North of England evidence based guideline development project: guideline on the use of aspirin as secondary prophylaxis for vascular disease in primary care. North of England Aspirin Guideline Development Group

The challenges of treating peripheral arterial disease

Today, peripheral arterial disease (PAD) patients need effective medical care for an extended period of their lifetime. Therefore, different treatment modalities have to be tied sequentially into an effective therapeutic chain. First, preventive measures have to be reinforced and risk factors tightly controlled. Furthermore, antiplatelet agents have to be applied in every PAD patient to reduce the risk of cardiac and cerebral ischemic events, restenosis or reocclusion after revascularization, and possibly also progression of the PAD itself. Angiotensin-converting enzyme (ACE) inhibitors should be entertained in high-risk groups such as PAD patients with diabetes. In the claudicant, exercise therapy should be strongly encouraged and vasoactive drugs considered for those who are not good candidates for either exercise training or revascularization. In patients with disabling claudication or critical limb ischemia, revascularization procedures are highly effective. Especially for high-grade stenoses or short arterial occlusions, percutaneous transluminal angioplasty (PTA) should be the method of fi rst choice followed by the best surgical procedure later on. To achieve good long-term effi cacy, a close follow-up including objective tests of both the arterial lesion and hemodynamic status, surveillance of secondary preventive measures and risk factor control is mandatory.

Ultrasonography of carotid plaque for the prevention of stroke

A carotid ultrasonography is a non-invasive technique that provides an accurate and reliable characterization of the broad spectrum of carotid arteriosclerosis, from the intima-media thickness to the atherosclerotic plaque. Carotid ultrasonography has become a useful tool for identifying patients at high risk of stroke and selecting those who can benefit most from revascularization therapies such as carotid endarterectomy and stenting. In addition to the degree of stenosis, plaque echomorphology has emerged in recent years as an important contributory factor to stroke risk. Changes in plaque echogenicity, as measured by the quantitative computer-assisted ultrasonography index, could be a marker of plaque instability as well as an indicator of plaque remodeling, thereby providing the means for monitoring anti-atherosclerosis drugs such as statins.

Regulations of the key mediators in inflammation and atherosclerosis by aspirin in human macrophages

Although its role to prevent secondary cardiovascular complications has been well established, how acetyl salicylic acid (ASA, aspirin) regulates certain key molecules in the atherogenesis is still not known. Considering the role of matrix metalloproteinase-9 (MMP-9) to destabilize the atherosclerotic plaques, the roles of the scavenger receptor class BI (SR-BI) and ATP-binding cassette transporter A1 (ABCA1) to promote cholesterol efflux in the foam cells at the plaques, and the role of NF-κB in the overall inflammation related to the atherosclerosis, we addressed whether these molecules are all related to a common mechanism that may be regulated by acetyl salicylic acid. We investigated the effect of ASA to regulate the expressions and activities of these molecules in THP-1 macrophages. Our results showed that ASA inhibited MMP-9 mRNA expression, and caused the decrease in the MMP-9 activities from the cell culture supernatants. In addition, it inhibited the nuclear translocation of NF-κB p65 subunit, thus the activity of this inflammatory molecule. On the contrary, acetyl salicylic acid induced the expressions of ABCA1 and SR-BI, two molecules known to reduce the progression of atherosclerosis, at both mRNA and protein levels. It also stimulated the cholesterol efflux out of macrophages. These data suggest that acetyl salicylic acid may alleviate symptoms of atherosclerosis by two potential mechanisms: maintaining the plaque stability via inhibiting activities of inflammatory molecules MMP-9 and NF-κB, and increasing the cholesterol efflux through inducing expressions of ABCA1 and SR-BI.

History of the concept of ‘levels of evidence’ and their current status in relation to primary prevention through lifestyle interventions

Primary prevention is a major option to reduce the burden of chronic disease in populations. Because lifestyle interventions have proved to be effective, lifestyle recommendations including nutritional advice are made abundantly. However, both their credibility and their effectiveness are often considered not to be high. Therefore, scientific evidence should form the basis of recommendations and, as in clinical medicine, a rational approach should be followed for the evaluation of evidence. In this paper, the development and current concepts of ‘levels of evidence’ as they are applied in clinical medicine are outlined and their impact on evidence-based recommendations is discussed. Next, the question is raised as to how far the existing schemes are applicable to the evaluation of issues pertaining to primary prevention through lifestyle changes. Current schemes were developed mainly for clinical research questions and therefore place major emphasis on randomised controlled trials as the main and most convincing evidence in the evaluation process. These types of study are rarely available for lifestyle-related factors and might even not be feasible to obtain. Arguments are advanced to support the notion that a modification of currently existing ‘levels of evidence’ as developed for clinical research questions might be necessary. Thereby, one might be able to accommodate the specific aspects of evidence-related issues of recommendations for primary prevention through lifestyle changes, like dietary changes.

