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1.
Mol Psychiatry ; 20(9): 1030-6, 2015 Sep.
Artículo en Inglés | MEDLINE | ID: mdl-26033238

RESUMEN

Previous reports from National Institutes of Health and National Science Foundation have suggested that peer review scores of funded grants bear no association with grant citation impact and productivity. This lack of association, if true, may be particularly concerning during times of increasing competition for increasingly limited funds. We analyzed the citation impact and productivity for 1755 de novo investigator-initiated R01 grants funded for at least 2 years by National Institute of Mental Health between 2000 and 2009. Consistent with previous reports, we found no association between grant percentile ranking and subsequent productivity and citation impact, even after accounting for subject categories, years of publication, duration and amounts of funding, as well as a number of investigator-specific measures. Prior investigator funding and academic productivity were moderately strong predictors of grant citation impact.


Asunto(s)
Factor de Impacto de la Revista , Revisión de la Investigación por Pares , Estudios de Cohortes , Humanos , National Institute of Mental Health (U.S.) , National Institutes of Health (U.S.) , Estados Unidos
3.
Circulation ; 104(16): 1911-6, 2001 Oct 16.
Artículo en Inglés | MEDLINE | ID: mdl-11602493

RESUMEN

BACKGROUND: An attenuated heart rate recovery after exercise has been shown to be predictive of mortality. In prior studies, recovery heart rates were measured while patients were exercising lightly, that is, during a cool-down period. It is not known whether heart rate recovery predicts mortality when measured in the absence of a cool-down period or after accounting for left ventricular systolic function. METHODS AND RESULTS: We followed 5438 consecutive patients without a history of heart failure or valvular disease referred for exercise echocardiography for 3 years. Heart rate recovery was defined as the difference in heart rate between peak exercise and 1 minute later; a value

Asunto(s)
Ecocardiografía , Prueba de Esfuerzo/estadística & datos numéricos , Frecuencia Cardíaca , Disfunción Ventricular Izquierda/diagnóstico , Disfunción Ventricular Izquierda/mortalidad , Adulto , Anciano , Estudios de Cohortes , Electrocardiografía , Femenino , Humanos , Masculino , Persona de Mediana Edad , Análisis Multivariante , Ohio , Valor Predictivo de las Pruebas , Modelos de Riesgos Proporcionales , Reproducibilidad de los Resultados , Sensibilidad y Especificidad , Volumen Sistólico , Posición Supina , Tasa de Supervivencia , Disfunción Ventricular Izquierda/fisiopatología
4.
Circulation ; 100(24): 2411-7, 1999 Dec 14.
Artículo en Inglés | MEDLINE | ID: mdl-10595953

RESUMEN

BACKGROUND: An abnormally low chronotropic response and an abnormally high ventilatory response (V(E)/V(CO2)) to exercise are common in patients with severe heart failure, but their relative prognostic impacts have not been well explored. METHODS AND RESULTS: Consecutive patients with heart failure referred for metabolic stress testing who were not taking beta-blockers or intravenous inotropes (n=470) were followed for 1.5 years. The chronotropic index was calculated while peak V(O2) and V(E)/V(CO2) were directly measured. Chronotropic index and peak V(O2) were considered abnormal if in the lowest 25th percentiles of the patient cohort, whereas V(E)/V(CO2) was considered abnormal if in the highest 25th percentile. For comparative purposes, a group of 17 healthy controls underwent metabolic testing as well. Compared with controls, heart failure patients had markedly abnormal ventilatory and chronotropic responses to exercise. In the heart failure cohort, there were 71 deaths. In univariate analyses, predictors of death included high V(E)/V(CO2) low chronotropic index, low V(O2), low resting systolic blood pressure, and older age. Nonparametric Kaplan-Meier plots demonstrated that by dividing the population according to peak V(E)/V(CO2) and peak V(O2), it is possible to identify low, intermediate, and very high risk groups. In multivariate analyses, the only independent predictors of death were high V(E)/V(CO2) (adjusted relative risk [RR] 3.20, 95% CI 1.95 to 5.26, P<0.0001) and low chronotropic index (adjusted RR 1.94, 95% CI 1.18 to 3.19, P=0.0009). CONCLUSIONS: The ventilatory and chronotropic responses to exercise are powerful and independent predictors of heart failure mortality.


