- Email: [email protected]
Coronary heart disease prevention
Coronary Health Care (1999)3, 48-53 9 1999 Harcourt Brace & Co. Ltd
RESEARCH N E W S
Coronary heart disease prevention Belinda Linden Cardiac Nurse Advisor, British Heart Foundation
agreement so that cardiologists and physicians in the hospitals and community can provide the best possible advice.
Prevention of coronary heart disease in clinical practice. Summary of recommendations of the second joint task force of European and other Societies on coronary prevention (European Society of Cardiology, European Atherosclerosis Society and European Society of Hypertension). Wood D, De Backer G, Faergeman O, et al. 1998 European Heart Journal 19: 1434-1503. The Joint Task Force for the European Societies European Society of Cardiology, European Atherosclerosis Society and European Society of Hypertension have presented recommendations on coronary heart disease prevention in clinical practice. Priorities include:
OBESITY Randomized placebo controlled trial of Orlistat for weight loss and prevention of weight gain in obese patients. Sjostrom L, Rissanen A, Anderson T, et al. 1998 Lancet 352: 167-73. Flushing away the fat. Garrow J 1998 British Medical Journal 317: 830-831. Over the last 2 decades, obesity has been reported as the most important public health problem and yet the nation's weight has gradually increased. Since the first warnings 20 years ago the prevalence of obesity in the U K has doubled. Orlistat is a new drug that is hoped to treat obesity and works by inhibiting lipase activity from the pancreas so that 30% of dietary fat is not digested. A recent study reporting the benefits of Orlistat involved 743 obese patients who took the medication as well as a low fat, low calorie diet (Sjostrom et al. 1998). The patients either took Orlistat or placebo, and those taking Orlistat lost more weight. The drug is apparently not effective unless there is also a weight reducing diet which accounts for more than half of the loss. Garrow (1998) suggests that a well-supervised outpatient dieting programme could produce the same effect, and that it is completely misleading to suggest that this new drug will enable fat people to eat what they like and still lose weight. However, taking Orlistat may be a great incentive to encourage patients to reduce their fat intake
9 Patients with coronary heart disease or other atherosclerotic disease or healthy high-risk individuals. 9 Lifestyle recommendations such as stopping smoking, making healthy food choices, being physically active and achieving ideal weight. 9 Other equally important risk factors, i.e. maintaining blood pressure at < 140/90 mmHg, total cholesterol <5.0 mmol/1, LDL <3.0 mmol/1. When these measures are not achieved by lifestyle changes, blood pressure or cholesterol lowering, drug therapies should be used. 9 Other drug therapies include aspirin >75 mg for all patients with coronary, cerebral and peripheral atherosclerotic disease. 9 Beta-blockers for patients after myocardial infarction. 9 ACE inhibitors for patients with signs of heart failure at the time of myocardial infarction or with chronic left ventricular dysfunction (ejection fraction <40%). 9 Anticoagulants in selected coronary patients. 9 Screening of close relatives is recommended if there is evidence of premature coronary heart disease [men <55 years or women <65 years] or with close relatives if familial hypercholesterolaemia or other inherited dyslipidaemia is suspected.
REOPERATION FOR CORONARY ARTERY BYPASS GRAFTING Long term results of reoperation for recurrent angina with internal mammary artery versus saphenous vein grafts. Dougenis D, Brown AH 1998 Heart 80: 9-13. Arterial or venous conduits for redo coronary bypass grafting? Taggart DP 1998 Heart 80: 1-2.
The Task Force has summarized the key issues on coronary heart disease prevention on which there is 48
Research News 49 The internal mammary artery (IMA) has been increasingly preferred to vein conduits in coronary artery bypass grafting. This advance in treatment has led to reduced mortality and less need for repeat surgery. However, when re-operation is considered there appears to be a reluctance to use IMA grafts. Dougenis & Brown (1998) recently evaluated the long-term results with re-operations from 1982 to 1991 with internal mammary arteries versus saphenous vein grafts. Fifty-three patients received one or both IMA grafts, and 50 patients underwent saphenous vein grafting only. The long term results at 5 and 10 years after re-operation found IMA grafting to be superior to saphenous vein grafting in terms of freedom from cardiac events, angina, and actuarial survival after 3, 5 and l0 years. This was not a randomized controlled study, and although the two groups were said to be clinically and demographically comparable, the subgroup receiving the vein grafts at re-operation were older with a higher incidence of impaired left ventricular function. Taggart (1998) suggests that re-operation for patients with a stenosed left anterior descending artery offers substantial gain even with impaired left ventricular function. However, randomized controlled studies are needed for a clear indication of the real benefit of the IMA over saphenous vein grafting. The reports of benefit for the first operation would suggest similar benefit for a re-operation. The IMA offers a resistance to atherosclerosis, and better access for bypass procedures. Other arteries are being investigated as conduits such as the gastro-epiploic, inferior epigastric and more recently the radial artery.
CHOLESTEROL REDUCTION AS PRIMARY PREVENTION Primary prevention of acute coronary events with iovastatin in men and women with average cholesterol levels. Downs J, Clearfield, M, Weis S 1998. Journal of American Medical Association 279: 1615-1622. Epidemiological studies have shown a strong, independent, graded association between plasma cholesterol levels and coronary heart disease, and effective cholesterol lowering has substantially reduced myocardial infarction and other acute events. It remains uncertain whether the benefit from lowering LDL cholesterol levels can extend to patients with average total cholesterol levels, lower than average H D L levels, and without evidence of cardiovascular disease. The Airforce Texas coronary atherosclerosis prevention study (AFCAPS/TexCAPS) targeted a cohort of healthy men and women with average total cholesterol levels, but below average H D L cholesterol. Lovastatin or placebo was given to 6600 participants who also took a low cholesterol, low saturated fat diet (Downs et al. 1998). The group receiving lovastatin had significant falls in LDL cholesterol 9 1999 Harcourt Brace & Co. Ltd
(25%), total cholesterol (18%), triglycerides (15%), and 6% rise in H D L cholesterol, with 31% less major coronary events than the group receiving placebo which showed little change in cholesterol profile. This is the first major randomized controlled trial to show benefit to people with average total cholesterol and to indicate a role for including H D L in assessing risk of coronary artery disease. Downs et al. suggest that cholesterol reduction with lovastatin for both men and women with average total and LDL cholesterol levels could improve quality of life by reducing the risk of a first coronary event and thus extending survival. Assistance with data and funding was obtained from pharmaceutical research companies.
