Dr Rajiv Rampat (left) and Professor Adam Timmis discuss the lifestyle and drug treatment recommendations on secondary prevention following a myocardial infarction

  • Advise patients who have had an MI to:
    • quit smoking
    • consume alcohol within safe limits (<21 units/week for men and <14 units/week for women)
    • exercise for 20–30 minutes each day to the point of breathlessness
    • achieve and maintain a healthy weight
    • incorporate a Mediterranean-style diet
  • Patients should be offered the option of participation in a cardiac rehabilitation programme that has an exercise component
  • Treatment with a combination of an antiplatelet agent, an ACE inhibitor, a beta blocker, and a statin is recommended for all patients who have had an MI
  • Management of patients following an MI should incorporate recommendations from both the QOF and the NICE guideline
  • GPs should ensure that all patients who qualify for medication are offered treatment
  • Nurse-led secondary prevention clinics may be one way to improve medical treatment and lifestyle modification

Cardiovascular disease is the leading cause of death in the industrialised world, costing the NHS an estimated £3.2 billion in 2006.1 The National service framework for coronary heart disease, published in 2006, emphasised the role of primary care in reducing cardiovascular mortality through secondary prevention coupled with comprehensive cardiac rehabilitation programmes.2 There is strong evidence that adoption of multidisciplinary disease management programmes have a beneficial impact on cardiovascular morbidity and mortality.3

Guidelines aim to standardise medical practice with a view to improving patient care, reducing health inequalities, and providing a coherent, up-to-date, evidence-based framework through which health policies can be implemented nationally. The National Institute for Health and Care Excellence (NICE) is the leading organisation responsible for this task in the UK. In 2007, NICE issued Secondary prevention in primary and secondary care for patients following a myocardial infarction (MI).4 The NICE guideline builds on a previous guideline, which was published in 2001.5 It updates the role of pharmacotherapy and emphasises the importance of a multidisciplinary approach to improve prognosis after an acute MI. Recommendations are divided into two broad categories—lifestyle changes and drug therapy—which are detailed below.

Lifestyle interventions

The NICE guideline contains a number of key recommendations on lifestyle changes following an MI:4

  • Patients should be advised to quit smoking and offered the use of smoking cessation services where necessary
  • Alcohol consumption should be within safe limits (<21 units/week for men and <14 units/week for women), with avoidance of binge drinking
  • The benefits of physical activity are emphasised with a recommendation for 20–30 minutes of exercise each day to the point of breathlessness. For patients unable to achieve this target, the aim should be to gradually step-up their activity to increase exercise capacity. Specific advice should be tailored to meet the patient’s needs
  • Weight management is an important factor, and doctors are encouraged to provide patients with advice and support to achieve and maintain a healthy weight that is in line with NICE guidance6
  • A change in dietary regimen that incorporates a Mediterranean-style diet is recommended: more bread, fruit, vegetables, and fish; reducing intake of meat; and substituting butter and cheese with products based on vegetable and plant oils. In addition, the guideline recommends that at least 7 g of omega 3 fatty acids should be consumed per week, equivalent to 2–4 portions of oily fish. Individuals not achieving the target within 3 months of their MI should receive at least 1 g daily of omega 3 acid ethyl esters treatment for up to 4 years
  • After an MI all patients should be offered the option of participation in a cardiac rehabilitation programme, which has an exercise component.

Drug therapy

The NICE guideline recommends that all patients with a previous MI should be offered treatment for an indefinite period with the following classes of drugs: an antiplatelet agent, an angiotensin-converting enzyme (ACE) inhibitor, a beta blocker, and a statin provided there are no contraindications.4

Antiplatelet therapy
All patients should receive aspirin if it is not contraindicated. Dual antiplatelet therapy with clopidogrel should continue for 12 months following a non-ST segment elevation MI and for at least 4 weeks after a ST segment elevation MI. In case of intolerance to aspirin, clopidogrel monotherapy should be considered as an alternative. Treatment with a proton pump inhibitor and low-dose aspirin should be considered in patients with a history of aspirin-induced ulcer bleeding whose ulcers have healed, and who are negative for Helicobacter pylori.4

ACE inhibitors
Angiotensin-converting enzyme inhibitors should be titrated, if possible at weekly intervals, to the maximum tolerated or target dose. Renal function, serum electrolytes, and blood pressure should be measured before starting treatment and after each dose increment. Annual monitoring is recommended after maximal dose is achieved. If a patient is intolerant of the medication (e.g. because of cough), angiotensin II receptor blockers (ARBs) should be substituted.4

Beta blockers
Beta blockers should be titrated to the maximum tolerated dose, but if contraindicated, diltiazem or verapamil may be considered in patients without pulmonary congestion or left ventricular (LV) systolic dysfunction.4

Statins
All patients should be offered treatment with a statin and individuals who are intolerant should be considered for other lipid-lowering agents. Baseline liver enzymes should be measured before initiating treatment.4

