RESUMEN
OBJECTIVES: To gain insight into early mechanisms of aortic widening, we examined associations between the diameter of the abdominal aorta (AD) and cardiovascular disease (CVD) risk factors and biomarkers, as well as measures of subclinical atherosclerosis, in a multi-ethnic population. DESIGN: Cross-sectional cohort. METHODS: A total of 1926 participants (mean age 62, 50% women) underwent chest and abdomen scanning by computed tomography, ultrasound of the carotid arteries, and CVD risk factor assessment. AD was measured 5 cm above and at the bifurcation. RESULTS: In a model containing traditional CVD risk factors, biomarkers and ethnicity, only age (standardized ß = 0.97), male sex (ß = 1.88), body surface area (standardized ß = 0.92), current smoking (ß = 0.42), D-dimer levels (ß = 0.19) and hypertension (ß = 0.53) were independently and significantly associated with increasing AD (in mm) at the bifurcation; use of cholesterol-lowering medications predicted smaller AD (ß = -0.70) (P < 0.01 for all). These findings were similar for AD 5 cm above the bifurcation with one exception: compared to Caucasian-Americans, Americans of Chinese, African and Hispanic descent had significantly smaller AD 5 cm above the bifurcation (ß's = -0.59, -0.49, and -0.52, respectively, all P < 0.01), whereas AD at the bifurcation did not differ by ethnicity. Physical activity, alcohol consumption, diabetes and levels of IL-6, CRP and homocysteine were not independently associated with AD. Higher aortic and coronary artery calcium burden, but not common carotid artery intima-media thickness, were independently, but modestly (ß = 0.11 to 0.19), associated with larger AD. CONCLUSIONS: Incremental widening of the aortic diameter shared some, but not all, risk factors for occlusive vascular disease.
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Aorta Abdominal/patología , Aneurisma de la Aorta/etnología , Enfermedades de las Arterias Carótidas/etnología , Etnicidad/estadística & datos numéricos , Anciano , Anciano de 80 o más Años , Aorta Abdominal/diagnóstico por imagen , Aneurisma de la Aorta/diagnóstico por imagen , Aneurisma de la Aorta/patología , Aortografía/métodos , Enfermedades de las Arterias Carótidas/diagnóstico por imagen , Estudios Transversales , Dilatación Patológica , Femenino , Humanos , Modelos Lineales , Masculino , Persona de Mediana Edad , Medición de Riesgo , Factores de Riesgo , Tomografía Computarizada por Rayos X , Ultrasonografía , Estados UnidosRESUMEN
OBJECTIVE: To examine the associations between body mass index (BMI), waist circumference (WC) and risk of atrial fibrillation (AF) in Chinese adults. DESIGN, SUBJECTS AND MEASUREMENTS: A cross-sectional study was conducted to explore the association between obesity and atrial fibrillation among 18,615 Chinese (10,370 females) aged 35 years and above in 2004. AF was defined by electrocardiography and history. Obesity was classified by BMI and WC, including overweight (BMI: 24.0-27.9 kg m(-2); WC: 85.0-94.9 cm for men and 80.0-89.9 cm for women) and obesity (BMI: > or = 28.0 kg m(-2); WC: > or = 95 cm for men and > or = 90 cm for women), according to the Chinese Guidelines on Prevention and Treatment of Obesity in Adults. Multivariable logistic regression was used to analyze the association between obesity and AF. RESULTS: Age- and sex-adjusted prevalence of AF (n=194) was higher with increased BMI, with 0.9% for normal, 1.1% for overweight and 1.6% for obese (P(trend)<0.01) Chinese. Compared with normal BMI, multivariable-adjusted odds ratios (ORs) were 1.2 (95% confidence interval (CI): 0.8-1.7) for overweight BMI and 1.8 (95% CI: 1.2-2.8) for obese BMI (P(trend)<0.01). After excluding known secondary AF (valvular, postoperative and hyperthyroid) and unclassified AF, the corresponding multivariable-adjusted ORs were 1.4 (95% CI: 0.9-2.2) and 2.2 (95% CI: 1.3-3.7) (P (trend)<0.01). The same trends were observed for WC. Multivariable-adjusted OR was 2.6 (95% CI: 1.4-4.6) for participants with both BMI and WC obesity and 1.7 (95% CI: 1.0-2.9) for participants with both BMI and WC overweight in comparison with those with both BMI and WC in the normal range. CONCLUSION: Obesity, either defined by BMI or WC, was significantly associated with AF among middle-aged and elderly Chinese.