POINT OF CARE TESTING OF ASPIRIN RESISTANCE IN PATIENTS WITH VASCULAR DISEASE

INTRODUCTION

The reported range in rates of aspirin resistance (5.5-60%) may reflect difficulties in studying platelet function and the variety of tests used. This study used a platelet function analyzer (PFA-100) to prospectively document aspirin resistance in a cohort of patients with arterial disease.

METHODS

Patients with internal carotid artery (ICA) stenosis or intermittent claudication (IC) were recruited. Exclusion criteria were contraindications to aspirin, prescription of other medication with known antiplatelet effects or known platelet abnormalities. After prescription of 100 mg aspirin/day for 2 weeks an uncuffed venous blood sample was taken and analysed with the PFA-100. Aspirin resistance was defined as closure time (CT) less than the upper limit of normal (158 s collagen/epinephrine agonist; 118 s collagen/adenosine diphosphate (ADP) agonist).

RESULTS

Thirty-three patients with IC and 12 patients with ICA stenosis were recruited (n = 45). Median (range) age was 74 years (49-85) and the male to female ratio was 1.5:1. The median (range) CT was >300 (85 to >300) s with collagen/epinephrine and 100 (52 to >300) s with collagen/ADP agonist. Twelve patients (27%) in the collagen/epinephrine group had normal CT despite treatment with 100 mg aspirin, indicating resistance. Of the 33 patients with collagen/epinephrine CT prolonged by aspirin, 10 patients also had prolonged collagen/ADP CT, suggesting excessive platelet inhibition.

CONCLUSION

A significant proportion of patients taking aspirin do not show laboratory evidence of platelet inhibition and may not be protected from atherothrombotic events. The PFA-100 appears to be a useful tool to screen for both aspirin resistance and excessive aspirin mediated platelet inhibition.

National Stroke Association guidelines for the management of transient ischemic attacks

OBJECTIVE

Transient ischemic attacks are common and important harbingers of subsequent stroke. Management varies widely, and most published guidelines have not been updated in several years. We sought to create comprehensive, unbiased, evidence-based guidelines for the management of patients with transient ischemic attacks.

METHODS

Fifteen expert panelists were selected based on objective criteria, using publication metrics that predicted nomination by practitioners in the field. Prior published guidelines were identified through systematic review, and recommendations derived from them were rated independently for quality by the experts. Highest quality recommendations were selected and subsequently edited by the panelists using a modified Delphi approach with multiple iterations of questionnaires to reach consensus on new changes. Experts were provided systematic reviews of recent clinical studies and were asked to justify wording changes based on new evidence and to rate the final recommendations based on level of evidence and quality. No expert was allowed to contribute to recommendations on a topic for which there could be any perception of a conflict of interest.

RESULTS

Of 257 guidelines documents identified by systematic review, 13 documents containing 137 recommendations met all entry criteria. Six iterations of questionnaires were required to reach consensus on wording of 53 final recommendations. Final recommendations covered initial management, evaluation, medical treatment, surgical treatment, and risk factor management.

INTERPRETATION

The final recommendations on the care of patients with transient ischemic attacks emphasize the importance of urgent evaluation and treatment. The novel approach used to develop these guidelines is feasible, allows for rapid updating, and may reduce bias.

Antiplatelet therapy in peripheral occlusive arterial disease

BACKGROUND

Antiplatelet therapy (APT) in patients with peripheral occlusive arterial disease (POAD) may reduce cardiovascular (CV) morbidity and mortality by inhibiting atherothrombosis. This article reviews the current evidence for APT in patients with stable POAD and in patients undergoing revascularization procedures for POAD.

METHODS

A Medline and Pubmed literature search (January 1966 to February 2003) was conducted to identify articles relating APT and POAD. Manual cross referencing was also used.

RESULTS AND CONCLUSIONS

Meta-analyses suggest that APT (most commonly aspirin) in patients with stable POAD significantly reduces the incidence of nonfatal stroke, myocardial infarction and CV death. However, this conclusion is based on subset analysis of data predominantly involving patients with coronary and cerebrovascular atherosclerosis. There is a little direct evidence for the use of aspirin in patients with isolated POAD, but in practice, aspirin remains the most commonly used antiplatelet agent as high rates of coronary and cerebrovascular diseases are observed in this patient population. For patients with POAD without additional indicators of vascular risk, the protective effect of aspirin is unclear and dependent on the balance of risks and benefits in the individual patient. For patients undergoing peripheral revascularization, ticlopidine and aspirin in combination with dipyridamole are effective in maintaining patency after bypass procedures and following angioplasty/femoral endarterectomy. The efficacy of thienopyridines in peripheral angioplasty is uncertain, and the optimum timing and duration of APT relative to intervention are not known.