Other medication
Warfarin may be appropriate for patients who are intolerant of both aspirin and clopidogrel. Aldosterone antagonists should be given to patients who have had an acute MI and LV dysfunction and/or signs of heart failure. These agents should be started within 3–14 days of the MI, preferably after ACE inhibitor therapy. Renal function and serum potassium should be monitored before and during treatment; if hyperkalaemia is present, the dose should be halved or the drug discontinued.4

Implementation

Over the past two decades, there has been a steady decline in mortality from coronary heart disease (CHD) in the UK.7 This trend has been attributed to many factors including better provision of drug treatment for secondary prevention and a reduction in risk factors (e.g. smoking). Improvements in the prescription of drug treatment may be responsible for a drop in CHD mortality rates of 11% from 1981 to 2000.7 Education aimed at promoting awareness of secondary prevention has probably played an influential part. However, while there has been undeniable progress over the past few decades, there is still considerable room for improvement.8

The Department of Health introduced the quality and outcomes framework (QOF) in 2004 as a scheme to provide general practices with financial incentives based on achieving set targets.9 There is evidence that this ‘pay for performance’ strategy has contributed to an improvement in the provision of healthcare in primary practice, although this had already been on an upward trend.10,11 However, caution should be exercised if relying on the QOF indicators as a sole measure of performance as they do not cover all of the recommendations made by NICE. There is a very real danger of focusing resources predominantly on achieving targets, which may be detrimental to equally important measures that are not represented in the QOF.

There is a degree of variation in the national implementation of the NICE guideline on the secondary prevention of MI.12 One of the reasons may be a lack of consistency in the distribution and enforcement of the guidelines. This is variably the remit of either local hospitals or primary care trusts depending on the region. Nurse-led secondary prevention clinics have proved effective at improving both medical treatment and lifestyle modification.13,14

It is also noteworthy that while NICE is the leading body in providing national guidelines, other organisations and professional bodies also develop guidelines, and there can be discrepancies between recommendations. For example, the total cholesterol target in patients who have had an MI is: <4 mmol/l in the NICE guideline,4 but <5 mmol/l for the Scottish Intercollegiate Guidelines Network guideline,15 QOF,8 and the NSF for CHD.2

Drug therapy
There is compelling evidence that combined drug therapy for secondary prevention of MI results in significant risk reduction.16 Use of these drugs has been increasing over the last decade: in 2005 80% of men with ischaemic heart disease were on a statin, 75% on antiplatelet therapy, 55% on beta blockers, and 57% on ACE inhibitors; however, only 55% received combined triple therapy.17

Improving prescription rates through the QOF initiative is important, but this must be coupled with measures to improve patient compliance with the prescribed secondary prevention regimen.18,19 The use of drugs is lower in elderly patients, this is particularly apparent with the use of statins in older patients where there is a perception that treatment is not cost effective. This trend is particularly concerning as elderly patients constitute the group with the highest rate of cardiovasular events.20

There also appears to be gender discrimination in the provision of treatment,20,21 with women being unfairly disadvantaged despite the fact that medication benefits both men and women equally.22 This may be in part because of the fact that women with chest pain and normal coronary arteries present more frequently than men. This may lead to under-investigation of chest pain compared with men in the false belief that angina is more benign in women.20,23

The ‘polypill’ is a potentially attractive option that combines key treatments—statin, aspirin, and drugs for lowering blood pressure–within a single pill, but its efficacy remains to be proven in clinical trials.24 Although primarily aimed at primary prevention, it could also have a role in secondary prevention of MI.

Lifestyle changes
Lifestyle adjustments are notoriously more difficult to implement than prescription of regular medication. The Mediterranean diet advocated by NICE can be particularly problematic, especially in some ethnic communities where dietary patterns are so culturally rooted. Smoking cessation is another example of lifestyle adjustment that is difficult to achieve. However, notable advances have been made in recent years with the development of specialist smoking cessation services that embrace pharmacological methods and behavioural therapy.4,25

Conclusion

The NICE guideline provides a coherent framework from which optimal secondary prevention of MI can be achieved. Translating the guidance into practice poses a particular challenge in the primary care setting, but substantial progress has been made in recent years with changes in the prescribing environment, implementation of specialist and often nurse-led clinics, and treatment programmes.