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Pueblo Asiatico , Fibrilación Atrial/etiología , Obesidad/complicaciones , Circunferencia de la Cintura/fisiología , Adulto , Anciano , Fibrilación Atrial/epidemiología , Fibrilación Atrial/etnología , Índice de Masa Corporal , Enfermedades Cardiovasculares/epidemiología , Enfermedades Cardiovasculares/etnología , Enfermedades Cardiovasculares/prevención & control , Estudios Transversales , Femenino , Humanos , Incidencia , Masculino , Persona de Mediana Edad , Obesidad/epidemiología , Obesidad/etnología , Oportunidad Relativa , Factores de Riesgo , Encuestas y CuestionariosRESUMEN
BACKGROUND: Prognostic risk models have had limited success in predicting coronary events in subjects with multiple risk factors. We and others have proposed an alternative approach using radiographically detectable coronary calcium. We evaluated and compared the predictive value of these 2 approaches for determining coronary event risk in asymptomatic adults with multiple coronary risk factors. In addition, we assessed the predictive value of a risk model that included calcium score and cardiac risk-factor data. METHODS AND RESULTS: We recruited 1196 asymptomatic high-coronary-risk subjects who then underwent risk-factor assessment and cardiac electron-beam CT (EBCT) scanning and were followed up for 41 months with a 99% success rate. We applied the Framingham model and our data-derived risk model to determine the 3-year likelihood of a coronary event. The mean age of our cohort was 66 years, and mean 3-year Framingham risk was 3.3+/-3.6%. Sixty-eight percent (818 subjects) had detectable coronary calcium. There were 17 coronary deaths (1.4%) and 29 nonfatal infarctions (2. 4%). The receiver operating characteristic (ROC) curve areas calculated from the Framingham model, our data-derived risk model, and the calcium score were 0.69+/-0.05, 0.68+/-0.05, and 0.64+/-0.05, respectively (P=NS). When calcium score was included as a variable in the data-derived model, the ROC area did not change significantly (0.68+/-0.05 to 0.71+/-0.04; P=NS). CONCLUSIONS: Neither risk-factor assessment nor EBCT calcium is an accurate event predictor in high-risk asymptomatic adults. EBCT calcium score does not add significant incremental information to risk factors, and its use in clinical screening is not justified at this time.
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Calcinosis/complicaciones , Calcinosis/fisiopatología , Enfermedad Coronaria/complicaciones , Enfermedad Coronaria/fisiopatología , Anciano , Calcinosis/diagnóstico por imagen , Estudios de Cohortes , Enfermedad Coronaria/diagnóstico por imagen , Enfermedad Coronaria/mortalidad , Femenino , Estudios de Seguimiento , Humanos , Incidencia , Estudios Longitudinales , Masculino , Persona de Mediana Edad , Modelos Cardiovasculares , Infarto del Miocardio/epidemiología , Infarto del Miocardio/etiología , Pronóstico , Estudios Prospectivos , Curva ROC , Factores de Riesgo , Tomografía Computarizada por Rayos XRESUMEN
To compare four recently proposed methods of analyzing the exercise electrocardiogram with the conventional analysis of ST segment depression, 303 consecutive patients without myocardial infarction who had been referred for coronary arteriography underwent stress electrocardiography and stress thallium imaging. The specificity for the prediction of a greater than 50% coronary obstruction of 0.5, 1.0, 1.5 and 2.0 mm ST segment depression measured in the conventional way was 0.59, 0.73, 0.88 and 0.94, respectively. The specificity of a thallium perfusion defect was 0.79. Sensitivities of the conventional ST depressions, thallium defect, the change in the sum of the R amplitudes and the slope adjusted for heart rate increase were calculated and compared at the cited levels of specificity. R wave changes had a significantly lower sensitivity than did the conventionally analyzed ST depression at each level of specificity. Slope-adjusted ST depression had a slightly higher sensitivity than that of conventional ST depression only at a specificity of 0.73 (0.68 versus 0.65, p = 0.07). R wave-adjusted ST depression was significantly more sensitive than conventional ST depression only at a specificity of 0.94 (0.45 versus 0.36, p = 0.01). Heart rate-adjusted ST depression was more sensitive than conventional ST depression at all of the specificities except 0.59. This pattern of superior accuracy of heart rate-adjusted ST depressions was preserved for the prediction of multivessel coronary disease. Heart rate adjustment is a simpler and more accurate modification of the conventional electrocardiographic analysis than are the other three methods studied.