Asunto(s)
Insuficiencia Cardíaca/diagnóstico , Insuficiencia Cardíaca/mortalidad , Frecuencia Cardíaca , Esfuerzo Físico , Respiración , Adolescente , Adulto , Anciano , Presión Sanguínea , Dióxido de Carbono/análisis , Enfermedad Crónica , Estudios de Cohortes , Prueba de Esfuerzo , Femenino , Estudios de Seguimiento , Insuficiencia Cardíaca/fisiopatología , Humanos , Masculino , Persona de Mediana Edad , Análisis Multivariante , Oxígeno/análisis , Valor Predictivo de las Pruebas , Intercambio Gaseoso Pulmonar , Factores de Riesgo , Análisis de Supervivencia
5.
Circulation ; 104(9): 992-7, 2001 Aug 28.
Artículo en Inglés | MEDLINE | ID: mdl-11524391

RESUMEN

BACKGROUND: Established methods of risk assessment in percutaneous coronary intervention have focused on clinical and anatomical lesion characteristics. Emerging evidence indicates the substantial contribution of inflammatory processes to short-term and long-term outcomes in coronary artery disease. METHODS AND RESULTS: Within a single-center registry of contemporary percutaneous coronary revascularization strategies with postprocedural creatine kinase and clinical events routinely recorded, we assessed the association of baseline C-reactive protein with death or myocardial infarction within the first 30 days. Predictive usefulness of baseline C-reactive protein within the context of established clinical and angiographic predictors of risk was also examined. Among 727 consecutive patients, elevated baseline C-reactive protein before percutaneous coronary intervention was associated with progressive increase in death or myocardial infarction at 30 days (lowest quartile, 3.9%, versus highest quartile, 14.2%; P=0.002). Among clinical and procedural characteristics, baseline C-reactive protein remained independently predictive of adverse events, with the highest quartile of C-reactive protein associated with an odds ratio for excess 30-day death or myocardial infarction of 3.68 (95% CI, 1.51 to 8.99; P=0.004). A predictive model that included baseline C-reactive protein quartiles, American College of Cardiology/American Heart Association lesion score, acute coronary syndrome presentation, and coronary stenting appears strongly predictive of 30-day death or myocardial infarction within this population (C-statistic, 0.735) and among individual patients (Brier score, 0.006). CONCLUSIONS: Elevated baseline C-reactive protein portends heightened risk of 30-day death or myocardial infarction after coronary intervention. Coupled anatomic, clinical, and inflammatory risk stratification demonstrates strong predictive utility among patients undergoing percutaneous coronary intervention and may be useful for guiding future strategies.


Asunto(s)
Proteína C-Reactiva/metabolismo , Enfermedad Coronaria/terapia , Anciano , Angioplastia Coronaria con Balón , Enfermedad Coronaria/metabolismo , Enfermedad Coronaria/patología , Femenino , Humanos , Masculino , Persona de Mediana Edad , Análisis Multivariante , Infarto del Miocardio/metabolismo , Infarto del Miocardio/mortalidad , Infarto del Miocardio/patología , Valor Predictivo de las Pruebas , Pronóstico , Análisis de Supervivencia , Tasa de Supervivencia , Factores de Tiempo
6.
Circulation ; 104(18): 2205-9, 2001 Oct 30.
Artículo en Inglés | MEDLINE | ID: mdl-11684632

RESUMEN

BACKGROUND: Recent studies have supported the hypothesis that calcific aortic stenosis is the product of an active inflammatory process, with similarities to atherosclerosis. We sought to determine whether therapy with hydroxymethylglutaryl coenzyme A reductase inhibitors (statins) might slow the progression of aortic stenosis. METHODS AND RESULTS: A retrospective study of 174 patients (mean age 68+/-12 years) with mild to moderate calcific aortic stenosis was conducted. Patients required normal left ventricular function, /=2 echocardiograms performed at least 12 months apart. Fifty-seven patients (33%) received treatment with a statin; the remaining 117 (67%) did not. The statin group was older and had a higher prevalence of hypertension, diabetes mellitus, and coronary disease. During a mean follow-up of 21 months, patients treated with statin had a smaller increase in peak and mean gradient and a smaller decrease in aortic valve area. When annualized, the decrease in aortic valve area for the nonstatin group was 0.11+/-0.18 cm(2) compared with 0.06+/-0.16 cm(2) for those treated with a statin (P=0.03). In multivariate analysis, statin usage was a significant independent predictor of a smaller decrease in valve area (P=0.01) and a lesser increase in peak gradient (P=0.02). CONCLUSIONS: Statin-treated patients, despite a higher risk profile for progression, had reduced aortic stenosis progression compared with those not treated with a statin. These data provide justification for a prospective randomized trial to substantiate whether statin therapy slows the progression of aortic stenosis.


