Cardiovascular Disease

Transcription

1 NEW ZEALAND HEALTH STRATEGY DHB TOOLKIT Cardiovascular Disease To reduce the incidence of cardiovascular disease 2003 Edition 2: February 2003

2 Contents Contents...2 Executive summary...4 Introduction...5 Linkages Cardiovascular disease, risk assessment and management...6 Burden of cardiovascular disease in New Zealand...6 Cardiovascular risk factors...7 Cardiovascular assessment and risk management...8 Primary prevention of cardiovascular disease...9 Secondary prevention of cardiovascular disease...11 Cardiac rehabilitation...12 Secondary prevention of ischaemic stroke...12 Tools available for District Health Boards...14 Tools under development...14 Tools for future development Management of acute coronary syndromes...16 Acute coronary syndromes in New Zealand...16 Acute pre-hospital care...16 Hospital care...17 Tools available for District Health Boards...18 Tools under development...18 Tools for future development Heart failure...19 Heart failure in New Zealand...19 Management of heart failure...19 Tools available for District Health Boards Rheumatic heart disease...21 Rheumatic fever and heart disease in New Zealand...21 Tools available for District Health Boards Stroke services...23 Burden of stroke in New Zealand...23 Stroke care in New Zealand...23 Access to and quality of stroke services...24 Organised stroke care...25 Tools available for District Health Boards...26 Tools under development...26 Tools for future development Cardiovascular disease and Maori...27 Tools available for District Health Boards...27 New Zealand Health Strategy DHB Toolkit: Cardiovascular Disease Edition 2 2

3 Tools under development...30 Tools for future development Cardiovascular disease and Pacific peoples...31 Tools available for District Health Boards...31 Tools under development...32 Tools for future development...32 References...33 APPENDIX 1: Indicators...37 APPENDIX 2: Definitions...43 New Zealand Health Strategy DHB Toolkit: Cardiovascular Disease Edition 2 3

4 Executive summary Cardiovascular disease is the leading cause of death in New Zealand, accounting for 41 percent of all deaths in 1999, thus it has a large impact on the delivery of health services. Of the cardiovascular diseases, coronary artery disease is the major cause of death, followed by stroke, which is the greatest cause of disability in older people. The burden of cardiovascular disease is greatest among Maori and Pacific peoples, as the following evidence indicates. Mortality from all cardiovascular diseases is higher among Maori than the general population. Coronary heart disease is the leading single cause of death for Maori. Maori have the highest rate of hospital admissions for heart failure (nearly three times that of Europeans/others). Pacific peoples have the highest mortality rate for cerebrovascular disease and the highest hospital discharge rate for stroke. The chance of being dependent at 12 months post stroke is three times higher among Maori and Pacific peoples than among Europeans who have a stroke. Maori and Pacific peoples have the highest discharge rates for both rheumatic fever and rheumatic heart disease. One of the 13 population health objectives of the New Zealand Health Strategy is to reduce the incidence and disease impact of cardiovascular disease in New Zealand. In addressing this priority a Cardiovascular Expert Advisory Group was established to assist the Ministry of Health to identify those cardiovascular areas that would have the greatest population impact. Following a review of the evidence, an action plan was developed, which includes the following priority areas: cardiovascular risk screening and management acute coronary syndromes secondary prevention cardiac rehabilitation organised stroke care cardiovascular disease and Maori cardiovascular disease and Pacific peoples. The Cardiovascular Action Plan is currently being implemented over three years. Its main work includes: development of New Zealand cardiovascular cardiac and stroke guidelines for DHB providers development of national service specifications for cardiac and stroke services addressing inequalities, particularly for Maori and Pacific peoples. (Additional work on Reducing Inequalities in Health and a Reducing Inequalities Toolkit are available from the Ministry of Health.) consumer education addressing workforce issues. This toolkit provides evidence on each of the cardiovascular priority areas and information on cardiovascular tools currently available, tools under development and tools for future development. New Zealand Health Strategy DHB Toolkit: Cardiovascular Disease Edition 2 4

5 Introduction The New Zealand Health Strategy has identified 13 priority areas for population health. District Health Boards (DHBs) will be required to report annually on progress towards each of these priority areas. This toolkit provides information and resources to assist DHBs to achieve the objective of reducing the incidence and impact of cardiovascular disease in their communities. The toolkit was developed by the Clinical Services Directorate within the Ministry of Health in conjunction with a Cardiovascular Expert Advisory Group composed of clinicians, District Health Boards New Zealand (DHBNZ), consumers, Maori and Pacific peoples. As there were no existing cardiovascular strategies, the advisory group assisted the Ministry to produce a Cardiovascular Action Plan aimed at addressing those cardiovascular areas that would have the greatest population impact. The action plan was developed following a review of the evidence. It includes the following priority areas in which strategic work is currently being carried out: cardiovascular risk screening and management acute coronary syndromes secondary prevention cardiac rehabilitation organised stroke care cardiovascular disease and Maori cardiovascular disease and Pacific peoples. To assist DHBs this toolkit provides: evidence and information on each of the cardiovascular priority areas information on current cardiovascular tools that can be utilised by DHBs information on cardiovascular tools currently under development and tools for future development. Information is also provided on heart failure and rheumatic heart disease. Links This toolkit should be read in conjunction with the following Ministry of Health toolkits: Tobacco Improve nutrition Obesity Physical activity Diabetes New Zealand Health Strategy DHB Toolkit: Cardiovascular Disease Edition 2 5

