Managing cardiovascular risk in ‘at-risk’ populations

Cardiovascular risk assessment is currently very topical, with much debate about measurement and targets. Recent guidelines from the National Institute for Health and Clinical Excellence (NICE) on modification of blood lipids have provided helpful advice.(1)

The Group began by performing a SWOB analysis to examine the Strengths, Weaknesses, Opportunities and Barriers that exist in managing cardiovascular risk in at-risk populations.

Early detection of relevant risk factors was clearly a very important strength because disease in one territory may signify possible disease elsewhere. The proposed National Screening Project will go some way to address this issue. Early management is also important because treatment has been shown to be cost-effective.²

The NICE lipid modification clinical guideline and the Joint British Societies’ Guidelines (JBS 2) recommend that a strategy should be put in place to identify everyone over the age of 40 who is likely to be at high cardiovascular (CV) risk.^1,3 The Group agreed that it would be a strength for people to know their overall risk, rather than simply the levels of individual risk factors.

A major weakness in the management of cardiovascular risk is that many people carry a portfolio of risk factors. Using data from the Health Survey for England (2003), it has been estimated that at 20% cardiovascular disease (CVD) risk or higher, about 23% of men and 8% of women aged 40–74 years are potentially eligible for treatment (recognising that the Framingham equation has limitations).³

Since the evidence base in the elderly is not strong, there is uncertainty about how aggressively to treat older patients. The Group discussed the difference between the chronological age and the biological age of the patient, and concluded that judgements in this area rested with the skill of the physician. Some prescribed medications have unacceptable side effects, which makes management more difficult. Communication between the specialities, and between primary and secondary care, is critical to management of the at-risk individual.

The opportunities afforded by management of CV risk include engagement of patients, reduced events, improvement of quality of life and improved prognosis.

The barriers to management of CV risk are cost; the need for a clear follow-up policy and better communication between primary and secondary care; the need for education in this disease area; a gap in expectation between what physicians think patients were doing and what they are actually doing; lack of exercise; increasing obesity; and the consumption of unhealthy food, smoking and alcohol that is so prevalent in our society.

Identification of at-risk patients

The Group agreed with the JBS 2 recommendation that people with established cardiovascular disease and those who were asymptomatic but had an estimated multifactorial CVD risk >20% over 10 years should have equal priority for CVD prevention.³ The ‘hazardous waist’ was thought to be a useful indicator of the metabolic syndrome and risk factors that need to be addressed; and Group members were keen to risk-stratify hypertensives and to look for those with end-organ damage.

By contrast, the NICE lipid modification clinical guideline¹ clearly distinguishes between primary and secondary prevention. It specifies that primary prevention patients with ≥20% 10-year CVD risk should ‘discuss the need for risk reduction with their doctor and if a statin is appropriate, simvastatin 40 mg (or a drug of similar efficacy and acquisition cost) should be initiated. If there are potential drug interactions or if simvastatin 40 mg is contraindicated, a lower dose of simvastatin or pravastatin may be offered. Higher intensity statins should not be routinely offered to people for the primary prevention of CVD. There is no target level for total or low-density lipoprotein (LDL) cholesterol for people who are treated with a statin for primary prevention of CVD.’

‘Better communication between healthcare professionals is helpful in managing risk’

The Group talked about calculating risk, including the Framingham⁴ and QRISK⁵ models. The Scottish ASSIGN risk calculator is appropriate for the population of Scotland.⁶ Deprivation and lifestyle were agreed to be important, as was the role of family history. One patient in 500 has a family history of familial hypercholesterolaemia, with more than 80% going undetected.⁷ Family history of cardiomyopathy and sudden death should also be included. Erectile dysfunction is a marker of endothelial dysfunction for patients who may be at future vascular risk.⁸

It was agreed that risk stratification could be refined further using additional criteria such as 24-hour blood pressure and full lipid profile.

Risk modification

A key question concerning the Group was when risk factors should be treated to target and when to use a ‘fire and forget’ approach, in which the patient receives a pre-determined treatment without any requirement to follow up relevant parameters. After some debate, there was a consensus that it was important to treat the high-risk patient to target and that ‘fire and forget’ would be reasonable for those at low risk. This contrasts with the NICE lipid modification clinical guideline,¹ which does not recommend a target level for total or LDL cholesterol for primary prevention of CVD.