QUESTIONS ABOUT ATHEROSCLEROSIS Resolved and unresolved problems regarding coronary atherosclerosis: report of a presentation. Oliver M 1998 British Journal of Cardiology 5; 3: $27-$28. A recent presentation by Oliver (1998) discussed the resolved and unresolved concerns about atherosclerosis. Positive findings have included:
9 4S, LIPID, and CARE studies revolutionized the treatment of patients with coronary heart disease 9 WOSCOPS, AFCAPS/TexCAPS studies demonstrated benefits from cholesterol lowering among high-risk healthy people. However, many questions remain. These include: 9 If the evidence from the statin trials is so good why is atherosclerosis continuing despite treatment? 9 Does the benefit from cholesterol lowering continue beyond reductions over 50%? 9 Why does a reduction in clinical events occur before substantial changes appear in the established plaques within the coronary artery. 9 Where do the clinical benefits of cholesterol lowering actually lie? With the medication? With fewer lesions developing? 9 What makes the atheromatous plaque become unstable? Cholesterol appears to be the inflammatory agent with increased peroxidation from free radicals.
HEART FAILURE Heart failure: a medical hydra. Cleland JGF 1998
Lancet 352 (suppl I): 1-2. Organisation of the care of patients with heart failure Erhardt LR. Cline CMJ 1998 Lancet 352 (suppl I): 11-15. Epidemiology of heart failure and ventrieular dysfunction. Sharpe N Doughty R 1998 Lancet. 352 (suppl I): 15-19. Coronary Health Care (1999) 3 (1), 48-53
50
Coronary Health Care
Successes and failures of current treatments for heart failure. Cleland JGF, Swedberg K, Poole-Wilson PA 1998 Lancet 352 (Suppl I): 19-28. The prevalence of heart failure is increasing in both younger and older age groups. This may be due to improved treatment of myocardial infarction leading to increased survival among patients at risk of heart failure. Cleland (1998) reviews the successes achieved so far and difficulties facing doctors in controlling heart failure. Other reviews also cover the epidemiology of heart failure (Sharpe & Doughty 1998), current treatments (CMand et al. 1998), and the organization of patient care (Erhardt & Cline 1998). Erhardt & Cline suggest the need for closer collaboration between hospitals and primary care facilities as frequently patients are re-admitted to hospital. Nurses are expected to take on increased responsibilities in managing patients in the heart failure clinics. Erhardt & Cline warn that the results of randomized trials rather than non-randomized trials should be used to guide future strategies on outcomes in heart failure.
HEART FAILURE AND 'DO-NOTRESUSCITATE' ORDERS Resuscitation preferences among patients with severe congestive heart failure: results from the SUPPORT project. Krumholz HN, Phillips R, Hamel MB et al. 1998 Circulation 98: 648-655. Heart failure is the only major cardiovascular condition increasing in prevalence in the western world. Although congestive heart failure can be both debilitating and distressing, a recent study has highlighted the wide fluctuations in symptoms with this condition and the effect that these may have on patients' preferences for resuscitation (Krumholz et al. 1998). This multicentre study involved 936 interviews of both doctors and patients about 'do-not-resuscitate' orders. Some patients had different viewpoints 2 months after their initial response. Doctors misjudged their patients' positive preferences in about 24% of cases. More effective communication is needed to allow patients to have control over this important decision.
CALCIUM ANTAGONISTS AND DIABETES Calcium antagonists, appropriate therapy for diabetic patients with hypertension? Malmberg, K, Ryden L, Wedel H 1998 European Heart Journal 19: 1269-1272. The effects of nisoldipine as compared with enalapril on cardiovascular outcomes in patients with non-insulin dependent diabetes and hypertension. Estacio RO, Jeffers BW, Hiatt WR et al. 1998. New England Journal of Medicine 338: 645-652. Coronary Health Care (1999) 3 (1), 48-53
Outcome results of the Fosinopril vs Amlodipine Cardiovascular Events trial (FACET) in patients with hypertension and NIDDM. Tatti P, Pahor H, Byington RP et al. 1998. Diabetes Care 21: 597-603. Calcium antagonists are often recommended as suitable anti-hypertensive agent for patients with diabetes, as beta-blockers may tend to mask the symptoms of hypoglycaemia. There has been some inconclusive evidence suggesting that calcium antagonists may increase the risk of myocardial infarction among patients with cardiovascular disease. This subject is still open to debate. Two recent studies, the Appropriate Blood Pressure Control in Diabetes (ABCD) trial and the Fosinopril versus Amlodipine Cardiovascular Events Trial (FACET) have specifically addressed the use of calcium antagonists for the treatment of hypertension for patients with diabetes. The ABCD trial (Estacio et al. 1998) aimed to compare the effects of moderate versus intensive blood pressure control. Four hundred and seventy patients were given either nisoldipine or enalapril each at varying doses. This study was stopped prematurely as significantly more patients in the nisoldipine group had a, myocardial infarction than those taking enalapril. The FACET study (Tatti et al. 1998) compared the effects of fosinopril and amlodipine on blood lipids and diabetes control. Three hundred and eighty patients took either fosinopril or amlodipine and were followed up for 3.5 years. Both drugs were equally effective in lowering blood pressure with no obvious changes in cholesterol, more patients taking amlodipine suffered a myocardial infarction. The recent Hypertension Optimal Treatment (HOT) study (Hansson et al. 1998) found that blood pressure lowering was most effective for patients with diabetes in protecting them against cardiac events. Treatment was then with the calcium antagonist felodipine only supplemented with ACE inhibitors or beta-blockers if the blood pressure was inadequately controlled. Malmberg et al. (1998) suggest that beta-blockers and ACE inhibitors may have a protective effect by affecting the fibrinolytic process and the calcium antagonists may not have this protective effect or may have differing effects between the dihydropyridines. They advise that other blood pressure lowering drugs may be used as first line anti-hypertensive agents for patients with diabetes, but should be considered if the blood pressure fails to be adequately controlled. Felodipine may then be safely added to initial antihypertensive therapy.