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Enfermedad Coronaria/diagnóstico , Electrocardiografía , Esfuerzo Físico , Adulto , Anciano , Angiografía Coronaria , Prueba de Esfuerzo , Femenino , Frecuencia Cardíaca , Humanos , Masculino , Persona de Mediana Edad , Radioisótopos , TalioRESUMEN
Computer-assisted interpretation of the exercise electrocardiogram has been advocated to improve the accuracy of diagnosing coronary artery disease. Its accuracy was compared with a blinded visual interpretation of exercise-induced ST depression in 271 consecutive subjects without prior myocardial infarction who were referred for coronary angiography. The sensitivity of the visual and computer readings was 0.51 and 0.51, respectively, at a specificity of 0.87. Receiver operating characteristic curves were generated for the visual and computer ST depression in lead V5. Analysis of the areas under these curves showed no significant difference between them, indicating that computer-assisted analysis was not superior to unmodified visual analysis. A similar analysis was applied to two other computer indexes reported to be superior to visual assessments (treadmill exercise score and ST index). These computer indexes were not superior to a conventional visual analysis of leads I, II, V2, V4 and V5 in predicting severe disease (greater than 50% luminal narrowing). These results suggest that computer-assisted interpretation does not improve the accuracy of exercise electrocardiography in diagnosing coronary artery disease in subjects without prior myocardial infarction.
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Enfermedad Coronaria/diagnóstico , Diagnóstico por Computador , Prueba de Esfuerzo , Infarto del Miocardio/diagnóstico , Adulto , Anciano , Angiografía Coronaria , Enfermedad Coronaria/fisiopatología , Electrocardiografía , Reacciones Falso Positivas , Femenino , Humanos , Masculino , Persona de Mediana Edad , Infarto del Miocardio/fisiopatologíaRESUMEN
OBJECTIVES: To compare the significance of a specific feature of coronary atherosclerosis--coronary calcium--in asymptomatic black and white subjects with coronary risk factors. BACKGROUND: The natural history and clinical evolution of coronary atherosclerosis differs between blacks and whites. Differences in the underlying pathobiology of atherosclerosis may be one determinant of the ethnic variability in the clinical manifestation of coronary atherosclerosis. METHODS: In 1,375 high-risk but asymptomatic subjects (93 blacks [6.8%] and 1,282 whites [93.2%]) with at least one risk factor but no prior evidence of coronary disease, we assessed coronary risk factors, calculated Framingham risk of a coronary event and evaluated coronary calcium with digital subtraction fluoroscopy. We then followed these subjects clinically for 70 +/- 13 months, noting the occurrence of the following coronary events: death due to coronary heart disease (CHD); myocardial infarction (MI); angina pectoris; and performance of coronary bypass or angioplasty. RESULTS: Risk factor profiles were similar in black and white subjects (6-year Framingham risk 15 +/- 7% in blacks, 14 +/- 8% in whites [NS]). Coronary calcium was present in 59.9% of white subjects but only 35.5% of black subjects (p = 0.0001). Nevertheless, after 70 months of follow-up, more blacks than whites (22 blacks [23.7%] vs. 190 whites [14.8%]; p = 0.04) suffered one of the following end points: CHD death, MI, angina or revascularization. The age, gender and coronary risk-adjusted odds ratio of black race for at least one event was 2.16 (95% CI 1.34 to 3.48). CONCLUSIONS: Despite having a lowered prevalence of coronary calcium than high risk whites, high risk blacks suffer more CHD events. Coronary calcium therefore does not carry the same pathobiologic significance in blacks that it does in whites, consistent with the concept that there are specific racial differences in the natural history of CHD and its evolution into clinically manifest events.