Aspirin under fire: aspirin use in the primary prevention of coronary heart disease

The issue of aspirin use in the primary prevention of cardiovascular disease is still debated because of conflicting opinions on risks versus benefits. Recently, a United States Food and Drug Administration (FDA) panel rejected the approval of aspirin in the setting of primary prevention in moderate-risk patients. However, the United States Preventive Services Task Force recommends that clinicians discuss aspirin therapy with patients at increased risk for having a future coronary event. During the past 15 years, many large randomized trials have specifically addressed this issue and helped shape the decisions of the FDA panel and the Preventive Services Task Force. These trials lend a handful of experiences and results, with no clear recommendations for antiplatelet therapy in the setting of primary prevention of coronary heart disease (CHD). Recently, trial results have been assimilated into practical tools for risk stratification to guide aspirin use in this setting. An overview and critical evaluation of the work performed thus far is provided in order to lend insight into the ongoing debate and, through use of the Framingham CHD risk prediction score sheets, to better equip practitioners faced with the decision of giving aspirin to "relatively" healthy individuals for CHD primary prevention.

Stabilization of advanced atherosclerosis in low-density lipoprotein receptor-deficient mice by aspirin

COX-1-dependent eicosanoid formation accelerates atherogenesis, and low-dose aspirin reduces early atherosclerosis. However, the role of aspirin in modulating progression of vascular atherosclerotic lesions once established is less investigated. We wished to determine the effect of low-dose aspirin on vascular inflammation, plaque composition, and progression of established atherosclerosis. Low-density lipoprotein receptor-deficient mice (LDLR(-/-)) were fed a high-fat diet for 3 months. At this time, one group of mice underwent baseline analysis. Two additional groups, while continuing the high-fat diet, were randomized to receive placebo or aspirin for additional 3 months. At the end of the study, LDLR(-/-) mice that had received aspirin had suppressed biosynthesis of thromboxane B2, the major products of COX-1 activity, reduced monocyte chemoattractant protein-1, and soluble intercellular adhesion molecule-1 levels compared with controls. Compared with baseline, the placebo group had significant progression of atherosclerosis. In contrast, aspirin treated mice showed a significant reduction in progression of atherosclerosis, and a significant decrease in foam cell content. These results suggest that in murine atherosclerosis, low-dose aspirin retards progression of established and advanced vascular atherosclerotic lesions by suppressing the formation of bioactive lipids and vascular inflammation.

Guidelines on the management of secondary prophylaxis of vascular events in stable patients in primary care

Atherothrombosis, thrombus formation superimposed on an existing atherosclerotic plaque, is an acute process leading to ischaemic events such as myocardial infarction, stroke and critical limb ischaemia. Patients presenting with clinical conditions associated with atherothrombosis are at increased risk of subsequent vascular events. The beneficial effect of antiplatelet therapies for short-term and long-term secondary prevention of atherothrombotic events has been established. These guidelines aim to provide evidence-based recommendations that will assist in the antiplatelet-mediated secondary prophylaxis of vascular events in patients with stable cardiovascular disease treated in the primary healthcare setting. Medline and the Cochrane library were accessed using free-text strategies in the domains of antiplatelet agents and antithrombotics. Development of the guidelines was driven by a series of Steering Committee meetings, in which the quality of relevant studies was assessed and identified using narrative summary. These guidelines present evidence and recommendations for the treatment of numerous atherothrombotic indications depending on individual patient circumstances.

Wound care for elderly patients: advances and clinical applications for practicing physicians

Chronic ulcers (wounds) are commonly encountered in medical practice, particularly in elderly patients who have chronic medical conditions. Health care providers must be adept at diagnosing chronic ulcers and optimizing medical treatment. We describe the best medical practice for the 4 common types of chronic ulcers: pressure ulcers, ischemic ulcers, venous ulcers, and neuropathic ulcers. We emphasize the importance of nutrition and proper wound care as a foundation for the management of all chronic ulcers. There is a unique therapeutic goal for each chronic ulcer. Pressure relief should be provided for both pressure ulcers and neuropathic ulcers. Ischemic ulcers require revascularization. Patients with venous ulcers need adequate edema control. We outline advances in each of these areas and discuss the newest developments in wound care, including growth factors, hyperbaric oxygen, and vacuum-assisted devices. Chronic ulcers in elderly patients can heal with proper diagnosis and good medical care.