THE ROLE OF ACE INHIBITORS Are ACE inhibitors cardioprotective? Katz R 1998 British Journal of Cardiology: Editorial 5; 8: 404-405. 9 1999 Harcourt Brace & Co. Ltd
Research News
Effect of enalapril on mortality and development of heart failure in asymptomatic patients with reduced left ventricular ejection fractions. The SOLVD Investigators 1992 New England Journal of Medicine 327: 669-677. Effect of captopril on mortafity and morbidity in patients with left ventricular dysfunction after myocardial infarction. Pfeffer MA, Braunwald E, Moye LA 1992 New England Journal of Medeicine 327: 669-677. ACE inhibitors have been increasingly used to control blood pressure, to protect left ventricular function after myocardial infarction, and as treatment of congestive heart failure. Past studies of patients with asymptomatic left ventricular failure have found that ACE inhibitors not only protect the myocardium, but are also linked with a reduced risk of myocardial infarction and unstable angina (SOLVD 1992; Pfeffer et al. 1992). There appears to be evidence that ACE inhibitors may have other mechanisms of cardiac protection. Katz (1998) discusses the evidence suggesting that ACE inhibitors may protect the endothelium, and stabilize the atherosclerotic plaque, and therefore reduce the risk of ischaemic events. Two large trials are under way: EUROPA (European trial of reduction of cardiac events with perindopril), and PEACE (Prevention of events with angiotensin converting enzyme inhibition). These may provide clearer answers. ONGOING TRIALS OF ANGIOTENSIN ANTAGONISTS
News: Current trends in heart failure management. Loshak D 1998 British Journal of Cardiology 5; 8: 406-407. Patients intolerant to ACE inhibitors are often prescribed angiotensin antagonists that are at present only licensed for treating hypertension. Loshak (1998) describes the findings reported at a recent Heart Failure Update '98 meeting discussing the ongoing trials evaluating these drugs. The RESOLVD trial comparing the effect of the angiotensin antagonist candesartan with enalapril for patients with heart failure was stopped due to excess deaths in the candesartan group. The SPICE study of patients intolerant to ACE inhibitors reported 78% tolerance but concluded that a larger trial was needed. Although the ELITE trial found losartan superior to captopril for heart failure, questions remain about the interpretation of this study. The ELITE II study is now underway and should help clarify any benefit of losartan for patients with heart failure. VIAGRA
Department of Health issues ban on Viagra Scripts. Wilson C 1998 Doctor 17 September: 1. 9 1999 Harcourt Brace & Co. Ltd
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Acute myocardial infarction associated with sildenafil. Feenstra J, van Drie Pierik R, Lacle C et al. 1998 Lancet 352: 957-958. Oral sildenafil in the treatment of erectile dysfunction. Goldstein I, Lue TF 1998 New England Journal of Medicine 338: 1397-1404. Impotence or erectile dysfunction is a common problem affecting about 10% of the male population. It causes considerable distress to patients and can severely affect marital relationships. The drug sildenafil (Viagra) has provoked intense media interest. Several trials have evaluated the effectiveness of sildenafil and these have found the drug to be effective with minimal side effects. This effect was unrelated to the cause of the erectile dysfunction. Sildenafil works by inhibiting the breakdown of the hormone cyclic GMP, leading to increased blood flow and vasorelaxation of the vessels in the penis. A recent report by Feenstra (1998) describes a patient without any history of coronary artery disease who suffered a heart attack 30 minutes after taking sildenafil. This suggests that vasodilation can also occur in other parts of the body, and that redistribution of blood flow may undermine the blood flow to the coronary arteries and provoke an increased susceptibility to a heart attack. These results suggest that careful assessment of a patient's family history as well as underlying symptoms and risk factors are necessary before any treatment with its drug is offered, and close follow-up of its effects are monitored. Two major concerns are that there will be inadequate evaluation of the patient's underlying condition before treatment, and that some men will consider that the treatment will enhance their sexual performance and therefore allow the drug to be abused. The Department of Health's decision to ban the prescription of Viagra on the NHS may well encourage alternative prescription methods that may involve a less than adequate assessment of patients underlying condition, family history or risk factors, which is best carried out by the patient's own general practitioner.
GUIDELINES ON ATRIAL FIBRILLATION MANAGEMENT Atrial fibrillation: current knowledge and recommendations. Levy S, Breithardt G, Campbell R et al 1998 European Heart Journal 19:1294-1320. Atrial fibrillation is a common arrhythmia where there is complete lack of co-ordinated atrial impulses. It is characterized on the ECG by the absence of consistent P waves before each QRS complex. Atrial fibrillation is believed to affect about 2% of the population. It is slightly more common among men than women and its prevalence increases with age. Patients with atrial fibrillation have a twofold risk of mortality compared with the general population. Coronary Health Care (1999) 3 (1), 48-53
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Coronary Health Care
A 26-page report by the Study Group on Atrial Fibrillation of the European Society of Cardiology discusses in depth the clinical presentation, causes, mechanisms, treatments and recommendations for management of atrial fibrillation with algorithms to aid clinical management (Levy et al. 1998). Although in about 30% of patients with atrial fibrillation there is no detectable underlying heart disease (lone atrial fibrillation) it is important that all possible underlying conditions are excluded. Atrial fibrillation may be related to acute causes which, when treated, may mean that the atrial fibrillation does not recur. These include heavy alcohol intake, acute myocardial infarction, acute pericarditis or myocarditis, hyperthyroidism, acute pulmonary disease, or cardiomyopathy. Levy et al. suggest a management scheme for the use of drugs and other treatments. The treatment will depend on whether the atrial fibrillation is paroxysmal, persistent or permanent. Either aspirin or warfarin should be given in all cases. Paroxysmal atrial fibrillation may just require reassurance, or possibly a beta-blocker, propafenone or flecainide. Persistent atrial fibrillation should ideally be reverted to sinus rhythm as soon as possible. Early electrical cardioversion should be attempted if the patient is seen within 24 hours. If the atrial fibrillation is diagnosed later, anticoagulation 4 weeks prior to cardioversion is needed. Otherwise anti-arrhythmic drugs such as propafenone or flecainide may be given. In permanent or chronic atrial fibrillation where sinus rhythm cannot be restored, rate control is advised with Digoxin or a beta-blocker or a calcium antagonist such as verapamil or diltiazem.