Asunto(s)
Población Negra , Calcinosis/etnología , Enfermedad Coronaria/etnología , Población Blanca , Anciano , Calcinosis/diagnóstico por imagen , Estudios de Cohortes , Angiografía Coronaria/métodos , Angiografía Coronaria/estadística & datos numéricos , Enfermedad Coronaria/diagnóstico por imagen , Femenino , Fluoroscopía/métodos , Fluoroscopía/estadística & datos numéricos , Estudios de Seguimiento , Humanos , Masculino , Persona de Mediana Edad , Pronóstico , Estudios Prospectivos , Factores de Riesgo , Técnica de SustracciónRESUMEN
OBJECTIVES: Our goals were to develop and validate a multivariate algorithm for estimating the incremental probability of the presence of coronary artery disease. BACKGROUND: Multivariate methods, including logistic regression analysis, have been extensively applied to diagnostic exercise testing. However, few previous studies have included both an incremental design and external validation. METHODS: A retrospective collection of clinical, exercise test and catheterization data was performed involving four U.S. referral medical centers. All patients had no prior history of coronary disease and had undergone coronary angiography < or = 3 months after exercise stress testing. An algorithm was developed in one center (590 patients with a 41% prevalence of coronary artery disease) with the use of logistic regression analysis and was validated in the other three centers (1,234 patients, 70% prevalence). The algorithm incorporated pretest variables (age, gender, symptoms, diabetes, cholesterol), exercise electrocardiographic (ECG) variables (mm of ST segment depression, ST slope, peak heart rate, metabolic equivalents [METs], exercise angina) and one thallium variable. Discrimination was measured with receiver operating characteristic curve analysis. Calibration (that is, reliability) was assessed from a comparison of probability estimates and the actual prevalence of disease. RESULTS: The overall incremental receiver operating characteristic curve areas for the validation group were pretest, -0.738 +/- 0.016; postexercise ECG, 0.78 (SE 0.017); and postthallium, 0.82 (SE 0.016); p < 0.01 for both increments. Within the three validation institutions, the institution with a disease prevalence closest to that of the derivation institution had the best incremental receiver operating characteristic curve areas. There was a stepwise incremental improvement in calibration especially from exercise ECG to thallium testing. CONCLUSIONS: An incremental multivariate algorithm derived in one center reliably estimated disease probability in patients from three other centers. The incremental value of testing was best demonstrated when the derivation and validation groups had a similar disease prevalence. This algorithm may be useful in decision making that relates to the diagnosis of coronary disease.
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Algoritmos , Enfermedad Coronaria/epidemiología , Prueba de Esfuerzo , Angiografía Coronaria , Enfermedad Coronaria/diagnóstico , Análisis Discriminante , Electrocardiografía , Estudios de Evaluación como Asunto , Prueba de Esfuerzo/estadística & datos numéricos , Humanos , Modelos Logísticos , Análisis Multivariante , Prevalencia , ProbabilidadRESUMEN
The failure of exercise-induced ST segment depression to consistently predict prognosis in patients after myocardial infarction could be a result of population differences and the rest electrocardiogram (ECG). These hypotheses were tested by studying 198 veterans who survived a myocardial infarction, underwent a submaximal predischarge treadmill exercise test and were followed up for cardiac events for 2 years. During the 2 years, 29 deaths, 19 reinfarctions and 28 revascularization procedures were documented. The prevalence of death or reinfarction was two times higher in patients who had exercise-induced ST depression than in patients who did not. However, in the 55 patients without Q waves, the risk increased to 11 times for an abnormal ST response. These findings suggest that exercise-induced ST depression only predicts high risk in patients after myocardial infarction whose ECG at rest does not exhibit Q waves and that differences in the prevalence of rest ECG patterns are the most likely explanation for the failure of agreement among prior studies.
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Electrocardiografía , Infarto del Miocardio/diagnóstico , Esfuerzo Físico , Prueba de Esfuerzo , Estudios de Seguimiento , Humanos , Masculino , Persona de Mediana Edad , Pronóstico , Factores de Riesgo , Factores de TiempoRESUMEN
Ultrafast computed tomography was used to detect and quantify coronary artery calcium levels in 584 subjects (mean age 48 +/- 10 years) with (n = 109) and without (n = 475) clinical coronary artery disease. Fifty patients who underwent fluoroscopy and ultrafast computed tomography were also evaluated. Twenty contiguous 3 mm slices were obtained of the proximal coronary arteries. Total calcium scores were calculated based on the number, areas and peak Hounsfield computed tomographic numbers of the calcific lesions detected. In 88 subjects scored by two readers independently, interobserver agreement was excellent with identical total scores obtained in 70. Ultrafast computed tomography was more sensitive than fluoroscopy, detecting coronary calcium in 90% versus 52% of patients. There were significant differences (p less than 0.0001) in mean total calcium scores for those with versus those without clinical coronary artery disease by decade: 5 versus 132, age 30 to 39 years; 27 versus 291, age 40 to 49 years; 83 versus 462, age 50 to 59 years; and 187 versus 786, age 60 to 69 years. Sensitivity, specificity and predictive values for clinical coronary artery disease were calculated for several total calcium scores in each decade. For age groups 40 to 49 and 50 to 59 years, a total score of 50 resulted in a sensitivity of 71% and 74% and a specificity of 91% and 70%, respectively. For age group 60 to 69 years, a total score of 300 gave a sensitivity of 74% and a specificity of 81%. The negative predictive value of a 0 score was 98%, 94% and 100% for age groups 40 to 49, 50 to 59 and 60 to 69 years, respectively. Ultrafast computed tomography is an excellent tool for detecting and quantifying coronary artery calcium.
