Role of the general practitioner in managing patients with myocardial infarction: impact of thrombolytic treatment. Report of a British Heart Foundation Working Group.

Thrombolytic treatment, combined with aspirin, has been shown to reduce mortality by half in patients in hospital with suspected acute myocardial infarction if it is given early after the onset of symptoms. This fact adds to the importance of prompt and skillful intervention. At present in the United Kingdom the median time for receiving suitable management for this condition is about four to six hours. With better organisation this delay could, in most areas, be reduced to two or three hours. A major change in the care of patients with myocardial infarction is needed in which the general practitioner should have a crucial role. Health authorities, hospital physicians, general practitioners, and the ambulance services must coordinate their efforts if the potential reduction in mortality is to be realised. The district medical officer should consult colleagues and draw up guidelines for organising the care of patients who have had heart attacks. The management of patients who have had heart attacks in the community and in hospital should be continually audited. There are dangers inherent in the use of thrombolytic treatment, particularly when conditions other than myocardial infarction are treated in error. This treatment should be given only when the diagnosis is highly probable and when close observation of the patient can be ensured during the ensuing hours. Thrombolytic treatment should not, therefore, be given out of hospital except when trained, equipped personnel are in attendance. Treatment can be given in any hospital (including community hospitals) provided there are adequate diagnostic facilities and suitably experienced nursing staff.     

Attitudes of general practitioners to prehospital thrombolysis.

OBJECTIVE--To investigate reasons for general practitioners not giving thrombolytic treatment to eligible patients with acute myocardial infarction. DESIGN--Postal questionnaires were sent to 424 general practitioners. SUBJECTS--97 general practitioners who had taken part in the Grampian region early anistreplase trial, 185 whose practices in Scotland were at least 24 km from a district general hospital, and 142 who had attended postgraduate conferences at which thrombolysis had been discussed; 87, 158, and 125 respectively responded. MAIN OUTCOME MEASURES--Answers to questions about readiness to use thrombolytic treatment. RESULTS--Response rate was 87% (370/424). Almost all respondents (350) were convinced of benefits of thrombolysis for acute myocardial infarction, and 277 were convinced that there were additional benefits from its administration in the community at first opportunity. Most doctors working 16 km or more from hospital thought that giving treatment at home would appreciably save time (200/274). Most doctors agreed that they could make time to give thrombolytic treatment (278), and would be willing to record an electrocardiogram (284), and would be able to interpret it (280). Sixty four respondents (17%) reported using thrombolytic treatment in previous year. Among non-users, 150 (49%) were unwilling to use thrombolytic treatment without further training. While many non-users (210 (69%)) were willing to use thrombolytic treatment without encouragement from Department of Health, 184 (60%) were unwilling to use it unless encouraged to do so by their local cardiologist. CONCLUSIONS--The need to become better informed about thrombolysis and lack of encouragement from local cardiologists were important factors preventing wider use of thrombolytic treatment in the community by general practitioners.     

Feasibility,safety, and efficacy of domiciliary thrombolysis by general practitioners: Grampian region early anistreplase trial. GREAT Group.

OBJECTIVE--To assess the feasibility, safety, and efficacy of domiciliary thrombolysis by general practitioners. DESIGN--Randomised double blind parallel group trial of anistreplase 30 units intravenously and placebo given either at home or in hospital. SETTING--29 rural practices in Grampian admitting patients to teaching hospitals in Aberdeen (average distance 36 (range 16-62) miles). PATIENTS--311 patients with suspected acute myocardial infarction and no contraindications to thrombolytic therapy seen at home within four hours of onset of symptoms. MAIN OUTCOME MEASURES--Time saving, adverse events, Q wave infarction, left ventricular function. RESULTS--Anistreplase was administered at home 101 minutes after onset of symptoms, while anistreplase was given in hospital 240 minutes after onset of symptoms (median times). Adverse events after thrombolysis were infrequent and, apart from cardiac arrest, not a serious problem when they occurred in the community: seven of 13 patients were resuscitated after cardiac arrest out of hospital. By three months after trial entry the relative reduction of deaths from all causes in patients given thrombolytic therapy at home was 49% (13/163 (8.0%) v 23/148 (15.5%); difference -7.6% (95% confidence interval -14.7% to -0.4%), p = 0.04). Full thickness Q wave infarction was less common in patients with confirmed infarction receiving treatment at home (65/122 (53.3%) v 76/112 (67.9%); difference -14.6% (95% confidence interval -27.0% to -2.2%), p = 0.02). CONCLUSIONS--General practitioners provided rapid pre-hospital coronary care of a high standard. Compared with later administration in hospital, giving anistreplase at home resulted in reduction in mortality, fewer cardiac arrests, fewer Q wave infarcts, and better left ventricular function. Benefits were most marked where thrombolytic therapy was administered within two hours of the onset of symptoms.     