6 1. Cardiovascular disease, risk assessment and management Key points Cardiovascular disease is the leading cause of mortality in New Zealand. It accounted for 41 percent of all deaths in Maori have the highest rates of mortality for all categories of cardiovascular disease. The major modifiable risk factors for cardiovascular disease are smoking, hypertension, high serum cholesterol, diabetes, obesity, exercise and diet. Those at highest absolute risk derive the most benefit from treatment. Although there are no national systematic cardiovascular screening programmes, tools are available for cardiovascular risk assessment by providers. There are also effective primary and secondary interventions for reducing and managing cardiovascular risk. National strategic work includes the development of New Zealand guidelines for risk assessment and for primary and secondary prevention of cardiovascular disease. It also includes modelling work to investigate the costs and benefits of screening populations for different levels of cardiovascular risk. DHBs should identify the cardiovascular burden within their population, particularly for Maori and Pacific peoples, and determine service provision within their DHBs in preparation for the development of national service specifications for stroke and cardiac services. Burden of cardiovascular disease in New Zealand Cardiovascular diseases are diseases affecting the heart and circulatory system. They include ischaemic heart disease, rheumatic heart disease, cerebrovascular disease and other forms of vascular and heart disease. Cardiovascular disease is the leading cause of death in New Zealand, accounting for 41 percent of all deaths in It is also the leading cause of years lost to premature mortality, accounting for 33 percent of life years lost between 45 and 64 years of age (Hay 2001). Although coronary artery disease is declining in New Zealand (Ministry of Health 1998), it still results in the highest number of deaths of cardiovascular disease-related deaths (91 per 100,000). It is the second leading cause of death following cancer. Coronary heart disease accounted for 23 percent of all deaths in 1999, of which just over 52 percent were attributable to myocardial infarction. Eighty-five percent of coronary heart disease deaths occur in those over 65 years (Hay 2001). Stroke is the third leading cause of death in New Zealand (33 per 100,000). It accounted for 10 percent of all deaths in 1999, of which most occurred in those over 65 years (Hay 2001). Mortality from all cardiovascular diseases is higher among Maori than the general population. Coronary heart disease is the leading single cause of death for Maori. Maori men are 1.8 times more likely to die from coronary heart disease than non-maori males (221 per 100,000 compared to 122 per 100,000). Maori women are 1.8 times more likely to die from coronary heart disease than non-maori women (97 per 100,000 compared to 55 per 100,000) (Hay 2001). The coronary heart disease mortality rate for Maori aged under 65 years is almost three times higher than that of non-maori in this age group. Death rates from cerebrovascular disease are 1.2 times higher in Maori than in non-maori, and from hypertensive disease they are five times higher (Hay 2001). New Zealand Health Strategy DHB Toolkit: Cardiovascular Disease Edition 2 6

7 Mortality rates from coronary heart disease for Pacific peoples are lower than rates for Maori (199 per 100,000 compared to 267 per 100,000 in 1999) but higher than European/others (158 per 100,000). Mortality rates for cerebrovascular disease are higher for Pacific peoples (115 per 100,000) than for Maori (82 per 100,000) and others (64 per 100,000) (1999 figures) (Ministry of Health 2002a). Mortality rates for coronary heart disease are higher among those in lower socioeconomic classes (Kawachi et al 1991). The cost of cardiovascular disease in New Zealand is considerable. In the early 1990s the cost of coronary artery disease was estimated at between $306 million and $467 million ($179 million in direct costs). Hospital costs for stroke have been estimated at $58 million; the cost of stroke to the country as a whole has been estimated at $154 million a year. Cardiovascular drugs alone cost in excess of $100 million and contribute to over 20 percent of Pharmac expenditure (Pharmac 2001). Cardiovascular risk factors There is abundant evidence that the following factors increase cardiovascular risk. Cigarette smoking Cigarette smoking is associated with a two- to three-fold increase in coronary artery disease, stroke and peripheral vascular disease (Levy et al 1990). It is also thought to be the single most preventable cause of heart disease. Population prevalence of smoking is estimated at around 25 percent (Ministry of Health 2002b). The prevalence of smoking for Maori is much higher, at 44 percent for Maori men and 51 percent for Maori women (Ministry of Health 2002b). Refer to Tobacco Facts 2002 for more information. Hypertension Hypertension is a major risk factor for coronary artery disease and is the most important risk factor for stroke. It has been estimated that among those aged 15 years and over, nearly 22 percent of males and 18.2 percent of females have high blood pressure (Ministry of Health 1999b). Cholesterol The association between cholesterol level and risk of developing cardiovascular disease has been found to be continuous and graded. That is, the risk of cardiovascular disease mortality increases with rising cholesterol levels. Diabetes Diabetes is a major risk factor for coronary artery disease, stroke and peripheral vascular disease (Eastman and Keen 1997). It is associated with a two- to three-fold increased risk in coronary artery disease in men and a four- to five-fold increase in premenopausal women (Fuller et al 1980; Rosengren et al 1989). There is a five-fold increase in heart failure among diabetics (Yudkin and Hendra 1992). It is the leading cause of death in type 1 and type 2 diabetics (SIGN 1997). Refer to the diabetes toolkit for further information. Obesity People who are obese (ie, with a body mass index (BMI) of 30 or greater) are two to three times more likely to develop coronary heart disease than those who are not obese (Agencies for Nutrition Action 2001). Mortality from cardiovascular disease begins to increase with a BMI above 25. The 1997 National Nutrition Survey estimated that 17 percent of New Zealanders are New Zealand Health Strategy DHB Toolkit: Cardiovascular Disease Edition 2 7

