Risk estimation and the prevention of cardiovascular disease. SIGN 149, 2017

This guideline provides advice on the management of cardiovascular risk, both for primary and secondary prevention. It is primarily intended for healthcare professionals in Scotland, where 15% of people over the age of 16 have some form of cardiovascular disease.

RISK ESTIMATION

Overprediction of CVD risk means that people with less to gain potentially become patients and face a lifetime of drug treatment. Underprediction of risk means people with a lot to gain may not be offered preventive treatment.

In Scotland, use the ASSIGN score, which has been adapted to the Scottish population. Elsewhere in the UK, use QRISK2.

People with the following risk factors should be considered at high risk of cardiovascular events:

• Established cardiovascular disease (CVD)
• Stage 3 or higher chronic kidney disease or micro- or macroalbuminuria, or
• Familial hypercholesterolaemia, or
• Who are over the age of 40 and have diabetes, or
• Who are under the age of 40 who have had diabetes for at least 20 years, who have evidence of target organ damage, or who have significantly raised cardiovascular risk factors

People should be considered at high risk if they have a ≥20% risk of a first cardiovascular event within 10 years.

Cardiovascular risk assessment should be offered at least once every 5 years in adults over the age of 40.

People should be considered at high risk if they have a ≥20% risk of a first cardiovascular event within 10 years.

They should be supported to make lifestyle changes and be offered drug therapy to reduce their absolute risk. Consider offering an annual review to address CVD risk factors and to discuss lifestyle modification and medicines adherence.

LIFESTYLE MODIFICATION

Diet

• Diets low in saturated fats should be recommended – no more than 30g saturated fat per day for men, 20g for women.
• Omega-3 supplementation should not be recommended – there is no evidence that it offers the same protective benefits as eating fish.
• Recommend reducing dietary salt to no more than 6g per day (about a teaspoonful). People with hypertension should be advised to reduce salt intake as much as possible.
• Increased fruit and vegetable consumption is recommended for the entire population
• Recommend a Mediterranean diet supplemented with 30g extra virgin olive oil or unsalted nuts a day for people at high risk of, or established, CVD.
• Use the Eatwell Guide to help people make informed dietary choices
• Advise people to lose weight through diet and/or physical activity: weight loss of 3 – 11kg leads to reduction in systolic blood pressure of 1mmHg per kg; weight loss ≥3kg reduces LDL cholesterol of 0.2-0.3mmol/l.
• Dieticians are better than doctors at giving dietary advice to lower cholesterol – but nurses and self-help resources are just as good as dieticians

Physical activity

Regular activity has both preventive and therapeutic effects on CHD, stroke, obesity, diabetes – and on cancer, musculoskeletal disorders, cancer and mental health problems.

• Aim to be active daily for at least 150 minutes of moderate intensity
• Minimise the amount of time spent sitting over extended periods

Smoking

Although the overall prevalence of smoking has decreased in recent years, among some groups smoking rates remains as high as 75%.

• Everyone who smokes should be advised to stop and offered support and pharmacotherapy to help them quit.
• Varenicline or combination nicotine replacement therapy (NRT) should be offered alone or as part of a smoking cessation programme to increase long-term quit rates.
• Bupropion and single NRT can also be considered.
• Nicotine-containing e-cigarettes are not licensed as smoking cessation treatments.

Alcohol consumption

• Patients with or without evidence of CVD should be advised to lower alcohol consumption and that even light to moderate alcohol consumption may increase cardiovascular risk.
• Men and women should not regularly drink more than 14 units per week, and should have several drink free days each week.

