RESUMEN
OBJECTIVES: To determine whether case fatality rates in South Asian (Bangladeshi, Indian and Pakistani) patients with acute myocardial infarction have shown similar declines to those reported for white patients during the past 15 years. DESIGN: Cross-sectional, observational study. SETTING: Coronary care unit in east London. PATIENTS: 2640 patients-29% South Asian-admitted with acute myocardial infarction between January 1988 and December 2002. MAIN OUTCOME MEASURES: Differences over time in rates of in-hospital death, ventricular fibrillation and left ventricular failure. RESULTS: The proportion of South Asians increased from 22% in 1988-92 to 37% in 1998-2002. Indices of infarct severity were similar in South Asian and white patients, with declining frequencies of ST elevation infarction (88.2% to 77.5%, p < 0.0001), Q wave development (78.1% to 56.9%, p < 0.0001) and mean (interquartile range) peak serum creatine kinase concentrations (1250 (567-2078) to 1007 (538-1758) IU/l, p < 0.0001) between 1988-92 and 1998-2002. Rates of in-hospital death (13.0% to 9.4%, p < 0.01), ventricular fibrillation (9.2% to 6.0%, p < 0.001) and left ventricular failure (33.2% to 26.5%, p < 0.0001) all declined; these changes did not interact significantly with ethnicity. Odds ratios for the effect of time on risk of death increased from 0.81 (95% CI 0.70 to 0.93) to 1.02 (95% CI 0.87 to 1.21) after adjustment for ethnicity and indices of infarct severity (ST elevation, peak creatine kinase, Q wave development and treatment with a thrombolytic). CONCLUSIONS: In the past 15 years, death from acute myocardial infarction among South Asians has declined at a rate similar to that seen in white patients. This is largely caused by reductions in indices of infarct severity.
Asunto(s)
Pueblo Asiatico/estadística & datos numéricos , Infarto del Miocardio/mortalidad , Población Blanca/estadística & datos numéricos , Estudios Transversales , Femenino , Mortalidad Hospitalaria , Humanos , Londres/epidemiología , Masculino , Persona de Mediana Edad , Infarto del Miocardio/etnología , Pronóstico , Fibrilación Ventricular/etnología , Fibrilación Ventricular/mortalidadRESUMEN
OBJECTIVES: To evaluate the impact the National Service Framework (NSF) for coronary heart disease has had on emergency treatment and outcomes in patients presenting with acute coronary syndromes. DESIGN: Retrospective cohort study. SETTING: Coronary care units of two district general hospitals. RESULTS: Data from 3371 patients were recorded, 1993 patients in the 27 months before the introduction of the NSF and 1378 patients in the 24 months afterwards. After the introduction of the NSF in-hospital mortality was significantly reduced (95 patients (4.8%) v 43 (3.2%), p = 0.02). This was associated with a reduction in the development of Q wave myocardial infarction (40.6% v 33.3%, p < 0.0001) and in the incidence of left ventricular failure (15.9% v 12.3%, p = 0.003). The proportion of patients receiving thrombolysis increased (69.4% v 84.7%, p < 0.0001) with a decrease in the time taken to receive it (proportion thrombolysed within 20 minutes 12.1% v 26.6%, p < 0.0001). The prescription of beta blockers (51.9% v 65.8%, p < 0.0001), angiotensin converting enzyme inhibitors (37% v 66.4%, p < 0.0001), and statins (55.2% v 72.7%, p < 0.0001) improved and the proportion of patients referred for invasive investigation increased (18.3% v 27.0%, p < 0.0001). Trend analysis showed that improvements in mortality and thrombolysis were directly associated with publication of the NSF, whereas the improvements seen in prescription of beta blockers and statins were the continuation of pre-existing trends. CONCLUSIONS: In the two years that followed publication of the NSF the initial treatment and outcome of patients presenting with acute coronary syndromes improved. Some of the improvements can be attributed to the NSF but others are continuations of pre-existing trends.
Asunto(s)
Enfermedad Coronaria/terapia , Tratamiento de Urgencia/tendencias , Antagonistas Adrenérgicos beta/uso terapéutico , Inhibidores de la Enzima Convertidora de Angiotensina/uso terapéutico , Aspirina/uso terapéutico , Cateterismo Cardíaco/métodos , Estudios de Cohortes , Unidades de Cuidados Coronarios , Enfermedad Coronaria/mortalidad , Tratamiento de Urgencia/métodos , Femenino , Mortalidad Hospitalaria , Hospitales de Distrito , Hospitales Generales , Humanos , Inhibidores de Hidroximetilglutaril-CoA Reductasas/uso terapéutico , Londres/epidemiología , Masculino , Infarto del Miocardio/mortalidad , Infarto del Miocardio/prevención & control , Estudios Retrospectivos , Síndrome , Terapia Trombolítica/métodos , Factores de Tiempo , Resultado del Tratamiento , Disfunción Ventricular Izquierda/mortalidad , Disfunción Ventricular Izquierda/prevención & controlRESUMEN
AIMS: To compare major determinants of myocardial oxygen demand (heart rate, blood pressure and rate pressure product) in patients with and without diabetes admitted with acute coronary syndromes. METHODS: A cross-sectional study of the relation between diabetes and haemodynamic indices of myocardial oxygen demand in 2542 patients with acute coronary syndromes, of whom 1041 (41.0%) had acute myocardial infarction and 1501 (59.0%) unstable angina. RESULTS: Of the 2542 patients, 701 (27.6%) had diabetes. Major haemodynamic determinants of myocardial oxygen demand were higher in patients with than without diabetes: heart rate 80.0 +/- 20.4 vs. 75.2 +/- 19.2 beats/minute (P < 0.0001); systolic blood pressure 147.3 +/- 30.3 vs. 143.2 +/- 28.5 mmHg (P = 0.002); rate-pressure product 11533 +/- 4198 vs. 10541 +/- 3689 beats/minute x mmHg (P < 0.0001). Multiple regression analysis confirmed diabetes as a significant determinant of presenting heart rate [multiplicative coefficient (MC) 1.05; 95% confidence interval (CI) 1.03-1.07; P < 0.0001], rate pressure product (MC 1.09; CI 1.05-1.12; P < 0.0001) and systolic blood pressure, which was estimated to be 3.9 mmHg higher than in patients without diabetes (P=0.003). These effects of diabetes were independent of a range of baseline variables including acute left ventricular failure and mode of presentation (unstable angina or myocardial infarction). CONCLUSIONS: In acute coronary syndromes, heart rate and other determinants of myocardial oxygen demand are higher in patients with than without diabetes, providing a potential contributory mechanism of exaggerated regional ischaemia in this high-risk group.
