Nội dung

S I GN Scottish Intercollegiate Guidelines Network 96 Management of stable angina A national clinical guideline 1 Introduction 1 2 Diagnosis and assessment 3 3 Pharmacological management 7 4 Interventional cardiology and cardiac surgery 12 5 Stable angina and non-cardiac surgery 19 6 Psychological and cognitive issues 28 7 Patient issues and follow up 34 8 Sources of further information and support for patients and carers 37 9 Implementation and audit 39 10 Development of the guideline 41 Abbreviations 45 References 47 February 2007 Copies of all SIGN guidelines are available online at www.sign.ac.uk KEY TO EVIDENCE STATEMENTS AND GRADES OF RECOMMENDATIONS LEVELS OF EVIDENCE 1++ High quality meta-analyses, systematic reviews of randomised controlled trials (RCTs), or RCTs with a very low risk of bias 1+ Well conducted meta-analyses, systematic reviews of RCTs, or RCTs with a low risk of bias 1- Meta-analyses, systematic reviews of RCTs, or RCTs with a high risk of bias 2 High quality systematic reviews of case control or cohort studies High quality case control or cohort studies with a very low risk of confounding or bias and a high probability that the relationship is causal ++ 2+ Well conducted case control or cohort studies with a low risk of confounding or bias and a moderate probability that the relationship is causal 2- Case control or cohort studies with a high risk of confounding or bias and a significant risk that the relationship is not causal 3 Non-analytic studies, eg case reports, case series 4 Expert opinion GRADES OF RECOMMENDATION Note: The grade of recommendation relates to the strength of the evidence on which the recommendation is based. It does not reflect the clinical importance of the recommendation. A At least one meta-analysis, systematic review of RCTs, or RCT rated as 1++ and directly applicable to the target population; or A body of evidence consisting principally of studies rated as 1+, directly applicable to the target population, and demonstrating overall consistency of results B A body of evidence including studies rated as 2++, directly applicable to the target population, and demonstrating overall consistency of results; or Extrapolated evidence from studies rated as 1++ or 1+ C A body of evidence including studies rated as 2+, directly applicable to the target population and demonstrating overall consistency of results; or Extrapolated evidence from studies rated as 2++ D Evidence level 3 or 4; or Extrapolated evidence from studies rated as 2+ Good practice points  Recommended best practice based on the clinical experience of the guideline development group This document is produced from elemental chlorine-free material and is sourced from sustainable forests Scottish Intercollegiate Guidelines Network Management of stable angina A national clinical guideline February 2007 © Scottish Intercollegiate Guidelines Network ISBN 1 899893 89 X First published 2007 SIGN consents to the photocopying of this guideline for the purpose of implementation in NHSScotland Scottish Intercollegiate Guidelines Network 28 Thistle Street, Edinburgh EH2 1EN www.sign.ac.uk 1 INTRODUCTION 1 Introduction 1.1 why is angina important? The recorded prevalence of angina varies greatly across UK studies.1 The Scottish Health Survey (2003) reports the prevalence of angina, determined by the Rose Angina Questionnaire to be 5.1% and 6.7% in males aged 55-64 and 65-74 respectively.2 For the same age groups in women the equivalent rates were 4% and 6.8%. This compares with general practitioner (GP) record data in the British Regional Heart Study from across the UK of 9.2% and 16.2% for men in the same age groups.3 The average GP will see, on average, four new cases of angina each year.4 Practice team information submitted by Scottish general practices to Information Services Division (ISD) Scotland allows the calculation of an annual prevalence rate for Scotland (the proportion of the population who have consulted their general practice because of a definite diagnosis of angina based on ISD’s standard morbidity grouping). In the year ending March 2005 the annual prevalence rate is given as 8.3 for men and 7.6 for women per 1,000 population. This equates to an estimated number of patients seen in Scotland in that year for angina of 42,600 with 68,200 patient contacts.5 A diagnosis of angina can have a significant impact on the patient’s level of functioning. In one survey, angina patients scored their general health as twice as poor as those who had had a stroke.6 In another survey, patients had a low level of factual knowledge about their illness and poor medication adherence.7 A Tayside study showed that in patients with angina, symptoms are often poorly controlled, there is a high level of anxiety and depression, scope for lifestyle change and an ongoing need for frequent medical contact.8 1.2 The need for a guideline In recent years there has been a decline in the rate of major coronary events and death from coronary heart disease (CHD).9 However, data from the British Regional Heart Study based on GP records which included Scotland has shown an annual increase of 2.6% in first diagnosed angina in the 20 years of follow up to the year 2000 in males aged 40-59 at entry.3 This increase reflects the diagnosis as it occurred in clinical practice without objective criteria to confirm the presence of underlying CHD. The rise in the rate of new angina diagnoses eliminates any overall fall in the diagnosis of CHD. General practitioners are being advised to ensure that patients presenting with symptoms consistent with angina are rapidly assessed. The development of rapid access chest pain clinics has been encouraged to allow this to happen.10 Evidence based diagnostic practice and the prioritisation of investigation in patients with symptoms consistent with angina are required. 