THE IMPLANTABLE 'ATRIOVERTER' Atrial fibrillation: current knowledge and recommendations. Levy S, Breithardt G, Campbell R et al. 1998 European Heart Journal 19: 1294-1320. Atrial fibrillation is believed to affect about 2% of the population. It is slightly more common among men than women and its prevalence increases with age. Treatment may vary widely between patients. In some patients sinus rhythm can be restored by external electrical cardioversion or with anti-arrhythmic drugs. Persistent atrial fibrillation should ideally be reverted to sinus rhythm as soon as possible, as atrial fibrillation has a tendency to recur particularly when it has persisted for some time. Electrical cardioversion is most successful when atrial fibrillation has been present for only a short time. In order to facilitate repeated cardioversion, a device similar in many respects to the implantable defibrillator has been produced and is being evaluated. It has the advantage of restoring sinus rhythm as early as possible and may prevent the changes that affect the heart with Coronary Health Care (1999) 3 (1), 48-53
prolonged bouts of atrial fibrillation. The 'implantable atrioverter' delivers low energy shocks to restore sinus rhythm as effectively and comfortably as possible with a minimum of risk in causing other abnormal heart rhythms. Electrodes are implanted in the atrium and the ventricle. In the first instance, although the device can recognize and confirm the presence of atrial fibrillation, it is programmed so that the doctor can initiate the discharge. In a second phase the device will be programmed so that the patient can activate the discharge and ultimately it may be used in an automatic mode. Although patients find the sensation rather like a kick in the chest they will often tolerate it to be rid of an unpleasant and limiting arrhythmia. Refinement of the model may allow it to be easily tolerable and highly efficient. It has so far been found to be safe and effective, but its use is likely to be confined to selected patients with atrial fibrillation. More trials are needed before this device is widely used.
EXTERNAL AUTOMATED DEFIBRILLATION Use of automated external defibrillators by police officers for treatment of out-of-hospital cardiac arrest. Mosesso VN, Davis EA, Auble TE et al. 1998 Annals of Emergency Medicine 32; 2: 200-207. The importance of early defibrillation in improving a chance of survival has been impressed upon all emergency services and the general public. As the introduction of first responder defibrillators is relatively recent, estimates of lives saved are important in evaluating the effectiveness of those who provide this service. A recent study involved the training of police officers in seven suburban communities in the USA (Mosesso et al. 1998). The police officers often got to the scene before the paramedics. The police officers were instructed to use the defibrillators as soon as they had found no pulse. The time to defibrillation was cut from 11.8 minutes (the average time recorded before the study began) to 8.7 minutes. When the police arrived at the scene before the paramedics during this study, there was a 26% survival rate compared to 3% when the paramedics attended to the patient.
RELATIVES AND RESUSCITATION Psychological effect of witnessed resuscitation on bereaved relatives. Robinson S, Mackensie-Ross S, Campbell-Hewson M et al. 1998 Lancet 352 614-617. The potential distress caused by defibrillation and other aggressive measures to resuscitate a patient has led to the usual exclusion of patients from the clinical area during resuscitation. A recent pilot study of 18 relatives has addressed this decision by either allowing or not allowing one relative 9 1999 Harcourt Brace & Co. Ltd
Research News the choice to remain with the patient during the resuscitation process (Robinson et al. 1998). All relatives were supported during and after the resuscitation process irrespective of whether they remained in the resuscitation room. These 18 relatives were questioned at 3 and 9 months after the event to find out about their psychological reactions to either of these approaches. The eight patients who witnessed the resuscitation were less anxious, depressed, and traumatized by being present than those who were excluded from the area. It also appeared that the clinical staff benefited from the presence of the relative as it placed the patient in the right context. Although this was a small pilot study these findings suggest that a larger study may encourage professionals to offer patients' relatives the choice to remain with the patient during resuscitation.
TRENDS IN MORTALITY FROM CORONARY HEART DISEASE
The falling mortality from coronary heart disease: a clinicopathological perspective. The United Kingdom Heart Attack Study (UKHAS) Collaborative Group 1998 Heart 80: 12t-126. Perspectives on trends in mortality and case fatality from coronary heart attacks: the need for a better definition of acute myocardial infarction. TunstallPedoe H 1998 Heart 80:112-113. Myocardial and coronary deaths in the World Health Organisation MONICA project-registration procedures,
9 1999 Harcourt Brace & Co. Ltd
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event rates and case fatality rates in 38 populations from 21 counties in 4 continents. Tunstall-Pedoe H, Kuulasea K, Amonyal P et al. (for WHO MONICA project) 1994 Circulation 90: 583412. Regional Office for Europe: Myocardial Infarction Community Registers. World Health Organisation 1976 Public Health in Europe No 5. Copenhagen. WHO. Mortality from coronary heart disease (CHD) appears to have declined by about 30% since 1980. The UK Heart Attack Study (UKHAS) Collaborative Group (1998) argues that official statistics are based on death certificates that are often inaccurate. They compared the official death rates with recordings of coronary deaths defined by strict clinical and pathological criteria in three health districts Brighton, South Glamorgan, and York. They found that estimates of mortality for coronary heart disease in these regions were similar to official figures up to the age of 65 years. However, beyond the age of 65 years there were 20% fewer deaths from CHD than reported in official figures. Tunstall-Pedoe (1998) suggests that heart attack registers and diagnoses may have variable criteria and may exclude unexplained sudden death. The WHO in 1960 used loose criteria of chest pain, ECG changes and cardiac enzymes to describe either definite or possible myocardial infarctions. The MONICA project redefined the end point of non-fatal events as 'definite myocardial infarction'. In contrast the UKHAS Group have used the patient history and/or ECG changes and/or raised cardiac enzymes as criteria.