Asunto(s)
Enfermedad Coronaria/metabolismo , Diabetes Mellitus/metabolismo , Miocardio/metabolismo , Oxígeno/metabolismo , Enfermedad Aguda , Presión Sanguínea/fisiología , Enfermedad Coronaria/complicaciones , Estudios Transversales , Femenino , Frecuencia Cardíaca/fisiología , Humanos , Masculino , Persona de Mediana Edad , Factores SexualesRESUMEN
OBJECTIVES: To analyse the relation between serum glucose concentration and hospital outcome across the whole spectrum of acute coronary syndromes. METHODS: This was a prospective cohort study of 2127 patients presenting with acute coronary syndromes. The patients were stratified into quartile groups (Q1 to Q4) defined by serum glucose concentrations of 5.8, 7.2, and 10.0 mmol/l. The relation between quartile group and major in-hospital complications was analysed. RESULTS: The proportion of patients with acute myocardial infarction increased incrementally across the quartile groups, from 21.4% in Q1 to 47.9% in Q4 (p < 0.0001). The trend for frequency of in-hospital major complications was similar, particularly left ventricular failure (LVF) (Q1 6.4%, Q4 25.2%, p < 0.0001) and cardiac death (Q1 0.7%, Q4 6.1%, p < 0.0001). The relations were linear, each glucose quartile increment being associated with an odds ratio of 1.46 (95% confidence interval (CI) 1.27 to 1.70) for LVF and 1.52 (95% CI 1.17 to 1.97) for cardiac death. Although complication rates were higher for a discharge diagnosis of acute myocardial infarction than for unstable angina, there was no evidence that the effects of serum glucose concentration were different for the two groups, there being no significant interaction with discharge diagnosis in the associations between glucose quartile and LVF (p = 0.69) or cardiac death (p = 0.17). Similarly there was no significant interaction with diabetic status in the associations between glucose quartile and LVF (p = 0.08) or cardiac death (p = 0.09). CONCLUSION: Admission glycaemia stratified patients with acute coronary syndromes according to their risk of in-hospital LVF and cardiac mortality. There was no detectable glycaemic threshold for these adverse effects. The prognostic correlates of admission glycaemia were unaffected by diabetic status and did not differ significantly between patients with acute myocardial infarction and those with unstable angina.
Asunto(s)
Angina de Pecho/sangre , Glucemia/análisis , Infarto del Miocardio/sangre , Análisis de Varianza , Estudios de Cohortes , Muerte Súbita Cardíaca , Femenino , Hospitalización , Humanos , Hiperglucemia/sangre , Masculino , Persona de Mediana Edad , Pronóstico , Estudios Prospectivos , Síndrome , Disfunción Ventricular Izquierda/sangre , Disfunción Ventricular Izquierda/etiologíaRESUMEN
OBJECTIVES: To compare serum potassium concentrations in diabetic and non-diabetic patients in the early phase of acute coronary syndromes. BACKGROUND: Acute phase hypokalaemia occurs in response to adrenergic activation, which stimulates membrane bound sodium-potassium-ATPase and drives potassium into the cells. It is not known whether the hypokalaemia is attenuated in patients with diabetes because of the high prevalence of sympathetic nerve dysfunction. METHODS: Prospective cohort study of 2428 patients presenting with acute coronary syndromes. Patients were stratified by duration of chest pain, diabetic status, and pretreatment with beta blockers. RESULTS: The mean (SD) serum potassium concentration was significantly higher in diabetic than in non-diabetic patients (4.3 (0.5) v 4.1 (0.5) mmol/l, p < 0.0001). Multivariate analysis identified diabetes as an independent predictor of a serum potassium concentration in the upper half of the distribution (odds ratio 1.66, 95% confidence interval 1.38 to 2.00). In patients presenting within 6 hours of symptom onset, there was a progressive increase in plasma potassium concentrations from 4.08 (0.46) mmol/l in patients presenting within 2 hours, to 4.20 (0.47) mmol/l in patients presenting between 2-4 hours, to 4.24 (0.52) mmol/l in patients presenting between 4-6 hours (p = 0.0007). This pattern of increasing serum potassium concentration with duration of chest pain was attenuated in patients with diabetes, particularly those with unstable angina. Similar attenuation occurred in patients pretreated with beta blockers. CONCLUSION: In acute coronary syndromes, patients with diabetes have significantly higher serum potassium concentrations and do not exhibit the early dip seen in non-diabetics. This may reflect sympathetic nerve dysfunction that commonly complicates diabetes.