Aspirin (100 mg) used for prevention of pre-eclampsia in nulliparous women: the Essai Régional Aspirine Mère-Enfant study (Part 1)

OBJECTIVE

To reduce the incidence of pre-eclampsia in nulliparous women, in accordance with the suggestion of a recent meta-analysis that low dose aspirin might decrease this incidence by more than half if used early enough in and at a sufficient dose during pregnancy (more than 75 mg).

DESIGN

Multicentre randomised double-blinded placebo-controlled trial.

SETTING

Twenty eight centres in Northern of France and one in Belgium.

POPULATION

Three thousand and two hundred ninety-four nulliparous women recruited between 14 and 20 weeks.

METHODS

Randomisation to either 100 mg aspirin or placebo daily from inclusion through 34 weeks.

MAIN OUTCOME MEASURES

Preeclampsia was defined as hypertension (> or =140 and or 90 mmHg) associated with proteinuria (> or =0.5 g/L).

RESULTS

The aspirin (n = 1644) and placebo (n = 1650) groups did not differ significantly in the mothers' incidence of pre-eclampsia (28 of 1632 [1.7%] vs 26 of 1637 [1.6%]; relative risk, RR, 1.08, 95% CI 0.64-1.83), hypertension, HELLP syndrome or placental abruption, or in the children's incidence of perinatal deaths or birthweight below the 10th centile. The incidence of babies with birthweight below the third centile was significantly higher in the aspirin group, with no explanation. The incidence of maternal side effects was higher in the aspirin group, principally because of a significantly higher rate of haemorrhage.

CONCLUSIONS

Aspirin at a dose of 100 mg does not reduce the incidence of pre-eclampsia in nulliparous women. Aspirin (100 mg) is associated with an increase in bleeding complications.

Geographical variation in cardiovascular disease, risk factors, and their control in older women: British Women's Heart and Health Study

OBJECTIVES

To measure the geographical variation in prevalence of cardiovascular disease, risk factors, and their control in a nationally representative sample of older British women.

METHODS

Baseline survey using general practitioner record review, a self completed questionnaire, research nurse interview, and physical examination in a randomly selected sample of women aged 60-79 drawn from 23 towns in England, Scotland, and Wales.

RESULTS

Of 7,173 women invited and eligible to participate, information was obtained on 4,286 (60%). One in five women had a doctor diagnosis of any one of myocardial infarction, angina, heart failure, stroke, or peripheral vascular disease. Fifty per cent of women were hypertensive, 12% smoked, and over one quarter were obese. Fifty per cent had a total cholesterol level greater than 6.5 mmol/l, though only 3% had low high density lipoprotein concentrations. Cardiovascular disease prevalence varied by geographical region being highest in Scotland: age adjusted prevalence (95% confidence intervals) 25.0% (21.5% to 28.8%) and lowest in South England: age adjusted prevalence (95% confidence intervals) 15.4% (13.5% to 17.6%). The geographical variations in cardiovascular disease prevalence were attenuated by adjustment for risk factors and socioeconomic position; further adjustment for health service use (as indicated by aspirin or statin use) reduced the differences further. However, variation remained even after full adjustment for these factors: odds ratio (95% confidence intervals) comparing Midlands and Wales to South England 1.15 (0.82 to 1.61) and comparing Scotland to South England 1.53 (1.08 to 2.14). Of women with cardiovascular disease, 12% were current smokers, a third had uncontrolled hypertension, a third were obese, and 90% had a blood cholesterol over 5 mmol/l. Only 41% were taking antiplatelet drugs and 22% were taking a statin.

CONCLUSIONS

Older British women have a higher prevalence of cardiovascular disease and risk factors than previously documented. The workload consequences of attempting to control risk factors and ensure optimal secondary prevention for older British women are considerable. Geographical variations in cardiovascular disease prevalence in older women are somewhat, but not fully, explained by variations in major risk factors, socioeconomic position, and health service utilisation.

Pharmacological treatment of elderly patients with acute coronary syndromes without persistent ST segment elevation