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Calcinosis/diagnóstico por imagen , Angiografía Coronaria , Enfermedad Coronaria/diagnóstico por imagen , Tomografía Computarizada por Rayos X/métodos , Adulto , Anciano , Calcinosis/epidemiología , Enfermedad Coronaria/epidemiología , Femenino , Fluoroscopía , Humanos , Masculino , Persona de Mediana Edad , Variaciones Dependientes del Observador , Valor Predictivo de las Pruebas , Sensibilidad y EspecificidadRESUMEN
To evaluate the variability in the reported accuracy of the exercise electrocardiogram (ECG) for predicting severe coronary disease, meta analysis was applied to 60 consecutively published reports comparing exercise-induced ST depression with coronary angiographic findings. The 60 reports included 62 distinct study groups comprising 12,030 patients who underwent both tests. Both technical and methodologic factors were analyzed. Wide variability in sensitivity and specificity was found (mean sensitivity 81% [range 40% to 100%, SD 12%]; mean specificity 66% [range 17% to 100%, SD 16%]). All three variables found to be significantly and independently related to sensitivity were methodologic (the exclusion of patients with right bundle branch block, the comparison with another exercise test thought to be superior in accuracy and the exclusion of patients taking digitalis). Exclusion of patients with right bundle branch block and comparison with a "better" exercise test were both significantly associated with sensitivity for the prediction of triple vessel or left main coronary artery disease. Adjustment of exercise-induced ECG changes for changes in heart rate was strongly associated with the specificity for critical disease (partial R2 = 0.436, p = 0.0001).
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Enfermedad Coronaria/diagnóstico , Electrocardiografía , Ejercicio Físico , Angiografía Coronaria , Enfermedad Coronaria/epidemiología , Enfermedad Coronaria/patología , Prueba de Esfuerzo , Humanos , Masculino , Metaanálisis como Asunto , Análisis Multivariante , Valor Predictivo de las PruebasRESUMEN
Thirty-one consecutive patients undergoing intravenous blurred mask digital subtraction right ventriculography were submitted to first pass radionuclide angiography. Second order mask resubtraction of end-diastolic and end-systolic right ventricular digital image frames was executed using preinjection end-diastolic and end-systolic frames to rid the digital subtraction images of mis-registration artifact. End-diastolic and end-systolic perimeters were drawn manually by two independent observers with a light pen. Ejection fractions calculated from the integrated videodensitometric counts within these perimeters correlated well with those derived from the first pass radionuclide right ventriculogram (r = 0.84) and the interobserver correlation was acceptable (r = 0.91). Interobserver differences occurred more frequently in patients with atrial fibrillation and in those whose tricuspid valve planes were difficult to discern on the digital subtraction right ventriculograms. These results suggest that videodensitometric analysis of digital subtraction right ventriculograms is an accurate method of determining right ventricular ejection fraction and may find wide clinical applicability.
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Absorciometría de Fotón/métodos , Gasto Cardíaco , Ventrículos Cardíacos/diagnóstico por imagen , Volumen Sistólico , Adulto , Anciano , Computadores , Femenino , Cardiopatías/diagnóstico por imagen , Humanos , Masculino , Persona de Mediana Edad , Ácido Pentético , Cintigrafía , Técnica de Sustracción , Tecnecio , Pentetato de Tecnecio Tc 99m , Tecnología Radiológica , Grabación de Cinta de VideoRESUMEN
OBJECTIVES: This investigation sought to determine the relative prognostic value of coronary calcific deposits and coronary angiographic findings for predicting coronary heart disease-related events in patients referred for angiography. BACKGROUND: The relation among coronary calcification, coronary stenoses and coronary heart disease-related events is of interest on a clinical as well as a pathophysiologic basis. METHODS: Four hundred ninety-one symptomatic patients underwent coronary angiography and electron beam computed tomography at five different centers between April 1989 and December 1993. The electron beam computed tomograms were interpreted by a cardiologist with no knowledge of the coronary angiographic and clinical data. Receiver operating characteristic (ROC) curves were constructed to determine the relation between electron beam computed tomographic and coronary angiographic findings. A follow-up telephone survey was completed in 86% of patients. The records for all patients who died or were admitted to the hospital for chest pain or suspected myocardial infarction were reviewed by three other cardiologists with no knowledge of the coronary angiographic and electron beam computed tomographic study results. RESULTS: The mean (+/- SE) area under the ROC curve was 0.75 +/- 0.02 for the coronary calcium score, indicating moderate discriminatory power for this score for predicting angiographic findings. Thirteen coronary heart disease-related deaths and eight nonfatal acute infarctions occurred over 30 +/- 13 months. Scores were sorted in ascending order and divided into quartiles of equal size. One patient in the first quartile had a fatal myocardial infarction (coronary calcium score range 0 to 2.1); 2 in the second quartile (range 2.1 to 75.3), 8 in the third quartile (range 75.3 to 397.1) and 10 in the fourth quartile (> 397.1) had a coronary heart disease-related event. Application of bivariate logistic regression showed that log score but not number of angiographically diseased vessels significantly predicted the probability of a coronary heart disease-related event occurring during follow-up. CONCLUSIONS: Electron beam computed tomographic calcium scores correlate moderately well with angiographic findings. These scores predict coronary heart disease-related events in patients undergoing angiography as well as do the number of angiographically affected arteries.