General practitioners' management of acute myocardial infarction and cardiac arrest: relevance to thrombolytic treatment.

A questionnaire was sent to 61 general practitioners who had participated 18 months previously in a study of their experience of cardiopulmonary resuscitation and defibrillation in acute myocardial infarction. Fifty (82%) replies were received. Only 16 of the 50 respondents thought that every general practitioner should have a defibrillator, but 46 thought that every group practice should have one. Most practitioners felt the need for more tuition and practice in advanced life support, but 15 did not have the practice defibrillator with them when on call. Only nine doctors normally had an electrocardiograph with them when on call, most relying on clinical acumen to make an operational diagnosis; there appeared to be reluctance to use any drugs other than opiates and atropine in the management of acute myocardial infarction. This study highlights the difficulty of maintaining readiness to deal effectively with myocardial infarction in the community and the problems of relying on the electrocardiogram in deciding who should be given thrombolytic treatment.     

尿激酶静脉溶栓治疗急性心肌梗死的疗效观察--附35例报告

目的 观察尿激酶静脉溶栓治疗急性心肌梗死的疗效.方法将66例急性心肌梗塞住院患者随机分成两组,溶栓组35例在常规治疗的同时,用尿激酶静脉溶栓治疗,非溶栓组仅用常规治疗,两组进行比较分析.结果 溶栓组血管再通率74.3%,非溶栓组为25.81%,两组间有明显差异(P<0.05),住院4周的病死率,溶栓组为2.86%,非溶栓组为16.16%,两组间有显著差异(P<0.01).结论 尿激酶静脉溶栓能明显提高急性心肌梗死患者的血管再通率和抢救成功率,降低近期病死率.     

Guidelines for the use of intravenous thrombolytic agents in acute myocardial infarction. Ontario Medical Association Consensus Group on Thrombolytic Therapy.

A consensus group convened under the auspices of the Ontario Medical Association produced guidelines for the use of intravenous thrombolytic agents in acute myocardial infarction. The guidelines, updated to December 1988, include the following points. 1) Any hospital that routinely accepts the responsibility for looking after patients with acute myocardial infarction could offer thrombolytic therapy if monitoring facilities are available and if the staff are experienced in the treatment of cardiac rhythm disturbances. 2) Before treatment, all patients must be carefully screened for factors predisposing to hemorrhagic complications. 3) A physician should be clearly designated as responsible for the care of the patient receiving an infusion and be available in the event of problems. 4) For the two approved agents the usual dosages are as follows: streptokinase, 1.5 million units given over 1 hour; and tissue-type plasminogen activator (tPA), 100 mg over 3 hours, delivered as 60 mg in the first hour (of which 6 to 7 mg should be given as a bolus in the first 1 to 2 minutes) and then an infusion of 20 mg/h over the next 2 hours. 5) Intravenous thrombolytics should be considered for any patient with presumed acute myocardial infarction, as suggested by prolonged chest pain or other appropriate symptoms and typical electrocardiographic changes. Expeditious treatment is critical, since myocardial necrosis occurs within hours. 6) Emergency angiography is indicated for patients with hemodynamic compromise and no apparent response to streptokinase or tPA and in those with recurrent chest pain suggestive of acute myocardial infarction despite an apparent response to intravenous thrombolysis. Angiography before discharge is recommended for patients with postinfarction angina or evidence from noninvasive testing of significant residual ischemic risk. 7) There is insufficient evidence to choose between streptokinase and tPA on the basis of the two most important outcome measures: patient survival and myocardial preservation. More conclusive evidence comparing tPA, streptokinase and another promising agent, acylated plasminogen-streptokinase activator complex, will be available in 1989-90.     