Asunto(s)
Estenosis de la Válvula Aórtica/tratamiento farmacológico , Calcinosis/tratamiento farmacológico , Inhibidores de Hidroximetilglutaril-CoA Reductasas/uso terapéutico , Anciano , Estenosis de la Válvula Aórtica/complicaciones , Estenosis de la Válvula Aórtica/diagnóstico por imagen , Atorvastatina , Calcinosis/complicaciones , Calcinosis/diagnóstico por imagen , HDL-Colesterol/sangre , LDL-Colesterol/sangre , Progresión de la Enfermedad , Ecocardiografía , Electrocardiografía/efectos de los fármacos , Ácidos Grasos Monoinsaturados/uso terapéutico , Femenino , Fluvastatina , Estudios de Seguimiento , Ácidos Heptanoicos/uso terapéutico , Humanos , Indoles/uso terapéutico , Lovastatina/uso terapéutico , Masculino , Análisis Multivariante , Pravastatina/uso terapéutico , Pirroles/uso terapéutico , Estudios Retrospectivos , Factores de Riesgo , Simvastatina/uso terapéutico , Resultado del Tratamiento , Triglicéridos/sangre , Grado de Desobstrucción Vascular/efectos de los fármacos
7.
J Am Coll Cardiol ; 18(5): 1287-94, 1991 Nov 01.
Artículo en Inglés | MEDLINE | ID: mdl-1833430

RESUMEN

To determine whether long-term blood pressure levels correlate with left ventricular mass, echocardiographic measurements were performed in 152 men and 299 women who were participants in the Framingham Heart Study. All subjects were free of obesity and cardiovascular and pulmonary disease, were not taking antihypertensive medications and had echocardiographic studies that were adequate for estimating left ventricular mass. Thirty-year average systolic blood pressure was correlated with left ventricular mass (corrected for height) (r = 0.27, p less than 0.001 in men; r = 0.31, p less than 0.001 in women). Multivariate linear regression analyses taking into account age and body mass index showed 30-year average systolic blood pressure to be a significant independent predictor of left ventricular mass (p less than 0.01 in men and women). Systolic blood pressure at echocardiography was not independently associated with left ventricular mass when 30-year systolic blood pressure was entered into the multivariate model. The prevalence of left ventricular hypertrophy was associated with 30-year average systolic blood pressure (odds ratio for every 20-mm Hg increase in blood pressure: 3.20, p less than 0.05 in men; 3.27, p less than 0.001 in women). The increase in left ventricular mass associated with 30-year average systolic blood pressure reflected changes in left ventricular wall thickness but not in left ventricular internal dimension. Thirty-year average diastolic blood pressure was also correlated with left ventricular mass but to a lesser degree than was systolic blood pressure (r = 0.18, p less than 0.05 in men; r = 0.18, p less than 0.01 in women).(ABSTRACT TRUNCATED AT 250 WORDS)


Asunto(s)
Envejecimiento/fisiología , Presión Sanguínea/fisiología , Ecocardiografía , Adulto , Estatura/fisiología , Índice de Masa Corporal , Cardiomegalia/epidemiología , Femenino , Estudios de Seguimiento , Ventrículos Cardíacos/diagnóstico por imagen , Humanos , Masculino , Persona de Mediana Edad , Prevalencia , Estudios Prospectivos , Valores de Referencia , Análisis de Regresión
8.
J Am Coll Cardiol ; 26(4): 1039-46, 1995 Oct.
Artículo en Inglés | MEDLINE | ID: mdl-7560597