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Calcinosis/diagnóstico por imagen , Calcinosis/epidemiología , Angiografía Coronaria , Enfermedad Coronaria/diagnóstico por imagen , Enfermedad Coronaria/epidemiología , Supervivencia sin Enfermedad , Femenino , Humanos , Procesamiento de Imagen Asistido por Computador , Modelos Logísticos , Masculino , Persona de Mediana Edad , Valor Predictivo de las Pruebas , Pronóstico , Curva ROC , Sensibilidad y Especificidad , Tomografía Computarizada por Rayos X/métodosRESUMEN
OBJECTIVES: This research investigated the prognostic significance of radiographically detectable coronary calcific deposits. BACKGROUND: Coronary calcific deposits are almost always associated with coronary atherosclerosis. We investigated the association between fluoroscopically determined coronary calcium and coronary heart disease end points at 1 year of follow-up. METHODS: This prospective population-based cohort study was conducted in the suburbs of Los Angeles. Fourteen hundred sixty-one asymptomatic adults with an estimated > or = 10% risk of having a coronary heart disease event within 8 years underwent cardiac cinefluoroscopy for assessment of coronary calcium at initiation of the study. Clinical status including angina, documented myocardial infarction, myocardial revascularization and death from coronary heart disease were determined after 1 year. RESULTS: The prevalence of calcific deposits was high (47%). A follow-up examination at 1 year was successfully completed in 99.9% of subjects. Six subjects (0.4%) had died from coronary heart disease and 9 (0.6%) had had a nonfatal myocardial infarction. Thirty-seven subjects (2.5%) reported angina pectoris, and 13 (0.9%) had undergone myocardial revascularization. Fifty-three subjects had at least one event during the 1-year period. Radiographically detectable calcium was associated with the presence of at least one of these end points, with a risk ratio of 2.7 (confidence limits 1.4, 4.6). The presence of coronary calcium was an independent predictor of at least one end point when controlling for age, gender and risk factors. However, three deaths due to coronary heart disease and two nonfatal myocardial infarctions occurred in subjects without detectable coronary calcium. CONCLUSIONS: The presence of coronary calcific deposits incurs an increased risk of coronary heart disease events in asymptomatic high risk subjects at 1 year. This increased risk is independent of that incurred by standard risk factors.
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Calcinosis/diagnóstico por imagen , Enfermedad Coronaria/diagnóstico por imagen , Isquemia Miocárdica/epidemiología , Anciano , Calcinosis/complicaciones , Cinerradiografía , Enfermedad Coronaria/complicaciones , Femenino , Humanos , Modelos Logísticos , Masculino , Persona de Mediana Edad , Isquemia Miocárdica/etiología , Isquemia Miocárdica/mortalidad , Pronóstico , Estudios Prospectivos , Factores de RiesgoRESUMEN
The aim of this investigation was to determine the difference in accuracy between two frequently published noninvasive indicators of severity of coronary artery disease (exercise-induced ST segment depression and heart rate-adjusted ST depression [ST/HR index]). The study was designed as a survey of consecutive patients undergoing exercise electrocardiography and coronary angiography. There were a total of 2,270 patients without prior myocardial infarction or cardiac valvular disease referred for angiography from eight institutions in three countries; 401 of these patients had triple-vessel or left main coronary artery disease. The sensitivities of ST depression and ST/HR index in detecting triple-vessel or left main coronary artery disease were, respectively, 75% and 78% (p = 0.08) at cut point values where their specificities were equal (64%). This small increase in the accuracy of the ST/HR index was evident only at peak exercise heart rates below the median value of 132 beats/min, where the sensitivities of ST depression and ST/HR index were 73% and 76% (p = 0.03), respectively, at cut point values corresponding to a specificity of 60%. These results were consistent at all eight participating institutions. The increase in accuracy achieved by dividing exercise-induced ST depression by heart rate is small and confined exclusively to a low exercise heart rate. This lack of superiority cannot be generalized to all methods of heart rate adjustment.