1.3 angina as a symptom Angina is used to describe a clinical syndrome of chest pain or pressure precipitated by activities such as exercise or emotional stress which increase myocardial oxygen demand. Although classical stable angina can be predictable in onset, reproducible and relieved by rest or glyceryl trinitrate, other factors and circumstances can influence its development. Angina can be caused by various cardiovascular conditions but this guideline is restricted to the clinical situation where reduced myocardial perfusion is due to arterial narrowing resulting from underlying atherosclerotic coronary heart disease. A small minority of patients have objective evidence of myocardial ischaemia in the absence of any obvious structural abnormality of the coronary arteries. Stable angina is usually assessed in the outpatient setting. It is important when taking a clinical history to identify and manage appropriately those patients whose symptoms may be due to the more severe changes of plaque erosion and rupture occurring as part of the spectrum of acute coronary syndrome (see SIGN guideline 93 on acute coronary syndromes).11 1  MANAGEMENT OF STABLE ANGINA 1.4 the remit of the guideline In addition to examining the most appropriate models of care and referral this guideline examines the investigations necessary to confirm the presence of CHD. The optimum medical treatment to relieve symptoms is considered as well as the optimum management of those patients with angina requiring non-cardiac surgery. In the 10 years up to 2004 the number of coronary artery bypass grafts carried out each year in Scotland has increased only slightly (2,452 to 2,637). In the same period percutaneous coronary interventions (PCI) have increased fourfold (1,028 to 4,133) with changing trends in stent implantation.12 The relative benefits of different interventions and the provision of patient education are examined as well as whether psychological interventions can help improve symptoms and quality of life. 1.4.1 Patient version A patient version of this guideline is available from the SIGN website: www.sign.ac.uk 1.4.2 additional advice to nhsscotland from NHS quality improvement scotland and the scottish medicines consortium NHS QIS processes multiple technology appraisals (MTAs) for NHSScotland that have been produced by the National Institute for Health and Clinical Excellence (NICE) in England and Wales. The Scottish Medicines Consortium (SMC) provides advice to NHS Boards and their Area Drug and Therapeutics Committees about the status of all newly licensed medicines and any major new indications for established products. SMC advice and NHS QIS validated NICE MTAs relevant to this guideline are summarised in the section on implementation. 1.5 Statement of intent This guideline is not intended to be construed or to serve as a standard of care. Standards of care are determined on the basis of all clinical data available for an individual case and are subject to change as scientific knowledge and technology advance and patterns of care evolve. Adherence to guideline recommendations will not ensure a successful outcome in every case, nor should they be construed as including all proper methods of care or excluding other acceptable methods of care aimed at the same results. The ultimate judgement must be made by the appropriate healthcare professional(s) responsible for clinical decisions regarding a particular clinical procedure or treatment plan. This judgement should only be arrived at following discussion of the options with the patient, covering the diagnostic and treatment choices available. It is advised, however, that significant departures from the national guideline or any local guidelines derived from it should be fully documented in the patient’s case notes at the time the relevant decision is taken. 1.6 review and updating This guideline was issued in 2007 and will be considered for review in three years. Any updates to the guideline in the interim period will be noted on the SIGN website: www.sign.ac.uk  2 DIAGNOSIS AND ASSESSMENT 2 Diagnosis and assessment 2.1 establishing a diagnosis Angina is a symptom that suggests that an individual may have underlying CHD. Investigation to confirm the severity and extent of underlying CHD may also allow management strategies to be developed and optimise cardiovascular risk reduction.13 A significant proportion of patients with chest pain may not have angina and assessment should also try to identify alternative diagnoses at an early stage. Angina often varies in severity and patients who have unstable angina (acute coronary syndrome) are outside the remit of this guideline, as these patients usually require more urgent and immediate management (see SIGN guideline 93 on acute coronary syndromes).11 Patients with stable angina are usually managed in the primary care setting, but may present in a number of healthcare settings. An initial diagnosis of angina can be made within primary care but this should be supported by further assessment and risk stratification, which will normally require specialist input. 