Home care for patients with suspected myocardial infarction: use made by general practitioners of a hospital team for initial management.

Two hundred and sixty three general practitioners were offered the use of a hospital based service consisting of a medical senior house officer, a nurse attached to a coronary care unit, and a specially equipped ambulance estate car to help with the initial management of patients with suspected myocardial infarction who might be suitable for home care. One hundred and sixty nine general practitioners registered as potential users of this service; during 22 months they called the hospital team to see 271 patients, 235 of whom the team suspected had indeed suffered a myocardial infarction. During the same period, however, these general practitioners also admitted 317 patients with suspected myocardial infarction directly to hospital. Other general practitioners admitted 323 patients and deputising doctors 258. A further 529 patients with suspected infarction were admitted without the intervention of a general practitioner. Of the patients seen by the team, 54 required immediate admission to hospital; 17 of the remaining patients who initially appeared suitable for home care later required admission to hospital. In a large city such as Nottingham the provision of hospital based facilities to help general practitioners with home management is unlikely to make an appreciable impact on the overall pattern of care of patients with suspected myocardial infarction.     

e-Transmission of ECGs for expert consultation results in improved triage and treatment of patients with acute ischaemic chest pain by ambulance paramedics

Aims

In pre-hospital settings handled by paramedics, identification of patients with myocardial infarction (MI) remains challenging when automated electrocardiogram (ECG) interpretation is inconclusive. We aimed to identify those patients and to get them on the right track to primary percutaneous coronary intervention (PCI).

Methods and results

In the Rotterdam-Rijnmond region, automated ECG devices on all ambulances were supplemented with a modem, enabling transmission of ECGs for online expert interpretation. The diagnostic protocol for acute chest pain was modified and monitored for 1 year.Patients with an ECG that met the criteria for ST-elevation myocardial infarction (STEMI) were immediately transported to a PCI hospital. ECGs that did not meet the STEMI criteria, but showed total ST deviation ≥800?µv were transmitted for online interpretation by the ECG expert. Online supervision was offered as a service if ECGs showed conduction disorders, or had an otherwise ‘suspicious’ pattern according to the ambulance paramedics.We enrolled 1,076 patients with acute ischaemic chest pain who did not meet the automated STEMI criteria. Their mean age was 63 years; 64% were men. After online consultation, 735 (68%) patients were directly transported to a PCI hospital for further treatment. PCI within 90?min was performed in 115 patients.

Conclusion

During a 1-year evaluation of the modified pre-hospital triage protocol for patients with acute ischaemic chest pain, over 100 acute MI patients with an initially inconclusive ECG received primary PCI within 90?min. Because of these results, we decided to continue the operation of the modified protocol.

     

Quality improvement report: Safety and efficacy of nurse initiated thrombolysis in patients with acute myocardial infarction

ProblemDelay in starting thrombolytic treatment in patients arriving at hospital with chest pain who are diagnosed as having acute myocardial infarction.DesignAudit of “door to needle times” for patients presenting with chest pain and an electrocardiogram on admission that confirmed acute myocardial infarction. A one year period in each of three phases of development was studied.

Background and setting

The goal of the national service framework for coronary heart disease is that by April 2002, 75% of eligible patients should receive thrombolysis within 30 minutes of arriving at hospital. A district general hospital introduced a strategy to improve door to needle times. In phase 1 (1989-95), patients with suspected acute myocardial infarction, referred by general practitioners, were assessed in the coronary care unit; all other patients were seen first in the accident and emergency department. In phase 2 (1995-7), all patients with suspected acute myocardial infarction were transferred directly to a fast track area within the coronary care unit, where nurses assess patients and doctors started treatment.

