Secondary Prevention in Coronary Heart Disease (CHD)

Details of the rationale for indicators, and proposed methods of data collection and monitoring

CHD - Rationale for Inclusion of Indicator Set
Coronary heart disease (CHD) is the single commonest cause of premature death in the UK. The research evidence relating to the management of CHD is well established and if implemented can reduce the risk of death from CHD and improve the quality of life for patients. This indicator set focuses on the management of patients with established CHD consistent with clinical priorities in the four nations.

CHD Indicator 1
The practice can produce a register of patients with coronary heart disease

CHD 1.1 Rationale
In order to call and recall patients effectively in any disease category and in order to be able to report on indicators for coronary heart disease, practices must be able to identify their patient population with CHD. This will include all patients who have had coronary artery revascularisation procedures such as coronary artery bypass grafting (CABG).

CHD 1.2 Preferred Coding
Practices should record those with a past history of myocardial infarction as well as those with a history of CHD.

CHD - G3%
Myocardial Infarction - G30

CHD 1.3 Reporting and Verification
The practice reports the number of patients on its CHD disease register and the number of patients with CHD as a proportion of total list size.

Verification - PCOs may compare the expected prevalence with the reported prevalence.

CHD Indicator 2
The percentage of patients with newly diagnosed angina (diagnosed after 1 April 2003) who are referred for exercise testing and/or specialist assessment

CHD 2.1 Rationale
Diagnosis of coronary heart disease

The Quality and Outcomes Framework does not specify how the diagnosis of angina is made or confirmed. This will vary from patient to patient, eg clinical history, response to medication, results of investigations, hospital letters etc.

In general, angina is a clinical diagnosis. Patients with suspected angina should have a 12 lead ECG performed. The presence of an abnormal ECG supports a clinical diagnosis of coronary heart disease.

An abnormal ECG also identifies a patient at higher risk of suffering new cardiac events in the subsequent year. However, a normal ECG does not exclude coronary artery disease.

Reference Grade B Recommendation SIGN Guideline 51

Further Information: http://www.sign.ac.uk/guidelines/fulltext/51/index.html

As an additional assessment (rarely for diagnosis), patients with newly diagnosed angina should be referred for exercise-testing or myocardial perfusion scanning.

The aim of further investigation is to provide diagnostic and prognostic information and to identify patients who may benefit from further intervention.

Exercise tolerance testing (ETT) has been shown to be of value in assessing prognosis of patients with coronary artery disease. An ETT is also helpful in patients at high risk of CHD, where a positive test can provide useful prognostic information.

Patients should not be referred for an ETT if:

- they are on maximal medical treatment and still have angina symptoms
- the diagnosis of CHD is unlikely (these patients should be referred to a cardiologist)
- they are physically incapable of performing the test
- they have clinical features suggestive of aortic stenosis or cardiomyopathy
- the results of stress testing would not affect management.

Reference Grade B Recommendation SIGN Guideline 51

Further Information: http://www.sign.ac.uk/guidelines/fulltext/51/section2.html

Specialist Referral
An alternative to referral for exercise-testing is referral to a specialist for evaluation. Referral would normally be to a cardiologist, general physician or GP with a special interest.

CHD 2.2 Preferred Coding
Exercise testing - 3213%
Referral to specialist* - 8H44

*The Read code refers to referral to cardiologist but should be used in this context for referral to a general physician or GP with special interest.

CHD 2.3 Reporting and Verification
The practice should report those patients who have had an exercise tolerance test or been referred to a specialist within 12 months of being added to the register in whom a new diagnosis of coronary heart disease has been made since 1 April 2003.

In verifying that this information has been correctly recorded, a number of approaches could be taken by the Primary Care Organisation:

1. Inspection of the output from a computer search that has been used to provide information on this indicator.
2. Inspection of a sample of records of patients with CHD diagnosed since 1 April 2003 to look at the proportion with recorded exercise tolerance testing or referral
3. Inspection of a sample of records of patients for whom a record of exercise tolerance testing or referral is claimed, to see if there is evidence of this in the medical records.

CHD Indicator 3
The percentage of patients with coronary heart disease whose notes record smoking status in the past 15 months, except those who have never smoked where smoking status need be recorded only once

CHD 3.1 Rationale
The following modifiable lifestyle factors are known to be associated with an increased risk of coronary heart disease:

- Tobacco smoking
- Excessive alcohol consumption
- Physical inactivity
- Obesity.

