Secondary prevention of cardiovascular disease

The Quality and Outcomes Framework has provided incentives to offer a range of interventions to patients with known cardiovascular disease, but the some of the thresholds will change from April

Primary prevention is the effort made to prevent an unwelcome health event from occurring at all. A good example would be the use of vaccination to prevent serious childhood infections. Tertiary prevention is the effort made to reduce the consequences of an illness. A good example would be the use of physiotherapy after a stroke to improve mobility and independence.

Secondary prevention is the effort made to prevent a health problem occurring again, and the Quality and Outcomes Framework (QOF) provides general practices with a financial incentive to offer a range of interventions to patients who are already known to have cardiovascular disease, in order to prevent a heart attack. The patients eligible for secondary prevention are those who have had a previous heart attack, but also those with angina and also those who have had a coronary artery intervention such as coronary artery bypass grafting (CABG) or angioplasty of a coronary artery. Heart failure is covered by a different set of indicators.

Coronary heart disease (CHD) is big business for the NHS. The British Heart Foundation, a charity whose website offers a wealth of useful information for patients and health professional alike, regularly publishes statistics about CHD.¹

• Each year in the UK there are about 124,000 heart attacks.
• Each year in the UK about 80,000 coronary angioplasties and CABGs are performed
• The chance of death after a heart attack in the UK is falling, but still compares unfavourably with some other Western European countries

CHD is also big business for undertakers.

• Cardiovascular diseases are the biggest killers in the UK
• Heart attacks resulted in 88,000 deaths in the UK in 2008
• Death rates from CHD are highest in the north and lowest in the south of Britain

It has been known for many years that secondary prevention interventions for CHD are worthwhile, and before the QOF many general practices had already set up systematic systems of patient care, usually in the form of specified clinics. Just what constitutes secondary prevention has been modified as new evidence has emerged, so what was good practice 20 years ago would not be considered as good now.

It has also been long recognised that if you want a job in general practice doing properly, then you are better getting a practice nurse to do it rather than a doctor. So traditionally the CHD clinic is the nurse's territory.

You will not be surprised that there is a QOF requirement to have a CHD register. This also effectively means that there is a QOF requirement that the practice is computerised and that all healthcare professionals know how to enter data. It is certainly possible to have a register without resort to a computer, but a computer and appropriate software makes it so much easier.

CHD13 was a new indicator for 2011-12 and replaced the old CHD2 which, for the same points and payment stages, required either a specialist assessment or an exercise test to confirm the diagnosis. The change is a semantic one as most general practices (mine included) do not have access to exercise testing without referral to a specialist.

A diagnosis of angina has lifelong implications both for the patient concerned and for their medical advisors. Making an accurate diagnosis is therefore very important.

CHD13 is also testimony to the link between our friends at the QOF and our equally wonderful friends at NICE. Because of this link, the QOF documentation2 includes a much fuller justification for the targets than has been the case in previous versions. It makes compelling good sense that the people controlling the purse strings should have close relations with the people with the evidence. As long as the QOF targets are consistent with the evidence then primary healthcare professionals can pursue them in the confidence that there is no conflict between clinical excellence and financial reward.

It has been known for at least 20 years that optimising blood pressure results in a lowering of the risk of future coronary events. The British Hypertension Society recommends a target of 140/85 mmHg for patients who already have CHD. The QOF accepts that its target of 150/90 mmHg is a 'pragmatic audit standard',2 which is another way of saying that there is no justification for their target except that it is easier to achieve than the real target, and that anyway as far as blood pressure is concerned then lower is always better.

Another impressive 17 points are offered for getting cholesterol under control. This is curious since, as far as CHD is concerned, controlling cholesterol is probably more important than controlling blood pressure. The target of 5mmol/l is conceded as an 'audit standard' - NICE suggests a total cholesterol target of 4mmol/l.³ NICE also suggests that anyone who has had a heart attack should take a statin, whatever their cholesterol level,4 on the not unreasonable assumption that if your coronary arteries are furring up with cholesterol, then whatever the measured level of your cholesterol is, it must - by definition - be too high. This is covered in CHD14.

CHD6 also presents the QOF target-setters at their silliest. For this year the maximum funding for CHD6 requires attainment of 75% rather than the 71% of last year. Can this seriously be justified as an attempt to raise standards? To the cynical it may be viewed as an attempt to cut costs.