Asunto(s)
Enfermedad Coronaria/sangre , Angiopatías Diabéticas/sangre , Potasio/sangre , Enfermedad Aguda , Antagonistas Adrenérgicos beta/uso terapéutico , Glucemia/análisis , Dolor en el Pecho/sangre , Dolor en el Pecho/etiología , Estudios de Cohortes , Enfermedad Coronaria/etiología , Angiopatías Diabéticas/etiología , Femenino , Hospitalización , Humanos , Hipopotasemia/sangre , Hipopotasemia/tratamiento farmacológico , Hipopotasemia/etiología , Masculino , Persona de Mediana Edad , Estudios Prospectivos , Estrés Fisiológico/sangre , Síndrome , Factores de TiempoRESUMEN
BACKGROUND: Shortening prehospital delay has been identified as an important means of improving responses to reperfusion treatment. If this increases the risk profile of the population delivered to hospital, it may paradoxically cause a deterioration in hospital mortality. OBJECTIVE: To examine the interaction between arrival time (time from onset of chest pain to arrival at hospital) and thrombolytic treatment in determining the early outcome of acute myocardial infarction. METHODS: Prospective cohort study of 1723 patients with acute myocardial infarction who were potentially eligible for thrombolytic treatment (ST elevation on ECG; arrival time < or = 12 hours). RESULTS: All patients were eligible for thrombolysis but only 1098 (80%) received it. Patients who did not receive thrombolytic treatment were older (66 (58-73) v 61 (53-70) years, p < 0.001), more commonly female (32.1% v 24.8%, p < 0.01), and had higher frequencies of previous infarction (28.6% v 15.6%, p < 0.001) and left ventricular failure (37.5% v 26.9%, p < 0.01) than patients who received thrombolytic treatment. For the group as a whole, 30 day mortality was 11.7% and was unaffected by arrival time, but in patients who did not receive thrombolysis an arrival time of < or = 6 hours was associated with significantly higher 30 day mortality than an arrival time of 6-12 hours (24.3% v 2.6%, p = 0.002). Conversely, in patients who did receive thrombolysis an arrival time of < or = 6 hours was associated with a lower 30 day mortality than an arrival time of 6-12 hours (8.5% v 14.5%, p < 0.02). CONCLUSIONS: Shortening prehospital delay in acute myocardial infarction will tend to increase the risk profile of patients presenting to emergency departments. The data presented here indicate that this may increase hospital mortality if underutilisation of thrombolytic treatment among high risk groups is not diminished.
Asunto(s)
Servicios Médicos de Urgencia/organización & administración , Hospitalización/estadística & datos numéricos , Infarto del Miocardio/tratamiento farmacológico , Terapia Trombolítica/métodos , Anciano , Estudios de Cohortes , Muerte Súbita Cardíaca/etiología , Femenino , Mortalidad Hospitalaria , Humanos , Masculino , Persona de Mediana Edad , Infarto del Miocardio/mortalidad , Estudios Prospectivos , Factores de Riesgo , Análisis de Supervivencia , Factores de TiempoRESUMEN
BACKGROUND: Early discharge after myocardial infarction is safe and feasible. Factors that delay discharge need to be identified in order to improve care and reduce bed occupancy. OBJECTIVE: To investigate the potential of the restricted weekend service that operates in most hospitals to delay patient discharge. DESIGN: Prospective cohort study. SUBJECTS AND SETTING: 2541 consecutive patients with acute myocardial infarction admitted to the coronary care unit of three local district hospitals over a 12 year period. RESULTS: Clinical factors affecting the duration of stay were age, sex, and severity of infarction. Thus older patients and women stayed significantly longer, as did patients with enzymatically large infarcts. Day of week also had an important influence on duration of stay. Discharge occurred most often on a Friday (p = 0.006) and least often over the weekend (p = 0.0001). Patients were preferentially discharged on a Friday if the length of stay was more than 72 hours. Thus patients admitted on a Sunday or Monday were usually discharged the following Friday, corresponding to a median duration of stay of five or four days, respectively. For patients admitted on Tuesday to Saturday, weekend discharge was avoided and the median duration of stay was six to eight days. CONCLUSIONS: For patients with acute myocardial infarction, discharge decisions were influenced appropriately by clinical indicators of risk, but inappropriately by the day of the week. Thus weekend discharge was generally avoided, leading to variations in length of stay that were largely determined by the day of the week on which admission occurred rather than clinical need.