CoronaryHealth Care (1999) 3 (1), 48-53
RESEARCH N E W S
Coronary heart disease prevention Belinda Linden Cardiac Nurse Advisor, British Heart Foundation
agreement so that cardiologists and physicians in the hospitals and community can provide the best possible advice.
Prevention of coronary heart disease in clinical practice. Summary of recommendations of the second joint task force of European and other Societies on coronary prevention (European Society of Cardiology, European Atherosclerosis Society and European Society of Hypertension). Wood D, De Backer G, Faergeman O, et al. 1998 European Heart Journal 19: 1434-1503. The Joint Task Force for the European Societies European Society of Cardiology, European Atherosclerosis Society and European Society of Hypertension have presented recommendations on coronary heart disease prevention in clinical practice. Priorities include:
OBESITY Randomized placebo controlled trial of Orlistat for weight loss and prevention of weight gain in obese patients. Sjostrom L, Rissanen A, Anderson T, et al. 1998 Lancet 352: 167-73. Flushing away the fat. Garrow J 1998 British Medical Journal 317: 830-831. Over the last 2 decades, obesity has been reported as the most important public health problem and yet the nation's weight has gradually increased. Since the first warnings 20 years ago the prevalence of obesity in the U K has doubled. Orlistat is a new drug that is hoped to treat obesity and works by inhibiting lipase activity from the pancreas so that 30% of dietary fat is not digested. A recent study reporting the benefits of Orlistat involved 743 obese patients who took the medication as well as a low fat, low calorie diet (Sjostrom et al. 1998). The patients either took Orlistat or placebo, and those taking Orlistat lost more weight. The drug is apparently not effective unless there is also a weight reducing diet which accounts for more than half of the loss. Garrow (1998) suggests that a well-supervised outpatient dieting programme could produce the same effect, and that it is completely misleading to suggest that this new drug will enable fat people to eat what they like and still lose weight. However, taking Orlistat may be a great incentive to encourage patients to reduce their fat intake
9 Patients with coronary heart disease or other atherosclerotic disease or healthy high-risk individuals. 9 Lifestyle recommendations such as stopping smoking, making healthy food choices, being physically active and achieving ideal weight. 9 Other equally important risk factors, i.e. maintaining blood pressure at < 140/90 mmHg, total cholesterol <5.0 mmol/1, LDL <3.0 mmol/1. When these measures are not achieved by lifestyle changes, blood pressure or cholesterol lowering, drug therapies should be used. 9 Other drug therapies include aspirin >75 mg for all patients with coronary, cerebral and peripheral atherosclerotic disease. 9 Beta-blockers for patients after myocardial infarction. 9 ACE inhibitors for patients with signs of heart failure at the time of myocardial infarction or with chronic left ventricular dysfunction (ejection fraction <40%). 9 Anticoagulants in selected coronary patients. 9 Screening of close relatives is recommended if there is evidence of premature coronary heart disease [men <55 years or women <65 years] or with close relatives if familial hypercholesterolaemia or other inherited dyslipidaemia is suspected.
REOPERATION FOR CORONARY ARTERY BYPASS GRAFTING Long term results of reoperation for recurrent angina with internal mammary artery versus saphenous vein grafts. Dougenis D, Brown AH 1998 Heart 80: 9-13. Arterial or venous conduits for redo coronary bypass grafting? Taggart DP 1998 Heart 80: 1-2.
The Task Force has summarized the key issues on coronary heart disease prevention on which there is 48
Research News 49 The internal mammary artery (IMA) has been increasingly preferred to vein conduits in coronary artery bypass grafting. This advance in treatment has led to reduced mortality and less need for repeat surgery. However, when re-operation is considered there appears to be a reluctance to use IMA grafts. Dougenis & Brown (1998) recently evaluated the long-term results with re-operations from 1982 to 1991 with internal mammary arteries versus saphenous vein grafts. Fifty-three patients received one or both IMA grafts, and 50 patients underwent saphenous vein grafting only. The long term results at 5 and 10 years after re-operation found IMA grafting to be superior to saphenous vein grafting in terms of freedom from cardiac events, angina, and actuarial survival after 3, 5 and l0 years. This was not a randomized controlled study, and although the two groups were said to be clinically and demographically comparable, the subgroup receiving the vein grafts at re-operation were older with a higher incidence of impaired left ventricular function. Taggart (1998) suggests that re-operation for patients with a stenosed left anterior descending artery offers substantial gain even with impaired left ventricular function. However, randomized controlled studies are needed for a clear indication of the real benefit of the IMA over saphenous vein grafting. The reports of benefit for the first operation would suggest similar benefit for a re-operation. The IMA offers a resistance to atherosclerosis, and better access for bypass procedures. Other arteries are being investigated as conduits such as the gastro-epiploic, inferior epigastric and more recently the radial artery.
CHOLESTEROL REDUCTION AS PRIMARY PREVENTION Primary prevention of acute coronary events with iovastatin in men and women with average cholesterol levels. Downs J, Clearfield, M, Weis S 1998. Journal of American Medical Association 279: 1615-1622. Epidemiological studies have shown a strong, independent, graded association between plasma cholesterol levels and coronary heart disease, and effective cholesterol lowering has substantially reduced myocardial infarction and other acute events. It remains uncertain whether the benefit from lowering LDL cholesterol levels can extend to patients with average total cholesterol levels, lower than average H D L levels, and without evidence of cardiovascular disease. The Airforce Texas coronary atherosclerosis prevention study (AFCAPS/TexCAPS) targeted a cohort of healthy men and women with average total cholesterol levels, but below average H D L cholesterol. Lovastatin or placebo was given to 6600 participants who also took a low cholesterol, low saturated fat diet (Downs et al. 1998). The group receiving lovastatin had significant falls in LDL cholesterol 9 1999 Harcourt Brace & Co. Ltd
(25%), total cholesterol (18%), triglycerides (15%), and 6% rise in H D L cholesterol, with 31% less major coronary events than the group receiving placebo which showed little change in cholesterol profile. This is the first major randomized controlled trial to show benefit to people with average total cholesterol and to indicate a role for including H D L in assessing risk of coronary artery disease. Downs et al. suggest that cholesterol reduction with lovastatin for both men and women with average total and LDL cholesterol levels could improve quality of life by reducing the risk of a first coronary event and thus extending survival. Assistance with data and funding was obtained from pharmaceutical research companies.