Evidence-based management of acute coronary syndromes (ACS) without persistent ST segment elevation involves a rational, stepwise approach to the selection of therapies with potential benefit for elderly patients. Specifically, in elderly patients with ACS without persistent ST segment elevation, therapy should be administered based on the likelihood of unstable angina or non-ST elevation myocardial infarction being present and the risks and benefits of each individual therapy. All elderly patients with suspected ACS should receive anti-ischaemic therapy consisting of beta-blockers and nitrates, and antiplatelet therapy with aspirin unless clear contraindications exist. For patients with a moderate likelihood of ACS being present, defined as prior coronary disease or recurrent pain despite the use of anti-ischaemic therapies, unfractionated heparin or enoxaparin should be added to aspirin for more intense anticoagulation. In patients with high-risk clinical features, defined as ischaemic electrocardiographic changes and positive cardiac markers such as troponins, therapy with clopidogrel or glycoprotein IIb/IIIa inhibitors should be considered in addition to aspirin and heparin. Furthermore, high-risk patients should be managed with an early invasive strategy that includes prompt cardiac catheterisation within 24 to 48 hours and appropriate use of revascularisation as determined by the findings of the catheterisation. An evidence-based approach to the treatment of elderly patients with ACS without persistent ST segment elevation will help to improve the use of beneficial therapies and interventions that are recommended by current practice guidelines.

Hemorrhagic complications of oculoplastic surgery

PURPOSE

To determine the incidence and risk factors of hemorrhagic complications associated with selected oculoplastic procedures.

METHODS

A prospective study was performed to document the severity of intraoperative hemorrhage and postoperative bruising in patients undergoing oculoplastic procedures. The use of anticoagulant or platelet-inhibiting medications, systemic medical conditions, patient age, patient sex, and type of procedure were examined to identify risk factors for hemorrhagic complications.

RESULTS

Troublesome intraoperative bleeding prolonged surgery in 9.2% of cases. Severe bleeding with the potential to affect surgical outcome was encountered in 0.4% of procedures. There was little correlation between severity of bleeding and degree of postoperative bruising. Male sex, a history of heart disease, or age >60 years imparted a slightly greater risk of intraoperative bleeding. Age >60 years, hypertension, or recent cessation of aspirin may increase the risk of postoperative bruising. A history of previous stroke increased the risk of postoperative bleeding. There was no statistical difference in the incidence of hemorrhagic complications among patients currently treated with antiplatelet/anticoagulant agents, those who had stopped these medications before surgery, and those who were not treated with these agents. No patient had permanent sequelae related to hemorrhage. Two patients had postoperative systemic complications possibly attributable to withholding anticoagulant/antiplatelet medications in preparation for surgery.

CONCLUSIONS

Although serious hemorrhagic complications may be associated with oculoplastic procedures, the incidence of these complications is low. The decision to withhold antiplatelet or anticoagulant medications before surgery should be individualized. Selected procedures can be safely performed without stopping these agents.

Prevention of cardiovascular diseases. Coronary artery disease, congestive heart failure, and stroke

Cardiovascular disease leads to significant morbidity and mortality in the older population. Results of risk reduction can be dramatic in terms of patient survival and quality of life. This article reviews evidence for cardiovascular risk factors and disease prevention in older adults. Interventions which reduce morbidity and mortality from coronary artery disease, heart failure, and cerebrovascular disease in the elderly population are examined. Attention is given to the role of cardiovascular disease in older women and in minorities, subsets not well-represented in many studies.

A randomised controlled trial of the effect of educational outreach by community pharmacists on prescribing in UK general practice

BACKGROUND

Educational outreach visits are commonly used to promote changes in prescribing in family practice. However, the effectiveness of outreach visits has not been evaluated across a range of settings.

AIM

To estimate the effectiveness of educational outreach visits on United Kingdom (UK) general practice prescribing and to examine the extent to which practice characteristics influenced outcome.

DESIGN OF STUDY

Randomised controlled trial.

SETTING

General practices in 12 health authorities in England.

METHOD

Educational outreach visits were made to practices that received two of four guidelines. Each practice provided data on treatment of patients for all four guidelines for both pre and post-intervention periods. The primary outcome is average effect across all four guidelines. Secondary analyses examined the predictive effect of practice and guideline characteristics.

RESULTS

Seventy per cent of practices approached agreed to take part in the intervention. Overall, educational outreach was associated with a significant improvement in prescribing practice (odds ratio [OR] = 1.24 [95% CI = 1.07 to 1.42]), a 5.2% (95% CI = 1.7% to 8.7%) increase in the number of patients treated within the guideline recommendations. Smaller practices (two or fewer full-time equivalent practitioners) responded much more favourably to educational outreach than larger practices. Smaller practices improved their performance in line with the guidelines by 13.5% (95% CI = 6% to 20.9%) attributable to outreach, while larger practices improved by only 1.4% (95% CI = -2.4% to 5.3%, P-value for interaction <0.001).

CONCLUSION

In large practices, educational outreach alone is unlikely to achieve worthwhile change. There is good evidence to support the use of educational outreach visits in small practices.

Costs of aspirin and statins in general practice

BACKGROUND

Aspirin and statins are the two drugs most commonly indicated for secondary prevention of atherosclerotic disease in the UK. Statin treatment, which is more expensive, is under-prescribed.

