Keywords
INTRODUCTION
In recent years our knowledge of the epidemiology of acute myocardial infarction (AMI) in Spain has increased considerably. Population-based registries like MONICA and REGICOR have made it possible to know the incidence and rate of AMI in Spain,1,2 whereas hospital registries like PRIAMHO and RISCI provide information about the treatment and results obtained in patients with AMI after admission to coronary units.3,4 However, information is lacking on the treatment of AMI in hospital emergency services (HES), and the resources used at that stage, although almost all patients with AMI are admitted to hospitals from emergency areas.
This article reports data on the treatment and evolution in emergency services of patients whose diagnosis at the end of the emergency room stay was AMI. Data were collected prospectively at a total of 35 Spanish hospitals over a 3-week period.
MATERIAL AND METHODS
In 1998-1999, the EVICURE study was carried out (Evaluation of the Treatment of Cardiac Ischemia in Spanish Hospital Emergency Services [Evaluación del tratamiento de la Isquemia Cardíaca en los Servicios de Urgencias Hospitalarios Españoles]), a project of the Ischemic Heart Disease group of the Spanish Society of Urgent and Emergency Medicine, whose methodology and results have been published.5 Briefly, it is a prospective, multicenter, observational study. In this study, 35 hospitals of 15 autonomic communities participated, which covered a total population of 11 124 000 inhabitants, who had a total of 2 946 337 emergencies attended each year. Fifteen hospitals attended 30 000 to 70 000 emergencies/year, 9 hospitals attended 70 000 to 100 000 emergencies, and 11 hospitals, 100 000 to 200 000 emergencies. The study included all patients who concluded their stay in the emergency area of the hospital with a diagnosis of ischemic heart disease (IHD). These patients were classified according to the diagnosis at discharge from the HES as a) AMI; b) cardiac sudden death; c) unstable angina, and d) patients seen for symptoms related to ischemic heart disease, but not classifiable as acute coronary syndrome (ACS).
Data were collected over a 3-week period (7 to 13 December 1998, 18 to 24 January 1999, and 1 to 7 March 1999). During these periods, all patients who met the entrance criteria were included in the study.
The diagnosis of AMI, made when the patient left the HES, was based on the presence of at least two of the three criteria formulated by the World Health Organization (WHO): clinical, enzymatic, and electrocardiographic.4
RESULTS
Of 2216 patients with a diagnosis of IHD included in the study (1.3% of visits to the HES), the final diagnosis was AMI in 600 patients (27.1%), unstable angina (UA) in 1067 (48.1%), and sudden cardiac arrest in 28 (1.3%). In the remaining 512 patients, the symptoms could not be classified as acute coronary syndrome. Patients with AMI had a mean age of 66.9±12.7 years, 70.3% were men, and only 28.3% had a history of ischemic heart disease.
While patients were in the emergency services, the drugs most often given were acetylsalicylic acid (ASA) (59.8%), nitrates (57.8%), and i.v. heparin (24.3%). Fibrinolytics were administered to 11.5% of patients in the HES (Table 1).
The destination of patients with AMI is described in Table 2. It should be noted that 15 patients (2.5%) died in the HES and 80 patients (13.3%) were hospitalized in general wards. Patients with AMI usually remained in the HES for a long time, as shown by the data in Table 2, in which patients are distributed by their destination.
DISCUSSION
The present study analyzes the treatment of patients with AMI from a vantage point that has not often been explored. It contributes information usually overlooked in studies of AMI, whether population or hospital studies. Nevertheless, some results are of evident epidemiological and clinical interest. Thus, the lethality of AMI in HES has not been published in the literature, to our knowledge, and perhaps should be added to the results of hospital mortality.
Analysis of the treatments given in the HES also yields noteworthy data. In view of national and international recommendations,6,7 the use of ASA in the HES should be close to 100%. However, only 77% of patients received ASA. Therefore, the use of ASA in HES is low.8 The same occurred with fibrinolysis, which was only administered to 15.5% of patients with AMI before hospitalization. Although prehospital fibrinolysis has its detractors, fibrinolysis administered in HES is a safe procedure that saves time, as Torrado et al9 have demonstrated.
In this study, 13.5% of patients with AMI were not admitted to the coronary unit, compared with 10.9% in the IBERICA study10 made in 1997 in 8 Spanish autonomic communities. Both figures contradict the classic recommendation that patients with AMI should always be admitted to coronary units, and only exceptionally to other wards.6 Admission to general wards may be determined by the characteristics of the patient, infarction, hospital, the availability of beds in the area, or delay in reaching the emergency service or in obtaining the diagnosis.
The stay in the HES of patients with AMI is prolonged, lasting a mean time of 111 min for the overall group (Table 2). Although no relevant data like the door-to-ECG and door-to-injection times are available, these times are assumed to be prolonged and longer than necessary.6,7
Study limitations
The EVICURE Study was designed from the vantage point of emergency services, which determines some of the limitations of this study. The study does not include the follow-up of patients while hospitalized. Therefore, it is possible that some patients with AMI may not have been detected in the HES. The opposite phenomenon cannot be excluded either, and the diagnosis of AMI may sometimes have not been confirmed later. On the other hand, if the new definition of AMI,11 which was published after this study concluded, had been applied, the number of patients with AMI would have been different. In addition, not having information on the state of patients at discharge deprives us of information that could have been of interest.
The fact that the behavior of the ST segment at admission was not recorded makes it impossible to establish what proportion of patients had an indication for immediate revascularization treatment. Therefore, the proportion of patients that received fibrinolysis can only be assessed indirectly. However, in the registries in which similar admission criteria were used, such as PRIAMHO,3 the proportion of patients who received fibrinolytic treatment exceeded 40%.
CONCLUSIONS
Ischemic heart disease is responsible for about 1.3% of visits to HES in Spain. Of them, approximately one-fourth are for AMI. Once patients reach the HES, 2.5% of those who have AMI die. The stay of patients with AMI in the HES is prolonged but, nonetheless, ASA and, probably, fibrinolytics, are given infrequently. Therefore, there is clearly room for improving the quality of care given to our patients.
Correspondence: Dr. A. Loma-Osorio Montes.
Área de Cardiología y Críticos. Hospital Txagorritxu.
Jose Atxotegui, s/n. 01009 Vitoria-Gasteiz. España.
E-mail: aloma@scisquemica.net