The revised Joint British Societies' (JBS 3) guidelines on prevention of cardiovascular disease (CVD) in clinical practice recommend that CVD prevention should focus equally on the following three groups of patients who are at high risk of CVD:
- Apparently healthy individuals with 20% or greater risk over 10 years of developing symptomatic atherosclerotic disease.
- People with diabetes mellitus (type 1 or 2).
- People with established atherosclerotic CVD.
Cardiovascular risk calculation
Whenever risk factors are identified they should not be considered in isolation, but the 10-year CVD risk should be calculated and used as the basis for recommendations to reduce the risk.
Risk assessment should include ethnicity, smoking habit history, family history of CVD and measurements of weight, waist circumference, blood pressure, lipids (total cholesterol and high-density lipoprotein (HDL) cholesterol) and glucose. The American Heart Association (AHA) guidelines also recommend recording the pulse rate and rhythm to screen for atrial fibrillation:
More recently the European Society of Cardiology (ESC) recommends a total CVD risk assessment using the SCORE (= Systemic Coronary Risk Evaluation) project approach. This consists of charts which provide a risk assessment over a patient's lifetime, with different charts for high- and low-risk countries. This replaces the notion of primary and secondary CVD prevention. For example, patients with CKD and no other cardiac risk factors should be treated as very high-risk.
For further details see separate article Cardiovascular Risk Assessment.
The healthy individual
The European Health Charter in 2007 made a public health announcement describing the healthy to have the following characteristics:
- No use of tobacco.
- Physical activity - at least 30 minutes, five times a week.
- Healthy eating.
- Not overweight.
- BP <140/90 mm Hg.
- Total cholesterol <5 mmol/L.
- Normal glucose metabolism.
- Avoidance of stress.
Clinical Editor's comments (September 2017)
Dr Hayley Willacy draws your attention to the recently released paper in the Heart Journal drawing attention to the differences between the sexes in adhering to treatment. After adjusting for several factors that could have influenced the results, they found that, compared with men, women were less likely to achieve targets for total cholesterol (8% vs 14%), LDL cholesterol (22% vs 33%) and blood glucose (71% vs 76%), or to be physically active or non-obese. In contrast, women had better control of blood pressure (45% vs 38%) and were more likely to be a non-smoker than men. Overall, women were less likely than men to achieve all treatment targets, but no significant differences were found for all lifestyle targets. Sex disparities in reaching treatment targets were smaller in Europe than in Asia and the Middle East. Women in Asia were more likely than men to reach all lifestyle targets, but the reverse was seen in Europe and the Middle East.
Reduction of risk of developing CVD involves lifestyle modifications, drug treatment and effective management of any overt underlying medical condition - eg, diabetes, hypertension, hyperlipidaemia[2, 3, 5].
All patients with CVD can benefit from programmes to encourage behavioural change[6, 3]. However, greater access for patients could be achieved through the automatic referral of all eligible patients to cardiac rehabilitation; hospital-based programmes are effective, and evidence suggests that patients who choose not to access them can also benefit from home-based or community-based schemes.
- Consider setting up a disease register and systematic recall with a nurse-led secondary prevention clinic. Evidence supports their efficacy in the short term, but is lacking over a 10-year follow-up.
- Smoking cessation: all patients should be actively discouraged from smoking - repeated brief supportive advice, combined with nicotine replacement therapy when needed. Passive smoking may also increase risk but this remains contentious.
- Keep total dietary intake of fat to a maximum of 30% of total energy intake, with intake of saturated fats 10% or less of total fat intake and the intake of dietary cholesterol to less than 300 mg/day. Saturated fats should be replaced with an increased intake of monounsaturated fats.
- Consumption of fresh fruit and vegetables should be increased to at least five portions per day. A Mediterranean diet has been shown to reduce mortality. Regular intake of fish (twice a week) and at least one of those to be oily fish.
- Limit the intake of salt to less than 100 mmol/L per day (less than 5 g of salt per day)[3, 11].
- Alcohol consumption should be limited to three units per day (21 units per week) for men and two units per day (14 units per week) for women.
- Patients should be encouraged to exercise regularly:
- Exercise training has been shown to slow the progression or partially reverse the severity of coronary atherosclerosis.
- Aerobic exercise can modify all the components of the metabolic syndrome with a decrease in blood pressure and triglycerides, increase in HDL, and an improvement of insulin sensitivity.
- Weight control:
- Overweight patients should be encouraged to lose weight through a combination of diet and exercise.
- Maintain an ideal body weight for adults (body mass index 20-25 kg/m2) and avoid central obesity (waist circumference in white Caucasians less than 102 cm (40 inches) in men and less than 88 cm (circa 34½ inches) in women); in Asians, the recommended targets are less than 90 cm (35 inches) in men and less than 80 cm (circa 31½ inches) in women.