DRUG TREATMENT

ANTIPLATELET THERAPY

• Aspirin is not recommended for primary prevention of cardiovascular disease
• Aspirin is not recommended for people with diabetes who do not have a diagnosis of CVD
• People who have established atherosclerotic disease should be treated with 75mg aspirin daily
• People who have had a stroke or transient ischaemic attack and who are in sinus rhythm should be considered for treatment with clopidogrel 75mg daily or low dose aspirin (75-300mg/day) and dipyridamole (200mg bd) to prevent stroke recurrence

LIPID LOWERING

The higher the level of cholesterol, the greater the risk of a coronary event. LDL cholesterol makes up 60-70% of total cholesterol and is a powerful risk factor. LDL cholesterol is not measured in lipid testing but can be calculated indirectly:

LDL=TC–HDL–(TG/2.2) (all in mmol/l).

HDL cholesterol is calculated as TC–HDL.

Non-fasting blood samples for lipid testing are generally acceptable for cardiovascular risk assessment in most people.

• A lipid profile to assess cardiovascular risk should include total cholesterol, HDL cholesterol and triglycerides (not during intercurrent illness).
• Encourage lifestyle measures to reduce cholesterol
• Before commencing or changing statin therapy, discuss risks and benefits of treatment
• After commencing statin therapy, repeat lipid measurements: if the reduction in non-HDL cholesterol is less than 1mmol/l or 40%, check adherence and lifestyle changes

Without CVD

• If at high cardiovascular risk, offer treatment with atorvastatin 20mg/day (no need to change if already on a different statin).
• Exclude secondary causes of dyslipidaemia

With established CVD

• Offer intensive therapy with atorvastatin 80mg/day

Statin safety

• Do not prescribe simvastatin 80mg – increased risk of myopathy
• Offer pravastatin or rosuvastatin as alternatives to atorvastatin to patients taking medications that affect cytochrome P450 metabolism
• Do not prescribe statins to patients with active liver disease or persistently abnormal liver function tests, or
• To women who are pregnant, could be pregnant or who are breastfeeding
• If reported statin intolerance persists, offer an alternative statin

Other agents

• Patients with familial hypercholesterolaemia should be offered statin therapy regardless of cardiovascular risk
• Consider combination therapy with ezetimibe where cholesterol-lowering is inadequate on maximum tolerated statin therapy
• Consider ezetimibe as monotherapy when statins are contraindicated
• Consider a PCSK9 inhibitor for patients with heterozygous familial hypercholesterolaemia and elevated LDL cholesterol despite statin +/- ezetimibe
• Do not routinely prescribe fibrates or nicotinic acid for primary or secondary prevention

BLOOD PRESSURE LOWERING

Everyone with a persistent clinic blood pressure ≥140/90mmHg or a family history of hypertension should be offered lifestyle advice to help reduce their BP and CVD risk.

• People with clinical evidence of CVD and sustained clinic systolic BP >140mmHg and/or diastolic BP >90mmHg should be offered blood pressure lowering drug therapy.
• Drug treatment should be offered to people who have had a stroke or TIA even when their BP would be considered normal to reduce the risk of recurrence.
• People with diabetes should be considered for BP-lowering drug treatment even if their systolic BP is
• All people with stage 3 or higher chronic kidney disease, or micro- or macroalbuminuria should be offered BP-lowering treatment.

BP targets

• The target for people with uncomplicated hypertension is <140/90mmHg
• For people with established CVD and diabetes, chronic kidney disease or target organ damage, a lower target should be considered – <135/85mmHg
• Lowering BP to below 130/80mmHg is not routinely recommended as it brings limited additional benefits and causes significant adverse events, especially in frail or elderly patients.

PSYCHOLOGICAL ISSUES

Depression, anxiety, social isolation or lack of social support are risk factors for the development and prognosis of CVD, and should be considered when assessing individual list. Treatments for patients with mood and/or anxiety disorders and CVD should be considered. SSRIs are recommended for patients with depression and CHD, although in patients receiving multiple drugs for CVD prevention, the increased risk of bleeding should be considered.

Reference

Risk estimation and the prevention of cardiovascular disease. SIGN 149, 2017 https://www.sign.ac.uk/assets/sign149.pdf