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Prevention of cardiovascular disease: new guidelines, new tools, but challenges remain
  1. Joep Perk1,
  2. Ian Graham2,
  3. Guy De Backer3
  1. 1Linnaeus University, Health and Caring Sciences, Kalmar, Sweden
  2. 2Trinity College, Adelaide and Meath Hospital, Dublin, Ireland
  3. 3Department of Public Health, University of Ghent, Ghent, Belgium
  1. Correspondence to Dr Joep Perk, Linnaeus University, Health and Caring Sciences, Kalmar, 391 82 Sweden; joep.perk{at}lnu.se

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The publication of the new “Joint British Societies’ consensus recommendations for the prevention of cardiovascular disease (JBS3)” in a supplement to Heart1 raises several questions. Should the prevention of cardiovascular disease (CVD) still be a priority for clinical practice and for health policy decision makers? If so, why? Given the recent guidelines from Europe2 and America,36 do we need more?

Over the past decades there has been an impressive decline in age standardised mortality due to CVD. In several European countries CVD mortality rates have more than halved, but the case for prevention remains robust. In the majority of countries, CVD is still the leading cause of premature mortality, of reduced disability adjusted life-years (DALYs), and of high direct and indirect healthcare costs.

Even if developments in acute interventions and effective drug treatment have contributed to reduced mortality, changes in health behaviour and risk factor control at the population level explain the major part of the decline.7

Risk factor control

Despite these findings, risk factor control even in subjects at highest risk—those with established CVD—remains suboptimal. Large surveys of the clinical practice of preventive cardiology, such as EUROASPIRE III8 and EURIKA,9 have shown that in spite of an increase in the use of cardioprotective drugs, many patients with CVD do not reach the target levels set in the 2007 European guidelines. Furthermore, using the National Health and Nutrition Examination Survey 1988–1994 and subsequent 2-year cycles during 1999–2008, it is estimated that the American Heart Association (AHA) target of improving cardiovascular health by 20% by 2020 will not be reached if current trends continue.10 According to the World Health Organization1,1 80% of all CVD could be prevented, but apparently this remains an unrealistic vision. Clearly, the challenges facing prevention, both in public health and in clinical practice, continue to be strong, as does the need for ongoing preventive efforts. Therefore, the publication of the JBS3 guidelines,1 shortly after the 2013 US guidance, is both timely and relevant to the ongoing need for preventive efforts.

The three sets of documents from Europe,2 the USA,36 and the UK1 focus on the assessment and management of persons at increased CVD risk. While the underlying rationale is agreed, there are some distinct differences in emphasis. All of these guidelines accept the principle that an estimate of total CV risk should be used to help the clinician in choosing the most appropriate strategy for the primary prevention of CVD. Having said that, and as pointed out by Ridker,1,2 recent randomised controlled trials relevant to CVD prevention have focused on single risk factors rather than total risk—probably because they are almost always funded by industries with an interest in a specific drug.

Risk calculators

Different risk calculators are advocated for the assessment of total CVD risk. The SCORE algorithm, used in the European guidelines, estimates the 10-year CVD mortality risk, based upon gender, age, smoking, systolic blood pressure, total cholesterol, and high density lipoprotein (HDL) cholesterol, using a large European database. It can be used with a simple desktop chart or in an electronic application (Heartscore). The risks derived are combined with other relevant data such as established CVD, diabetes, and renal impairment to assign subjects to very high, high, moderate, and low risk categories.

The US document recommends a risk calculator that assesses the 10-year risk for a first hard atherosclerotic CVD event related to gender, age, smoking, systolic blood pressure, total and HDL cholesterol, and diabetes. It is based upon the best available data from community based cohorts of adults, with adjudicated endpoints for coronary heart disease (CHD) death, non-fatal myocardial infarction, and fatal or non-fatal stroke. The document has been criticised on the grounds that the new risk calculator may overestimate risk, and because the proposed threshold for statin treatment for symptom-free persons would imply a considerable widening of the population in need of treatment.

JBS3 has chosen QRISK Lifetime as the basis because it provides the option of a calculation of the 10-year absolute risk for CVD mortality and morbidity and of the lifetime risk. It is based on a UK population and should therefore only be used with caution in other populations. In addition to the items in SCORE and the US calculator it includes ethnicity, heredity, height, weight, and the presence of chronic kidney disease, atrial fibrillation, and rheumatoid arthritis. The derivation dataset is very large but is not based on randomly selected population samples, and substantial data are missing. The method must be used in an electronic version and at present no cut-off level for treatment has been defined pending a final decision from National Institute for Health and Care Excellence (NICE). The website of the calculator was open for testing at the time of preparing this editorial. The calculator appeared to be a user-friendly and informative model. External validations of both the American College of Cardiology (ACC)/AHA and JBS3 risk estimation systems are limited.