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Enfermedad Coronaria/diagnóstico , Electrocardiografía , Prueba de Esfuerzo , Frecuencia Cardíaca/fisiología , Sesgo , Angiografía Coronaria , Enfermedad Coronaria/epidemiología , Enfermedad Coronaria/mortalidad , Electrocardiografía/métodos , Electrocardiografía/estadística & datos numéricos , Europa (Continente)/epidemiología , Prueba de Esfuerzo/métodos , Prueba de Esfuerzo/estadística & datos numéricos , Femenino , Humanos , Masculino , Persona de Mediana Edad , Pronóstico , Curva ROC , Derivación y Consulta , Estados Unidos/epidemiologíaRESUMEN
To evaluate the comparative effects of methodologic factors on the reported accuracies of two standard exercise tests, 56 publications comparing the exercise thallium scintigram with the coronary angiogram were analyzed for conformation to five methodologic standards. Analyzed were adequate definition of study group, avoidance of a limited challenge group, avoidance of workup bias, and blinded analysis of the coronary angiogram and myocardial scintigram. Study group characteristics and technical factors were also reviewed. Better conformation with methodologic standards was found than has been reported previously for treadmill exercise testing. Furthermore, study group characteristics and technical factors were better predictors of sensitivity and specificity than were methodologic deficiencies. Only workup bias and test blinding were significantly associated with test accuracy. The percentage of patients with previous myocardial infarction had the highest correlation and was independently and directly related to sensitivity and inversely related to specificity.
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Enfermedad Coronaria/diagnóstico , Prueba de Esfuerzo/métodos , Corazón/diagnóstico por imagen , Radioisótopos de Talio , Angiografía Coronaria , Electrocardiografía , Estudios de Evaluación como Asunto , Humanos , Esfuerzo Físico , Cintigrafía , Proyectos de Investigación , Estadística como AsuntoRESUMEN
PURPOSE: To determine the predictive value of coronary calcifications for coronary heart disease events in high-risk, asymptomatic adults: PATIENTS AND METHODS: A prospective cohort study of 1,461 high-risk, asymptomatic subjects were followed for 55 months with a 98% success rate. Coronary risk factor assessment and cardiac fluoroscopy with digital subtraction enhancement were performed to determine the number of calcified coronary arteries. RESULTS: Fifty-eight percent of this cohort (852 subjects) had fluoroscopically detectable coronary calcification: 437 (30%) had calcium in one, 253 (17%) in two, and 162 (11%) in all three coronary vessels. There were 90 (6%) deaths, 35 (39%) attributable to coronary heart disease, and 43 (3%) nonfatal myocardial infarctions. Subjects with calcification in more than one major coronary artery were 2.2 times more likely to suffer coronary death or nonfatal infarction (P = 0.001) than were subjects with one or no calcified arteries. Multivariable logistic regression analysis showed that only the number of calcified arteries, age, total cholesterol, history of diabetes, and left ventricular hypertrophy by electrocardiogram were associated independently with the incidence of coronary death or infarction in these subjects. CONCLUSIONS: Coronary calcification predicts coronary heart disease death or infarction in high-risk asymptomatic adults as well as do standard risk factors.
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Calcinosis/diagnóstico , Enfermedad Coronaria/diagnóstico , Adulto , Anciano , Anciano de 80 o más Años , Estudios de Cohortes , Enfermedad Coronaria/mortalidad , Supervivencia sin Enfermedad , Femenino , Fluoroscopía , Humanos , Modelos Logísticos , Masculino , Análisis Multivariante , Infarto del Miocardio/diagnóstico , Estudios Prospectivos , Factores de RiesgoRESUMEN
Technical and methodological factors might affect the reported accuracies of diagnostic tests. To assess their influence on the accuracy of exercise thallium scintigraphy, the medical literature (1977 to 1986) was non-selectively searched and meta-analysis was applied to the 56 publications thus retrieved. These were analyzed for year of publication, sex and mean age of patients, percentage of patients with angina pectoris, percentage of patients with prior myocardial infarction, percentage of patients taking beta-blocking medications, and for angiographic referral (workup) bias, blinding of tests, and technical factors. The percentage of patients with myocardial infarction had the highest correlation with sensitivity (0.45, p = 0.0007). Only the inclusion of subjects with prior infarction and the percentage of men in the study group were independently and significantly (p less than 0.05) related to test sensitivity. Both the presence of workup bias and publication year adversely affected specificity (p less than 0.05). Of these two factors, publication year had the strongest association by stepwise linear regression. This analysis suggests that the reported sensitivity of thallium scintigraphy is higher and the specificity lower than that expected in clinical practice because of the presence of workup bias and the inappropriate inclusion of post-infarct patients.
