the Framingham 1991 10-year risk equations that are currently in use to assess CVD risk. The following factors should be considered when using the Framingham 1991 risk-assessment tool:4

  • age
  • sex
  • systolic blood pressure (mean of two previous readings)
  • total cholesterol
  • high density lipoprotein (HDL)cholesterol
  • smoking status
  • presence of left ventricular hypertrophy.

The use of Framingham 1991 risk equations may overestimate risk in people in the UK as it is based on US population data.4 Framingham equations should not be used to calculate risk in people with:4

  • CHD or angina
  • stroke or transient ischaemic attack
  • peripheral vascular disease
  • people already considered as high risk—with hypercholesterolaemia or other monogenic disorder of lipid metabolism, or people with diabetes.

Advice to patients

The NICE guideline recommends that people should be given individualised and easy-to-understand information about their absolute risk of CVD. They should also be told about the absolute benefits and harms of an intervention over a 10-year period. Healthcare professionals are advised to present the information numerically, and use appropriate diagrams and text (examples are given at www.npci.org.uk).

Risk estimation modifiers

If treatment decisions are to be based on the risk score, especially if it is close to the 20% threshold, other factors predisposing to premature CVD that might not be included in the risk score should be considered, such as severe obesity (BMI >40 kg/m2), as well as socioeconomic status. The estimated CVD risk should be increased by the following factors:4

  • 1.5 in people with a first-degree relative with a history of premature CHD (younger than 55 years in males, younger than 65 years in females)
  • between 1.5 and 2.0 if more than one first-degree relative has a history of premature CHD
  • 1.4 for men of south Asian ethnicity.

If the patient is aged 75 years or older, he or she should be considered at increased risk of CVD. This is increased if the patient also smokes or has high blood pressure. These people will probably experience better health as a result of treatment with statins but healthcare professionals should consider the benefits and risks of treatment, the patient’s informed preference, and any co-morbidities that contraindicate the treatment.

Primary prevention of CVD

Lipid modification therapy for primary prevention should not be offered until all other CVD risk factors that can be adjusted have been considered and steps have been taken to manage them as well as possible. This includes undertaking baseline blood tests and clinical assessment, and treating co-morbidities and secondary causes of dyslipidaemia. Assessment should be based on history, examination, and investigations, including blood tests (see Box 1). At least one fasting lipid sample should be taken to measure total, low density lipoprotein (LDL) and HDL cholesterol levels, and triglycerides before commencing any treatment.4

Primary prevention is much more than just assessing a patient’s eligibility for statin therapy. The guideline makes recommendations on physical activity, dietary advice, weight management, alcohol consumption, and smoking cessation (see below).

Box 1: Primary and secondary prevention: pretreatment assessment

In order to complete an assessment, data will be needed on the patient’s:

  • smoking status
  • alcohol consumption
  • blood pressure
  • body mass index or other measure of obesity

Further information required includes test results for:

  • fasting total cholesterol, LDL cholesterol, HDL cholesterol, and triglycerides (if fasting levels are not already available)
  • fasting blood glucose
  • renal function
  • liver function (transaminases)
  • thyroid-stimulating hormone if dyslipidaemia is present
LDL=low density lipoprotein; HDL=high density lipoprotein

Lifestyle

The NICE guideline advises that patients with pre-existing CVD, or people classified as being at high risk of developing CVD should:4

  • take 30 minutes of moderate intensity physical activity on at least 5 days a week. If co-morbidities, medical conditions, or personal circumstances prevent this, they should exercise at their maximum safe capacity. Physical activity that can form part of everyday life is recommended, such as brisk walking, climbing the stairs, or cycling. It can be as effective to undertake shorter sessions of 10 minutes or more at several times during the day as one longer session
  • consume a diet that includes at least five portions of fruit and vegetables each day and with total fat intake 30% or less of total energy intake, saturated fats 10% or less of total energy intake, and dietary cholesterol <300 mg/day. Saturated fats should be avoided where possible, with monounsaturated and polyunsaturated fats replacing them. Weekly intake should include at least two portions of fish, one of them being an oily fish, although pregnant women should eat no more than two portions of oily fish in a week (see www.eatwell.gov.uk/healthydiet)
  • lose weight if they are overweight or obese and should be given advice and support on maintaining a healthy weight in line with the NICE guideline on Obesity6
  • avoid binge drinking and limit alcohol consumption—up to 3–4 units per day for men, and up to 2–3 units per day for women
  • stop smoking if they are smokers—smokers who want to quit should be offered advice and support, and referral to NHS Stop Smoking services (or other intensive support service). If referral is not accepted, they should be offered pharmacological help to quit in line with NICE guidance.7,8