2.1.1 clinical ASSESSMENT Patients with stable angina should have the diagnosis made, where possible, following a carefully obtained clinical assessment. Clinical history is the key component in the evaluation of the patient with angina; often the diagnosis can be made on the basis of clinical history alone. While a number of scoring systems are available to assess patients with chest pain and stable angina, an accurate clinical assessment is of key importance. There are several typical characteristics of stable angina which should increase the likelihood of underlying CHD. These include:14  type of discomfort – often described as tight, dull or heavy  location – often retrosternal or left side of chest and can radiate to left arm, neck, jaw and back  relation to exertion – angina is often brought on with exertion or emotional stress and eased with rest  duration – typically the symptoms last up to several minutes after exertion or emotional stress has stopped  other factors – angina may be precipitated by cold weather or following a meal. 4 The predominant features described by some patients are discomfort and heaviness or breathlessness, rather than pain. Chest discomfort, irrespective of its site, is more likely to be angina when precipitated by exertion and relieved by rest. It is also characteristically relieved by glyceryl trinitrate. Not all patients will present with typical characteristics and the clinician should be aware of other symptoms such as breathlessness and burping which may be the initial presenting symptom. Angina can be graded by severity on the Canadian Cardiovascular Society (CCS) class scale of I-IV15 (see Table 1). Table 1: Canadian Cardiovascular Society Angina Classification Class Description Class I Ordinary activity such as walking or climbing stairs does not precipitate angina Class II Angina precipitated by emotion, cold weather or meals and by walking up stairs Class III Marked limitations of ordinary physical activity Class IV Inability to carry out any physical activity without discomfort – anginal symptoms may be present at rest.  MANAGEMENT OF STABLE ANGINA The likelihood of a diagnosis of angina increases with the number of cardiovascular risk factors in individual patients. These include:      smoking hypertension diabetes family history of CHD (first degree relative – male <55 years/female <65 years) raised cholesterol and other lipids. These risk factors are best initially addressed in the primary care setting where lifestyle advice can be provided and support offered, where necessary. If symptoms persist, more objective evaluation of symptoms may be necessary to establish the severity of any underlying CHD. In addition to assessment of conventional risk factors, (see SIGN guideline 97 on risk estimation and the prevention of cardiovascular disease)73 patients should have the following evaluated:        body mass index (BMI) or waist circumference murmur evaluation haemoglobin level fasting blood glucose thyroid function depression and social isolation physical activity. A number of scoring systems have been proposed to assess the severity and prognostic impact of angina.16,17 While these scoring systems may be accurate in the patient groups included in the cohorts studied, their use in routine clinical practice cannot be recommended, but they may have a role in influencing the clinical decision making process. 2++ 2+ When a general practitioner identifies a patient with stable angina, further assessment at a cardiology outpatient clinic is desirable. 2.1.2  Patients with suspected angina should have a detailed initial clinical assessment which includes history, examination and an assessment of blood pressure, haemoglobin, thyroid function, cholesterol and glucose levels.  Those patients who should be considered for early referral to secondary care include those with new onset angina and those with established coronary heart disease with an increase in symptoms. Non-cardiac chest pain Angina pain is not usually sharp or stabbing in nature. It is not usually influenced by respiration or eased with antacids and simple analgesia. The initial clinical assessment is important as it may reduce anxiety and distress resulting in unnecessary hospital admissions and consultations.18 Low risk patients, such as young women with atypical symptoms, should be assessed in primary care where possible. Much of this assessment includes explaining symptoms, discussing concerns and providing reassurance where necessary. A diagnosis of non-cardiac chest pain should be given early and confidently as correct management may reduce morbidity.19 A rehabilitation programme based on cognitive behaviour principles for patients with chest pain but normal coronary arteries, found that those who continued to attribute symptoms to cardiac causes had worse outcomes.20   If the diagnosis is uncertain, clinicians should not give the impression that the patient has angina. This may lead the patient to have false beliefs, which may be difficult to change even after further investigations have ruled this out. 2+ 4 2 DIAGNOSIS AND ASSESSMENT 2.1.3 diagnostic tools Electrocardiography A baseline 12 lead electrocardiogram (ECG) should be performed in every patient with suspected angina.21 A normal 12 lead ECG does not exclude a diagnosis of coronary heart disease.22 An abnormal resting ECG increases the probability that a patient has CHD, but gives no indication as to the severity of any associated obstructive coronary heart disease.23 A 12 lead ECG can also highlight the presence of atrial fibrillation or left ventricular hypertrophy. The interpretation of resting or exercise ECGs is operator-dependent.24 2++ 3 Exercise tolerance testing The majority of patients with suspected angina will be referred for exercise tolerance testing (ETT), which is also known as exercise ECG or stress ECG. Exercise is usually performed by treadmill testing or on a static bicycle and may be unsuitable for patients who have poor mobility, peripheral arterial disease or limiting respiratory or musculoskeletal conditions. The sensitivity and specificity of ETT in establishing the diagnosis of CHD is dependent on the cohort of patients studied. Sensitivity is higher in patients with triple vessel disease and lower in patients with single vessel disease.25 