AIM

To assess the expenditure in Greater Manchester general practices on aspirin and statins.

DESIGN

Survey of general practice records.

METHODS

Practice registers were searched for patients receiving regular prescriptions for aspirin. For each patient, the next patient of the same sex, aged within +/- 5 years, not on aspirin, acted as a control. Details of all medications were recorded. In a sub-study, records of 100 patients on aspirin were studied to determine indications for aspirin prescription.

RESULTS

There were 1003 (511 men, 492 women) in each group; mean age was 70 years in both groups. In the sub-study, 79% of patients received aspirin for established vascular disease, 9% for hypertension, 5% for diabetes mellitus, 5% for unknown reasons and 2% for arthritis. Of the patients on aspirin, 67% received dispersible aspirin 75 mg/day. The rest were on higher doses (10%) or on more expensive preparations (22%), costing up to 22.4 p/day. The mean daily cost of aspirin was 1.7p. Dyspepsia treatment was received by 266 patients and 194 controls (p<0.001). There was a wide range of dyspepsia medications (10-306p/day), averaging in the groups as a whole 15.5p/day in patients and 12.5p/day in controls. Of the patients on aspirin, 28% received statins, compared to 4% of controls. Mean daily expenditure on statins in patients was 23.4p.

CONCLUSION

Assuming the difference in the use of medication for dyspepsia between patients and controls was due to aspirin, the full cost of aspirin treatment was 4.7p/day. Statins were probably under-prescribed in aspirin-takers, many of whom would have been at high CHD risk.

What is the place of beta-blockade in patients who have experienced a myocardial infarction with preserved left ventricular function? Evidence and (mis)interpretation

Beta blockers have long been used in patients who have experienced a myocardial infarction. However, many new therapies are available for this patient group, and as a result, the current role of beta blockers may have become uncertain. In this article we address a series of questions related to the important and continuing role of beta blockade after myocardial infarction.

Is aspirin "the weakest link" in cardiovascular prophylaxis? The surprising lack of evidence supporting the use of aspirin for cardiovascular disease

It is currently fashionable to prescribe aspirin, long-term to people with or at high risk of vascular events due to atherosclerosis. There is a moderately conclusive evidence for a short-term benefit after an acute vascular event. However, there is remarkably little evidence that long-term aspirin is effective for the prevention of vascular events and managing side effects may be expensive. Reductions in nonfatal vascular events may reflect an ability of aspirin to alter cosmetically the presentation of disease without exerting real benefit. Cardiovascular medicine appears prone to fads and fashions that are poorly substantiated by evidence. The current fashion for prescribing aspirin is reminiscent of the now discredited practice of widespread prescription of class I anti-arrhythmic drugs for ventricular ectopics. We should learn from experience.

Does aspirin attenuate the effect of angiotensin-converting enzyme inhibitors in hypertension or heart failure?

There is a wealth of data that suggests an important interaction between aspirin and angiotensin-converting enzyme inhibitors in patients with chronic stable cardiovascular disease. The interaction is less obvious in the postinfarction setting, possibly reflecting the fact that many patients stop their aspirin therapy within a few months of such an event. An interaction is biologically plausible, because there is considerable evidence that angiotensin-converting enzyme inhibitors exert important effects through increasing the production of vasodilator prostaglandins, whereas aspirin blocks their production through inhibition of cyclooxygenase, even at low doses. There is some evidence that low-dose aspirin may raise systolic and diastolic blood pressure. There is also considerable evidence that aspirin may entirely neutralize the clinical benefits of angiotensin-converting enzyme inhibitors in patients with heart failure. In addition, aspirin may have an adverse effect on outcome in patients with heart failure that is independent of any interaction with angiotensin-converting enzyme inhibitors, possibly by blocking endogenous vasodilator prostaglandin production and enhancing the vasoconstrictor potential of endothelin. The evidence is not sufficient to justify advising long-term aspirin therapy for patients with cardiovascular disease in general, and for those with heart failure in particular. Thus, the lack of evidence of benefit with aspirin in patients with heart failure and coronary disease, along with growing evidence that aspirin is directly harmful in patients with heart failure and that aspirin may negate the benefits of angiotensin-converting enzyme inhibitors suggest that, unless there is an opportunity to randomize the patient into a study of antithrombotic strategies, then aspirin should be withdrawn or possibly substituted with an anticoagulant or an antiplatelet agent that does not block cyclooxygenase. In contrast, there is fairly robust evidence for a benefit of both aspirin and angiotensin-converting enzyme inhibitors during the first 5 weeks after a myocardial infarction, with little evidence of an interaction. The combination of aspirin and angiotensin-converting enzyme inhibitors is warranted during this period, after which discontinuation or substitution of aspirin with another agent should be considered.