8 now obese (ie, have a BMI greater than 30) compared to 11 percent in 1989 (Ministry of Health 1999a). Physical activity People who are sedentary are 1.9 times more likely to die from coronary artery disease than active people, irrespective of other factors (Berlin and Colditz 1990). A similar finding is produced by other systematic reviews and studies (Eaton 1992; Sherman et al 1999). Physical activity can also reduce the risk of stroke (Gillum et al 1996). The New Zealand Nutrition survey identified that over one third of New Zealanders (40 percent) are physically inactive. Absolute risk and cumulative effect of risk factors It is widely accepted that a person s risk of cardiovascular disease is determined by the synergistic effect of all the cardiovascular risk factors. The Framingham study (Jackson 1996) identified that a cumulative effect of risk in the presence of two or more risk factors results in a higher absolute risk of cardiovascular disease. Figure 1 demonstrates the cardiovascular risk over an eight-year period for 40-year-old men with the same four systolic blood pressure groups but with different numbers of risk factors. There is nearly a 20-fold difference in cardiovascular risk between the first and last groups. Those at highest absolute risk can be expected to receive the greatest benefit from treatment. It is important to note that in this study physical activity and obesity are considered to have an effect through the other risk factors (NHS Centre for Reviews and Dissemination 1998). Figure 1: CVD risk in 40-year-old men by SBP and other risk factors, Framingham, USA CVD risk per CVD 1000 risk in per years in 8 years SBP mmhg SBP high chol mmhg high gluc intol. chol gluc cigarettes intol cigarettes LVH LVH Source: R Jackson (1999). Reproduced with permission. Cardiovascular assessment and risk management The Cardiovascular Expert Advisory Group has identified cardiovascular risk assessment and management as a national priority area. Cardiovascular risk is managed through both: primary prevention, defined as the long term management of people at increased risk but with no evidence of cardiovascular disease (BMJ Publishing Group 2000) secondary prevention, defined as the long-term management of people who have existing cardiovascular disease, have had a cardiovascular event, have had a cardiovascular surgical procedure and are at risk of a cardiovascular event (BMJ Publishing Group 2000). New Zealand Health Strategy DHB Toolkit: Cardiovascular Disease Edition 2 8

9 There are currently no national systematic risk assessment and management screening programmes for the primary and secondary prevention of cardiovascular disease. In part, they are absent because of international debate over the level of risk at which cardiovascular risk screening and treatment should occur given scarce national resources. Some individual provider groups (eg, First Health and Procare) offer cardiovascular risk programmes. Assessment and treatment of cardiovascular risk are an important part of the roles of primary and secondary providers. Current guidance for providers on the level of risk at which patients should be treated is based on an absolute risk assessment used in the hypertension and lipid guidelines. References for these publications are included later in this section. Primary prevention of cardiovascular disease Assessment of risk for the primary prevention of cardiovascular disease is the role of primary care providers. Interventions are directed at modifying cardiovascular risk factors to reduce the absolute risk of cardiovascular disease. Effective primary prevention interventions include: quitting smoking reducing high blood pressure improving lipid profiles more intensive control of diabetes changing lifestyle factors (dietary patterns, reducing weight and increasing physical activity). Cigarette smoking Effective measures to decrease smoking in the population are outlined in the tobacco control toolkit. Interventions include population media strategies, Quitline, the provision of health professional advice (particularly by doctors) and the use of nicotine replacement therapy. Hypertension Interventions to lower blood pressure include salt reduction, weight loss, exercise and antihypertensive drug therapy. Another is a dietary pattern high in fruits and vegetables, whole grain cereals, low-fat dairy products, fish (especially oily fish), chicken and lean meat. From rigorous meta-analyses of randomised trials of antihypertensive medications (chiefly diuretics or beta-blockers), data have demonstrated a consistent reduction in mean systolic/diastolic blood pressure (Collins et al 2000). The estimated reduction in the risk of having a cardiovascular event over five years is 2 3 percent for each 1 mm Hg drop in systolic blood pressure (Mulrow et al 1997). The treatment and management of hypertension are outlined in the Guidelines for the Management of Mildly Raised Blood Pressure in New Zealand, developed in 1995 by the New Zealand Guidelines Group. Cholesterol lowering Interventions to lower blood cholesterol include dietary advice, the use of plant sterols, weight loss, exercise and cholesterol-lowering drug therapy. However, one type of cholesterol-lowering drug (statins) has the most significant effect. A recent meta-analysis of the five major statin trials reported reductions of total cholesterol by 20 percent, low density lipids (LDL) by 28 percent and triglycerides by 13 percent, along with an increase in high density lipids (HDL) by 5 percent. After an average of five years treatment, the risk of coronary heart disease mortality was reduced by 31 percent, cardiovascular deaths by 27 percent and all-cause mortality by 21 percent. It has been demonstrated that the risk reduction is similar for men, women, older people and the middle aged (LaRosa et al 1999). New Zealand Health Strategy DHB Toolkit: Cardiovascular Disease Edition 2 9