Asunto(s)
Enfermedad Coronaria/diagnóstico , Prueba de Esfuerzo/métodos , Radioisótopos de Talio , Adulto , Angiografía Coronaria , Enfermedad Coronaria/diagnóstico por imagen , Femenino , Humanos , Masculino , Persona de Mediana Edad , Infarto del Miocardio/diagnóstico por imagen , Cintigrafía , Proyectos de Investigación , Sensibilidad y Especificidad , Estadística como AsuntoRESUMEN
The objective of this study was to predict the prognosis of patients who become symptomatic after having undergone coronary artery bypass grafting (CABG) using clinical and exercise test responses. A retrospective analysis was performed of all veterans referred for clinical indications to a Veterans Administration Medical Center for a treadmill test after having undergone CABG. Of 2,044 patients who were exercise tested from April 1984 to May 1987, 296 had previously undergone CABG. Clinical data considered included age, sex, medication and symptom status, history of myocardial infarction, type of myocardial infarction and time from CABG. The exercise test responses considered were MET level, maximal heart rate, maximal systolic blood pressure, chest pain pattern and ST-segment response. During a 2-year follow-up after exercise testing, there were 15 deaths, 11 nonfatal myocardial infarctions, 6 repeat CABGs and 3 percutaneous transluminal coronary angioplasties. Although MET level and maximal heart rate were significantly related to prognosis and no patient who exceeded 8 METs died, the predictive power of these exercise test responses was low and ST-segment depression was not predictive at all. The inability of the exercise electrocardiogram to predict cardiac events in patients after CABG requires the use of other methods of testing to identify those who need invasive studies and intervention.
Asunto(s)
Puente de Arteria Coronaria , Prueba de Esfuerzo , Infarto del Miocardio/cirugía , Angiografía , Angiografía Coronaria , Electrocardiografía , Femenino , Estudios de Seguimiento , Humanos , Masculino , Persona de Mediana Edad , Infarto del Miocardio/diagnóstico , Pronóstico , Estudios RetrospectivosRESUMEN
To compare the accuracy of cinefluoroscopy, exercise electrocardiography and thallium perfusion imaging in diagnosing coronary artery disease (CAD), these 3 studies were performed in 297 subjects without prior acute myocardial infarction who were referred for coronary angiography. Of the 137 patients who had more than 50% angiographic diameter narrowing in at least 1 major coronary artery, 91 (67%) were correctly identified by cinefluoroscopy, 90 (66%) by stress electrocardiography and 100 (73%) by thallium imaging. Of the 164 patients with no more than 50% diameter narrowing, the proportion of patients correctly identified as normal were 81%, 72% and 79%, respectively. Cardiac cinefluoroscopy correctly classified 74% of the 297 subjects as to their disease status (more than 50% coronary narrowing), compared to 69% for stress electrocardiography and 76% for thallium imaging. There was no significant difference between the sensitivity or specificity of the test combination of stress electrocardiography and cinefluoroscopy and the combination of stress electrocardiography and thallium imaging. Cardiac cinefluoroscopy, a relatively cost-effective diagnostic test, is similar in accuracy to other, more expensive noninvasive diagnostic examinations for CAD.
Asunto(s)
Cinerradiografía , Enfermedad Coronaria/diagnóstico por imagen , Factores de Edad , Angiocardiografía , Enfermedad Coronaria/complicaciones , Electrocardiografía , Prueba de Esfuerzo , Femenino , Humanos , Hipertensión/complicaciones , Masculino , Persona de Mediana Edad , Cintigrafía , Factores Sexuales , TalioRESUMEN
A novel method in the measurement of left ventricular (LV) area using noncontrast electron beam computed tomography (EBCT) was introduced and studied as a diagnostic and prognostic marker for coronary artery disease. Larger LV area measured by noncontrast EBCT was significantly associated with angiographic coronary disease and was a better predictor of coronary disease events than log calcium score.