Risk stratification after acute myocardial infarction by Doppler stroke distance measurement.

OBJECTIVE: To establish the value of Doppler stroke distance measurement as a predictor of mortality risk following acute myocardial infarction. DESIGN: Follow up study. SETTING: Coronary care unit of a teaching and district general hospital. SUBJECTS: 378 patients (mean age 61 years) with acute myocardial infarction followed up for a mean of five years (range 2-7 years); 299 (79%) patients received thrombolysis. MAIN OUTCOME MEASURES: Stroke distance (the systolic velocity integral of blood flow in the aortic arch (percentage of age predicted normal value)); presence or absence of left ventricular failure on the admission chest radiograph; the codified admission ECG; death during follow up. RESULTS: Mean (SD) stroke distance was 81 (19)% and five year survival 76%. For patients with stroke distance > 100% (n = 60), 82-100% (n = 134), 63-81% (n = 122), and < 63% (n = 62), the one month mortality rates were 0%, 1.5%, 4%, and 18%, respectively; the corresponding estimates for mortality at five years were 17%, 19%, 24%, and 43%. Survival was independently related to age (p < 0.0001), stroke distance (p < 0.0001), and chest radiograph appearance (p = 0.002), but not to ECG codes (p = 0.31) or receipt of thrombolysis (p = 0.60). The areas under receiver operator characteristic plots for stroke distance measurements were 82%, 76%, 71%, and 65% for deaths within one month, six months, one year, and two years, respectively. CONCLUSIONS: The bedside measurement of stroke distance stratifies mortality risk after acute myocardial infarction. The predictive ability of this simple measure of left ventricular systolic function compares well with published accounts of the more complex measurement of ejection fraction.

Latitude-related changes in the amplitude of annual mortality rhythm. The biological equator in man.

There is extensive literature describing the effect of season on mortality rates, especially in cardiovascular and respiratory disease. This study compares latitude with the extent of seasonal variation of monthly deaths from all causes. In developed countries, there is a peak of deaths in winter and a trough in summer. Monthly numbers of deaths were established in 89 countries in the Northern and Southern Hemisphere. Using cosinor analysis, the extent of seasonal variation (amplitude) was established and correlated with latitude. The amplitude of seasonality was greatest in mid-latitude around 35 degrees, but low or absent near the equator and subpolar regions. The amplitude can differ at the same latitude. The weather in equatorial regions and in habitations near the Arctic Circle is very different, but death has a similar seasonal rhythm. The purpose is to record this epidemiological finding even though no simple explanation is provided. Weather alone cannot explain it, and it is possible that day length (photoperiod) has an important, but complex, underlying role.

Thrombolysis in peripheral general practices in Scotland: another rule of halves.

OBJECTIVE: To facilitate the adoption of thrombolysis by general practitioners in peripheral practices in Scotland. DESIGN: Survey of practice policies on the management of acute myocardial infarction before and after practice visits by a consultant physician acting as a facilitator; survey of hospital consultants' attitudes to thrombolysis by general practitioners. SETTING: One hundred and eighty-two practices, with an enlisted total of 550,000 patients, located at least 30 minutes from a district general hospital; 23 such hospitals serving these peripheral practices. MAIN OUTCOME MEASURES: Possession of electrocardiograph and defibrillator; adoption of a policy of giving thrombolytic therapy. RESULTS: The majority of practices possessed an electrocardiograph (87%) and a defibrillator (76%). At the time of the visits, 67 practices (37%) already had a policy of giving thrombolytic therapy. When contacted one year later 91 practices (50%) had such a policy. In the interval between visits and follow-up, few had received any encouragement from any source to use this treatment. Hospital consultants' attitudes to thrombolysis by general practitioners were generally negative, and support from local and national health authorities has been inadequate. CONCLUSIONS: Provision of timely thrombolytic therapy for the one tenth of the Scottish population living at least 30 minutes from a district general hospital is a major public health problem for which there is a ready solution: pre-hospital thrombolysis administered by general practitioners has been shown to be feasible, fast, safe, efficacious and cost-effective. To translate this evidence into practice requires a concerted effort from all the professionals involved, and must be directed and supported by local and national management of the National Health Service in Scotland.