Reference SIGN Guideline 41
European Task Force European Society of Cardiology

Further Information: http://www.sign.ac.uk/guidelines/fulltext/41/index.html
Further Information: http://www.escardio.org/scinfo/Guidelines/98prevention.pdf

It is anticipated that all these risk factors are likely to be assessed annually, as part of a routine annual assessment. Reporting for the purpose of the contract will focus on smoking status.

It is recognised that lifelong non-smokers are very unlikely to start smoking and indeed find it quite irritating to be asked repeatedly regarding their smoking status. Smoking status for this group of patients need only be recorded once.

CHD 3.2 Preferred Coding
Never Smoked - 1371
Ex-Smoker - 137L
Smoker - 137R

CHD 3.3 Reporting and Verification
The aim of this indicator is to ensure that the smoking status of all patients in the previous year is known, making the assumption that patients who have never smoked will continue not to smoke (in order to avoid keeping asking them).

The numerator of the indicator is the number of CHD patients who have never smoked plus the number who have been recorded as ex- or current smokers in the past 15 months. The denominator is the total number of CHD patients. Thus:

CHD Indicator 4
The percentage of patients with coronary heart disease who smoke, whose notes contain a record that smoking cessation advice or referral to a specialist service, where available, has been offered in the last 15 months

CHD 4.1 Rationale
There is strong evidence that stopping smoking reduces the risk of myocardial infarction in patients with CHD.

Many strategies have been used to help people to stop smoking. A meta-analysis of controlled trials in patients post myocardial infarction showed that a combination of individual and group smoking cessation advice, and assistance reinforced on multiple occasions - initially during cardiac rehabilitation and reinforced by primary care teams - gave the highest success rates.

Reference Grade B recommendation SIGN Guidelines 41/51

Further Information: http://www.sign.ac.uk/guidelines/fulltext/51/index.html
Further Information: http://www.sign.ac.uk/guidelines/fulltext/41/index.html

A number of studies have recently shown benefits from the prescription of nicotine replacement therapy or buproprion in patients who have indicated a wish to quit smoking. Further guidance is available from the National Institute for Clinical Excellence.

Further Information: http://www.nice.org.uk/pdf/NiceNRT39GUIDANCE.pdf

In a significant number of PCOs across the UK specialist smoking cessation clinics are now available. Referral to such clinics, where they are available, can be discussed with patients. This should also be recorded as smoking cessation advice.

The recording of advice given does not necessarily reflect the quality of the intervention. It is therefore proposed that in the framework only smoking advice should be part of the reporting framework. Clinicians may choose to record advice given in relation to other modifiable risk factors.

CHD 4.2 Preferred Coding
Smoking Cessation Advice - 8CAL

CHD 4.3 Reporting and Verification
The practice should report the percentage of patients on the CHD register who are current smokers who have been offered smoking cessation advice in the last 15 months.

CHD Indicator 5
The percentage of patients with coronary heart disease whose notes have a record of blood poressure in the previous 15 months

CHD 5.1 Rationale
Epidemiological data indicate that continued hypertension following the onset of CHD increases the risk of a cardiac event and that the reduction of blood pressure reduces risk.

Patients with known CHD should have their blood pressure measured at least annually.

CHD 5.2 Preferred Coding
Examination of BP - 246.

CHD 5.3 Reporting and Verification
Practices should report the percentage of patients on the CHD register who have had a blood pressure recorded in the last 15 months.

CHD Indicator 6
The percentage of patients with coronary heart disease in whom the last blood pressure reading (measured in the last 15 months) is 150/90 or less

CHD 6.1 Rationale
The British Hypertension Society Guidelines propose an optimal blood pressure of 140 mm Hg or less systolic and 85 mm Hg or less diastolic for patients with CHD. This guideline also proposes a pragmatic audit standard of a blood pressure reading of 150/90 or less (http://www.bhsoc.org/, under 'Resources').

A major overview of randomised trials showed that a reduction of 5-6 mm Hg in blood pressure sustained over 5 years reduces coronary events by 20-25% in patients with coronary heart disease (Collins et al. Lancet 1990; 335: 827-38.)