10 In 2000 lipid modifying agents resulted in the highest expenditure ($36.6 million) of the drugs in the pharmaceutical schedule (Pharmac 2001). This cost could be far greater if more eligible people took up statins. Currently approximately 50 percent of 160,000 patients who are eligible for statins are receiving them. In interpreting this level of access, it should be noted that approximately 45,000 people are receiving alternative lipid lowering drugs, mainly fibrates (Pharmac 2001). The lipid guidelines developed by the National Heart Foundation are the current guide to the management of lipid lowering. These guidelines are currently being updated and are being incorporated into a New Zealand guideline on the assessment and management of cardiovascular risk (see section below on tools under development). Coinciding with this work is a review by Pharmac of the eligibility criteria for statins due to a decrease in their price. Diabetes As stated above, men with diabetes are two to three times more likely to die from coronary heart disease and premenopausal women with diabetes are four to five times more likely to die from coronary heart disease. The prospective diabetes study in the United Kingdom found that the ECG readings of 15 percent of men and 23 percent of women indicated myocardial ischaemia at diagnosis of diabetes (Morrish et al 1991). It is therefore suggested that it is important that all diabetics are assessed and treated for cardiovascular risk (SIGN 1997). The Scottish Intercollegiate Guidelines Network has developed guidelines for the management of diabetic cardiovascular disease (SIGN 1997). These guidelines recommend that diabetics should be assessed for cardiovascular risk factors yearly and that glycaemic control to reduce cardiovascular risk should be optimised. As for other people at cardiovascular risk, they also recommend reduction of smoking, weight management, lipid reduction and changes to lifestyle. The management of diabetic cardiovascular disease is included in the guideline currently being developed for the assessment and management of cardiovascular risk. Lifestyle factors Reduction in weight has been shown to reduce blood pressure. From 76 randomised controlled trials (RCTs) evaluating the effect of weight loss on blood pressure, an analysis demonstrated that a 10 kg weight loss in hypertensive patients was associated with an average reduction of 7 mm Hg systolic and 3 mm Hg diastolic blood pressure compared with controls. Reduction in weight can also reduce lipid levels (National Heart, Lung and Blood Institute 1998). A meta-analysis has shown that physical activity alone (aerobic exercise) independent of caloric reduction through diet results in a modest weight loss of 3 kg in men and 1.4 kg in women (World Health Organization 1990). Diet and physical activity together produce a greater weight loss than either therapy alone. Over nine months to two years, a combination of diet and physical activity resulted in weight loss approximately 1.5 to 3 kg greater than diet alone (National Heart, Lung and Blood Institute 1998). Primary care providers need to be able to provide advice on weight maintenance, nutrition and physical activity. Information on obesity, physical activity and nutrition is available from the Ministry of Health toolkits. Other information on nutrition and physical activity for providers is available through the National Heart Foundation of New Zealand. Information on physical activity and green prescriptions is also available for providers through the Hillary Commission. The Hillary Commission (2001) identified that general practitioners write about 4,000 green prescriptions a year, with the most common prescription being walking. New Zealand Health Strategy DHB Toolkit: Cardiovascular Disease Edition 2 10