Pharmacology

The NICE guideline on Lipid modification recommends statin therapy for the primary prevention of CVD in adults with a 20% or greater 10-year risk of developing the disease. Initial treatment should be with simvastatin 40 mg. In case of contraindications or possible drug interactions a lower dose or an alternative drug such as pravastatin may be prescribed. No evidence of the clinical effectiveness of higher intensity statins (those used in doses that produce greater cholesterol lowering than simvastatin 40 mg, for example atorvastatin 40 mg) and on combining statins with other drugs was identified for primary prevention. The guideline does not, therefore, recommend using target levels of cholesterol for the primary prevention of CVD.5 Patients should be offered treatment with a statin for the prevention of CVD in a similar manner to the use of aspirin.

Fibrates, nicotinic acid, and resins are not routinely indicated for the primary prevention of CVD, although if statins are not tolerated, fibrates or an anion exchange resin may be considered.

It is unnecessary to repeat lipid measurement once a patient has begun statin therapy for primary prevention. Review of drug treatment should be guided by clinical judgement and patient preference and a decision taken whether to review the lipid profile.

Secondary prevention of CVD

Where clinical evidence of CVD is found in adults, treatment with statins is recommended. For secondary prevention, treatment should not be delayed by management of modifiable risk factors. Blood tests and clinical assessment should be performed as for assessment of cardiovascular risk (see Box 1), and co-morbidities and secondary causes of dyslipidaemia should be treated.

Statin therapy is recommended for adults with clinical evidence of CVD but fibrates, nicotinic acid, and resins should only be considered where statins are not tolerated. Treatment should be initiated with simvastatin 40 mg. As is the case for primary prevention, a lower dose of simvastatin or an alternative such as pravastatin may be used in the case of contraindications or possible drug interactions. When statins are being prescribed for secondary prevention, if a total cholesterol of less than 4 mmol/l or an LDL cholesterol level of less than 2 mmol/l is not being achieved, an increase of dose to simvastatin 80 mg or an alternative with similar efficacy and acquisition cost should be considered. However, before prescribing a higher intensity statin, co-morbidities, multiple drug therapy, and patient preference should be considered. The clinician should enable the patient to make an informed choice by discussing the risks and benefits of treatment.

Prescription of higher intensity statins, with the same provisos, for patients with acute coronary syndrome should begin straight away and should not wait until results of lipid level tests are known. Approximately 3 months after treatment has begun, a fasting lipid sample should be taken.

Monitoring statin treatment

Before commencing statin treatment baseline liver enzymes (transaminases) should be measured and the test should be repeated within 3 months of the treatment start date and again at 12 months. However, no further measure should be made unless it is clinically indicated. If the result of the initial measurement reveals raised liver enzymes, although less than three times the upper limit of normal, patients should not be routinely denied statin therapy.

Sometimes a patient already receiving statins may need treatment for another illness that might increase the likelihood of drug and food interactions, or he or she might need to take additional pharmacotherapy. In these cases their clinician should consider prescribing a reduced dose of the statin, or stopping it temporarily or permanently. Patients should be advised of possible side-effects of the treatment and should consult their GP if they experience any muscle symptoms, such as pain, tenderness, or weakness. In these cases, creatine kinase should be measured, although it is not necessary to monitor it on a routine basis when patients taking statins have none of these symptoms.

Summary

The new guideline from NICE on Lipid modification highlights the important role of primary care, and promotes the adoption of a systematic strategy to identify those people at risk and to offer them the benefit of lifestyle advice and preventive care. The emphasis is on treating patients according to their overall level of risk rather than treating cholesterol levels in isolation. The innovative use of the general practice electronic patient record and the routine data collected allows practitioners to search for and offer treatment to those patients in their community who are at highest risk.