Key measures for improvement

Median door to needle time in phase 1 of 45 minutes (range 5-300 minutes), with 38% of patients treated within 30 minutes. Median door to needle time in phase 2 of 40 minutes (range 5-180 minutes), with 47% treated within 30 minutes

Strategies for change

In phase 3 (1997-2001), all patients with suspected acute myocardial infarction were transferred directly to the fast track area and assessed by a “coronary care thrombolysis nurse.” If electrocardiography confirmed the diagnosis of acute myocardial infarction, the nurse could initiate thrombolytic therapy (subject to guidelines and exclusions determined by the consultant cardiologists).

Effects of change

Median door to needle time in phase 3 of 15 minutes (range 5-70 minutes), with 80% of patients treated within 30 minutes. Systematic clinical review showed no cases in which a nurse initiated inappropriate thrombolysis.

Lessons learnt

Thrombolysis started by nurses is safe and effective in patients with acute myocardial infarction. It may provide a way by which the national service framework''s targets for door to needle times can be achieved.     

Magnitude of benefit from earlier thrombolytic treatment in acute myocardial infarction: new evidence from Grampian region early anistreplase trial (GREAT)

OBJECTIVE--To generalise from the results of the Grampian region early anistreplase trial (GREAT) and to express the benefit of earlier thrombolysis in terms of lives saved per hour of earlier treatment. DESIGN--Multivariate analysis of a randomised double blind trial. SETTING--29 rural practices in Grampian region and teaching hospitals in Aberdeen. SUBJECTS--311 patients with suspected acute myocardial infarction and without contraindications to thrombolysis who were seen by their general practitioners within four hours of the start of symptoms. INTERVENTIONS--Anisterplase 30 units given intravenously, either by general practitioners before hospitalisation or later in hospital. MAIN OUTCOME MEASURE--Death within 30 months of entry into trial. RESULTS--Death within 30 months was positively related to age (P < 0.0001) and to delay between start of symptoms and thrombolytic treatment (P = 0.0004). However, the probability of dying rose exponentially with earlier presentation, so death within 30 months was negatively related to the logarithm of the time of randomisation (P = 0.0163). In patients presenting two hours after start of symptoms each hour''s delay in receiving thrombolysis led to the loss of 21 lives per 1000 within 30 days (95% confidence interval 1 to 94 lives per 1000) (P = 0.03) and 69 lives per 1000 within 30 months (16 to 141 lives per 1000) (P = 0.0004). CONCLUSIONS--The magnitude of the benefit from earlier thrombolysis is such that giving thrombolytic treatment to patients with acute myocardial infarction should be accorded the same degree of urgency as the treatment of cardiac arrest.     

Prospective evaluation of eligibility for thrombolytic therapy in acute myocardial infarction.

OBJECTIVES--To determine the proportion of patients presenting with acute myocardial infarction who are eligible for thrombolytic therapy. DESIGN--Cohort follow up study. SETTING--The four coronary care units in Auckland, New Zealand. SUBJECTS--All 3014 patients presenting to the units with suspected myocardial infarction in 1993. MAIN OUTCOME MEASURES--Eligibility for reperfusion with thrombolytic therapy (presentation within 12 hours of the onset of ischaemic chest pain with ST elevation > or = 2 mm in leads V1-V3, ST elevation > or = 1 mm in any other two contiguous leads, or new left bundle branch block); proportions of (a) patients eligible for reperfusion and (b) patients with contraindications to thrombolysis; death (including causes); definite myocardial infarction. RESULTS--948 patients had definite myocardial infarction, 124 probable myocardial infarction, and nine ST elevation but no infarction; 1274 patients had unstable angina and 659 chest pain of other causes. Of patients with definite or probable myocardial infarction, 576 (53.3%) were eligible for reperfusion, 39 had definite contraindications to thrombolysis (risk of bleeding). Hence 49.7% of patients (537/1081) were eligible for thrombolysis and 43.5% (470) received this treatment. Hospital mortality among patients eligible for reperfusion was 11.7% (55/470 cases) among those who received thrombolysis and 17.0% (18/106) among those who did not. CONCLUSIONS--On current criteria about half of patients admitted to coronary care units with definite or probable myocardial infarction are eligible for thrombolytic therapy. Few eligible patients have definite contraindications to thrombolytic therapy. Mortality for all community admissions for myocardial infarction remains high.     

Myocardial infarction: a comparison between home and hospital care for patients.