Asunto(s)
Unidades de Cuidados Coronarios/organización & administración , Unidades de Cuidados Coronarios/estadística & datos numéricos , Infarto del Miocardio/terapia , Alta del Paciente/estadística & datos numéricos , Anciano , Estudios de Cohortes , Femenino , Vacaciones y Feriados , Hospitales de Distrito/organización & administración , Hospitales de Distrito/estadística & datos numéricos , Humanos , Tiempo de Internación/estadística & datos numéricos , Londres , Masculino , Persona de Mediana Edad , Admisión y Programación de Personal , Estudios Prospectivos , Factores de TiempoRESUMEN
OBJECTIVES: The goal of this study was to determine the interaction between smoking and the glycoprotein IIIa P1(A2) polymorphism in patients admitted with non-ST-elevation acute coronary syndromes (ACS). BACKGROUND: An increased incidence of the P1(A2) polymorphism in smokers presenting with ST-elevation acute myocardial infarction (AMI) has recently been reported. We, therefore, postulated that, as a consequence of this interaction, fewer smokers with the P1(A2) polymorphism would present with non-ST-elevation ACS. METHODS: We performed a prospective cohort analysis of 220 white Caucasoid patients admitted with non-ST-elevation ACS fulfilling Braunwald class IIIb criteria for unstable angina who were stratified by smoking status. RESULTS: There were twice as many nonsmokers as smokers. Nonsmokers compared with smokers were older (mean [SD]; 63.9 [11.2] vs. 57.6 [10.3]; p < 0.0001), more likely to have had a previous admission with unstable angina (24.3% vs. 13.2%; p = 0.051) and AMI (45.8% vs. 30.3%; p < 0.026), more likely to have undergone revascularization (24.3% vs. 1.8%; p = 0.028) and were more likely to be on aspirin on admission (60.4% vs. 44.7%; p = 0.026). The proportion of nonsmokers positive for the P1(A2) polymorphism was equivalent to that expected for this population but was significantly reduced in smokers (28.7% vs. 10%; Pearson chi-square = 9.09, p = 0.0026). In a logistic regression model, the odds ratio (OR) for being positive for the P1(A2) polymorphism was significantly reduced by smoking (OR [interquartile range]: 0.26 [0.11 to 0.62]; p = 0.0026). CONCLUSIONS: There is a significant reduction in the P1(A2) polymorphism in smokers admitted with non-ST-elevation ACS compared with nonsmokers, which suggests an interaction between smoking and this polymorphism.
Asunto(s)
Angina Inestable/genética , Infarto del Miocardio/genética , Complejo GPIIb-IIIa de Glicoproteína Plaquetaria/genética , Polimorfismo Genético , Fumar/efectos adversos , Enfermedad Aguda , Angina Inestable/sangre , Distribución de Chi-Cuadrado , Femenino , Genotipo , Humanos , Modelos Logísticos , Masculino , Persona de Mediana Edad , Infarto del Miocardio/sangre , Estudios Prospectivos , Estadísticas no Paramétricas , Síndrome , Población BlancaRESUMEN
OBJECTIVES: This study was done to determine the effects of angiotensin-converting enzyme (ACE) inhibition and other clinical factors on troponin release in non-ST-elevation acute coronary syndrome (ACS). BACKGROUND: Troponin is now widely used as a marker of risk in ACS, but determinants of its release have not been defined. METHODS: This was a prospective cohort study of 301 consecutive patients admitted with non-ST-elevation ACS. Baseline clinical data were recorded, ACE gene polymorphism was determined and serial blood samples were obtained for troponin-I assay. RESULTS: Significant troponin-I release (>0.1 microg/l) was detected in 93 (31%) patients. Pretreatment with ACE inhibitors, recorded in 53 patients (17.6%), independently reduced the odds of troponin-I release (odds ratio 0.25; 95% confidence intervals 0.10 to 0.64) and was associated with lower maximum troponin-I concentrations (median [interquartile range]) compared with patients not pretreated with ACE inhibitors (0.44 microg/l [0.19 to 2.65 microg/l] vs. 4.18 microg/l [0.91 to 12.41 microg/l], p = 0.01). Pretreatment with aspirin, recorded in 173 patients (57.5%), did not significantly reduce the odds of troponin-I release after adjustment but was associated with lower maximum troponin-I concentrations compared with patients not pretreated with aspirin (2.31 microg/l [0.72 to 8.02 microg/l] vs. 5.85 microg/l [1.19 to 12.79 microg/l], p = 0.05). The ACE genotyping (n = 268) showed 81 patients (30%) DD homozygous and 77 (29%) II homozygous. There was no association between ACE genotype and troponin release. CONCLUSIONS: We conclude that ACE inhibition reduces troponin release in non-ST-elevation ACS. This is likely to be mediated by the beneficial effects of treatment on vascular reactivity and the coagulation system.
Asunto(s)
Angina Inestable/sangre , Inhibidores de la Enzima Convertidora de Angiotensina/farmacología , Isquemia Miocárdica/sangre , Sistema Renina-Angiotensina/efectos de los fármacos , Troponina/sangre , Anciano , Angina Inestable/fisiopatología , Endotelio Vascular/metabolismo , Femenino , Genotipo , Humanos , Modelos Logísticos , Masculino , Persona de Mediana Edad , Isquemia Miocárdica/fisiopatología , Estudios Prospectivos , Síndrome , Vasodilatación/efectos de los fármacosRESUMEN
OBJECTIVES: This study was designed to assess the interaction between aspirin and C-reactive protein (CRP) release in unstable angina. BACKGROUND: C-reactive protein release in acute coronary syndromes may be a response to myocardial necrosis or may reflect the inflammatory process that drives atherogenesis. Aspirin has the potential to influence CRP release, either by its anti-inflammatory activity or by reducing myocardial necrosis. The clinical significance of this potential interaction has not previously been tested. METHODS: We conducted a prospective cohort study of 304 consecutive patients admitted with non-ST-elevation acute coronary syndromes. Serial blood samples were obtained for CRP and troponin I assay. End points were cardiac death and nonfatal myocardial infarction during follow-up for 12 months. RESULTS: A total of 174 patients (57%) were taking aspirin before admission. Patients taking aspirin had lower troponin I concentrations throughout the sampling period, only 45 (26.0%) having concentrations >0.1 mg/l compared with 48 (37.8%) patients not taking aspirin (p = 0.03). Maximum CRP concentrations were also lower in patients taking aspirin (8.16 mg/l [3.24 to 24.5]) than in patients not taking aspirin (11.3 mg/l [4.15 to 26.1]), although the difference was not significant. However, there was significant interaction (p = 0.04) between prior aspirin therapy and the predictive value of CRP concentrations for death and myocardial infarction at 12 months. Thus, odds ratios (95% confidence intervals) for events associated with an increase of 1 standard deviation in maximum CRP concentration were 2.64 (1.22-5.72) in patients not pretreated with aspirin compared with 0.98 (0.60-1.62) in patients pretreated with aspirin. CONCLUSIONS: The association between CRP and cardiac events in patients with unstable angina is influenced by pretreatment with aspirin. Modification of the acute-phase inflammatory responses to myocardial injury is the major mechanism of this interaction.