No guideline that seeks to provide realistic and pragmatic advice on the provision of care within a publically funded healthcare system can ignore explicit consideration of the cost and workload implications of pursuing a given approach. The recommendations in this guideline explicitly address these issues by considering the cost effectiveness of strategies for the primary and secondary prevention of CVD.

This new NICE guideline represents developmental standards for the NHS, healthcare professionals, and cardiac networks. Those who commission services can be reassured that services based on its recommendations provide an accepted and recognised foundation for modern, high-quality care.

NICE implementation tools

NICE has developed the following tools to support implementation of its guideline on lipid modification. They are now available to download from the NICE website: www.nice.org.uk.

Costing tools

National cost reports and local cost templates for the guideline have been produced:

  • costing reports are estimates of the national cost impact arising from implementation based on assumptions about current practice, and predictions of how it might change following implementation of the guideline
  • costing templates are spreadsheets that allow individual NHS organisations and local health economies to estimate the costs of implementation taking into account local variation from the national estimates, and they quickly assess the impact the guideline may have on local budgets.

Slide set

The slides are aimed at supporting organisations to raise awareness of the guideline at a local level and can be edited to cater for local audiences. They do not cover all the recommendations from the guideline but contain key messages, and should be used in conjunction with the Quick Reference Guide.

Click here for CPD questions on this article and the NICE guideline on lipid modification

  • For primary prevention, modifiable lifestyle factors such as diet and smoking should be addressed first
  • For primary prevention in people with a 10-year CVD risk exceeding 20%, simvastatin 40 mg or, in the case of possible drug interactions, a lower dose or an alternative such as pravastatin is recommended
  • There will be a nationwide programme (England) to screen for CVD risk factors from 2009 involving pharmacists and other professionals as well as GP practicesa
  • For secondary prevention, treatment with simvastatin in doses up to 80 mg to achieve total cholesterol levels less than 4 mmol/l and LDL cholesterol levels of less than 2 mmol/l is recommended
  • Statins of higher acquisition costs are not recommended except for acute coronary syndrome
  • Lipid modification for diabetes is covered in separate NICE guidance on diabetes
  • Non-adherence to this guidance, especially with regard to prescription of higher intensity statins, represents a major financial risk to PBC prescribing budgets
  • Costs of statins:b
      • simvastatin 40 mg £1.40/month, 80mg £4.63/month
      • pravastatin 20 mg £4.36/month, 40 mg £6.80/month
      • atorvastatin 20 mg £24.64/month, 40 mg/80 mg £28.21/month
      • rosuvastatin 5 mg/10 mg £18.03/month, 20 mg £26.02/month
  1. Department of Health. National Service Framework for Coronary Heart Disease: Modern Standards and Service Models. London: DH, 2000.
  2. National Institute for Health and Care Excellence. Statins for the prevention of cardiovascular events. Technology Appraisal 94. London: NICE, 2006.
  3. National Institute for Health and Care Excellence. MI: secondary prevention. Secondary prevention in primary and secondary care for patients following a myocardial infarction. Clinical Guideline 48. London: NICE, 2007.
  4. National Institute for Health and Care Excellence. Lipid modification: cardiovascular risk assessment and the modification of blood lipids for the primary and secondary prevention of cardiovascular disease. Clinical Guideline 67. London: NICE, 2008.
  5. National Collaborating Centre for Primary Care. Lipid modification: cardiovascular risk assessment and the modification of blood lipids for the primary and secondary prevention of cardiovascular disease. London: Royal College of General Practitioners, 2008.
  6. National Institute for Health and Care Excellence. Obesity: guidance on the prevention, identification, assessment and management of overweight and obesity in adults and children. Clinical Guideline 43. London: NICE, 2006.
  7. National Institute for Health and Care Excellence. Smoking cessation services in primary care, pharmacies, local authorities and workplaces, particularly for manual working groups, pregnant women and hard to reach communities. Public Health Guidance 10. London: NICE, 2008.
  8. National Institute for Health and Care Excellence. Varenicline for smoking cessation. Technology Appraisal 123. London: NICE, 2007.G