In terms of modification of risk, the Quality and Outcomes Framework (QOF)⁹ has moved things forward. In 2007, for example, 81.9% of patients with coronary heart disease achieved the QOF target of 5.0 mmol/L for total cholesterol.¹⁰

The Group felt that, for the high-risk under-75s, physicians should be aiming for the JBS 2 targets of 4.0 and 2.0 mmol/L³ but targets of 5.0 and 3.0 mmol/L might be more appropriate for a population approach to primary prevention, unless it became possible to risk-stratify patients more accurately. Patients over 75 years are more difficult to manage than those under 75 years but they are also the population at the highest risk. Over-75s with a long expected lifespan should be targeted for intensive therapy but more research is necessary to define which patients should receive this treatment.

Follow-up

The discussion then turned to follow-up and who should be responsible for continued follow-up. Good discharge information is particularly important, as the information needs to be incorporated into GP databases. Summaries generated by computer database may generate more helpful discharge documents than handwritten summaries.¹¹

A one-stop hospital review would be valuable to ensure that all the loose ends were tied up, but thereafter follow-up would be most cost-effective in the community. Vascular clinics, for example, could be set up in primary care for patients with known CVD, diabetes and coronary heart disease.

Much of the work in these clinics could be done by nurses and healthcare assistants. They would be useful in encouraging patients to ‘know their numbers’. The NICE lipid modification clinical guideline¹ states that “once a person has been started on a statin for primary prevention, repeat lipid measurement is unnecessary. Clinical judgement and patient preference should guide the review of drug therapy.”

Barriers and solutions

The key barriers remained: cost, poor follow-up, poor communication between primary and secondary care, poor education, the ageing population and lack of evidence in older patients, poor concordance with medications given to patients, and the unhealthy food lobby.

The health service needed a multidisciplinary approach in which all the disciplines would give patients the same messages and goals. This would require better communication between primary and secondary care – the Group felt it was a pity that face to face meetings between GPs and consultants had diminished in the last few years as they represented a lost opportunity to communicate, develop team working and share experiences •

Discussion

Q: What are the top three solutions?

A: First, the population should know their numbers and their CVD risk, which would give them ownership of their own health. More education was still needed on how to use treatments effectively, how to target patients and what goals to aim for. Lastly, better communication between primary and secondary care would ensure patients received the right treatment in the right place at the right time.

References

1. National Institute for Health and Clinical Excellence. Clinical Guideline 67. Lipid Modification. Cardiovascular risk assessment and the modification of blood lipids for the primary and secondary prevention of cardiovascular disease. May 2008.
2. Ward S, Lloyd Jones M, Pandor A et al. A systematic review and economic evaluation of statins for the prevention of coronary events. Health Technol Assess 2007;11:1–178.
3. JBS 2: Joint British Societies’ guidelines on prevention of cardiovascular disease in clinical practice. Heart 2005;91(Suppl v):v1–v52.
4. Grundy SM, Pasternak I. Greenland P et al. Assessment of cardiovascular risk by use of multiple-risk-factor assessment equations: a statement for healthcare professionals from the American Heart Association and the American College of Cardiology. Circulation 1999;100:1481–92.
5. Hippisley-Cox J, Coupland C, Vinogradova Y et al. Derivation and validation of QRISK, a new cardiovascular disease risk score for the UK: prospective open cohort study. BMJ 2007;335:136.
6. Woodward M, Tunstall-Pedoe H, Brindle P for the SIGN Group on risk estimation. Adding social deprivation and family history to cardiovascular risk assessment: the ASSIGN score from the Scottish Heart Health Extended Cohort (SHHEC). Heart 2007;93:172-6.
7. Watts GF, Lewis B, Sullivan DR. Familial hypercholesterolemia: a missed opportunity in preventive medicine. Nat Clin Pract Cardiovasc Med 2007;4:404–05.
8. Hodges LD, Kirby M, Solanki J et al. The relationship between erectile dysfunction and cardiovascular disease. Int J Clin Pract 2007;61:2019–25.
9. National Prescribing Centre. GMS Contract: Quality and Outcomes Framework targets for cholesterol 2006/7. www.npc.co.uk/nat_campaigns/statins/Statin_1.pdf (accessed 21 February 2008).
10. QMAS database 2006/07. Data as at end of March 2007.
11. Van Walraven C, Laupacis A, Seth R et al. Dictated versus database-generated discharge summaries: a randomised clinical trial. CMAJ 1999;160:319–26.