QUESTIONS ABOUT ATHEROSCLEROSIS Resolved and unresolved problems regarding coronary atherosclerosis: report of a presentation. Oliver M 1998 British Journal of Cardiology 5; 3: $27-$28. A recent presentation by Oliver (1998) discussed the resolved and unresolved concerns about atherosclerosis. Positive findings have included:
9 4S, LIPID, and CARE studies revolutionized the treatment of patients with coronary heart disease 9 WOSCOPS, AFCAPS/TexCAPS studies demonstrated benefits from cholesterol lowering among high-risk healthy people. However, many questions remain. These include: 9 If the evidence from the statin trials is so good why is atherosclerosis continuing despite treatment? 9 Does the benefit from cholesterol lowering continue beyond reductions over 50%? 9 Why does a reduction in clinical events occur before substantial changes appear in the established plaques within the coronary artery. 9 Where do the clinical benefits of cholesterol lowering actually lie? With the medication? With fewer lesions developing? 9 What makes the atheromatous plaque become unstable? Cholesterol appears to be the inflammatory agent with increased peroxidation from free radicals.
HEART FAILURE Heart failure: a medical hydra. Cleland JGF 1998
Lancet 352 (suppl I): 1-2. Organisation of the care of patients with heart failure Erhardt LR. Cline CMJ 1998 Lancet 352 (suppl I): 11-15. Epidemiology of heart failure and ventrieular dysfunction. Sharpe N Doughty R 1998 Lancet. 352 (suppl I): 15-19. Coronary Health Care (1999) 3 (1), 48-53
50
Coronary Health Care
Successes and failures of current treatments for heart failure. Cleland JGF, Swedberg K, Poole-Wilson PA 1998 Lancet 352 (Suppl I): 19-28. The prevalence of heart failure is increasing in both younger and older age groups. This may be due to improved treatment of myocardial infarction leading to increased survival among patients at risk of heart failure. Cleland (1998) reviews the successes achieved so far and difficulties facing doctors in controlling heart failure. Other reviews also cover the epidemiology of heart failure (Sharpe & Doughty 1998), current treatments (CMand et al. 1998), and the organization of patient care (Erhardt & Cline 1998). Erhardt & Cline suggest the need for closer collaboration between hospitals and primary care facilities as frequently patients are re-admitted to hospital. Nurses are expected to take on increased responsibilities in managing patients in the heart failure clinics. Erhardt & Cline warn that the results of randomized trials rather than non-randomized trials should be used to guide future strategies on outcomes in heart failure.
HEART FAILURE AND 'DO-NOTRESUSCITATE' ORDERS Resuscitation preferences among patients with severe congestive heart failure: results from the SUPPORT project. Krumholz HN, Phillips R, Hamel MB et al. 1998 Circulation 98: 648-655. Heart failure is the only major cardiovascular condition increasing in prevalence in the western world. Although congestive heart failure can be both debilitating and distressing, a recent study has highlighted the wide fluctuations in symptoms with this condition and the effect that these may have on patients' preferences for resuscitation (Krumholz et al. 1998). This multicentre study involved 936 interviews of both doctors and patients about 'do-not-resuscitate' orders. Some patients had different viewpoints 2 months after their initial response. Doctors misjudged their patients' positive preferences in about 24% of cases. More effective communication is needed to allow patients to have control over this important decision.
CALCIUM ANTAGONISTS AND DIABETES Calcium antagonists, appropriate therapy for diabetic patients with hypertension? Malmberg, K, Ryden L, Wedel H 1998 European Heart Journal 19: 1269-1272. The effects of nisoldipine as compared with enalapril on cardiovascular outcomes in patients with non-insulin dependent diabetes and hypertension. Estacio RO, Jeffers BW, Hiatt WR et al. 1998. New England Journal of Medicine 338: 645-652. Coronary Health Care (1999) 3 (1), 48-53
Outcome results of the Fosinopril vs Amlodipine Cardiovascular Events trial (FACET) in patients with hypertension and NIDDM. Tatti P, Pahor H, Byington RP et al. 1998. Diabetes Care 21: 597-603. Calcium antagonists are often recommended as suitable anti-hypertensive agent for patients with diabetes, as beta-blockers may tend to mask the symptoms of hypoglycaemia. There has been some inconclusive evidence suggesting that calcium antagonists may increase the risk of myocardial infarction among patients with cardiovascular disease. This subject is still open to debate. Two recent studies, the Appropriate Blood Pressure Control in Diabetes (ABCD) trial and the Fosinopril versus Amlodipine Cardiovascular Events Trial (FACET) have specifically addressed the use of calcium antagonists for the treatment of hypertension for patients with diabetes. The ABCD trial (Estacio et al. 1998) aimed to compare the effects of moderate versus intensive blood pressure control. Four hundred and seventy patients were given either nisoldipine or enalapril each at varying doses. This study was stopped prematurely as significantly more patients in the nisoldipine group had a, myocardial infarction than those taking enalapril. The FACET study (Tatti et al. 1998) compared the effects of fosinopril and amlodipine on blood lipids and diabetes control. Three hundred and eighty patients took either fosinopril or amlodipine and were followed up for 3.5 years. Both drugs were equally effective in lowering blood pressure with no obvious changes in cholesterol, more patients taking amlodipine suffered a myocardial infarction. The recent Hypertension Optimal Treatment (HOT) study (Hansson et al. 1998) found that blood pressure lowering was most effective for patients with diabetes in protecting them against cardiac events. Treatment was then with the calcium antagonist felodipine only supplemented with ACE inhibitors or beta-blockers if the blood pressure was inadequately controlled. Malmberg et al. (1998) suggest that beta-blockers and ACE inhibitors may have a protective effect by affecting the fibrinolytic process and the calcium antagonists may not have this protective effect or may have differing effects between the dihydropyridines. They advise that other blood pressure lowering drugs may be used as first line anti-hypertensive agents for patients with diabetes, but should be considered if the blood pressure fails to be adequately controlled. Felodipine may then be safely added to initial antihypertensive therapy.