Systematic review of antiplatelet therapy for the prevention of myocardial infarction, stroke or vascular death in patients with peripheral vascular disease

BACKGROUND

Antiplatelet agents may prevent vascular events and death in patients with peripheral vascular disease (PVD).

METHODS

A systematic review of 39 randomized controlled trials of antiplatelet therapy in patients with PVD was performed.

RESULTS

For patients with PVD the number suffering a non-fatal myocardial infarction, non-fatal stroke or vascular death in the antiplatelet group was 6.5 per cent compared with 8.1 per cent in the placebo group (odds ratio 0.78 (95 per cent confidence interval (c.i.) 0.63--0.96); P = 0.02), favouring antiplatelet treatment. For infrainguinal bypass surgery (ten trials) and balloon angioplasty (two) the differences were still in favour of antiplatelet therapy, but they did not reach statistical significance. In five trials of aspirin against another antiplatelet agent, 8.4 per cent in the aspirin group suffered a vascular event compared with 6.6 per cent in the second antiplatelet group (odds ratio 0.76 (95 per cent c.i. 0.64--0.91); P < 0.01), favouring ticlopidine/clopidogrel/aspirin + dipyridamole against aspirin alone.

CONCLUSION

Antiplatelet therapy reduces serious vascular events and vascular death in patients with PVD. For infrainguinal arterial surgery or balloon angioplasty the benefit remains unproven, but the number of trials to date is small. There is also evidence to support the use of antiplatelet drugs other than aspirin for the prevention of vascular events in those with PVD.

Evidence-based guideline for the primary care management of stable angina

This is an updated version of the first North of England Stable Angina Guideline (1,2) and summarizes the full guideline. (3) This paper presents all the recommendations within the guideline; and where these are new or substantially altered from the original version, it also presents a summary of the supporting evidence. The aims and methods of development (summarized in Box 1) of this guideline are unchanged from the original version, to which readers are directed for more detail. The research questions raised during the development of this guideline are shown in Box 2.

Recommendations for the outpatient surveillance of renal transplant recipients. American Society of Transplantation

Many complications after renal transplantation can be prevented if they are detected early. Guidelines have been developed for the prevention of diseases in the general population, but there are no comprehensive guidelines for the prevention of diseases and complications after renal transplantation. Therefore, the Clinical Practice Guidelines Committee of the American Society of Transplantation developed these guidelines to help physicians and other health care workers provide optimal care for renal transplant recipients. The guidelines are also intended to indirectly help patients receive the access to care that they need to ensure long-term allograft survival, by attempting to systematically define what that care encompasses. The guidelines are applicable to all adult and pediatric renal transplant recipients, and they cover the outpatient screening for and prevention of diseases and complications that commonly occur after renal transplantation. They do not cover the diagnosis and treatment of diseases and complications after they become manifest, and they do not cover the pretransplant evaluation of renal transplant candidates. The guidelines are comprehensive, but they do not pretend to cover every aspect of care. As much as possible, the guidelines are evidence-based, and each recommendation has been given a subjective grade to indicate the strength of evidence that supports the recommendation. It is hoped that these guidelines will provide a framework for additional discussion and research that will improve the care of renal transplant recipients.

Antithrombotic and antihypertensive management 3 months after ischemic stroke : a prospective study in an inner city population

BACKGROUND AND PURPOSE

We sought to examine the frequency, predictors, and effects of nontreatment with antithrombotic and antihypertensive therapies 3 months after ischemic stroke.

METHODS

The population-based South London Community Stroke Register prospectively collected data on first-in-a-lifetime strokes between 1995 and 1997. Among patients registered with ischemic stroke, treatment status with antithrombotic and antihypertensive therapies was examined 3 months after the event.

RESULTS

In a cohort of 457 patients with ischemic stroke, 393 (86.0%) were considered appropriate for antiplatelet medication, 32 (7.0%) for anticoagulant medication, and 254 (55.9%) for antihypertensive medication. The rates of nontreatment observed 3 months after the event were 24.4% for antiplatelet, 59.4% for anticoagulant, and 29.5% for antihypertensive medication. Independent risk factors for nontreatment with antithrombotic therapies (antiplatelets and anticoagulants) were the subtype of stroke (nonlacunar infarct: OR=1. 60, 95% CI 1.07 to 2.54), stroke severity measured by the Glasgow Coma Scale (GCS) score (GCS </=13: OR 2.08, 95% CI 1.18 to 3.66) and the Barthel Index (BI) score 5 days after the event (BI </=10: OR 1. 85, 95% CI 1.17 to 2.93). For antihypertensive therapies the stroke subtype (OR 2.46, 95% CI 1.33 to 4.54), GCS score (OR 2.97, 95% CI 1. 35 to 6.53), BI score (OR 2.33, 95% CI 1.27 to 4.29), and ethnicity (Caucasian: OR 2.43, 95% CI 1.15 to 5.14) were independently associated with nontreatment. Cox regression modeling showed no significant association between the treatment status and recurrence-free 3-year survival rates after controlling for severity and subtype of stroke.