11 Secondary prevention of cardiovascular disease Assessment of risk for the secondary prevention of cardiovascular disease is the role of primary and secondary care providers. Interventions are directed at modifying cardiovascular risk to reduce the risk of further events or death. As in primary prevention, interventions include quitting smoking (the CVD risk becoming that of a non-smoker within two to five years; LaRosa et al 1999), reducing high blood pressure, lowering lipid levels, controlling diabetes more intensively and modifying lifestyle. Other interventions are additional drug therapy, revascularisation and cardiac rehabilitation. Drug therapy In those with established coronary heart disease, there is substantial evidence of benefit (ie, reduction in coronary artery disease morbidity and mortality) with the use of aspirin, betablockers, ACE inhibitors and lipid modifying drugs (BMJ Publishing Group 2000; Koudstaal 2000). Aspirin is an antiplatelet therapy effective in reducing mortality in people who are having or have had myocardial infarction and in preventing an initial or subsequent stroke (BMJ Publishing Group 2000). Beta-blockers have an effect on beta receptors that decrease cardiac work and myocardial oxygen demand. Beta-blockers reduce the risk of all-cause mortality, coronary mortality, recurrent non-fatal myocardial infarction and sudden death in people after myocardial infarction (BMJ Publishing Group 2000). ACE inhibitors can reduce rates of death and hospitalisation for people who have a recurrent non-fatal myocardial infarction and who have left ventricular dysfunction. The effect in people who have had a myocardial infarction but no left ventricular dysfunction has not been properly evaluated (BMJ Publishing Group 2000) Statins can reduce the need for revascularisation (either angioplasty or coronary artery bypass surgery) by as much as 37 percent (BMJ Publishing Group 2000). In a recent study, only 32 percent of patients who had had a previous heart attack were on a lipid-lowering agent (Ellis 1998). Revascularisation Revascularisation procedures include angioplasty (PTCA) and coronary artery bypass graft (CABG). Randomised controlled trials up to the mid-1980s have found that, compared with medical treatment, coronary artery bypass surgery causes a greater risk of death in the first year but reduced risk of death at 5 and 10 years. Greatest benefit occurred in people with more severe disease. Intracoronary stents have been found to be superior in the long term compared to PTCA (BMJ Publishing Group 2000). The issue of medical treatment versus revascularisation is subject to ongoing research and debate. Revascularisation procedures are prioritised using referral guidelines for specialist assessment, access criteria for first specialist assessment and clinical priority access criteria (CPAC) for access to procedures or surgery. These guidelines and criteria have been developed by clinicians since 1997 and take into account both the ability to benefit from revascularisation procedures and the need of patients requiring these procedures. Final prioritisation decisions by clinicians take into account both the CPAC score at which procedures are carried out and the funding threshold of hospitals. Such decisions are reported on quarterly by hospitals. New Zealand Health Strategy DHB Toolkit: Cardiovascular Disease Edition 2 11

12 Cardiac rehabilitation Cardiac rehabilitation is a multidisciplinary approach that aims to modify cardiac risk through lifestyle change, to improve functional capacity and self-confidence and to reduce psychological distress. Rehabilitation programmes usually include exercise training, risk factor modification, education (including diet) and counselling. In the past, cardiac rehabilitation has been chiefly prescribed for patients following a heart attack but it is now recognised that people with all forms of cardiovascular disease may well benefit from this approach. Randomised controlled secondary prevention trials of exercise-based cardiac rehabilitation following myocardial infarction have shown a reduction in total mortality and cardiovascular mortality by 20 to 25 percent (O Connor et al 1989; Oldridge et al 1988). Cardiac rehabilitation has also been shown to produce significant direct cost saving through reduced hospital admissions, hospital costs, disability benefits and support services, while improving quality and duration of life. Currently 37 centres in New Zealand offer phase 1 and 2 cardiac rehabilitation. The provision of cardiac rehabilitation varies considerably across the country. There is variation in facilities, equipment, format of the service, duration of the programmes and the number of sessions offered. In a recent audit of a large institution, the National Heart Foundation identified that 56 percent of those eligible for cardiac rehabilitation do not attend, and of those who do attend only 19 percent actually complete the programme. Reasons for non-attendance could include lack of referral from health professionals and lack of knowledge of cardiac rehabilitation services by patients (Parks et al 2000). A New Zealand guideline for cardiac rehabilitation has recently been completed by the National Heart Foundation and the New Zealand Guidelines Group. This guideline provides comprehensive information on the management of the rehabilitation of cardiac patients, information on audit of cardiac rehabilitation services and a set of performance indicators. It is intended that the cardiac rehabilitation guideline will inform future development of National cardiac service specifications. A copy of the guideline can be viewed on the New Zealand Guidelines Group website. Secondary prevention of ischaemic stroke Secondary prevention of stroke should commence in the first week following a stroke. Interventions are directed at modifying risk factors to reduce the risk of further strokes and cardiovascular events. A clear patient management plan involving both the patient and caregivers is essential. It is also important that there is effective co-ordination among hospital, primary care and other providers to ensure that the plan is implemented. Interventions to prevent further strokes can include reduction of blood pressure, quitting smoking, treatment of dyslipidaemia, antiplatelet treatment, carotid endarterectomy, treatment of atrial fibrillation and other comorbidities. Reduction of blood pressure Hypertension is the most important reversible risk factor for stroke. It is recommended that hypertension is treated after a patient has had a stroke or a transient ischaemic attack (TIA) and should follow standard guidelines. It is important, however, that blood pressure treatment is not commenced until one to two weeks after a stroke. Lowering blood pressure in the first few days after stroke reduces cerebral blood flow and may increase the size of the cerebral infarct (Stroke Foundation of New Zealand 1996). New Zealand Health Strategy DHB Toolkit: Cardiovascular Disease Edition 2 12