CHD 6.2 Preferred Coding
Blood pressure -numeric value

CHD 6.3 Reporting and Verification
Practices should report the percentage of patients on the CHD register whose last recorded blood pressure is 150/90 or less. This reading should have been in the last 15 months.

CHD Indicator 7
The percentage of patients with coronary heart disease whoe notes have a record of total cholesterol in the previous 15 months

CHD 7.1 Rationale
A number of trials have demonstrated that cholesterol lowering with statins significantly reduces cardiovascular or all-cause mortality in patients with angina or in patients following myocardial infarction.
Grade C Recommendation SIGN Guideline 51

Further Information: http://www.sign.ac.uk/guidelines/fulltext/51/section2.html

It is unclear from the literature how frequently cholesterol measurement should be undertaken, but the English National Service Framework (NSF) on CHD recommends annually.

The majority of trials include only patients under 75. However, most national guidance makes no distinction on the basis of age, and age 'cut-offs' are not generally included.

CHD 7.2 Preferred Coding
Serum Cholesterol - 44P%

CHD 7.3 Reporting and Verification
Practices should report the percentage of patients on the CHD register who have a record of total cholesterol in the last 15 months.

In verifying that this information has been correctly recorded, a number of approaches could be taken by a Primary Care Organisation:

1. Inspection of the output from a computer search that has been used to provide information on this indicator
2. Inspection of a sample of records of patients with CHD to look at the proportion with recorded serum cholesterol
3. Inspection of a sample of records of patients for whom a record of serum cholesterol is claimed, to see if there is evidence of this in the medical records.

CHD Indicator 8
The percentage of patients with coronary heart disease whose last measured total cholesterol (measured in last 15 months) is 5mmol/l or less

CHD 8.1 Rationale
A number of Randomised Controlled Trials of statin therapy in the secondary prevention of CHD have shown a reduction in relative risk of cardiac events irrespective of the starting level of cholesterol (see reference in 7.1). It is likely that National Guidelines relating to statin therapy in patients with CHD will change to recommend statin therapy for all patients with CHD irrespective of their starting level of total cholesterol.

However, currently the Joint British Recommendations on Prevention of Coronary Heart Disease in Clinical Practice and SIGN Guidelines 41 and 51 recommend that patients who have a cholesterol of greater than 5mmol/l should be offered lipid lowering therapy.

The guidance here is given in terms of total cholesterol, as this is used in national guidance and in trials. However, future guidance may relate to reduction of LDL cholesterol, which is the more important component.

CHD 8.2 Preferred Coding
Cholesterol value - numeric value

CHD 8.3 Reporting and Verification
Practices should report the percentage of patients on the CHD register who have a record of total cholesterol in the last 15 months which is 5mmol/l or less.

In verifying that this information has been correctly recorded, a number of approaches could be taken by a Primary Care Organisation:

1. Inspection of the output from a computer search that has been used to provide information on this indicator
2. Inspection of a sample of records of patients with CHD to look at the proportion with recorded serum cholesterol 5mmol/l or less
3. Inspection of a sample of records of patients for whom a record of serum cholesterol at 5mmol/l is claimed, to see if there is evidence of this in the medical records.

CHD Indicator 9
The percentage of patients with coronary heart disease with a record in the last 15 months that aspirin, an alternative anti-platelet therapy, or an anti-coagulant is being taken (unless a contraindication or side-effects are recorded)

CHD 9.1 Rationale
Aspirin (75-150mg per day) should be given routinely and continued for life in all patients with CHD unless there is a contraindication. Clopidogrel (75mg/ day) is an effective alternative in patients with contraindications to aspirin, or who are intolerant of aspirin. Aspirin should be avoided in patients who are anticoagulated.
Grade A Recommendation SIGN Guidelines 41/51

Further Information: http://www.sign.ac.uk/guidelines/fulltext/51/index.html
Further Information: http://www.sign.ac.uk/guidelines/fulltext/41/index.html

CHD 9.2 Preferred Coding
OTC Aspirin - 8B3T

Other drugs will be prescribed and picked up on drug search.

Medication stopped, interaction - 8BI6
Aspirin prophylaxis contraindicated - 8I24.
Warfarin contraindicated - 8I25.
Adverse reaction to warfarin - TJ421
Adverse reaction to salicylates - TJ53.
History of aspirin allergy - ZV148

CHD 9.3 Reporting and Verification
Practices should report the percentage of patients on the CHD register who are prescribed aspirin, clopidogrel or warfarin within the last 15 months or have a record of taking over-the-counter (OTC) aspirin updated in the last 15 months.