RESUMEN

OBJECTIVES: The purpose of this investigation was to derive population-based reference values for M-mode echocardiographic dimensions that can be applied in epidemiologic studies, clinical trials and clinical practice and to determine optimal methods for adjusting these dimensions for body size. BACKGROUND: M-mode echocardiography remains an important modality for studying cardiovascular disease; this is especially true with regard to detecting target organ damage in systemic hypertension. Most previously published reference values were derived from hospital-based series or relatively small samples and were not gender specific. METHODS: Using a sample of 288 men and 524 women who were between 20 and 45 years of age and who were free of cardiovascular disease, reference values were derived for end-diastolic and end-systolic left ventricular internal dimensions, left ventricular wall thickness and left atrial dimension. The relations between these dimensions and height, a measure of body size relatively independent of obesity, were investigated using various regression models. RESULTS: Nomograms for mean and 95th percentile values in men and women were constructed on the basis of linear regression models relating echocardiographic dimensions to height. Adjustment for body surface area greatly attenuated associations between obesity and cardiac dimensions in a separate healthy but less restricted sample of 411 men and 503 women. CONCLUSIONS: Gender-specific M-mode reference values and nomograms, with mean and 95th percentile values for echocardiographic dimensions as a function of height, are reported. The use of body surface area as means of body size adjustment is called into question.


Asunto(s)
Estatura , Ecocardiografía , Adulto , Superficie Corporal , Estudios de Cohortes , Femenino , Humanos , Hipertrofia Ventricular Izquierda/diagnóstico por imagen , Hipertrofia Ventricular Izquierda/epidemiología , Modelos Lineales , Masculino , Massachusetts/epidemiología , Persona de Mediana Edad , Estudios Prospectivos , Valores de Referencia , Muestreo , Factores Sexuales
9.
J Am Coll Cardiol ; 19(1): 130-4, 1992 Jan.
Artículo en Inglés | MEDLINE | ID: mdl-1729324

RESUMEN

Increased left ventricular mass has been shown to be a significant independent predictor of cardiovascular risk. The purpose of this study was to assess the separate and combined relations of obesity and hypertension with left ventricular mass and geometry. Echocardiographic findings in subjects in the Framingham Heart Study who were free of cardiopulmonary disease and were not taking cardiovascular medications were examined. M-mode studies that were adequate for estimating left ventricular mass were available in 624 men and 1,209 women. Height and weight measured at the time of echocardiography were used to calculate body mass index (in kg/m2), a measure of obesity. Casual sitting blood pressure measurements were obtained to detect rest hypertension. In subgroup analyses of lean normotensive, obese normotensive, lean hypertensive and obese hypertensive subjects, hypertension and obesity each had significant independent associations with left ventricular mass and wall thickness (all p less than 0.001 in men and women). Obesity was also associated with left ventricular internal diameter (p less than 0.001 in men and women). There were no synergistic influences of hypertension and obesity on any echocardiographic left ventricular variables. It is concluded that obesity and hypertension each have distinct associations with left ventricular mass and geometry. These strengths of association are additive but not synergistic.


Asunto(s)
Hipertensión/fisiopatología , Obesidad/fisiopatología , Adulto , Presión Sanguínea , Estatura , Peso Corporal , Ecocardiografía , Femenino , Ventrículos Cardíacos/diagnóstico por imagen , Ventrículos Cardíacos/fisiopatología , Humanos , Hipertensión/diagnóstico por imagen , Hipertensión/epidemiología , Masculino , Massachusetts/epidemiología , Persona de Mediana Edad , Obesidad/diagnóstico por imagen , Obesidad/epidemiología , Tamaño de los Órganos/fisiología , Análisis de Regresión
10.
J Am Coll Cardiol ; 30(1): 83-90, 1997 Jul.
Artículo en Inglés | MEDLINE | ID: mdl-9207625