Blood pressure management
See also separate article Management of Hypertension:
- The optimal blood pressure target is less than 140 mm Hg systolic and less than 85 mm Hg diastolic.
- In selected higher-risk people (eg, established atherosclerotic disease, diabetes, and chronic kidney disease) a lower blood pressure target of less than 130 mm Hg and less than 80 mm Hg may be more appropriate.
- Recommended for all people following myocardial infarction unless there are contra-indications.
- Angiotensin-converting enzyme (ACE) inhibitors:
- Recommended for people with symptoms or signs of heart failure at the time of myocardial infarction, or for those with persistent left ventricular systolic dysfunction (ejection fraction less than 40%) following infarction.
- Should be considered for others with coronary artery disease, especially if the blood pressure is not below the target of less than 130 mm Hg systolic and less than 80 mm Hg diastolic.
- An angiotensin-II receptor antagonist is an alternative to an ACE inhibitor if an ACE inhibitor is associated with side-effects.
- An ACE inhibitor should be considered in combination with a thiazide diuretic in all people with an established stroke, especially if the blood pressure is not below the target of less than 130 mm Hg systolic and less than 80 mm Hg diastolic.
- Calcium-channel blockers (CCBs) and diuretics:
- These should be considered in all high-risk people if the blood pressure is not below the target (although purely as secondary prevention agents, CCBs are ineffective).
See also separate article Hyperlipidaemia:
- The optimal total cholesterol target is less than 4.0 mmol/L and low-density lipoprotein (LDL) cholesterol less than 2.0 mmol/L, or a 25% reduction in total cholesterol and a 30% reduction in LDL cholesterol, whichever gets the person to the lowest absolute value[3, 5].
- Fasting lipids should be estimated at least eight weeks after an acute cardiovascular event and, if necessary, the dose of statin up-titrated to achieve the total and LDL cholesterol targets. HDL cholesterol and fasting triglycerides should be measured and considered at the same time.
- Statins are recommended for:
- All high-risk people with established atherosclerotic disease.
- In the following people with diabetes:
- All those who are aged 40 years or more with either type 1 or type 2 diabetes.
- People aged 18-39 years with either type 1 or type 2 diabetes and who have at least one of the following:
- Retinopathy (preproliferative, proliferative, maculopathy).
- Nephropathy, including persistent microalbuminuria.
- Poor glycaemic control (HbA1c greater than 9%).
- Elevated blood pressure requiring antihypertensive therapy.
- Raised total blood cholesterol (greater than 6.0 mmol/L).
- Features of metabolic syndrome (central obesity and fasting triglyceride greater than 1.7 mmol/L (non-fasting >2.0 mmol/L) and/or HDL cholesterol less than 1.0 mmol/L in men or less than 1.2 mmol/L in women).
- Family history of premature CVD in a first-degree relative.
- Primary prevention for those who are at >10% risk of developing CVD.
- There is a greater risk of developing muscle problems when the patient is also taking amlodipine or diltiazem. The dose of statin may need adjusting.
- Other classes of lipid-lowering drugs (particularly fibrates, bile acid sequestrants, cholesterol absorption inhibitors, nicotinic acid, omega-3 (n-3) fatty acids) should be considered in addition to a statin if the total and LDL cholesterol targets have not been achieved, or if there are other lipid abnormalities - eg, HDL cholesterol or triglycerides.
Blood glucose and diabetes
- In all high-risk people the optimal fasting glucose is less than 6.0 mmol/L.
- For people with impaired fasting glycaemia or impaired glucose tolerance: review annually to reassess glucose regulation and all other cardiovascular risk factors.
- People with types 1 and 2 diabetes mellitus: rigorous control of glycaemia. The optimal target for glycaemic control in diabetes is a fasting or preprandial glucose value of 4.0-6.0 mmol/L and an HbA1c less than 6.5%.
- Coronary or peripheral atherosclerosis:
Cerebral atherosclerotic disease (non-haemorrhagic):
- Aspirin 75 mg daily is recommended for life for all people with coronary or peripheral atherosclerotic disease. If aspirin is contra-indicated, or there are side-effects, then clopidogrel is appropriate.
- Results in primary prevention are inconclusive. Recent studies have found that aspirin doubles the risk of gastrointestinal bleeding and current opinion is that this outweighs any benefits which might be conferred in reducing the onset of CVD.
- Anticoagulation should be considered for selected people at risk of systemic embolisation from large myocardial infarctions, heart failure, left ventricular aneurysm, or paroxysmal tachyarrhythmias.
- All people with a history of cerebral infarction, or transient ischaemic attack, and who are in sinus rhythm, should take low-dose aspirin plus modified-release (MR) dipyridamole for two years following the initial event to prevent stroke recurrence as well as other vascular events.