Non-invasive assessment of cardiac output in children.

BACKGROUND: Stroke distance, the systolic velocity integral of aortic blood flow, is a linear analogue of stroke volume; its product with heart rate is minute distance, analogous to cardiac output. OBJECTIVE: To investigate the feasibility of assessing cardiac output in children with a simple non-invasive Doppler ultrasound technique, and to determine the normal range of values. METHODS: Peak aortic blood velocity, stroke distance, and minute distance were measured through the suprasternal window in 166 children (mean age 9.6 years, range 2-14) using a portable non-imaging Doppler ultrasound instrument. RESULTS: The technique was well tolerated by all the children participating. Mean peak aortic blood velocity was 138 cm/s and was independent of age. Mean stroke distance was 31.8 cm and showed a small but significant increase with age; mean minute distance was 2490 cm and fell with age, as did heart rate. CONCLUSIONS: Suprasternal Doppler ultrasound measurement of stroke distance is a convenient, well tolerated, non-invasive technique for the assessment of cardiac output in children. The normal range of values during childhood has been established. The technique has great potential for assessing hypovolaemia in children.

Call to needle times after acute myocardial infarction in urban and rural areas in northeast Scotland: prospective observational study.

OBJECTIVE: To determine call to needle times and consider how best to provide timely thrombolytic treatment for patients with acute myocardial infarction. DESIGN: Prospective observational study. SETTING: City, suburban, and country practices referring patients to a single district general hospital in northeast Scotland. SUBJECTS: 1046 patients with suspected acute myocardial infarction given thrombolytic treatment. MAIN OUTCOME MEASURES: Time from patients' calls for medical help until receipt of opiate or thrombolytic treatment, measured against a call to needle time of 90 minutes or less, as proposed by the British Heart Foundation. RESULTS: General practitioners were the first medical contact in 97% (528/544) of calls by country patients and 68% (340/502) of city and suburban patients. When opiate was given by general practitioners, median call to opiate time was about 30 minutes (95% within 90 minutes) in city, suburbs, and country; call to opiate delay was about 60 minutes in city and suburban patients calling "999" for an ambulance. One third of country patients received thrombolytic treatment from their general practitioners with a median call to thrombolysis time of 45 minutes (93% within 90 minutes); this compares with 150 minutes (5% within 90 minutes) when this treatment was deferred until after hospital admission. In the city and suburbs, no thrombolytic treatment was given outside hospital, and only a minority of patients received it within 90 minutes of calling; median call to thrombolysis time was 95 (46% within 90 minutes) minutes. CONCLUSIONS: The first medical contact after acute myocardial infarction is most commonly with a general practitioner. This contact provides the optimum opportunity to give thrombolytic treatment within the British Heart Foundation's guideline.

Secondary prevention in coronary heart disease: baseline survey of provision in general practice.

OBJECTIVE: To determine secondary preventive treatment and habits among patients with coronary heart disease in general practice. DESIGN: Process of care data on a random sample of patients were collected from medical records. Health and lifestyle data were collected by postal questionnaire (response rate 71%). SETTING: Stratified, random sample of general practices in Grampian. SUBJECTS: 1921 patients aged under 80 years with coronary heart disease identified from pre-existing registers of coronary heart disease and nitrate prescriptions. MAIN OUTCOME MEASURES: Treatment with aspirin, beta blockers, and angiotensin converting enzyme inhibitors. Management of lipid concentrations and hypertension according to local guidelines. Dietary habits (dietary instrument for nutritional evaluation score), physical activity (health practice indices), smoking, and body mass index. RESULTS: 825/1319 (63%) patients took aspirin. Of 414 patients with recent myocardial infarction, 131 (32%) took beta blockers, and of 257 with heart failure, 102 (40%) took angiotensin converting enzyme inhibitors. Blood pressure was managed according to current guidelines for 1566 (82%) patients but lipid concentrations for only 133 (17%). 673 of 1327 patients (51%) took little or no exercise, 245 of 1333 (18%) were current smokers, 808 of 1264 (64%) were overweight, and 627 of 1213 (52%) ate more fat than recommended. CONCLUSION: In terms of secondary prevention, half of patients had at least two aspects of their medical management that were suboptimal and nearly two thirds had at least two aspects of their health behaviour that would benefit from change. There seems to be considerable potential to increase secondary prevention of coronary heart disease in general practice.