Asunto(s)
Angina Inestable/tratamiento farmacológico , Aspirina/uso terapéutico , Proteína C-Reactiva/metabolismo , Anciano , Angina Inestable/inmunología , Angina Inestable/mortalidad , Aspirina/efectos adversos , Biomarcadores/sangre , Estudios de Cohortes , Femenino , Estudios de Seguimiento , Humanos , Masculino , Persona de Mediana Edad , Infarto del Miocardio/tratamiento farmacológico , Infarto del Miocardio/inmunología , Infarto del Miocardio/mortalidad , Estudios Prospectivos , Riesgo , Tasa de Supervivencia , Troponina I/sangreRESUMEN
AIMS: To define the trends in management and outcome of acute myocardial infarction over the first decade since the widespread adoption of thrombolytic therapy. METHODS: Prospective cohort study of 1737 consecutive patients with acute myocardial infarction admitted for coronary care between January 1988 and December 1997. RESULTS: Trend analysis with comparison of early (1988-1992) and late (1993-1997) cohorts showed significant increments in median age (interquartile range) from 62 (54-70) to 64 (55-72) years (P < 0.01) but the proportion of smokers fell from 72.7% to 65.8% (P < 0.01). The proportion of patients receiving thrombolytic therapy increased from 70% to 78.1% (P < 0.01) as median door-to-needle times fell significantly from 92 (60-145) to 68 (45-123) minutes (P < 0.01). The proportion of patients discharged on aspirin increased from 88.2% to 95.9% (P < 0.01), -blockers increased from 37.4% to 45.8% (P < 0.01), and angiotensin converting enzyme inhibitors increased from 12.4% to 35.7% (P < 0.01). Median hospital stay fell from 9 (7-11) to 6 (5-9) days (P < 0.0001). Although the severity of infarction declined, judged by reductions in the frequency of Q-wave development from 78.1% to 73.9% (P = 0.01) and peak CK from 1250 (569-2085) to 1004 (511-1722) IU/l, survival (95% confidence intervals) for the early and late cohorts did not change significantly either at 30 days [0.86 (0.83-0.88) vs. 0.85 (0.83-0.88)] or at 1 year [0.79 (0.76-0.81) vs 0.78 (0.76-0.81)]. CONCLUSION: The decade from 1988-1997 saw significant changes in the demographic characteristics and risk factor profiles of patients with acute myocardial infarction admitted for coronary care. We observed trends towards increasingly aggressive antithrombotic treatment and early discharge policies, with more patients being prescribed drugs for secondary prevention. The combined effects of these complex changes on the outcome of infarction defy simple analysis and there was no palpable change in short- and longer-term.
Asunto(s)
Servicios Médicos de Urgencia/tendencias , Mortalidad Hospitalaria , Infarto del Miocardio/tratamiento farmacológico , Infarto del Miocardio/mortalidad , Terapia Trombolítica , Anciano , Aspirina/uso terapéutico , Femenino , Fibrinolíticos/uso terapéutico , Humanos , Tiempo de Internación , Londres/epidemiología , Masculino , Persona de Mediana Edad , Análisis Multivariante , Infarto del Miocardio/epidemiología , Modelos de Riesgos Proporcionales , Estudios Prospectivos , Riesgo , Análisis de Supervivencia , Tasa de SupervivenciaRESUMEN
OBJECTIVE: To examine the influence of socioeconomic deprivation on case fatality following acute myocardial infarction. DESIGN: Prospective cohort observational study. SETTING: General hospital. PATIENTS: 1417 white and south Asian patients admitted with acute myocardial infarction between January 1988 and December 1996, and classified by the Carstairs socioeconomic deprivation score of the enumeration district of residence. MAIN OUTCOME MEASURES: 30 day and one year survival. RESULTS: There was little variation across deprivation groups in age, sex, or smoking status, though a higher proportion of patients from more deprived enumeration districts were diabetic and of south Asian origin, and a higher proportion of them developed Q wave infarction and left ventricular failure. There was no appreciable variation in clinical treatment with deprivation. Patients from more deprived enumeration districts had a higher risk of recurrent ischaemic events (death, recurrent myocardial infarction, or unstable angina) over the first 30 days: event free survival (95% confidence interval (CI)) of the most deprived quartile was 0.79 (95% CI 0.74 to 0.83) compared with 0.85 (95% CI 0.80 to 0.88) in the least deprived quartile. The unadjusted hazard ratio corresponding to an increase from the 5th to 95th centile of the deprivation distribution was 1.54 (95% CI 1.02 to 2.32), and 1.59 (95% CI 1.03 to 2.44) after adjustment for age, sex, racial group, diabetes, acute treatment with thrombolysis and aspirin, and left ventricular failure. Survival from 30 days to one year, however, did not show a socioeconomic gradient (hazard ratio adjusted for the same variables was 1.07 (95% CI 0.68 to 1.70)). CONCLUSIONS: In patients hospitalised with acute myocardial infarction, there is a strong association between early recurrent ischaemic events and socioeconomic deprivation that is not accounted for by clinical presentation or treatment. This association appears to be attenuated over time.
