Article

Expanded Lipid Testing Critical to Managing Coronary Artery Disease

Abstract

Citation:European Cardiovascular Disease 2007;3(2):24–6

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Coronary artery disease (CAD) is the leading cause of death in the US, and accounts for approximately US$100 billion in healthcare costs every year.1 Metabolic syndrome describes a combination of medical disorders that increase the risk of developing cardiovascular disease (CVD).2 Risk factors include central obesity, hypercholesterolaemia, hypertension and insulin resistance or glucose intolerance. In many patients, metabolic syndrome is coupled with type 2 diabetes, which further increases the risk of developing CVD.

The third National Health and Nutrition Examination Survey (NHANES) reported an age-adjusted metabolic syndrome prevalence of 24.1%.3 According to data from the World Health Organization (WHO), ischaemic disease accounts for approximately 86 in every 100,000 deaths per year in Western Europe and 350 in 100,000 in Eastern Europe.4 This figure is set to rise, however, due to an increase in worldwide obesity and the general change to sedentary lifestyles.5 Moreover, recent reports have demonstrated that the typical population affected is beginning to widen into younger age groups, who were previously considered at low risk of developing the syndrome.6 From 2001 to 2004, a study examined the prevalence of metabolic syndrome in patients aged 18–45 years who suffered from myocardial infarction.6 It was reported that 72% of patients in this population presented with all five criteria for metabolic syndrome, which indicates the shift in risk of developing CVD towards younger generations.

It has been suggested that a move away from reactive treatment and towards prevention should be made in order to reduce the number of cases of CVD. Dyslipidaemia has been associated with an increase in the risk of developing CAD in several large epidemiological studies.7 In Western societies, most cases of dyslipidaemia are hyperlipidaemias due to lifestyle and diet; therefore, a means of reducing the level of lipids in the blood could prevent the occurrence of CAD. A reduction in low-density lipoprotein cholesterol (LDL-C) levels resulted in reductions in CAD events and total mortality, demonstrating that the monitoring and control of lipid levels represents a method for prevention of CAD.

Persistence and Compliance with Therapy

In 1996, Project Hyperlipidemia, IMproved Persistence And Compliance with Therapy (ImPACT) was commenced to evaluate improvements that could be made to raise patient compliance and persistence with lipid-lowering therapy, increase the availability of information to patients, improve cholesterol levels of patients over time and increase the number of patients reaching and maintaining ideal lipid levels.

Twenty-six community centres were involved in the study, enrolling patients newly diagnosed with dyslipidaemia or those who were already receiving lipid-lowering medications but were poorly controlled. All patients provided a finger-prick blood sample every three months and a fasting lipid level was obtained and recorded at each visit, providing the opportunity to set treatment goals and targets with the patient. The routine lipid testing and immediate face-to-face advice and counselling by the practitioner achieved a compliance of 90% over a 12-month period. In comparison, a previous study noted only 50% compliance in elderly patients undergoing self-administered statin therapy.8

Overall, a reduction of 22% in LDL-C levels was noted, with progressive improvements seen over time. In the study, pharmacists demonstrated that they could identify and effectively treat patients with lipid disorders and support them to improve persistence, compliance and treatment goals in collaboration with patients and physicians.

Immediacy in Testing

The migration of laboratory-based analysis to the point-of-care setting must generally be regarded as beneficial to the physician and the patient. The convenience and the cost/benefit of, for example, blood-glucose testing and basic urine analysis in the point-of-care setting is indisputable. It provides immediate results, enables decision-making, allows for face-to-face interaction with patients during their visit and eliminates the need for a repeat visit to discuss the test results. Although difficult to measure, the convenience factor for the patient that point-of-care technology offers cannot be ignored, and this is likely to enable more patients to be identified at an early stage of their disease.

In terms of identifying patients with an elevated cardiac risk factor, the more patients who are tested for hypercholesterolaemia, the more patients will be identified, and treatment can be initiated at an early stage with obvious benefits for both the patient and the healthcare system. Emphasis must be placed on screening, documenting results, initiating therapy and following patients to improve the proportion of patients achieving target lipid goals. Recognition of the gap between evidence and practice in cholesterol risk management is increasing, and this awareness is an important first step. Innovative approaches to the management of patients with, or at risk of, CHD are required to improve the administration of appropriate lipid-lowering interventions to eligible patients.

Multidisciplinary team involvement at the level of the community may improve the proportion of patients screened, started on appropriate therapy and followed to target lipid goals. For example, dieticians can provide appropriate dietary counselling and community pharmacists can identify patients who would benefit from pharmacological therapy and work with patients and family physicians to optimise the proportion of patients achieving target lipid goals. Use of advanced measurement technology, such as point-of-care technology involving fingerstick blood samples, may assist in the identification, monitoring and follow-up of patients. Furthermore, reminder systems for both patients and physicians may help to ensure that repeat lipid panels and appropriate monitoring and follow-up are conducted. Further studies should investigate the reasons why patients are not reaching targets and evaluate ways to optimise therapy. In light of the enormous public health importance of CHD and the availability of safe and efficacious therapies, our next step must be to improve the process of cholesterol risk management and to ensure that funds are made available.