The true diagnostic value of exercise ECG lies in its relatively high sensitivity, but it is only moderately specific for the diagnosis of CHD in women.26 2+ 4 A normal exercise test may reassure many patients but it does not exclude a diagnosis of CHD. A highly abnormal ETT result is an indication for urgent further investigation. Myocardial perfusion scintigraphy Myocardial perfusion scintigraphy (MPS) with exercise or pharmacologic stress is an accurate and non-invasive investigation which reliably predicts the presence of CHD.27 Myocardial perfusion scintigraphy may be the appropriate initial diagnostic test in patients with pre-existing ECG abnormalities (eg left bundle branch block) or in those unable to adequately exercise and as part of the diagnostic strategy for suspected CHD in people with lower likelihood of CHD.28 It is also valuable in females who may have a low risk of underlying CHD but a high risk of a falsely positive ETT and in patients where identification of regional ischaemia would be of value (eg prior to PCI). Myocardial perfusion scintigraphy provides valuable independent and incremental prognostic information to that provided by ETT and this enables risk stratification of patients which informs treatment decisions.29 C Patients with suspected angina should usually be investigated by a baseline electrocardiogram and an exercise tolerance test. B Patients unable to undergo exercise tolerance testing or who have pre-existing electrocardiogram abnormalities should be considered for myocardial perfusion scintigraphy. 2++ 4 Coronary angiography Coronary angiography is the traditional benchmark investigation for establishing the nature, anatomy and severity of CHD. It is an invasive investigation and carries a mortality risk of around 0.1% for elective procedures.30 It requires referral to a cardiologist and is best reserved for those patients who are at high risk or continue to have symptoms despite optimal medical treatment and may require revascularisation. It may also provide valuable information regarding valvular and left ventricular function.  4 Coronary angiography should be considered after non-invasive testing where patients are identified to be at high risk or where a diagnosis remains unclear.  MANAGEMENT OF STABLE ANGINA Other investigations Newer investigations including stress echocardiography, magnetic resonance perfusion imaging (MRI) and multislice computed tomography (CT) scanning are also effective in establishing a diagnosis of CHD when performed by trained and skilled teams.31-33 These investigations are not part of routine clinical practice in NHSScotland, although their use may become more widespread as clinical and economic evaluations of their effectiveness become available. 14 2.2 models of care A variety of models have been developed to facilitate prompt identification and optimum management of patients with angina from those with potentially less severe causes of chest pain. These models of care have been designed in varying ways emphasising the development of a service which reflects local health needs and demands. While many of these services have a triage role, their design facilitates the early detection of patients who may have severe CHD who would benefit from early intervention. Optimum management of angina requires reassurance of low risk patients while appropriately identifying high risk patients and making the most efficient use of available resources. Rapid access chest pain clinics (RACPCs) have been advocated as a successful model of referral to secondary care for angina patients. These have been in existence for many years. The National Service Framework for Coronary Artery Disease suggested more of these clinics should be set up and rolled out across England and Wales to assess patients within two weeks of primary care referral.34 No evidence was provided to explain the specific target of two weeks. These clinics are run in a variety of ways, depending on local resources, where patients can be seen by cardiologists, specialist registrars, nurse specialists or GPs with special interest in cardiology. One detailed meta-analysis investigated a range of methods, including rapid access chest pain clinics, in the diagnosis and management of acute coronary syndromes (ACS), suspected myocardial infarction (MI) and exertional angina.21 Weak evidence was found to suggest that RACPCs may be associated with reduced admission to hospital of patients with non-cardiac pain, better recognition of ACS, earlier specialist assessment of exertional angina and earlier diagnosis of non-cardiac chest pain. In a simulation exercise of models of care for investigation of suspected exertional angina, RACPCs were predicted to result in earlier diagnosis of both confirmed CHD and non-cardiac chest pain than models of care based around open access exercise tests or routine cardiology outpatients, but they were more expensive. The benefits of RACPCs disappeared if waiting times for further investigation (eg angiography) were long (six months). The evidence around the cost effectiveness of RACPC for patients with suspected angina is very limited. One study showed operating such a clinic can be cost saving, compared to standard care, potentially reducing costs by about £60 per patient, with the savings coming from fewer unnecessary hospitalisations.35 However, the study is weak, results are very setting specific and may not generalise to other settings. B  Following initial assessment in primary care, patients with suspected angina should, wherever possible, have the diagnosis confirmed and the severity of the underlying coronary heart disease assessed in the chest pain evaluation service which offers the earliest appointment, regardless of model. 4 2++ 3