Asunto(s)
Infarto del Miocardio/mortalidad , Adulto , Anciano , Femenino , Humanos , Masculino , Persona de Mediana Edad , Análisis Multivariante , Modelos de Riesgos Proporcionales , Estudios Prospectivos , Recurrencia , Factores de Riesgo , Factores Socioeconómicos , Análisis de SupervivenciaRESUMEN
BACKGROUND: Women have excessive mortality rates after acute myocardial infarction compared with men. The extent to which this increased risk can be attributed to differences in treatment is not well-understood. METHODS: This was an observational follow-up study of 1737 patients admitted with acute myocardial infarction for coronary care between January 1, 1988, and December 31, 1997. RESULTS: Compared with men, women took longer to arrive at the hospital (132.5 minutes [range 76 to 291 minutes] vs 120 minutes [range 60 to 240 minutes]; P =.006), were less likely to receive aspirin acutely (87.8% vs 91.3%; P =.03), had longer door-to-needle times (90 minutes [range 60 to 143.5 minutes] vs 78 minutes [range 50 to 131 minutes]; P =.004), and were less likely to be given beta-blockers at hospital discharge (31.6% vs 44.9%; P <.0001). Estimated survival (95% confidence interval [CI]) at 30 days was only 78.4% (range 74.4% to 81.9%) for women compared with 88.0% (range 86.1% to 89.7%) for men. Women were older and more often white, but their excess risk (hazard ratio 2.09; 95% CI, 1.59-2.75) persisted after adjustment for age, racial group, and diabetes (hazard ratio 1.52; 95% CI, 1.15-2.01). Additional adjustment for emergency thrombolytic and aspirin therapy caused a further small reduction in the excess risk for women (hazard ratio 1.46; 95% CI, 1. 09-1.98), but with adjustment for aspirin and beta-blockers prescribed at discharge, the excess risk attributable to being female disappeared as the hazard ratio fell to 0.75 (95% CI, 0.31-1. 84). Estimated 30-day survival free of reinfarction and unstable angina was also lower for women than for men (75% [range 71% to 79%] vs 86% [range 84% to 88%]); again, the excess risk for women persisted despite adjustment for age and racial group before disappearing as treatment variables were introduced into the model. The influence of treatment variables on the differential risks for women and men disappeared at 12 months. CONCLUSIONS: This study has shown that women with acute myocardial infarction arrived later at the hospital, were less likely to be given aspirin therapy acutely, had longer door-to-needle times, and, on discharge from the hospital, were less likely to be prescribed beta-blockers for secondary prevention. The data suggest that the failure to treat women as vigorously as men made a significant contribution to their worse outcome.
Asunto(s)
Infarto del Miocardio/mortalidad , Infarto del Miocardio/terapia , Disfunción Ventricular/prevención & control , Salud de la Mujer , Antagonistas Adrenérgicos beta/uso terapéutico , Anciano , Aspirina/administración & dosificación , Supervivencia sin Enfermedad , Femenino , Fibrinolíticos/administración & dosificación , Humanos , Masculino , Persona de Mediana Edad , Infarto del Miocardio/complicaciones , Infarto del Miocardio/tratamiento farmacológico , Oportunidad Relativa , Inhibidores de Agregación Plaquetaria/administración & dosificación , Riesgo , Factores de Riesgo , Análisis de Supervivencia , Factores de Tiempo , Insuficiencia del Tratamiento , Resultado del Tratamiento , Reino Unido/epidemiología , Disfunción Ventricular/etiologíaRESUMEN
OBJECTIVE: To determine the changing risk of ventricular fibrillation, the prognostic implications, and the potential long term prognostic benefit of earlier hospital admission, after acute myocardial infarction. DESIGN: Prospective observational study. SETTING: A district general hospital in east London. PATIENTS: 1225 consecutive patients admitted to a coronary care unit with acute myocardial infarction. MAIN OUTCOME MEASURES: Time of onset of pain and ventricular fibrillation, and long term survival of patients admitted with acute myocardial infarction. RESULTS: The rate of ventricular fibrillation in these hospital inpatients was high in the first hour from onset of pain (118 events/1000 persons/h; 95% confidence interval (CI) 50.7 to 231) and fell rapidly to an almost constant low level by six hours; 27.4% of patients with early ventricular fibrillation died in hospital, compared with 11.6% of those without (p < 0.0001), but mortality in patients who survived to hospital discharge was not altered by early ventricular fibrillation (five year survival: 75.0% (95% CI 60.0% to 84.8%) with ventricular fibrillation v 73.3% (95% CI 69.6% to 76.6%) without ventricular fibrillation). CONCLUSIONS: Patients successfully resuscitated from early ventricular fibrillation have the same prognosis as those without ventricular fibrillation after acute myocardial infarction. Faster access to facilities for resuscitation must be achieved if major improvements in the persistently high case fatality of patients after acute myocardial infarction are to be made.