RESUMEN

OBJECTIVES: This study prospectively compared the incremental prognostic benefit of exercise echocardiography with that of exercise testing in a large cohort. BACKGROUND: Exercise echocardiography is widely accepted as a diagnostic tool, but the prognostic information provided by this test, incremental to clinical and stress testing evaluation, is ill-defined. METHODS: Clinical, exercise and echocardiographic variables were studied in a consecutive group of 500 patients undergoing exercise echocardiography. After exclusion of patients who underwent revascularization within 3 months of the stress test (n = 16, 3%) and those lost to follow-up (n = 21, 4%), the remaining 463 patients (mean [+/-SD] age 57 +/- 12 years, 302 men) were followed-up for 44 +/- 11 months. Outcome was related to the exercise and echocardiographic findings, and the incremental prognostic benefit of exercise echocardiography was compared with that of standard exercise testing. RESULTS: Cardiac events occurred in 81 patients (17%), including 33 (7%) with spontaneous events (cardiac death, myocardial infarction and unstable angina) and 48 with late revascularizations due to progressive symptoms. In a multivariate Cox proportional hazards model, the likelihood of any cardiac event was increased in the presence of ischemia (relative risk [RR] 5.06, 95% confidence interval [CI] 3.09 to 8.29, p < 0.001) and lessened by more maximal stress, measured as percent age-predicted maximal heart rate (RR per 5% increment 0.84, 95% CI 0.77 to 0.92, p < 0.001). Spontaneous events were more strongly predicted by ischemia (RR 8.20, 95% CI 3.41 to 19.71, p < 0.001) and percent age-predicted maximal heart rate (RR per 5% increment 0.78, 95% CI 0.67 to 0.91, p < 0.001). An interactive logistic regression model showed that the addition of echocardiographic to exercise and clinical data offered incremental predictive value. CONCLUSIONS: The presence of ischemia on the exercise echocardiogram can predict whether patients will experience an event. This relation is independent of, and incremental to, clinical and exercise data.


Asunto(s)
Enfermedad Coronaria/diagnóstico por imagen , Enfermedad Coronaria/fisiopatología , Ecocardiografía , Prueba de Esfuerzo , Anciano , Factores de Confusión Epidemiológicos , Ecocardiografía/métodos , Femenino , Humanos , Modelos Logísticos , Masculino , Persona de Mediana Edad , Análisis Multivariante , Isquemia Miocárdica/diagnóstico por imagen , Isquemia Miocárdica/fisiopatología , Valor Predictivo de las Pruebas , Pronóstico , Modelos de Riesgos Proporcionales , Estudios Prospectivos , Riesgo
11.
J Am Coll Cardiol ; 34(3): 754-9, 1999 Sep.
Artículo en Inglés | MEDLINE | ID: mdl-10483957

RESUMEN

OBJECTIVE: This study was performed to determine whether a delayed decline in systolic blood pressure (SBP) after graded exercise is an independent correlate of angiographic coronary disease. BACKGROUND: The predictive importance of the rate of SBP decline after exercise relative to blood pressure changes during exercise has not been well explored. METHODS: Among adults who underwent symptom-limited exercise treadmill testing and who underwent coronary angiography within 90 days, a delayed decline in SBP during recovery was defined as a ratio of SBPs at 3 min of recovery to SBP at 1 min of recovery >1.0. Severe angiographic coronary artery disease was defined as left main disease, three-vessel disease or two-vessel disease with involvement of the proximal left anterior descending artery. RESULTS: There were 493 subjects eligible for analyses (age 59 +/- 11 years, 78% male). Severe angiographic coronary disease was noted in 102 (21%). There were associations noted between a delayed decline in SBP during recovery and severe angiographic coronary disease (34% vs. 17%, odds ratio [OR] 2.59, confidence interval [CI] 1.58 to 4.25, p = 0.001). In multivariate logistic regression analyses adjusting for SBP changes during exercise and other potential confounders, a delayed decline in SBP during recovery remained predictive of severe angiographic coronary disease (adjusted OR 2.22, 95% CI 1.27 to 3.87, p = 0.005). CONCLUSIONS: A delayed decline in SBP during recovery is associated with a greater likelihood of severe angiographic coronary disease even after accounting for the change in SBP during exercise.