13 Quitting smoking The risk of stroke is increased in cigarette smokers by about 50 percent. It is important that the patient management plan identifies suitable strategies for assisting the patient to give up smoking (Stroke Foundation of New Zealand 1996). Treatment of dyslipidaemia The evidence that cholesterol-lowering drugs reduce the risk of further strokes is as yet incomplete. Randomised control trials have found that statins reduce the occurrence of strokes in people with coronary heart disease, but it is uncertain whether cholesterol-lowering drugs reduce the risk of recurrent stroke in patients with symptomatic cerebrovascular disease (BMJ Publishing Group 2000). Randomised control trials are ongoing to address this issue (BMJ Publishing Group 2000). In the meantime the Stroke Foundation guidelines recommend managing dyslipidaemia according to the standard lipid guidelines developed by the National Heart Foundation of New Zealand in Antiplatelet treatment Aspirin reduces the risk of further serious vascular events by about 25 percent. In an overview of randomised controlled trials, low doses (<150 mg/day) and high doses (>325 mg/day) of aspirin were effective in reducing the risk of recurrent vascular events (stroke, myocardial infarction or vascular death). Although the optimal dose is uncertain, doses of 325 mg/day or lower are safe, effective and cheap. A combination of aspirin and dipyridamole is a safe and effective alternative to aspirin alone (BMJ Publishing Group 2000; Stroke Foundation of New Zealand 1996). Clopidogrel is another effective antiplatelet treatment that can be used instead of aspirin, particularly for people who cannot tolerate aspirin. It is currently not subsidised in New Zealand but is under review by Pharmac. Before commencing aspirin or other antiplatelet treatment it is important that patients have an early CT scan to exclude a haemorrhagic stroke (Stroke Foundation of New Zealand 1996) Carotid endarterectomy Carotid endarterectomy is recommended only for patients who have severe stenosis (>70 percent) of the symptomatic carotid artery. To be eligible for this procedure, patients should have little or no functional problems as a result of their stroke or TIA. Carotid endarterectomies should be performed by a vascular surgeon who has a history of low rates of perioperative complications (perioperative stroke or death in the first month after carotid endarterectomy for symptomatic carotid stenosis of <6 percent) (BMJ Publishing Group 2000; Stroke Foundation of New Zealand 1996). Carotid angioplasty Carotid angioplasty is not currently recommended in the secondary prevention of stroke except in the setting of a clinical trial (BMJ Publishing Group 2000). Treatment of atrial fibrillation Non-valvular atrial fibrillation is a common cause of ischaemic stroke. Warfarin is the preferred treatment, reducing the risk of recurrent stroke in people with atrial fibrillation. This treatment is complex and requires rigorous monitoring. The target international normalised ratio (INR) should be 2.0 to 3.0. New Zealand Health Strategy DHB Toolkit: Cardiovascular Disease Edition 2 13

14 If warfarin cannot be administered safely to people with atrial fibrillation, then aspirin is recommended. However, aspirin is not as effective as warfarin (Stroke Foundation of New Zealand 1996, BMJ Publishing Group 2000). For patients with a recent ischaemic stroke who do not have severe symptomatic carotid stenosis or atrial fibrillation, anticoagulation does not reduce the risk of recurrent stroke or death. Rheumatic valvular heart disease The efficacy of warfarin in patients with rheumatic valvular heart disease with or without atrial fibrillation has not been assessed in randomised control trials. However, anecdotal experience clearly shows that anticoagulation reduces the risk of further cardioembolic events. Artificial heart valves Warfarin is usually given to people with bioprosthetic heart valves for three to six months unless the patient has atrial fibrillation, in which case it is continued indefinitely. If the patient has mechanical heart valves, warfarin and an antiplatelet agent should be given indefinitely. Secondary prevention in people who had a stroke following myocardial infarction The Stroke Foundation guidelines recommend the use of heparin and warfarin to reduce the risk of recurrent cerebral emboli in patients who have had a cerebral infarct following a myocardial infarction. Tools available for District Health Boards Five-year trends for key cardiovascular data to assist with needs analysis and DHB planning are included with this toolkit in electronic form here. The following tools are available elsewhere. Guidelines for the Management of Mildly Raised Blood Pressure in New Zealand 1995, available at The Lipid Guidelines are available from the National Heart Foundation of New Zealand; they are also published in the New Zealand Medical Journal vol 109, The Heart Foundation website is: The New Zealand Cardiac rehabilitation guidelines available at The National Heart Foundation produces pamphlets and guidelines for consumers and providers on cardiovascular risk, nutrition, cardiac rehabilitation and exercise for people with heart disease. Educational material is also available for the public. Absolute risk assessment tables are included in New Ethicals catalogue and the pharmaceutical schedule. Referral guidelines, access criteria for specialist assessment and CPAC tools for cardiac catheterisation, PTCA and CABG are all available from Elective Services. The Stroke Foundation s (1996) Life after Stroke: New Zealand guidelines for best practice in rehabilitation after stroke (currently being updated). Tools under development The following guidelines are currently under development and will be available from 31 June The CVD toolkit will be amended to include these guidelines once they are completed. The assessment and management of cardiovascular risk. The use of medications after cardiovascular disease. New Zealand Health Strategy DHB Toolkit: Cardiovascular Disease Edition 2 14

15 Life after Stroke: New Zealand guidelines for best practice in rehabilitation after stroke currently being updated and should be available from June Tools for future development Guidelines for the management of atrial fibrillation. National service specification for cardiac services. Consumer education resources. New Zealand Health Strategy DHB Toolkit: Cardiovascular Disease Edition 2 15