CONCLUSIONS

Secondary prevention for a common disease such as stroke appears to be inadequate in the study area. Healthcare professionals need to consider antithrombotic and antihypertensive therapies for all stroke patients.

A randomized trial of Evidence-based OutReach (EBOR): rationale and design

There is increasing interest in evaluating the methods used to implement the findings from medical research. This paper describes the Evidence-based OutReach (EBOR) trial, which is the first large randomized study in the United Kingdom that will evaluate the effectiveness and efficiency of educational outreach visits by trained pharmacists who are delivering messages derived from four evidence-based clinical practice guidelines. General practices form the unit of allocation and analysis. The study design addresses important factors that may influence the effectiveness of the intervention, such as the pharmacist who delivers the messages, the health authority in which practices are located, and the size of a practice.

A framework for incorporating cost-effectiveness in evidence-based clinical practice guidelines

In England, recent health care reforms emphasise the role of clinical guidelines in promoting effective and efficient health care. Introducing economic data into guidelines raises some methodological issues: specifically, the provision of valid and generalisable cost estimates, the weight placed upon cost 'evidence', and the presentation of cost-effectiveness information in a manner accessible to clinicians. A series of primary care guidelines, explicitly including consideration of health economic information, have recently been published, intended to help clinicians to aggregate the attributes of treatment choices to derive treatment recommendations consistent with both the clinical decision-making process and social objectives. Clinicians involved in developing guidelines responded well to the process and consistently managed to agree treatment recommendations, often after considerable debate about the evidence for treatment. In none of the guideline areas, all of which addressed common diseases, was there adequate information to estimate a cost per quality-adjusted-life-year, and it is unclear how helpful this approach would have been had it been possible. The implications of this method are discussed, guidance offered for economists new to guideline development and future areas of work identified.

Incorporating economic analysis in evidence-based guidelines for mental health: the profile approach

BACKGROUND: Many western health systems are currently developing the role of clinical guidelines to promote effective and efficient health care. However, introducing economic data into guideline methodology designed to assess the effectiveness of interventions raises some methodological issues. These include providing valid and generalizable cost estimates, the weight placed upon cost "evidence" and presenting cost-effectiveness information in a way that is helpful to clinicians. AIM OF THE STUDY: To explore a framework for including economic concepts in the development of a series of primary care guidelines, two of which address mental health conditions. METHODS: A profile approach, setting out best available evidence about the attributes of treatment choices (effectiveness, tolerability, safety, health service delivery, quality of life, resource use and cost), was used to help clinicians to derive treatment recommendations in a manner consistent with both the clinical decision-making process and social objectives. RESULTS: Clinicians involved in guideline development responded well to the process. Although there was often considerable debate about the meaning and importance of different aspects of evidence about treatment, in none of the guideline groups was there failure to agree treatment recommendations. DISCUSSION: The profile approach may be particularly useful in the field of mental health where disease processes may often feature very disparate effects, over long periods of time and impacting upon a broad circle of relatives, carers and agencies in addition to the patients themselves. CONCLUSION: A method has been applied in a series of primary care guidelines, which appears to enable clinicians to consider the issue of resource use alongside the various clinical attributes associated with treatment decisions. The basis of this work is the belief that guidance presenting physical measures describing effectiveness, adverse events, safety, compliance and quality of life, alongside resource consequences, is most likely to appropriately inform doctor-patient interactions. IMPLICATIONS FOR HEALTH CARE PROVISON AND USE: This research may provide a useful platform for other groups considering how to introduce cost-effectiveness concepts into guideline development groups. Whether guidelines change clinical behaviour remains a research question, and the subject of forthcoming trials. IMPLICATIONS FOR HEALTH POLICY FORMULATION: It is important that government agencies realize that guideline development is a health policy tool with prescribed methods to produce valid guidelines. Attempts to tamper with the methodology for cost-containment purposes or other political reasons are likely to discredit a useful mechanism for improving the scientific basis of health care provision. IMPLICATIONS FOR FURTHER RESEARCH: There are a number of limitations to completed work: for example it has a primary care focus and addresses fairly narrowly defined conditions. Work is ongoing to extend the scope to broader disease areas and to secondary care.