THE ROLE OF ACE INHIBITORS Are ACE inhibitors cardioprotective? Katz R 1998 British Journal of Cardiology: Editorial 5; 8: 404-405. 9 1999 Harcourt Brace & Co. Ltd
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Effect of enalapril on mortality and development of heart failure in asymptomatic patients with reduced left ventricular ejection fractions. The SOLVD Investigators 1992 New England Journal of Medicine 327: 669-677. Effect of captopril on mortafity and morbidity in patients with left ventricular dysfunction after myocardial infarction. Pfeffer MA, Braunwald E, Moye LA 1992 New England Journal of Medeicine 327: 669-677. ACE inhibitors have been increasingly used to control blood pressure, to protect left ventricular function after myocardial infarction, and as treatment of congestive heart failure. Past studies of patients with asymptomatic left ventricular failure have found that ACE inhibitors not only protect the myocardium, but are also linked with a reduced risk of myocardial infarction and unstable angina (SOLVD 1992; Pfeffer et al. 1992). There appears to be evidence that ACE inhibitors may have other mechanisms of cardiac protection. Katz (1998) discusses the evidence suggesting that ACE inhibitors may protect the endothelium, and stabilize the atherosclerotic plaque, and therefore reduce the risk of ischaemic events. Two large trials are under way: EUROPA (European trial of reduction of cardiac events with perindopril), and PEACE (Prevention of events with angiotensin converting enzyme inhibition). These may provide clearer answers. ONGOING TRIALS OF ANGIOTENSIN ANTAGONISTS
News: Current trends in heart failure management. Loshak D 1998 British Journal of Cardiology 5; 8: 406-407. Patients intolerant to ACE inhibitors are often prescribed angiotensin antagonists that are at present only licensed for treating hypertension. Loshak (1998) describes the findings reported at a recent Heart Failure Update '98 meeting discussing the ongoing trials evaluating these drugs. The RESOLVD trial comparing the effect of the angiotensin antagonist candesartan with enalapril for patients with heart failure was stopped due to excess deaths in the candesartan group. The SPICE study of patients intolerant to ACE inhibitors reported 78% tolerance but concluded that a larger trial was needed. Although the ELITE trial found losartan superior to captopril for heart failure, questions remain about the interpretation of this study. The ELITE II study is now underway and should help clarify any benefit of losartan for patients with heart failure. VIAGRA
Department of Health issues ban on Viagra Scripts. Wilson C 1998 Doctor 17 September: 1. 9 1999 Harcourt Brace & Co. Ltd
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Acute myocardial infarction associated with sildenafil. Feenstra J, van Drie Pierik R, Lacle C et al. 1998 Lancet 352: 957-958. Oral sildenafil in the treatment of erectile dysfunction. Goldstein I, Lue TF 1998 New England Journal of Medicine 338: 1397-1404. Impotence or erectile dysfunction is a common problem affecting about 10% of the male population. It causes considerable distress to patients and can severely affect marital relationships. The drug sildenafil (Viagra) has provoked intense media interest. Several trials have evaluated the effectiveness of sildenafil and these have found the drug to be effective with minimal side effects. This effect was unrelated to the cause of the erectile dysfunction. Sildenafil works by inhibiting the breakdown of the hormone cyclic GMP, leading to increased blood flow and vasorelaxation of the vessels in the penis. A recent report by Feenstra (1998) describes a patient without any history of coronary artery disease who suffered a heart attack 30 minutes after taking sildenafil. This suggests that vasodilation can also occur in other parts of the body, and that redistribution of blood flow may undermine the blood flow to the coronary arteries and provoke an increased susceptibility to a heart attack. These results suggest that careful assessment of a patient's family history as well as underlying symptoms and risk factors are necessary before any treatment with its drug is offered, and close follow-up of its effects are monitored. Two major concerns are that there will be inadequate evaluation of the patient's underlying condition before treatment, and that some men will consider that the treatment will enhance their sexual performance and therefore allow the drug to be abused. The Department of Health's decision to ban the prescription of Viagra on the NHS may well encourage alternative prescription methods that may involve a less than adequate assessment of patients underlying condition, family history or risk factors, which is best carried out by the patient's own general practitioner.
GUIDELINES ON ATRIAL FIBRILLATION MANAGEMENT Atrial fibrillation: current knowledge and recommendations. Levy S, Breithardt G, Campbell R et al 1998 European Heart Journal 19:1294-1320. Atrial fibrillation is a common arrhythmia where there is complete lack of co-ordinated atrial impulses. It is characterized on the ECG by the absence of consistent P waves before each QRS complex. Atrial fibrillation is believed to affect about 2% of the population. It is slightly more common among men than women and its prevalence increases with age. Patients with atrial fibrillation have a twofold risk of mortality compared with the general population. Coronary Health Care (1999) 3 (1), 48-53
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A 26-page report by the Study Group on Atrial Fibrillation of the European Society of Cardiology discusses in depth the clinical presentation, causes, mechanisms, treatments and recommendations for management of atrial fibrillation with algorithms to aid clinical management (Levy et al. 1998). Although in about 30% of patients with atrial fibrillation there is no detectable underlying heart disease (lone atrial fibrillation) it is important that all possible underlying conditions are excluded. Atrial fibrillation may be related to acute causes which, when treated, may mean that the atrial fibrillation does not recur. These include heavy alcohol intake, acute myocardial infarction, acute pericarditis or myocarditis, hyperthyroidism, acute pulmonary disease, or cardiomyopathy. Levy et al. suggest a management scheme for the use of drugs and other treatments. The treatment will depend on whether the atrial fibrillation is paroxysmal, persistent or permanent. Either aspirin or warfarin should be given in all cases. Paroxysmal atrial fibrillation may just require reassurance, or possibly a beta-blocker, propafenone or flecainide. Persistent atrial fibrillation should ideally be reverted to sinus rhythm as soon as possible. Early electrical cardioversion should be attempted if the patient is seen within 24 hours. If the atrial fibrillation is diagnosed later, anticoagulation 4 weeks prior to cardioversion is needed. Otherwise anti-arrhythmic drugs such as propafenone or flecainide may be given. In permanent or chronic atrial fibrillation where sinus rhythm cannot be restored, rate control is advised with Digoxin or a beta-blocker or a calcium antagonist such as verapamil or diltiazem.