Availability and Functionality of Systems

The technology to measure cholesterol and lipids has been available for several years, but it has not been widely used in the primary care setting. This technology works in a similar way to blood-glucose systems, i.e. in the form of a test strip and an instrument to read and display the result. A precise volume of whole blood is dispensed onto the test strip and inserted into the analyser. Red blood cells and other non-plasma components are removed from the plasma. The plasma reacts in a precisely controlled manner with a series of chemically impregnated membranes, ultimately producing a colour change in the final membrane layer. The analyser measures the colour intensity from the colour spectral profile and compares it with calibrated information contained inside to achieve an accurate result. The analyser then displays the result, which can be printed out, and stores the test information in its memory system for later recall.

One of these systems is the CardioChek PA, manufactured by Polymer Technology Systems, which offers tests for parameters such as total cholesterol, high-density lipoprotein (HDL), LDL and triglycerides, as either single tests or combination tests. The LDL test is directly measured and does not require the patient to be fasting. A finger-prick capillary blood sample is required and results are typically available within two minutes. Cholestech produces a similar device, the LDX, which costs more and has larger dimensions. Roche’s AccuTrend GCT is able to measure only glucose, cholesterol and triglycerides. Other cholesterol- and lipid-monitoring devices are in development, but have not yet obtained approval for use.

Comparison with Current Systems

In the current system, sending a venous blood sample to a laboratory or even asking a patient to visit a laboratory incurs costs. The true expense of the analysis includes not only the cost of the test in the laboratory, but also costs for transportation of the blood sample to the laboratory, administration fees and a follow-up visit to the physician.

This means that in many situations the costs and budgeting for these particular tests lie with the laboratories. In the UK, plans have been made for GPs in Scotland to have greater control over their budgets, which would mean that healthcare professionals, including pharmacists, would have the ability to use these point-of-care systems. Based on the reasons stated above, it seems logical that healthcare authorities implement a system that allows cholesterol/lipid testing to be performed at the primary care level and that financial means be made available.

Self-testing

Another aspect to consider is that self-diagnostics become more common when technologies become available. As with most conditions, there are advantages and disadvantages involving self-diagnosis. One of the main advantages is that home health-test kits provide 99% accuracy provided that all usage conditions are met. The patient benefits from low costs and less frequent visits to the physician. However, the risk is that an incorrectly performed or interpreted test might cause more worry and therefore have negative consequences. On the other hand, the use of home health-test kits can lead to better informed medication choices on behalf of the patient and reduce the excessive or unjustified use of over-the-counter (OTC) drugs. In some cases, these OTC treatments can negatively affect the condition, thus home health-test kits have risen in popularity.

While home tests are a valuable new tool and encourage widespread screening and ongoing monitoring of the condition, primary diagnosis tools must rest in the capable hands of healthcare professionals. Professional healthcare workers are in a better position to diagnose a problem accurately and suggest the best treatments available for improving the condition.

Self-diagnostics for hypercholesterolaemia are likely to become a favourite among health-conscious persons. In the US, this is already a growing trend and it is likely to be introduced in Europe as well. It is important that healthcare professionals help patients to help themselves by improving their understanding of their condition, as well as what the results of the tests mean.

Conclusions

Given the widespread and prevalent nature of CVD and metabolic syndrome, broader and more frequent testing of lipids within a broader age group than ever before is clearly indicated. Such testing should be conducted throughout the process of screening, diagnosis and ongoing monitoring, and should be introduced at the primary care level using point-of-care equipment. The key objective of point-of-care equipment is to generate a result quickly so that the appropriate treatment can be provided, leading to an improved clinical and economic outcome.

Initial and ongoing face-to-face consultation has been proved to improve compliance and thereby to improve the management of the condition. Economical, accurate systems are available today that are also fast, portable and convenient to use. Due to their small size and portability they can be used in office settings, pharmacies, clinics or mobile locations. Home cholesterol test systems are available now, some of which are capable of giving perfectly accurate results. They are, however, subject to human error. Typically, doctors do not like to rely on the home cholesterol test by itself, and should insist on confirming results with another test from the laboratory if treatment is being considered. Treatment should be proceeded with only when the laboratory test results prove positive. This does not detract from the value of home testing, which includes early identification of issues, as well as ongoing reinforcement of the need for a therapeutic regimen.

Widespread implementation of these various testing modalities, initially at the primary care level, has both clinical and economic benefits. They will encourage early identification, more effective treatment and an overall reduction in the prevalence of the underlying condition.

References

  1. American Heart Association. American Heart Association, 1999.
  2. Gami AS, Witt BJ, Howard DE, J Am Coll Cardiol, 2007;49(4):403–14.
    Crossref | PubMed
  3. Ford ES, Giles WH, Mokdad AH, Diabetes Care, 2004;27:2444–9.
    Crossref | PubMed
  4. WHO see http://data.euro.who.int/hfadb/ [last accessed 14th December 2007].
  5. Park YW, Zhu S, Palaniappan L, et al., Arch Intern Med, 2003;163:427–36.
    Crossref | PubMed
  6. Chung EH, Curran PJ, Sivasankaran S, et al., Am J Cardiol, 2007;100(7):1052–5.
    Crossref | PubMed
  7. Castelli WP, Association for Pharmacoeconomics and Outcomes Research Lipid Conference; November 1997; Orlando, FL.
  8. Benner JS, Glynn RJ, Mogun H, et al., JAMA, 2002;288(4):455–61.
    Crossref | PubMed