South African Dyslipidaemia Guideline Concensus Statement 2012

Published recently in the South African Medical Journal 2012; 102: 177-188 are the consensus guidelines for the management of dyslipidaemia. I have taken extracts directly from this paper to highlight the 2012 guidelines.

Introduction:

South Africa is a multi-ethnic society, with a large range of cultures and lifestyles at different stages of epidemiological transition. In all sub-populations, cardiovascular disease is a major cause of morbidity and mortality. Every day, approximately 80 people die of myocardial infarction or heart failure, while another 60 die due to stroke.

The INTERHEART Africa study indicated that more premature acute myocardial infarctions occur in sub-Saharan Africa than in any other of the 52 countries participating in the INTERHEART study.

This statistic reflects a lack of prevention, early detection and effective management of cardiovascular risk factors in the countries of this region.In particular in the black population increasing urbanisation and adoption of an unhealthy lifestyle, the prevalence of cardiovascular disease (CVD) and the incidence of premature death are likely to continue to increase.

Consequently, the timely institution of lifestyle modification, early diagnosis and effective management of CVD risk factors are essential to curb the epidemic of cardiac disease that has been seen in other countries.

In 2003, the South African Heart Association (SA Heart) and the Lipid and Atherosclerosis Society of Southern Africa (LASSA) officially adopted the European Guidelines for the Prevention of Cardiovascular Disease to replace the SA Lipid guidelines published in 2000.

The European document has recently been updated with the publication of the European Society of Cardiology (ESC)/European Society of Atherosclerosis (EAS) Guideline for the Management of Dyslipidaemias in 2011.

This Consensus Statement promotes current best management of dyslipidaemia and should be adopted by all health care professionals in South Africa.

Using a cardiovascular risk stratification score:

High risk for CVD

Individuals who are considered to be at very high risk of cardiovascular events (>30% risk of a suffering a cardiovascular event over next 10 years) are listed in Table 1. Patients in this group DO NOT require cardiovascular risk scoring, because the risk score will be an underestimate in these settings.

Risk scoring using well-documented key risk factors is appropriate to estimate the total cardiovascular risk in asymptomatic adults. This risk scoring is especially important in individuals with the following:

  • Those with hypertension and or on antihypertensive medication
  • Those who smoke any form of tobacco product
  • BMI ≥30 kg/m2 or waist circumference > 94 cm for men, >80 cm for women
  • People with “metabolic syndrome”
  • Family history for premature cardiovascular disease (in males < 55 years and female before 60 years)
  • Auto-immune chronic inflammatory disease such as rheumatoid arthritis, systemic lupus erythematosus, psoriasis

When to start screening for CVD (when to risk stratify):

In South Africa, because the prevalence of familial hypercholesterolaemia is as high as 1 in 100 in some communities, each individual should be tested, preferably with a full lipogram or at least TC/LDL-C, at least once in young adulthood (from 20 years of age). Particular attention should be paid to individuals with other risk factors for CVD (list above).

How to use the risk scoring system:

The European guidelines use the Systematic Coronary Risk Estimation(SCORE) system to estimate cardiovascular risk. Because this scoring system is based on an exclusively European population, it may not accurately reflect coronary risk in South Africa. While it is recognised that it would be impossible to accurately estimate risk in all South African subpopulations with a single data set, the Adult Treatment Panel (ATP) III Framingham risk tables provide and estimate of the 10-year risk of any cardiac event have been validated in white and black populations in the USA and are transportable to other culturally diverse populations. Consequently, we considered this approach to be more appropriate for South Africa. Nevertheless, these risk tables are likely to underestimate risk in South African black and Indian patients. The Framingham CHD tables may also underestimate total CVD risk in middle-aged and older women, whose risk of stroke and heart failure is typically higher than that of CHD. 

Consequently, more recent Framingham equations predict 10-year total CVD risk (including CHD, stroke, transient ischaemic attack and heart failure).The updated Framingham CVD risk tables for men and women and an algorithm for management and cholesterol goals have been incorporated into these recommendations (Appendix 1). Appendix 1a

Appendix 1b

Appendix 1c

Appendix 1d

The points are added to calculate the 10 year risk for men and women.

Points men

Points women

The risk is defined as the following:

Points risk

The goals of treatment follow the risk:

Treatment goals

In all cases of dyslipidaemia it is important to exclude and manage any secondary cause of abnormal lipids:

Secondary causes dyslipidaemia

The use of Statins:

Statins have demonstrated effectiveness in both primary and secondary prevention. The effect is dependent on the extent to which LDL-C is lowered and not on the type of statin used. At their maximum doses, the various statins differ in their capacity to lower LDL-C.

For every mmol/l reduction in LDL-C there is a:

  • 10% reduction in total mortality
  • 20% reduction in all-cause mortality
  • 23% recudtion in major cardiac events
  • 17% reduction in stroke

The effect of statin therapy is similar in all patient subgroups and becomes significant after 1 year, increasing progressively thereafter.

The scheme for introducing Statin therapy:

  • First evaluate the risk
  • Involve the patient in CV risk management and decisions
  • Identify the LDL-C target based on the risk
  • Calculate the % reduction in LDL-C required to reach target
  • Choose the Statin (and dose) most appropriate to achieve the desired reduction

Other Cholesterol lowering agents:

The cholesterol absorption inhibitor ezetimibe (Ezetrol) in combination with simvastatin (Inegy) was shown to reduce major atherosclerotic events in patients with advanced chronic kidney disease. Although no other outcome studies have been completed, ezetimibe is recommended:

  • As second-line treatment in combination with a statin when the LDL-C target is not reached at the highest tolerated statin dose.
  • When there is intolerance to statins (or high dose statin).
  • Bile acid sequestrants and nicotinic acid have cholesterol lowering properties. They may occasionally be useful alone or in combination with statin therapy. However, their side-effects limit wider application.

Finally the South African Heart Association/LASSA guidelines for lifestyle modification for patients with dyslipidaemia are summarized in Appendix 2:

Appendix 2

In summary:

Management 2

Additional tests:

The Consensus Statement also discusses the use of novel biomarkers of CVD (e.g. hs or us-CRP) and imaging technologies (e.g. coronary calcium scoring, carotid intima-media thickness) whilst is not recommended routinely these should be reserved to refine risk assessment in patients considered to be at moderate risk where there is uncertainty about whether to initiate drug therapy.

Measuring Lipoprotein – a (Lp-a) is appropriate in defining HIGH CVD risk subjects and/or when there is a family history of premature cardiovascular disease. 

Blessings for 2013

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