Secondary prevention clinics for coronary heart disease: randomised trial of effect on health.

OBJECTIVE: To evaluate the effects of secondary prevention clinics run by nurses in general practice on the health of patients with coronary heart disease. DESIGN: Randomised controlled trial of clinics over one year with assessment by self completed postal questionnaires and audit of medical records at the start and end of the trial. SETTING: Random sample of 19 general practices in northeast Scotland. SUBJECTS: 1173 patients (685 men and 488 women) under 80 years with working diagnoses of coronary heart disease who did not have terminal illness or dementia and were not housebound. INTERVENTION: Clinic staff promoted medical and lifestyle aspects of secondary prevention and offered regular follow up. MAIN OUTCOME MEASURES: Health status measured by the SF-36 questionnaire, chest pain by the angina type specification, and anxiety and depression by the hospital anxiety and depression scale. Use of health services before and during the study. RESULTS: There were significant improvements in six of eight health status domains (all functioning scales, pain, and general health) among patients attending the clinic. Role limitations attributed to physical problems improved most (adjusted difference 8.52, 95% confidence interval 4.16 to 12. 9). Fewer patients reported worsening chest pain (odds ratio 0.59, 95% confidence interval 0.37 to 0.94). There were no significant effects on anxiety or depression. Fewer intervention group patients required hospital admissions (0.64, 0.48 to 0.86), but general practitioner consultation rates did not alter. CONCLUSIONS: Within their first year secondary prevention clinics improved patients' health and reduced hospital admissions.

Secondary prevention in coronary heart disease: a randomised trial of nurse led clinics in primary care.

OBJECTIVE: To evaluate whether nurse run clinics in general practice improve secondary prevention in patients with coronary heart disease. DESIGN: Randomised controlled trial. SETTING: A random sample of 19 general practices in northeast Scotland. PATIENTS: 1173 patients (685 men and 488 women) under 80 years with working diagnoses of coronary heart disease, but without terminal illness or dementia and not housebound. INTERVENTION: Nurse run clinics promoted medical and lifestyle aspects of secondary prevention and offered regular follow up. MAIN OUTCOME MEASURES: Components of secondary prevention assessed at baseline and one year were: aspirin use; blood pressure management; lipid management; physical activity; dietary fat; and smoking status. A cumulative score was generated by counting the number of appropriate components of secondary prevention for each patient. RESULTS: There were significant improvements in aspirin management (odds ratio 3.22, 95% confidence interval 2.15 to 4.80), blood pressure management (5.32, 3.01 to 9.41), lipid management (3.19, 2.39 to 4.26), physical activity (1.67, 1.23 to 2.26) and diet (1.47, 1.10 to 1.96). There was no effect on smoking cessation (0.78, 0.47 to 1.28). Of six possible components of secondary prevention, the baseline mean was 3.27. The adjusted mean improvement attributable to intervention was 0.55 of a component (0.44 to 0.67). Improvement was found regardless of practice baseline performance. CONCLUSIONS: Nurse run clinics proved practical to implement in general practice and effectively increased secondary prevention in coronary heart disease. Most patients gained at least one effective component of secondary prevention and, for them, future cardiovascular events and mortality could be reduced by up to a third.

Audit of prehospital thrombolysis by general practitioners in peripheral practices in Grampian.