Asunto(s)
Infarto del Miocardio/complicaciones , Fibrilación Ventricular/complicaciones , Anciano , Urgencias Médicas , Femenino , Humanos , Funciones de Verosimilitud , Masculino , Persona de Mediana Edad , Infarto del Miocardio/etnología , Infarto del Miocardio/mortalidad , Oportunidad Relativa , Pronóstico , Análisis de Regresión , Riesgo , Tasa de Supervivencia , Fibrilación Ventricular/etnología , Fibrilación Ventricular/mortalidadRESUMEN
OBJECTIVE: To examine demographic and clinical characteristics of patients with acute myocardial infarction in order to identify factors affecting the electrocardiographic evolution of injury. METHODS: Prospective cohort study of 1399 consecutive patients with a first myocardial infarction. Baseline clinical data associated with ST elevation and Q wave development were identified and 12 month survival was estimated. RESULTS: Smoking had complex effects on the evolution of injury, increasing the odds of ST elevation (odds ratio (OR) 1.61; 95% confidence interval (CI) 1.08 to 2.36), but reducing the odds of Q wave development (OR 0.69, 95% CI 0.49 to 0.96). The effects of previous aspirin treatment were more consistent with reductions in the odds of ST elevation (OR 0.57, 95% CI 0.35 to 0.94) and Q wave development (OR 0.53, 95% CI 0.34 to 0. 84). ST elevation and Q wave development were both associated with an adverse prognosis, with estimated 12 month survival rates of 80. 6% (95% CI 78.2% to 83.1%) and 80.0% (95% CI 77.5% to 82.5%), respectively, compared with 86.5% (95% CI 81.2% to 91.9%) and 89.9% (95% CI 86.2% to 93.7%) for patients without these ECG changes. CONCLUSIONS: The thrombogenicity of the blood may be a major determinant of infarct severity. Smoking increases thrombogenicity and the likelihood of ST elevation, but because coronary occlusion is relatively more thrombotic in smokers, responses to both endogenous and exogenous thrombolysis are better, reducing the risk of Q wave development. Previous aspirin treatment reduces thrombogenicity, protecting against ST elevation and Q wave development.
Asunto(s)
Antiinflamatorios no Esteroideos/uso terapéutico , Aspirina/uso terapéutico , Electrocardiografía , Infarto del Miocardio/fisiopatología , Fumar/efectos adversos , Anciano , Intervalos de Confianza , Femenino , Humanos , Masculino , Persona de Mediana Edad , Infarto del Miocardio/mortalidad , Oportunidad Relativa , Pronóstico , Estudios Prospectivos , Fumar/mortalidad , Tasa de Supervivencia , Trombosis/prevención & controlRESUMEN
OBJECTIVES: To examine the criteria for selecting patients presenting with unstable angina for cardiac catheterisation and to assess the extent to which these criteria successfully incorporate high risk groups. METHODS AND RESULTS: This was a prospective cohort study of 517 patients admitted with unstable angina with 12 months follow-up; 139 patients (26.9%) had cardiac catheterisation 32 days or longer after presentation. The odds of early catheterisation were increased by regional ST segment depression on the presenting ECG (odds ratio (OR) 1.70, 95% confidence intervals (CI) 1.01-2.87) and ongoing ischaemic chest pain more than 12 hours after admission (OR 9.72, CI 6.10-15.49), and reduced by age over 65 years (OR 0.56, 95% CI 0.35-0.90) and heart failure (OR 0.26, CI 0.11-0.64). The 12-month rates of myocardial infarction (MI) or death were 8.6% and 17.7% (p = 0.01) in patients who were and were not referred for early cardiac catheterisation, respectively. Survival analysis showed that the odds of MI and death in the first 12 months were increased substantially by heart failure (OR 2.82, 95% CI 1.53-5.20) and age over 65 (OR 1.91, 95% CI 1.13-3.23). CONCLUSION: Selection for early cardiac catheterisation in this unstable angina population was largely ischaemia-driven, based on ongoing chest pain and ST segment depression. This policy was associated with a low event rate in the ischaemic group, but it failed to target elderly patients and those with heart failure who were at greatest risk of MI and death during the first year.
Asunto(s)
Angina Inestable/diagnóstico , Cateterismo Cardíaco/estadística & datos numéricos , Evaluación de Resultado en la Atención de Salud , Selección de Paciente , Sesgo de Selección , Anciano , Angina Inestable/epidemiología , Supervivencia sin Enfermedad , Electrocardiografía , Prueba de Esfuerzo , Femenino , Insuficiencia Cardíaca , Humanos , Londres/epidemiología , Masculino , Persona de Mediana Edad , Análisis Multivariante , Infarto del Miocardio/epidemiología , Infarto del Miocardio/prevención & control , Oportunidad Relativa , Estudios Prospectivos , Factores de RiesgoRESUMEN
BACKGROUND: About 75% of patients with acute myocardial infarction are older than 70 years, but patients in this age group are commonly treated less vigorously than younger patients. This differential treatment may partly reflect clinicians' misconceptions about the outlook of such patients, and the importance of age in clinical decisions. We examined how age does and should affect the management of patients and risk stratification in acute myocardial infarction. METHODS: In this prospective cohort study, we recruited 1225 consecutive patients admitted with acute myocardial infarction to a district general hospital in east London. The primary endpoint was death. We used tabulation and regression methods to analyse the association between age group and clinical variables. FINDINGS: Patients aged 70 years or older took a longer time to arrive in hospital and were less likely to receive thrombolysis or discharge beta-blockers than patients younger than 60 years: odds ratio 0.63 (95% CI 9.45-0.88) for thrombolysis and 0.25 (0.16-0.37) for beta-blockade, adjusted for sex, diabetes, previous acute myocardial infarction, Q wave infarction, and left-ventricular failure. Left-ventricular failure was the strongest independent predictor of death within 1 year of infarction with a hazard ratio of 4.76 (3.53-6.43), adjusted for age, sex, diabetes, and Q wave infarction. Patients aged 70 years or older without left-ventricular failure had significantly better survival at 1 year after acute myocardial infarction than patients under 60 years with left-ventricular failure. 70.8% (62.2-78.2) of the older patients who survived to hospital discharge were still alive 3 years later. INTERPRETATION: Elderly patients with acute myocardial infarction were treated less vigorously than younger patients. The prognosis of acute myocardial infarction, however, was substantially affected by the development of left-ventricular failure and other clinical indices, such that many older patients had a better outlook than younger patients with adverse clinical factors. In planning risk-based management, consideration of age independently of clinical status is inappropriate.