Asunto(s)
Presión Sanguínea , Angiografía Coronaria , Enfermedad Coronaria/diagnóstico por imagen , Enfermedad Coronaria/fisiopatología , Ejercicio Físico/fisiología , Anciano , Intervalos de Confianza , Angiografía Coronaria/métodos , Angiografía Coronaria/estadística & datos numéricos , Prueba de Esfuerzo/métodos , Prueba de Esfuerzo/estadística & datos numéricos , Femenino , Humanos , Modelos Logísticos , Masculino , Persona de Mediana Edad , Oportunidad Relativa , Pronóstico , Estudios Prospectivos , Sístole , Factores de Tiempo
12.
J Am Coll Cardiol ; 26(7): 1630-6, 1995 Dec.
Artículo en Inglés | MEDLINE | ID: mdl-7594096

RESUMEN

OBJECTIVES: This study was designed to assess the angiographic and prognostic implications of an exaggerated systolic blood pressure response to exercise ("exercise hypertension") in adults undergoing evaluation for suspected coronary artery disease. BACKGROUND: The clinical implications of exercise hypertension are unclear. METHODS: Subjects for this prospective cohort study were derived from a consecutive sample of 9,608 adults who were referred for treadmill testing and who augmented their systolic blood pressure by at least 10 mm Hg. There were 594 subjects who underwent coronary angiography within 90 days of treadmill testing. Exercise hypertension was defined as a peak exercise systolic blood pressure > or = 210 mm Hg in men and > or = 190 mm Hg in women. Severe angiographic coronary disease was defined as left main coronary artery disease (> or = 50% diameter stenosis), three-vessel disease (> or = 70% diameter stenosis) or two-vessel disease with > or = 70% diameter stenosis of the proximal left anterior descending coronary artery. All-cause mortality was assessed during a follow-up period of approximately 2 years. RESULTS: Exercise hypertension was present in 196 subjects (33%). Severe coronary disease was less common in subjects with exercise hypertension (14% vs. 25%, odds ratio 0.51, 95% confidence interval [CI] 0.32 to 0.81, p = 0.004). Exercise hypertension remained associated with a lower rate of severe coronary disease even after adjusting for rest hypertension, age, gender, exercise capacity and other possible confounders. During the follow-up period, there were 23 deaths; only 2 occurred in the group with exercise hypertension. After adjusting for severity of coronary disease, exercise hypertension remained associated with a lower mortality rate (adjusted relative risk 0.20, 95% CI 0.05 to 0.84, p = 0.03). CONCLUSIONS: In adults evaluated for coronary artery disease, exercise hypertension is associated with a lower likelihood of angiographically severe disease and a lower adjusted mortality rate.


Asunto(s)
Presión Sanguínea , Angiografía Coronaria , Enfermedad Coronaria/diagnóstico , Prueba de Esfuerzo , Estudios de Cohortes , Enfermedad Coronaria/diagnóstico por imagen , Enfermedad Coronaria/fisiopatología , Electrocardiografía , Femenino , Humanos , Hipertensión/etiología , Masculino , Persona de Mediana Edad , Pronóstico , Estudios Prospectivos , Sístole
13.
J Am Coll Cardiol ; 33(3): 750-8, 1999 Mar.
Artículo en Inglés | MEDLINE | ID: mdl-10080477

RESUMEN

OBJECTIVES: The aim of this study was to evaluate whether preoperative clinical and test data could be used to predict the effects of myocardial revascularization on functional status and quality of life in patients with heart failure and ischemic LV dysfunction. BACKGROUND: Revascularization of viable myocardial segments has been shown to improve regional and global LV function. The effects of revascularization on exercise capacity and quality of life (QOL) are not well defined. METHODS: Sixty three patients (51 men, age 66+/-9 years) with moderate or worse LV dysfunction (LVEF 0.28+/-0.07) and symptomatic heart failure were studied before and after coronary artery bypass surgery. All patients underwent preoperative positron emission tomography (PET) using FDG and Rb-82 before and after dipyridamole stress; the extent of viable myocardium by PET was defined by the number of segments with metabolism-perfusion mismatch or ischemia. Dobutamine echocardiography (DbE) was performed in 47 patients; viability was defined by augmentation at low dose or the development of new or worsening wall motion abnormalities. Functional class, exercise testing and a QOL score (Nottingham Health Profile) were obtained at baseline and follow-up. RESULTS: Patients had wall motion abnormalities in 83+/-18% of LV segments. A mismatch pattern was identified in 12+/-15% of LV segments, and PET evidence of viability was detected in 30+/-21% of the LV. Viability was reported in 43+/-18% of the LV by DbE. The difference between pre- and postoperative exercise capacity ranged from a reduction of 2.8 to an augmentation of 5.2 METS. The degree of improvement of exercise capacity correlated with the extent of viability by PET (r = 0.54, p = 0.0001) but not the extent of viable myocardium by DbE (r = 0.02, p = 0.92). The area under the ROC curve for PET (0.76) exceeded that for DbE (0.66). In a multiple linear regression, the extent of viability by PET and nitrate use were the only independent predictors of improvement of exercise capacity (model r = 0.63, p = 0.0001). Change in Functional Class correlated weakly with the change in exercise capacity (r = 0.25), extent of viable myocardium by PET (r = 0.23) and extent of viability by DbE (r = 0.31). Four components of the quality of life score (energy, pain, emotion and mobility status) significantly improved over follow-up, but no correlations could be identified between quality of life scores and the results of preoperative testing or changes in exercise capacity. CONCLUSIONS: In patients with LV dysfunction, improvement of exercise capacity correlates with the extent of viable myocardium. Quality of life improves in most patients undergoing revascularization. However, its measurement by this index does not correlate with changes in other parameters nor is it readily predictable.