BACKGROUND: In the Grampian region early anistreplase trial (GREAT), domiciliary thrombolysis by general practitioners was associated with a halving of one year mortality compared with hospital administration. However, after completion of the trial and publication of the results, the use of this treatment by general practitioners declined sharply. OBJECTIVE: To increase the proportion of eligible patients receiving timely thrombolytic treatment from their general practitioners. SETTING: Practices in Grampian located > or = 30 minutes' travelling time from Aberdeen Royal Infirmary, where patients with suspected acute myocardial infarction were referred after being seen by general practitioners. AUDIT STANDARD: A call-to-needle time of 90 minutes, as proposed by the British Heart Foundation (BHF). METHODS: Findings of this audit of pre-hospital management of acute myocardial infarction were periodically fed back to the participating doctors, when practice case reviews were also conducted. RESULTS: Of 414 administrations of thrombolytic treatment, 146 (35%) were given by general practitioners and 268 (65%) were deferred until after hospital admission. Median call-to-needle times were 45 (94% < or = 90) and 145 (7% < or = 90) minutes, respectively. Survival at one year was improved with prehospital compared with hospital thrombolysis (83% v 73%; p < 0.05). The proportion of patients receiving thrombolytic treatment from their general practitioners did not increase during the audit. CONCLUSIONS: In practices > or = 30 minutes from hospital, the BHF audit standard was readily achieved if general practitioners gave thrombolytic treatment, but not otherwise. Knowledge of the benefits of early thrombolysis, and feedback of audit results, did not lead to increased prehospital thrombolytic use. Additional incentives are required if general practitioners are to give thrombolytic treatment.

Quantification of the benefit of earlier thrombolytic therapy: five-year results of the Grampian Region Early Anistreplase Trial (GREAT).

OBJECTIVES: This report presents the 5-year results of the Grampian Region Early Anistreplase Trial (GREAT) and quantifies the benefit of earlier thrombolysis in terms that are generally applicable. BACKGROUND: Although it is accepted that the earlier thrombolytic therapy is given for acute myocardial infarction the greater the benefit, there are widely differing estimates of the magnitude of the time-related benefit of thrombolysis because of inappropriate trial design and analysis. METHODS: In a previously reported randomized trial, anistreplase (30 U) was given intravenously either before hospital admission or in the hospital, at a median time of 105 and 240 min, respectively, after onset of symptoms. Intention to treat and multivariate analyses of the 5-year results were performed. RESULTS: By 5 years, 41 (25%) of 163 patients had died in the prehospital treatment group compared with 53 (36%) of 148 in the hospital treatment group (log-rank test, p < 0.025). Delaying thrombolytic treatment by 1 h increases the hazard ratio of death by 20%, equivalent to the loss of 43/1,000 lives within the next 5 years (95% confidence interval 7 to 88, p = 0.012). Delaying thrombolytic treatment by 30 min reduces the average expectation of life by approximately 1 year. CONCLUSIONS: The magnitude of the benefit from earlier thrombolysis is such that giving thrombolytic therapy to patients with acute myocardial infarction should be accorded the same degree of urgency as treatment of cardiac arrest. Policies should be developed for giving thrombolytic therapy on-site if practicable and by the first qualified person to see the patient.

An economic evaluation of thrombolysis in a remote rural community.

OBJECTIVES: To assess the cost effectiveness of community thrombolysis relative to hospital thrombolysis by investigating the extra costs and benefits of a policy of community thrombolysis, then establishing the extra cost per life saved by community thrombolysis. DESIGN: Economic evaluation based on the results of the Grampian region early anistreplase trial. SETTING: 29 rural general practices and one secondary care provider in Grampian, Scotland. SUBJECTS: 311 patients recruited to the Grampian region early anistreplase trial. INTERVENTIONS: Intravenous anistreplase given either by general practitioners or secondary care clinicians. MAIN OUTCOME MEASURES: Survival at 4 years and costs of administration of thrombolysis. RESULTS: Relative to hospital thrombolysis, community thrombolysis gives an additional probability of survival at 4 years of 11% (95% confidence interval 1% to 22%) at an additional cost of 425 pounds per patient. This gives a marginal cost of life saved at 4 years of 3,890 pounds (1,990 pounds to 42,820 pounds). CONCLUSIONS: The cost per life saved by community thrombolysis is modest compared with, for example, the cost of changing the thrombolytic drug used in hospital from streptokinase to alteplase.

Myocardial salvage with early anistreplase treatment.