To compare the results of home and hospital treatment in men aged under 70 years who had suffered acute myocardial infarction within 48 hours 1895 patients were considered for study in four centres in south-west England. Four-hundred-and-fifty patients were randomly allocated to receive care either at home by their family doctor or in hospital, initially in an intensive care unit. The randomised treatment groups were similar in age, history of cardiovascular disease, and incidence of hypotension when first examined. They were followed up for up to a year after onset. The mortality rate at 28 days was 12% for the random home group and 14% for the random hospital group; the corresponding figures at 330 days were 20% and 27%. On average, older patients and those without initial hypotension fared rather better under home care. The patients who underwent randomisation were similar to those whose place of care was not randomised, except that the non-randomised group contained a higher proportion of initially hypotensive patients, whose prognosis was poor wherever treated. These results confirm and extend our preliminary findings. Home care is a proper form of treatment for many patients with acute myocardial infarction, particularly those over 60 years and those with an uncomplicated attack seen by general practitioners.     

Initiating thrombolytic therapy for acute myocardial infarction: whose job is it anyway?

Although thrombolytic therapy has clearly become the standard of care for acute myocardial infarction (AMI), its delivery in Canada continues to be extremely variable. Significant unnecessary delays in the initiation of this treatment still occur in many hospitals and constitute the most common avoidable cause of death in patients with AMI. The authors agree with the statement by representatives of the member organizations of the Emergency Cardiac Care Coalition (see pages 483 to 487 of this issue) that emergency service providers must get patients to hospital sooner and that all eligible patients should receive thrombolytic therapy within 30 minutes of their arrival at hospital. This objective requires that thrombolytic therapy be initiated by emergency physicians and be supported by well-established guidelines for its use.     

Early treatment of myocardial infarction in the community.

The prehospital management of acute myocardial infarction by general practitioners and emergency-treatment service physicians was analysed in 53 patients. The correct clinical diagnosis was made or suggested before admission in 47 patients. Only 25 patients received analgesics from the general practitioner, and 32 were still in pain and needed diamorphine on admission to hospital. Only one patient received antiarrythmic treatment. The findings suggest that, despite accurate clinical diagnosis of acute myocardial infarction, deficiencies exist in the prehospital phase of management and that education programmes are worth consideration.     

Inpatient deaths from acute myocardial infarction, 1982-92: analysis of data in the Nottingham heart attack register.

OBJECTIVE: To assess longitudinal trends in admissions, management, and inpatient mortality from acute myocardial infarction over 10 years. DESIGN: Retrospective analysis based on the Nottingham heart attack register. SETTING: Two district general hospitals serving a defined urban and rural population. SUBJECTS: All patients admitted with a confirmed acute myocardial infarction during 1982-4 and 1989-92 (excluding 1991, when data were not collected). MAIN OUTCOME MEASURES: Numbers of patients, background characteristics, time from onset of symptoms to admission, ward of admission, treatment, and inpatient mortality. RESULTS: Admissions with acute myocardial infarction increased from 719 cases in 1982 to 960 in 1992. The mean age increased from 62.1 years to 66.6 years (P < 0.001), the duration of stay fell from 8.7 days to 7.2 days (P < 0.001), and the proportion of patients aged 75 years and over admitted to a coronary care unit increased significantly from 29.1% to 61.2%. A higher proportion of patients were admitted to hospital within 6 hours of onset of their symptoms in 1989-92 than in 1982-4, but 15% were still admitted after the time window for thrombolysis. Use of beta blockers increased threefold between 1982 and 1992, aspirin was used in over 70% of patients after 1989, and thrombolytic use increased 1.3-fold between 1989 and 1992. Age and sex adjusted odds ratios for inpatient mortality remained unchanged over the study period. CONCLUSIONS: Despite an increasing uptake of the "proved" treatments, inpatient mortality from myocardial infarction did not change between 1982 and 1992.     

2017 ESC guidelines for the management of acute myocardial infarction in patients presenting with ST-segment elevation: comments from the Dutch ACS working group

On behalf of the Dutch ACS working group, we discuss the most important changes in recommendations in the 2017 ESC guidelines for the management of acute myocardial infarction in patients presenting with ST-segment elevation relevant for both the general and interventional cardiologist.     