Risk calculation—a risky business

Risk calculation remains a risky business.1,3 The use of an absolute 10-year risk will underestimate the lifetime risk in younger adults and in females, with the potential to delay preventive counselling. The additional use of relative risk as originally proposed in the 2003 European guidelines may help and appears to have been well accepted in general practice. The introduction of heart age or vascular age may be a useful addition: the ‘heart age’ of a person is calculated by estimating the age of someone of the same gender and with the same risk of an event, but with all other risk factors at optimal levels. While the concepts of risk age and lifetime risk are felt to be useful ways to explain risk to the public—which is certainly needed in order to promote heart healthy behaviour—this needs further testing.

The authors of the JBS3 guidelines have taken the concept of lifetime risk a step further since the 2012 European guidelines. Their ambition is to provide health workers, especially general practitioners, with answers to three key questions: Why should I start advising CVD risk reduction? When should I start? And what should I do? However relevant these questions are, it should be noted that the proposed model has to our knowledge not been tested on a large scale. This remains the major shortcoming of all three sets of guidelines: in comparison with new drugs or technical equipment where extensive documentation is needed for approval, the methods for risk assessment or calculators remain remarkably poorly tested. On the one hand wide application in clinical practice is advocated, while on the other hand little is yet known about feasibility, acceptance rate in a busy general practice, the understanding of the patient, or even the effect on individual behaviour. This is clearly an important challenge for future studies.

Management of cardiovascular risk

There are few differences in the management of cardiovascular risk between the European, US, and UK publications. Management is related to the level of risk, but the use of four different risk groups in the European guidance has not been taken over into the JBS3 document, which may be deplored. There is agreement on smoking cessation support, no major difference in the recommendation for physical activity, and minor differences in nutritional guidance: trans-unsaturated fatty acids are not mentioned, and a higher level of daily salt intake is in the JBS3 publication, but the role of physicians in combating the obesity epidemic is well underlined.

In the US guidelines no target value for low density lipoprotein (LDL) cholesterol has been included, in contrast to earlier UK and European guidelines, which has caused debate. In the UK material the use of non-HDL cholesterol is recommended with a target value for those at very high risk below 2.5 mmol/L, which is equivalent to 1.8 mmol/L of LDL cholesterol. The rationale for and the consequences of this change from LDL to non-HDL cholesterol remains less well documented. Even the cut-off level for individuals at high risk remains to be defined. The recommendations for blood pressure contain excellent guidance for the use of 24 h ambulatory measurement and for home measurement of blood pressure.

Differences in format, not science

The main differences between the three sets of guidelines lie in the format, not in the scientific content. The 2012 European guidelines represent a consensus between all the major European players in CVD prevention. They are shorter and are structured around five main questions, including a chapter on where CVD prevention programmes should be offered. They use the common ACC/AHA–European Society of Cardiology grading system for scientific evidence and in addition include the GRADE system to help give due emphasis to lifestyle measures. Considerable efforts have been made to make the information accessible through pocket guidelines and resources such as the prevention ‘toolkit’, available through http://www.escardio.org. The US guidelines are spread over four different publications, introduce a new risk calculator, and lack target values for blood lipids and guidance on smoking cessation. The JBS3 publication has excellent strict scientific merits, is considerably longer, advocates a new risk calculator, extends the application of lifetime risk, and does not use any grading of evidence or recommendation. Which format should be preferred? This remains a matter of personal choice by the individual health professional—some may prefer short practical guidance, others a more in-depth document.

Finding common ground between guidelines

One slightly disconcerting aspect of both the ACC/AHA and JBS3 guidelines is their apparent lack of awareness of guidelines from other countries and continents—for example, Europe, New Zealand, Australia, Canada, and indeed WHO. It is suggested that the challenge is to find common ground and complementarities between guidelines on prevention, rather than nit-picking about differences. There seems good agreement with regards to basic principles. It is more important to agree about the need to assess risk and advise accordingly than to argue too obsessively about how this is done, while reserving the right to comment on such aspects as the potential for excessive use of drugs1,4 Above all, the challenge is in implementation—making the key messages easily accessible to both health professionals and the public, and learning more about facilitating behaviour change.

In conclusion, there is still a need for guidance in CVD prevention, and JBS3 may well prove to be a valuable contribution, especially if the lifetime risk concept should lead to a better understanding of the need for preventive support by physicians and other health workers.

References

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Footnotes

  • Contributors JP compiled the first draft, whereafter IG and GDB contributed with several revisions.

  • Competing interests None.

  • Provenance and peer review Commissioned; internally peer reviewed.

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