This randomized, double-blind trial in 311 patients with acute myocardial infarction has shown that very early therapy with anistreplase outside the hospital is not only feasible, but provides a major survival advantage. The difference in the median delay to treatment between the group treated in the hospital and those treated earlier was 2 1/4 h. After 30 months, mortality in the early group was less than half that in the later group, so that every hour of delay beyond 2 h resulted in almost 7 additional deaths per 100 patients treated. This is a greater percentage loss of life than would have resulted from a similar delay in the provision of resuscitation for the prehospital cardiac arrest. Multivariate analysis showed that age, treatment delay, and time of presentation were significant risk factors, with patients presenting at 1 h having more than twice the mortality of those presenting at 4 h; the sicker the patient, the earlier the presentation. By 5 years, prehospital administration of anistreplase, by saving 2 h, resulted in an additional 57% of a year's survival per patient. This compares favorably with the projected 14% of a year survival per patient reported with TPA versus streptokinase in GUSTO. Prehospital therapy with anistreplase was highly cost effective when compared with streptokinase given in hospital, and the marginal cost-effectiveness ratio was much lower than that for TPA versus streptokinase derived from GUSTO.

Cardiac rehabilitation in Scotland: is current provision satisfactory?

BACKGROUND: Cardiac rehabilitation is an effective intervention, lowering mortality following myocardial infarction and reducing morbidity in patients with coronary heart disease. However, its level of provision was unclear. This study aimed to provide a comprehensive description in Scotland. METHODS: A national survey of hospital, general practice and community sources was conducted in 1994 to identify cardiac rehabilitation programmes in Scotland. Detailed information about each programme was collected by computer-assisted telephone interviews. RESULTS: Sixty-nine programmes were identified, providing out-patient cardiac rehabilitation to 4980 patients and in-patient cardiac rehabilitation to 8920 patients. This represented 17 per cent and 30 per cent of patients admitted to hospital with coronary heart disease (excluding heart failure), respectively. There was considerable geographical variation in provision and dependence on sources outside the health service for much funding. CONCLUSIONS: Despite evidence of benefits from randomized trials, the overall provision of cardiac rehabilitation in Scotland was low. Considerable inequity was demonstrated between different health board areas. There is opportunity for better provision, which would improve care for many patients with coronary heart disease.

Outpatient cardiac rehabilitation: are the potential benefits being realised?

OBJECTIVE: to give a comprehensive description of the practice of outpatient cardiac rehabilitation in Scotland. DESIGN: an identifying survey of 1,270 individuals in hospital, general practice and community sources nationally, followed by computer-assisted telephone interviews about programme characteristics with key personnel from identified cardiac rehabilitation schemes. OUTCOME MEASURES: patient provision, referral criteria and programme features. RESULTS: 65 programmes provided outpatient cardiac rehabilitation for 4,980 patients in one year, representing 17% of the 29,180 patients who survived admission to hospital with coronary heart disease. Cardiac rehabilitation practice varied widely: 53 (82%) programmes included exercise, although only 19 (29%) at the most beneficial level; 40 (62%) included relaxation training, although only three (5%) at a level shown to give benefit; 47 (72%) included education, although only 16 (25%) in a manner with reported benefits in randomised trials. CONCLUSIONS: outpatient cardiac rehabilitation was provided to a minority of patients with coronary heart disease. Programmes varied widely, and were often more limited than those reporting mortality and morbidity benefits in randomised trials. There is a substantial gap between current provision and practice of cardiac rehabilitation and that advocated in published guidelines.

An investigation of the changes in aortic diameter and an evaluation of their effect on Doppler measurement of cardiac output in pregnancy.

Measurement of cardiac output by means of Doppler ultrasound is based on the velocity of aortic blood flow and therefore requires that aortic diameter should not change between measurements. Work has been published which suggests that, in pregnancy, aortic diameter varies significantly with systemic blood pressure. The implication of this is that aortic diameter must be remeasured for each determination of cardiac output in pregnant patients. This study investigated the changes in aortic diameter with blood pressure in patients having spinal anaesthesia for caesarean section. Aortic diameter did appear to vary with blood pressure but this variation was within the error of the measurement and did not significantly affect the accuracy of the technique.