16 2. Management of acute coronary syndromes Key points Acute coronary syndromes include patients with unstable angina or acute myocardial infarction. A British study identified that 45 percent of those who have a myocardial infarction die within 30 days of myocardial infarction. Evidence indicates that in reducing morbidity and mortality in patients with acute coronary syndromes, it is important to have effective acute pre-hospital care (particularly for those in rural areas) and effective hospital assessment and management. Acute coronary syndromes in New Zealand Acute coronary syndromes include those patients who have: unstable angina, a syndrome that incorporates rest angina, new onset or crescendo effort angina, post-infarct angina, or angina after angioplasty or coronary bypass surgery acute myocardial infarction. The diagnosis of both these conditions is not clearcut. It is important to undertake an ECG and a number of blood tests (eg, to test the level of troponins) for a correct diagnosis and to establish early whether the person has had a myocardial infarction. New Zealand data shows that in 2000/2001, 7,338 people were admitted to hospital with a myocardial infarction and approximately 573 people died of a myocardial infarction during their stay in hospital NZ mortality data shows that Maori and Pacific peoples are more likely to die from a myocardial infarction within 30 days than Europeans/others. Thirty-day standardised mortality rates for Maori and Pacific peoples were and per 1,000 discharges respectively compared to per 1,000 discharges for Europeans/others (Ministry of Health 2002a). The above data does not include those people who die from myocardial infarction before they reach hospital. A two-year community- and hospital-based study examined case fatality outside hospital from acute coronary events in three British health districts. Its sample comprised 3,523 men and women under 75 years of age, including people who died before they reached hospital. The study found that 45 percent of people (1,589) who had an acute coronary event had died within 30 days of the event. Of the fatal events, 74 percent happened outside hospital; the likelihood of a fatal event occurring outside hospital was greater for people under 55 years (91 percent) than for those aged years (70 percent) (Norris et al 1998). In reducing morbidity and mortality of patients with acute coronary syndrome it is important that acute pre-hospital and hospital care is effectively set up to systematically assess and manage these patients. Acute pre-hospital care Normally all patients who have had chest pain for longer than 10 minutes that is not relieved by sublingual nitrates should be considered a medical emergency. They should be transferred to a hospital for urgent assessment (National Heart Foundation of Australia 2000). New Zealand Health Strategy DHB Toolkit: Cardiovascular Disease Edition 2 16

17 Those who live in rural areas or more than an hour from a hospital may experience delays in access to emergency services and treatment. The longer that treatment is delayed, the greater the risk of myocardial damage (Williams 1997). Early treatment with thrombolysis for eligible patients has been identified as important in reducing morbidity and mortality from myocardial infarction. It has been shown that thrombolytic treatment given within four hours after the onset of pain produces the best results (Cannon 2000). Several observational studies have shown that decreases in mortality of percent occur when thrombolytic therapy is given within one hour of the onset of chest pain. The reduction in mortality decreases to percent when given after three hours (Fibrinolytic Therapy Trialists Collaborative Group 1994). Randomised control trials of pre-hospital thrombolysis have shown an overall reduction in mortality of 17 percent (16 lives saved per 1,000 patients receiving pre-hospital thrombolysis) (European Myocardial Infarction Project Group 1993). Before giving thrombolysis, it is important that an ECG is carried out to confirm the diagnosis of myocardial infarction. Delays to receiving thrombolysis may occur because patients who have a myocardial infarction may delay seeking treatment or because access to ambulance services and the general practitioner is reduced. Further delays may occur once the patient has arrived in hospital. A New Zealand study in 1995 found that most of the delay before administration of thrombolysis occurred in the community (median 2.5 hours) (Porter et al 1995). This finding may arise partly because some people are not aware that they are having a heart attack. It has been estimated that around 30 percent of heart attacks are unrecognised, particularly in women, the elderly, post-operative patients, diabetics or others with chronic disease states (Fowles 1995). The NHS Service Framework for coronary heart disease states that people thought to be suffering a heart attack should, if indicated, receive aspirin and should be given thrombolysis within 60 minutes of calling for help. Achieving this timeframe would involve equipping and training community health professionals, ambulance or paramedical staff and rural general practitioners. New Zealand and Canadian recommendations suggest a door-to-needle delay of no more than 30 minutes after the arrival at hospital (Cox 1997; Porter et al 1995). Guidelines for the delivery of thrombolysis by general practitioners in New Zealand have been completed by the Cardiac Society and are currently undergoing the New Zealand Guideline Group endorsement process. These will be added to the toolkit when available. Hospital care Once the patient with unstable angina or myocardial infarction has been admitted to hospital, it is important to have a systematic process for assessing and managing these patients to ensure that patients receive the appropriate care. In a study of patients with chest pain presenting to emergency departments by Lee, Rouan and Weisberg (1987) showed that almost two thirds of these patients are admitted, but only about 15 percent are proven to have a myocardial infarction. Of those discharged, 1 to 5 percent have a myocardial infarction, which can result in up to 16 percent mortality (Jesse 1997). A new test is available in New Zealand that can identify the level of cardiac troponins. This measure indicates the level of myocardial damage and assists in enabling a more accurate diagnosis of unstable angina or myocardial infarction. In addition to other kinds of tests (eg, ECG), and other blood tests, it can more accurately classify patients with chest pain into categories of low, intermediate or high risk. It is suggested that those who are considered low risk, with normal cardiac troponins and ECG, could be discharged with a follow-up outpatient appointment whereas intermediate and high-risk patients who have an increaseded level of cardiac troponins would be admitted to hospital for investigation and appropriate treatment. Guidelines developed by the National Heart Foundation of Australia (2000) for unstable angina indicate that a structured chest pain service would enable better assessment, diagnosis and New Zealand Health Strategy DHB Toolkit: Cardiovascular Disease Edition 2 17