- For those who have a further ischaemic cerebrovascular event while taking aspirin and MR dipyridamole, then changing aspirin for clopidogrel should be considered.
- Anticoagulation with warfarin should be considered for all people with atrial fibrillation who are at moderate (aged 60-75 years without additional risk factors) to high risk (over 75 years, or over 60 years with other risk factors such as hypertension, diabetes, or left ventricular dysfunction) to reduce the risk of a further stroke.
- If oral anticoagulation is contra-indicated, or cannot be tolerated, antiplatelet therapy should be considered instead.
- There is no evidence of benefit for anticoagulation in people with ischaemic stroke who are in sinus rhythm.
- Amiodarone significantly reduces the risk of cardiac mortality after myocardial infarction in those with high risk of arrhythmic death.
- Beta-blockers (see above) have a favourable interaction with amiodarone, with additional reduction in mortality (however, sotalol increases mortality after myocardial infarction in those with left ventricular dysfunction).
After assessment with an exercise tolerance test, echocardiography, angiography, and scanning, the following may be beneficial where appropriate:
- Coronary artery bypass grafting: reduces mortality compared with medical treatment alone, particularly in those with poor left ventricular function.
- Percutaneous transluminal coronary angioplasty (PTCA).
- Intracoronary stent: particularly useful for restenosis after PTCA.
- Atherectomy by various methods, and transmyocardial laser revascularisation are less common procedures used.
Psychosocial risk factors
Increased CVD death and disability have been associated with:
- Low socio-economic status
- Social isolation
- Work-related stress
- Panic attacks
Some of these risk factors can be difficult to control for and require intervention at a government level.
Future aspects of CVD prevention
Effective CVD prevention depends in part on accurate determination of risk. Risk determination is more difficult in those who are asymptomatic. Newer aspects of risk determination include:
- Biomarkers of CVD - eg, high-sensitivity C-reactive protein and homocysteine.
- Imaging for atherosclerotic disease - this includes looking for plaques (eg, CT scan of the coronary arteries looking at calcium levels and/or imaging the carotid artery intima-media thickness).
Further reading and references
2016 European Guidelines on cardiovascular disease prevention in clinical practice; European Society of Cardiology (2016)
Cardiovascular disease prevention; NICE Public Health Guideline (June 2010)
Performance Measures for Primary Prevention of Cardiovascular Disease in Adults; American Heart Association, 2009
European guidelines on cardiovascular disease prevention in clinical practice; European Society of Cardiology (2012)
Zhao M, Vaartjes I, Graham I, et al; Sex differences in risk factor management of coronary heart disease across three regions. Heart. 2017 Sep 20. pii: heartjnl-2017-311429. doi: 10.1136/heartjnl-2017-311429.
Lipid modification - cardiovascular risk assessment and the modification of blood lipids for the prevention of primary and secondary cardiovascular disease; NICE Clinical Guideline, July 2014 (updated September 2016)
Murphy AW, Cupples ME, Smith SM, et al; Effect of tailored practice and patient care plans on secondary prevention of BMJ. 2009 Oct 29339:b4220. doi: 10.1136/bmj.b4220.
Cardiac Rehabilitation; British Heart Foundation
Clark AM, Dalal HM, Dafoe W, et al; Effectiveness of secondary prevention programmes in CHD. Lancet. 2009 May 16373(9676):1671
Delaney EK, Murchie P, Lee AJ, et al; Secondary prevention clinics for coronary heart disease: a 10-year follow-up of a Heart. 2008 Nov94(11):1419-23. Epub 2008 Jan 15.
CVD risk assessment and management; NICE CKS, December 2008 (UK access only)
He FJ, Li J, Macgregor GA; Effect of longer term modest salt reduction on blood pressure: Cochrane systematic review and meta-analysis of randomised trials. BMJ. 2013 Apr 3346:f1325. doi: 10.1136/bmj.f1325.
Guidelines for the management of arterial hypertension; ESH/ESC Clinical Practice Guidelines, European Society of Cardiology (2013)
Simvastatin patient information article; Medicines and Healthcare products Regulatory Agency (MHRA), October 2012
Baigent C, Blackwell L, Collins R, et al; Aspirin in the primary and secondary prevention of vascular disease: collaborative meta-analysis of individual participant data from randomised trials. Lancet. 2009 May 30373(9678):1849-60.
Barnett H, Burrill P, Iheanacho I; Don't use aspirin for primary prevention of cardiovascular disease. BMJ. 2010 Apr 21340:c1805. doi: 10.1136/bmj.c1805.
Julian DG, Camm AJ, Frangin G, et al; Randomised trial of effect of amiodarone on mortality in patients with Lancet. 1997 Mar 8349(9053):667-74.