  • Secondary prevention of MI is an ideal area for PBC consortia to agree a local care pathway to ensure all patients get optimal treatment
  • Specialist cardiac rehabilitation nursing services could be commissioned in the community to see all patients who have had an MI (and avoid hospital tariff charges)
  • Most of the drug therapies are now available generically at low acquisition cost and local formularies should ensure best value from the prescribing budget (in particular statins)
  • PBC consortia could stipulate, in contracts with secondary care services, their responsibilities in commencing secondary prevention after acute MI
  • Audits of the care pathway at key intervals (e.g. at hospital discharge, 3 months, and one year after the event) would ensure commissioned services are delivering their responsibility
  1. British Heart Foundation Statistics website. Healthcare and economic costs of CVD and CHD. www.heartstats.org/datapage.asp?id=101 (accessed 21 January 2010).
  2. Department of Health. National service framework for coronary heart disease: modern standards and service models. London: DH, 2000. Available at: www.dh.gov.uk/en/Publicationsandstatistics/Publications/PublicationsPolicyAndGuidance/DH_4094275
  3. McAlister F, Lawson F, Teo K et al. Randomised trials of secondary prevention programmes in coronary heart disease: Systematic review. BMJ 2001; 323 (7319): 957–962.
  4. 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. Available at: www.nice.org.uk/guidance/CG48
  5. National Institute for Heath and Clinical Excellence. Prophylaxis for patients who have experienced a myocardial infarction. Clinical Guideline A. London: NICE, 2001.
  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. Available at: www.nice.org.uk/guidance/CG43
  7. Unal B, Critchley J, Capewell S. Explaining the decline in coronary heart disease mortality in England and Wales, 1981–2000. Circulation 2004; 109 (9): 1101–1107.
  8. EUROASPIRE II Study Group. Lifestyle and risk factor management and use of drug therapies in coronary patients from 15 countries. Principal results from EUROASPIRE II Euro Heart Survey Programme. Eur Heart J 2001; 22 (7): 554–572.
  9. Department of Health. Quality and outcomes framework. Guidance—updated August 2004. London: DH, 2004. Available at: www.dh.gov.uk/en/Healthcare/Primarycare/Primarycarecontracting/QOF/index.htm
  10. Strong M, Maheswaran R, Radford J. Socioeconomic deprivation, coronary heart disease prevalence and quality of care: a practice-level analysis in Rotherham using data from the new UK general practitioner quality and outcomes framework. J Public Health 2006; 28 (1): 39–42.
  11. Cupples M, Byrne M, Smith S et al. Secondary prevention of cardiovascular disease in different primary healthcare systems with and without pay-for-performance. Heart 2008; 94 (12): 1594–1600.
  12. Ong S, Milne D, Morrell J. Post-MI clinical guidelines: variation in availability, development, content and implementation across the UK. Br J Cardiol 2009: 16 (3): 142–146.
  13. Campbell N. Secondary prevention clinics: improving quality of life and outcome. Heart 2004; 90 (Suppl IV): 29–32.
  14. Khunti K, Stone M, Paul S et al. Disease management programme for secondary prevention of coronary heart disease and heart failure in primary care: a cluster randomized controlled trial. Heart 2007; 93 (11): 1398–1405.
  15. Scottish Intercollegiate Guidelines Network. Risk estimation and the prevention of cardiovascular disease. SIGN 97. Edinburgh: SIGN, 2007. Available at: www.sign.ac.uk/pdf/sign97.pdf
  16. Hippisley-Cox J, Coupland C. Effects of combinations of drugs on all cause mortality in patients with ischemic heart disease: nested case-control analysis. BMJ 2005; 330 (7499): 1059–1063.
  17. DeWilde S, Carey I, Richards N et al. Trends in secondary prevention of ischemic heart disease in the UK 1994–2005: use of individual and combination treatment. Heart 2008; 94 (1): 83–88.
  18. Biondi-Zoccai G, Lotrionte M, Agostoni P et al. A systematic review and meta-analysis on the hazards of discontinuing or not adhering to aspirin among 50,279 patients at risk for coronary heart disease. Eur Heart J 2006; 27 (22): 2667–2674.
  19. Newby L, LaPointe N, Chen A et al. Long-term adherence to evidence-based secondary prevention therapies in coronary artery disease. Circulation 2006; 113 (2): 203–212.
  20. Simpson C, Hannaford P, Williams D. Evidence for inequalities in the management of coronary heart disease in Scotland. Heart 2005; 91 (5): 630–634.
  21. Hippisley-Cox J, Pringle M, Crown N et al. Sex inequalities in ischemic heart disease in general practice: Cross sectional survey. BMJ 2001; 32 (7290): 832–834.
  22. Wenger N, Lewis S, Welty F et al. Beneficial effects of aggressive low-density lipoprotein cholesterol lowering in women with stable coronary artery disease in the Treating to New Targets (TNT) study. Heart 2008; 94 (4): 434–439.
  23. Wenger N. Gender, coronary artery disease and coronary bypass surgery. Ann Intern Med 1990; 112 (8): 557–558.
  24. Wald N, Law M. A strategy to reduce cardiovascular deaths by more than 80%. BMJ 2003; 326 (7404): 1419.
  25. West R. Smoking: Prevalence, mortality and cessation in Great Britain. London: Cancer Research UK, UCL, 2007. Available at: www.rjwest.co.uk/resources/smokingcessation.docG