Asunto(s)
Infarto del Miocardio/tratamiento farmacológico , Antagonistas Adrenérgicos beta/uso terapéutico , Factores de Edad , Anciano , Anciano de 80 o más Años , Estudios de Cohortes , Intervalos de Confianza , Complicaciones de la Diabetes , Electrocardiografía , Femenino , Fibrinolíticos/uso terapéutico , Estudios de Seguimiento , Predicción , Hospitalización , Humanos , Masculino , Persona de Mediana Edad , Oportunidad Relativa , Pronóstico , Modelos de Riesgos Proporcionales , Estudios Prospectivos , Análisis de Regresión , Factores de Riesgo , Factores Sexuales , Tasa de Supervivencia , Terapia Trombolítica , Resultado del Tratamiento , Disfunción Ventricular Izquierda/complicacionesRESUMEN
OBJECTIVES: The purpose of this study was to examine clinical characteristics of patients with acute coronary syndromes to identify factors that influence the mode of presentation. BACKGROUND: In acute coronary syndromes, presentation with myocardial infarction or unstable angina has major prognostic implications, yet clinical factors affecting the mode of presentation are not well defined. METHODS: A prospective cohort study was made of 1,111 patients with acute coronary syndromes. Baseline demographic, clinical and biochemical data were compared in groups with myocardial infarction (n = 633) and unstable angina (n = 478). RESULTS: The risk of myocardial infarction relative to unstable angina was increased by age >70 years (odds ratio [OR] 2.21; 95% confidence interval [CI] 1.33 to 3.66), male gender (OR 1.56; CI 1.13 to 2.16) and cigarette smoking (OR 1.49; CI 1.09 to 2.03). A rise in admission creatinine from the 10th to the 90th centile of the distribution also increased the odds of myocardial infarction (OR 1.30; CI 1.05 to 1.94). Conversely, the risk of myocardial infarction relative to unstable angina was reduced by previous treatment with aspirin (OR 0.37; CI 0.27 to 0.52), hypertension (OR 0.64; CI 0.47 to 0.86) and previous acute coronary syndromes (OR 0.36; CI 0.26 to 0.51) and revascularization procedures (OR 0.36; CI 0.21 to 0.62). CONCLUSIONS: The clinical presentation of acute coronary syndromes may be influenced by various factors that have the potential to influence the coagulability of the blood, the collateralization of the coronary circulation and myocardial mass. Myocardial infarction is favored by cigarette smoking, advanced age and renal impairment, while unstable angina is favored by treatment with aspirin, hypertension, previous revascularization and previous coronary syndromes.
Asunto(s)
Angina Inestable/diagnóstico , Infarto del Miocardio/diagnóstico , Anciano , Angina Inestable/fisiopatología , Circulación Colateral , Circulación Coronaria , Creatinina/sangre , Femenino , Humanos , Hipertrofia Ventricular Izquierda/complicaciones , Masculino , Persona de Mediana Edad , Análisis Multivariante , Infarto del Miocardio/sangre , Infarto del Miocardio/complicaciones , Infarto del Miocardio/fisiopatología , Oportunidad Relativa , Estudios Prospectivos , Factores de Riesgo , Fumar/efectos adversosRESUMEN
AIM: To determine whether general practitioners (GPs) prefer structured computer-generated or standard dictated outpatient clinic letters. DESIGN: Questionnaire survey of all GPs referring patients to an open-access chest pain clinic at a district general hospital in London. The GPs were asked to compare three twinned examples of structured computer-generated and unstructured dictated letters. RESULTS: Of 93 respondents (response rate 77.5%), 75 (80.6%) preferred the computer-generated letter and 16 (17.2%) preferred the dictated letter (p < 0.0005). The preferred features of the computer-generated letter were its clear presentation, subheadings, and concise information. The computer-generated letter scored significantly higher than the dictated letter: for clarity, mean 8.2 vs 6.5 (p < 0.0005); content, mean 8.5 vs 6.9 (p < 0.0005); and readability, mean 8.2 vs 6.8 (p < 0.0005). The GPs in the survey considered a mean delay of 3.4 days to be acceptable for receiving the letter from the chest pain clinic. CONCLUSION: GPs prefer structured computer-generated letters to unstructured dictated letters for patients referred to an open-access chest pain clinic. Computer-generated correspondence allows rapid feedback of information to the referring GP, one of the key requirements of open-access clinics.