18 management of patients with chest pain. A number of structured chest pain units have been established in Australia and other countries. A structured chest pain assessment service has been shown to reduce discharge of those with a missed infarction from 4.5 to 0.4 percent, and to reduce hospital admissions from 57 percent to 47 percent (Graff et al 1997; Roberts et al 1997). A study of 773 consecutive patients presenting with acute chest pain concluded that a policy of early discharge of low-risk patients (without elevated troponin levels) was relatively safe. After patients with normal troponin levels at baseline and at least six hours later were discharged from the emergency department, their 30-day event rates for death or myocardial infarction were 1.1 percent for cardiac troponin T (ctnt) and 0.3 percent for cardiac troponin I (ctni) (Hamm et al 1997). Intermediate and high-risk patients would stay in hospital for more intensive management. There is debate around the appropriate treatment of unstable angina and acute myocardial infarction. This debate is mainly around acute medical care and acute revascularisation. A study of 2,457 patients showed that early revascularisation for eligible patients (PTCA or CABG) can reduce subsequent death and myocardial infarction by 22 percent and subsequent hospitalisation by 45 to 50 percent. It also reduces the overall length of stay (National Heart Foundation of Australia 2000). Although it may appear that acute revascularisation brings benefits, introducing this treatment nationally would incur a significant cost as revascularisation costs far more than acute medical care. If its nationwide introduction was to be considered, a comprehensive cost benefit analysis would need to be conducted. DHBs would need to consider this analysis in relation to current services and the overall prioritisation of services. Tools available for District Health Boards Cardiovascular trend data are included here with this toolkit in electronic format for DHB needs analysis. Tools under development Guidelines for pre-hospital administration of thrombolytic therapy by New Zealand General Practitioners available from New Zealand Guidelines Group. Guidelines for the management of acute coronary syndromes currently being developed by the New Zealand Cardiac Society. Tools for future development National service specification for cardiac services. Consumer education resources. New Zealand Health Strategy DHB Toolkit: Cardiovascular Disease Edition 2 18

19 3. Heart failure Key points Hospital admissions for heart failure are increasing. Maori have the highest rate of hospital admissions, at nearly three times that of non-maori and higher for those under 65 years of age. Pacific peoples also have high hospital admission rates, at just over twice the rates of others. Many hospital admissions for heart failure have been found to be preventable. There is good evidence for the effectiveness of heart failure treatment. Heart failure in New Zealand Heart failure occurs mainly as a result of coronary heart disease, but can also result from rheumatic heart disease, hypertension, cardiomyopathy and other cardiac diseases. It is a significant personal and public health problem and is increasing in prevalence. About two-thirds of all patients with heart failure die within five years of diagnosis and mortality rates increase with age. Doughty (1995) identified that of an average of 850 deaths caused by heart failure, twothirds occurred in patients over 75 years of age. Only 5 percent of deaths occurred in patients younger than 45 years of age. International literature shows growing hospital admission rates for heart failure and a high level of readmissions. In a New Zealand study of hospital discharge data from 1988 to 1991, more than 200 hospital admissions per 100,000 individuals involved a primary or secondary diagnosis of heart failure (Doughty 1995). About 40 percent of these admissions were readmissions in the same year. Many admissions have been found to be preventable. Poor compliance with prescribed drugs is an important cause of hospital readmission. Maori have the highest hospital admissions for heart failure. Standardised discharge rates for congestive heart failure in 2000/2001 were nearly three times those of Europeans/others (30.4 per 10,000 population compared to 11.9 per 10,000 population) (Ministry of Health 2002a), and are four or more times higher for Maori under the age of 65 years (Westbrooke et al 2001). Pacific peoples have a lower discharge rate for heart failure than Maori but have more than twice the discharge rate of Europeans/others (24.4 per 10,000 compared to 11.9 per 10,000) (Ministry of Health 2002a). The high discharge rates for heart failure for both Maori and Pacific peoples are likely to reflect the higher incidence of cardiovascular disease and diabetes in these populations. They may also reflect delays in access to primary care services and in detection and treatment of disease. It has been estimated that hospital admissions in New Zealand for heart failure in 1990 cost $48.7 million (Carr 1999). Hospital admissions for heart failure grew by 5.8% from 1996/97 to 1999/2000 (5,098 discharges to 5,394), but then decreased by 4.5% from 1999/00 to 2000/01 (5,394 discharges to 5,153) (Ministry of Health 2002a) Management of heart failure Heart failure is one of the few areas of medical treatment where there is good evidence for the effectiveness of treatment and clear evidence that early and consistent treatment prolongs life. It is important that patients are diagnosed accurately and managed appropriately to improve quality of life and to prevent unnecessary hospital admissions. New Zealand Health Strategy DHB Toolkit: Cardiovascular Disease Edition 2 19