Effect of "fast track" admission for acute myocardial infarction on delay to thrombolysis.

OBJECTIVE--To evaluate the impact of a fast track triage system for patients with acute myocardial infarction. DESIGN--Comparison of delays in admission to hospital and in receiving thrombolytic treatment before and after introducing fast track system with delays recorded in 1987-8. Patients fulfilling clinical and electrocardiographic criteria for myocardial infarction were selected for rapid access to the cardiac care team, bypassing evaluation by the medical registrar. SETTING--Major accident and emergency, cardiac and trauma centre. SUBJECTS--359 patients admitted to the cardiac care unit during 1 February to 31 July 1990 with suspected acute infarction. MAIN OUTCOME MEASURES--Accuracy of diagnosis and delay from arrival at hospital to thrombolytic treatment. RESULTS--248 of the 359 patients had myocardial infarction confirmed, of whom 127 received thrombolytic treatment. The fast track system correctly identified 79 out of 127 (62%) patients who subsequently required thrombolytic treatment. 95% (79/83) of patients treated with thrombolysis after fast track admission had the diagnosis confirmed by electrocardiography and enzyme analysis. The median delay from hospital admission to thrombolytic treatment fell from 93 minutes in 1987-8 to 49 minutes in fast track patients (p less than 0.001). Delay in admission to the cardiac care unit was reduced by 47% for fast tract patients (median 60 minutes in 1987-8 v 32 minutes in 1990, p less than 0.001) and by 25% for all patients (60 minutes v 45 minutes, p less than 0.001). CONCLUSION--This fast track system requires no additional staff or equipment, and it halves inhospital delay to thrombolytic treatment without affecting the accuracy of diagnosis among patients requiring thrombolysis.     

静脉溶栓时机对急性ST段抬高型心肌梗死患者溶栓效果及主要不良心脏事件发生率的影响

目的:探讨静脉溶栓时机对急性ST段抬高型心肌梗死患者溶栓效果及主要不良心脏事件发生率的影响。方法:将2016年1月至2017年12月我院接诊的314例急性ST段抬高型心肌梗死患者纳入本研究,按照溶栓治疗时间不同分为A组(发病至溶栓时间6 h)172例、B组(发病至溶栓时间为6～12 h)102例和C组(发病至溶栓时间12 h)40例,比较三组患者溶栓效果、溶栓后ST段回落情况以及住院期间主要不良心脏事件发生情况。结果:A组患者梗死冠脉溶通率、溶栓后ST段回落幅度高于B组和C组,且B组高于C组,差异均有统计学意义(P0.05)。A组患者治疗后ST段回落最大幅度所需时间、住院期间主要不良心脏事件总发生率低于B组和C组,且B组低于C组,差异均有统计学意义(P0.05)。结论:急性ST段抬高型心肌梗死患者发病后6 h内静脉溶栓治疗梗死冠脉溶通率更高、ST段回落效果更好,可降低住院期间主要不良心脏事件发生风险。     

D- 二聚体在急性心肌梗死诊断中的应用研究

目的:探讨D-二聚体在急性心肌梗死诊断中的应用价值,为提高急性心肌梗死的诊断准确性提供有益的参考.方法:以我院2010年1月至2011年1月收治的急性心肌梗死患者34例为实验组,以我院同期健康体检的34例为对照组,对两组的基础水平以及实验组溶栓治疗各时间点的D-二聚体水平进行检测分析.结果:在基础状态下实验组的D-二聚体为(1.59±0.31)mg/L,显著高于对照组(P＜0.05).实验组患者在溶栓治疗6h后的D-二聚体水平为(3.48± 1.40)mg/L,显著高于溶栓治疗前(P＜0.05).其余各时间点的测量值差异无统计学意义(P＞0.05).结论:D-二聚体检测有利于急性心肌梗死患者的诊断,对临床治疗和预后有较好的指导意义,是较好的心肌梗死诊断分子标志物.在发现D-二聚体水平异常时,应结合临床症状、心电图、胸部X光片的结果进行综合判断,确保诊断的可靠性.