CHD Indicator 10
The percentage of patients with coronary heart disease who are treated with a beta blocker (unless a contraindication or side-effects are recorded)

CHD 10.1 Rationale
Long term beta blockade remains an effective and well tolerated treatment that reduces mortality and morbidity in patients with angina and patients after myocardial infarction.

Although the trial evidence relates to mainly patients who have had a myocardial infarction, experts have generally extrapolated this evidence to all patients with CHD. Because the evidence is not based on all patients with CHD, the target levels for this indicator have been set somewhat lower than for other process indicators.

Grade A Recommendation SIGN Guidelines 41/51

Further Information: http://www.sign.ac.uk/guidelines/fulltext/51/index.html
Further Information: http://www.sign.ac.uk/guidelines/fulltext/41/index.html

CHD 10.2 Preferred Coding
Prescribed drugs will be picked upon drug search.

- blocker not indicated - 8I62.
- blocker refused - 8I36.

CHD 10.3 Reporting and Verification
The percentage of patients on the CHD register who have been prescribed a beta blocker in the last 6 months.

CHD Indicator 11
The percentage of patients with a history of myocardial infarction (diagnosed after 1 April 2003) who are currently treated with an ACE inhibitor

CHD 11.1 Rationale
A number of trials have shown reduced mortality following myocardial infarction with the use of ACE inhibitors. The Heart Outcome Prevention Evaluation (HOPE) showed that ACE inhibitors are also of benefit in reducing coronary events and progression of coronary arteriosclerosis in patients without left ventricular systolic dysfunction. This indicator is prospective with inclusion of patients diagnosed with a myocardial infarction after 1 April 2003.

Grade A Recommendation SIGN Guideline 41
Grade A Recommendation NICE Guideline A

Further Information: http://www.sign.ac.uk/guidelines/fulltext/41/index.html
Further information: http://www.escardio.org/scinfo/Guidelines/98prevention.pdf

CHD 11.2 Preferred Coding
Prescribed drugs will be picked upon drug search.

ACE inhibitors contra-indicated - 8I28.

CHD 11.3 Reporting and Verification
The percentage of patients who have had a myocardial infarction after 1 April 2003 who have been prescribed an ACE inhibitor or A2 antagonist in the last 6 months.

CHD Indicator 12
The percentage of patients with coronary heart disease who have a record of influenza immunisation in the preceding 1 September to 31 March

CHD 12.1 Rationale
This is a current recommendation from the Department of Health and the Joint Committee on Vaccination and Immunisation. (www.doh.gov.uk/greenbook/)

CHD 12.2 Preferred Coding
Flu Vaccination given - 65E
Flu vac contra-indicated - 8I2F.

CHD 12.3 Reporting and Verification
The percentage of patients on the CHD register who have had an influenza vaccination administered in the preceding 1 September to 31 March.

LVD - Rationale for Inclusion of Indicator Set
The commonest cause of heart failure is myocardial dysfunction, which is most usually systolic with reduced left ventricular contraction and emptying. This set of indicators relates to this disease process – left ventricular systolic dysfunction (LVSD) - and should be applied to patients with LVSD due to ischaemic heart disease.

Indicators for patients with normal systolic function are outwith the scope of this indicator set.

LVD Indicator 1
The practice can produce a register of patients with CHD and left ventricular dysfunction

LVD 1.1 Rationale
A register is a prerequisite for monitoring patients with LVD. For patients diagnosed prior to April 2003 it is accepted that various diagnostic criteria may have been used. For this reason the presence of the diagnosis of heart failure in the records will be acceptable. However, practices may wish to review patients previously diagnosed and if appropriate attempt to confirm the diagnosis by echocardiography.

LVD 1.2 Preferred Coding
LVD* - G581

*Note that there is no specific code for LVD. The code utilised is for LVF.

LVD 1.3 Reporting and Verification
The practice reports the number of patients with CHD and LVD and the number of patients with CHD and LVD as a proportion of total list size.

Verification - PCOs may compare the expected prevalence with the reported prevalence.