Antiplatelet agents reduce the risk of a subsequent heart attack by 35% (non-fatal heart attack) and 30% (fatal).⁵ Aspirin is still the preferred option, but clopidogrel is coming up on the rails with the news that clopidogrel is now the preferred option after a stroke.⁶ The recent plummet in the cost of clopidogrel since its patent expired will of course not have influenced this change, but don't be surprised if further revelations are round the corner. Given that the effect of antiplatelet drugs on the risk of further heart attack is of the same order of magnitude as cholesterol-lowering, the 7 points allocated appears a little sparse, especially as the stage payment targets are more rigorous.

The guidance2 is helpful on what constitutes a 'contraindication or side effect'. If your patient gets a rash or a more severe allergic reaction (e.g. anaphylaxis) on taking aspirin then it should be stopped. This is not a difficult problem as any patient who has experienced anaphylaxis will be reluctant to risk any more doses. Also some patients get significant indigestion on even small doses of aspirin (the recommendation is 75 to 150mg a day), and if this cannot be controlled by, for example, using a proton pump inhibitor such as omeprazole, then the aspirin must stop.

The routine use of a beta-blocker after a heart attack is another NICE recommendation. The use of a beta-blocker appears to reduce the risk of death after a heart attack by 40%,5 the same order of magnitude as the other drug interventions recommended. Any old beta-blocker will do,5 and benefit is conferred by being on the drug at all rather than the dose used. A beta blocker can also be used to reduce blood pressure. Atenolol is probably the most widely used beta-blocker in the UK, and only has to be taken once a day. Beta blockers can cause cold extremities, which is a bit of an issue in someone who already has circulation problems (otherwise he or she would not have had a heart attack). Also some experience vivid dreams, not necessarily unpleasant. If your routine enquiry about side effects prompts a twinkle in the eye and a sheepish grin, it is safe to assume that the side effect is being tolerated.

CHD14 is a partial replay of CHD9 and CHD10. Since 1 April 2011, patients who have had a heart attack have been required to be prescribed a whole raft of drugs - but this year, the lower threshold has been raised, from 40% to 45%.

Aspirin and beta blockers have already been discussed. The role of a statin has been mentioned above with relation to lipid-lowering, but CHD14 is in closer accord with NICE - this is another indicator identified in the guidance as a collaboration between NICE and the QOF. The use of an ACE inhibitor (e.g. ramipril) after a heart attack is associated with a reduction in all-cause death of around 10% - not as spectacular as the results with other drugs, but well worth having. However, ACE inhibitors make some people cough, a lot, in which case an angiotensin II receptor blocker (e.g. candestartan) is a reasonable alternative.⁵

Influenza is best avoided if you already have heart problems. The advice to offer a flu vaccination each year is a current recommendation from the Department of Health and the Joint Committee on Vaccination and Immunisation.

[X-head] CONCLUSION[text} Coronary heart disease is an important cause of morbidity and mortality. It is appropriate that the clinical domain attracts a lot of QOF attention. Strategies to stop heart disease sufferers having a subsequent heart attack have been known about for decades. Many of the proven strategies can be forged into targets, and the targets QOF have chosen are appropriate.

Other preventive strategies are covered elsewhere in the QOF. Smoking, weight and alcohol data are recorded in other QOF areas. However, some lifestyle issues which impact on CHD risk are not recorded anywhere - for example the quality of diet (use of fats, fruit, vegetables) and exercise levels. Such things are harder to systematise and put into targets, and are dependent on patients accurately recording their habits, but many practices already have templates to record such data and it is appropriate that some effort be made to capture it. So again it is a case of a good effort by the QOF, but still room for improvement.

REFERENCES

1. British Heart Foundation. Coronary heart disease statistics. 2010 edition. http://www.bhf.org.uk/publications/view-publication.aspx?ps=1001546

2. BMA/NHS Employers. Quality and Outcomes Framework guidance for GMS contract 2011/12. http://www.nhsemployers.org/Aboutus/Publications/Documents/QOF_guidance_GMS_contract_2011_12.pdf

3. NICE CG67 http://www.nice.org.uk/nicemedia/live/11982/40675/40675.pdf

4. NICE CG48 http://www.nice.org.uk/nicemedia/live/11008/30497/30497.pdf

5. Post Myocardial Infarction. Secondary prevention in primary and secondary care for patients following a myocardial infarction. Full guideline - Final Version

May 2007. National Collaborating Centre for Primary Care. http://www.nice.org.uk/nicemedia/live/11008/30495/30495.pdf

6. MeReC extra No 49 May 2011 http://www.npc.nhs.uk/merec/cardio/cdstroke/merec_extra_no49.php