THE IMPLANTABLE 'ATRIOVERTER' Atrial fibrillation: current knowledge and recommendations. Levy S, Breithardt G, Campbell R et al. 1998 European Heart Journal 19: 1294-1320. Atrial fibrillation is believed to affect about 2% of the population. It is slightly more common among men than women and its prevalence increases with age. Treatment may vary widely between patients. In some patients sinus rhythm can be restored by external electrical cardioversion or with anti-arrhythmic drugs. Persistent atrial fibrillation should ideally be reverted to sinus rhythm as soon as possible, as atrial fibrillation has a tendency to recur particularly when it has persisted for some time. Electrical cardioversion is most successful when atrial fibrillation has been present for only a short time. In order to facilitate repeated cardioversion, a device similar in many respects to the implantable defibrillator has been produced and is being evaluated. It has the advantage of restoring sinus rhythm as early as possible and may prevent the changes that affect the heart with Coronary Health Care (1999) 3 (1), 48-53
prolonged bouts of atrial fibrillation. The 'implantable atrioverter' delivers low energy shocks to restore sinus rhythm as effectively and comfortably as possible with a minimum of risk in causing other abnormal heart rhythms. Electrodes are implanted in the atrium and the ventricle. In the first instance, although the device can recognize and confirm the presence of atrial fibrillation, it is programmed so that the doctor can initiate the discharge. In a second phase the device will be programmed so that the patient can activate the discharge and ultimately it may be used in an automatic mode. Although patients find the sensation rather like a kick in the chest they will often tolerate it to be rid of an unpleasant and limiting arrhythmia. Refinement of the model may allow it to be easily tolerable and highly efficient. It has so far been found to be safe and effective, but its use is likely to be confined to selected patients with atrial fibrillation. More trials are needed before this device is widely used.
EXTERNAL AUTOMATED DEFIBRILLATION Use of automated external defibrillators by police officers for treatment of out-of-hospital cardiac arrest. Mosesso VN, Davis EA, Auble TE et al. 1998 Annals of Emergency Medicine 32; 2: 200-207. The importance of early defibrillation in improving a chance of survival has been impressed upon all emergency services and the general public. As the introduction of first responder defibrillators is relatively recent, estimates of lives saved are important in evaluating the effectiveness of those who provide this service. A recent study involved the training of police officers in seven suburban communities in the USA (Mosesso et al. 1998). The police officers often got to the scene before the paramedics. The police officers were instructed to use the defibrillators as soon as they had found no pulse. The time to defibrillation was cut from 11.8 minutes (the average time recorded before the study began) to 8.7 minutes. When the police arrived at the scene before the paramedics during this study, there was a 26% survival rate compared to 3% when the paramedics attended to the patient.
RELATIVES AND RESUSCITATION Psychological effect of witnessed resuscitation on bereaved relatives. Robinson S, Mackensie-Ross S, Campbell-Hewson M et al. 1998 Lancet 352 614-617. The potential distress caused by defibrillation and other aggressive measures to resuscitate a patient has led to the usual exclusion of patients from the clinical area during resuscitation. A recent pilot study of 18 relatives has addressed this decision by either allowing or not allowing one relative 9 1999 Harcourt Brace & Co. Ltd
Research News the choice to remain with the patient during the resuscitation process (Robinson et al. 1998). All relatives were supported during and after the resuscitation process irrespective of whether they remained in the resuscitation room. These 18 relatives were questioned at 3 and 9 months after the event to find out about their psychological reactions to either of these approaches. The eight patients who witnessed the resuscitation were less anxious, depressed, and traumatized by being present than those who were excluded from the area. It also appeared that the clinical staff benefited from the presence of the relative as it placed the patient in the right context. Although this was a small pilot study these findings suggest that a larger study may encourage professionals to offer patients' relatives the choice to remain with the patient during resuscitation.
TRENDS IN MORTALITY FROM CORONARY HEART DISEASE
The falling mortality from coronary heart disease: a clinicopathological perspective. The United Kingdom Heart Attack Study (UKHAS) Collaborative Group 1998 Heart 80: 12t-126. Perspectives on trends in mortality and case fatality from coronary heart attacks: the need for a better definition of acute myocardial infarction. TunstallPedoe H 1998 Heart 80:112-113. Myocardial and coronary deaths in the World Health Organisation MONICA project-registration procedures,
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event rates and case fatality rates in 38 populations from 21 counties in 4 continents. Tunstall-Pedoe H, Kuulasea K, Amonyal P et al. (for WHO MONICA project) 1994 Circulation 90: 583412. Regional Office for Europe: Myocardial Infarction Community Registers. World Health Organisation 1976 Public Health in Europe No 5. Copenhagen. WHO. Mortality from coronary heart disease (CHD) appears to have declined by about 30% since 1980. The UK Heart Attack Study (UKHAS) Collaborative Group (1998) argues that official statistics are based on death certificates that are often inaccurate. They compared the official death rates with recordings of coronary deaths defined by strict clinical and pathological criteria in three health districts Brighton, South Glamorgan, and York. They found that estimates of mortality for coronary heart disease in these regions were similar to official figures up to the age of 65 years. However, beyond the age of 65 years there were 20% fewer deaths from CHD than reported in official figures. Tunstall-Pedoe (1998) suggests that heart attack registers and diagnoses may have variable criteria and may exclude unexplained sudden death. The WHO in 1960 used loose criteria of chest pain, ECG changes and cardiac enzymes to describe either definite or possible myocardial infarctions. The MONICA project redefined the end point of non-fatal events as 'definite myocardial infarction'. In contrast the UKHAS Group have used the patient history and/or ECG changes and/or raised cardiac enzymes as criteria.
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