LVD Indicator 2
The percentage of patients with a diagnosis of CHD and left ventricular dysfunction (diagnosed after 1 April 2003) which has been confirmed by an echocardiogram

LVD 2.1 Rationale
Adequate pre-treatment investigation, examination and history-taking are important in all patients with suspected heart failure. The purpose of this assessment is to confirm or exclude a diagnosis of heart failure, to identify the cause of heart failure, ascertain aggravating factors and to act as a guide for future management and treatment.

Echocardiography is established as the single most important investigation in patients with heart failure. However, in primary care there may be pragmatic reasons why such an examination is not possible eg in frail immobile patients. A resting ECG is a useful screening tool. Significant LVD is unlikely in the presence of a completely normal ECG. The purpose of this indicator is to ensure that patients are correctly diagnosed as having heart failure, distinguishing them, for example, from patients with dependent oedema.

Grade C recommendation SIGN 35
Further Information: http://www.sign.ac.uk/guidelines/fulltext/36/index.html

It is recognised that echocardiography resources may be limited in parts of the country. For this reason the criterion is prospective and will apply to patients receiving a diagnosis from 1 April 2003 onwards. In addition, exception-reporting will be available in cases where it is logistically impossible for a patient to have an echocardiogram. However, in such areas, the PCO would be expected to commission adequate echocardiography facilities as a priority.

Normal concentrations of N-terminal pro-brain natriuretic peptide (NT-proBNP) can be used to rule out LVD in patients with suspected heart failure. These patients would not be added to the LVD register or require further investigation. High concentrations of NT-proBNP may identify patients who require further investigation to confirm the diagnosis.

LVD 2.2 Preferred Coding
Echo Abnormal - 58531

LVD 2.3 Reporting and Verification
The practice should report those patients who have had an echocardiogram within 12 months of being added to the register in whom a new diagnosis of left ventricular dysfunction has been made since 1 April 2003.

In verifying that this information has been correctly recorded, a number of approaches could be taken by a Primary Care Organisation:

1. Inspection of the output from a computer search that has been used to provide information on this indicator
2. Inspection of a sample of records of patients with CHD/LVD diagnosed after 1 April 2003 to look at the proportion with an echocardiogram result or referral
3. Inspection of a sample of records of patients for whom a record of echocardiogram is claimed, to see if there is evidence of this in the medical records.

LVD Indicator 3
The percentage of patients with a diagnosis of CHD and left ventricular dysfunction who are currently treated with ACE inhibitors (or A2 antagonists)

LVD 3.1 Rationale
In the absence of specific contraindications, all patients with left ventricular systolic dysfunction should be considered for treatment with an ACE inhibitor. ACE inhibitors have been shown to improve survival in patients with all grades of heart failure.

Grade A Recommendation SIGN 35
Further Information: http://www.sign.ac.uk/guidelines/fulltext/35/index.html

Evidence from trials suggests that the greatest benefits are achieved by treatment with maximum doses of ACE inhibitors (rather than choosing the dose that produces adequate symptomatic relief), and that moderate doses are less effective than high doses. ACE inhibitors should therefore be titrated up to the maximum BNF recommended doses wherever possible (which in some cases are lower than the doses used in trials). It is important to check renal function prior to commencing these drugs and after two weeks of treatment.

Where an ACE inhibitor produces unacceptable side-effects an angiotensin II receptor antagonist should be considered.

Grade A Recommendation SIGN 35
Further information: http://www.sign.ac.uk/guidelines/fulltext/35/index.html

A number of other therapeutic management options are recommended in the SIGN Guideline, for example the use of beta blockers.

Patients already treated with diuretics and/or digoxin and an ACE inhibitor, who are clinically stable and in NYHA classes I-III, should be considered for treatment with a beta blocker. Such patients should be under careful specialist supervision.

Grade A Recommendation SIGN 35
However, due to the complexity of their use and therefore the difficulty of including them as an indicator, they have not been included in the indicator set.

LVD 3.2 Preferred Coding
Prescribed drugs will be picked upon drug search.

ACE inhibitors contra indicated - 8I28.
A.11 antagonists contraindicated - 812H

LVD 3.3 Reporting and Verification
Practices should report the percentage of patients on the LVD register who have been prescribed an ACE inhibitor or A2 Inhibitor in the last 6 months.