Asunto(s)
Puente de Arteria Coronaria , Insuficiencia Cardíaca/fisiopatología , Isquemia Miocárdica/fisiopatología , Calidad de Vida , Disfunción Ventricular Izquierda/fisiopatología , Anciano , Cardiotónicos , Dobutamina , Ecocardiografía/métodos , Prueba de Esfuerzo , Femenino , Fluorodesoxiglucosa F18 , Estudios de Seguimiento , Insuficiencia Cardíaca/diagnóstico , Insuficiencia Cardíaca/cirugía , Humanos , Masculino , Isquemia Miocárdica/psicología , Isquemia Miocárdica/cirugía , Pronóstico , Estudios Prospectivos , Curva ROC , Radiofármacos , Sensibilidad y Especificidad , Tomografía Computarizada de Emisión , Disfunción Ventricular Izquierda/diagnóstico , Disfunción Ventricular Izquierda/cirugía , Función Ventricular Izquierda
14.
J Am Coll Cardiol ; 32(5): 1280-6, 1998 Nov.
Artículo en Inglés | MEDLINE | ID: mdl-9809937

RESUMEN

OBJECTIVES: This study sought to examine the prognostic importance of chronotropic incompetence among patients referred for stress echocardiography. BACKGROUND: Although chronotropic incompetence has been shown to be predictive of an adverse prognosis, it is not clear if this association is independent of exercise-induced myocardial ischemia. METHODS: Consecutive patients (146 men and 85 women; mean age 57 years) who were not taking beta-adrenergic blocking agents and were referred for symptom-limited exercise echocardiography were followed for a mean of 41 months. Chronotropic incompetence was assessed in two ways: (1) failure to achieve 85% of the age-predicted maximum heart rate and (2) a low chronotropic index, a heart rate response measure that accounts for effects of age, resting heart rate and physical fitness. RESULTS: The primary end point, a composite of death, nonfatal myocardial infarction, unstable angina and late (>3 months after the exercise test) myocardial revascularization, occurred in 41 patients. Failure to achieve 85% of the age-predicted maximum heart rate was predictive of events (relative risk [RR] 2.47, 95% confidence interval [CI] 1.28 to 4.79, p=0.007); similarly, a low chronotropic index was predictive (RR 2.44, 95% CI 1.31 to 4.55, p=0.005). Even after adjusting for myocardial ischemia and other possible confounders, failure to achieve 85% of age-predicted maximum heart rate was predictive (adjusted RR 2.20, 95% CI 1.11 to 4.37, p=0.02). A low chronotropic index also remained predictive (adjusted RR 1.85, 95% CI 0.98 to 3.47, p=0.06). CONCLUSIONS: Chronotropic incompetence is predictive of an adverse cardiovascular prognosis even after adjusting for echocardiographic myocardial ischemia.


Asunto(s)
Ecocardiografía , Frecuencia Cardíaca/fisiología , Isquemia Miocárdica/fisiopatología , Ecocardiografía/métodos , Prueba de Esfuerzo , Femenino , Estudios de Seguimiento , Humanos , Masculino , Persona de Mediana Edad , Isquemia Miocárdica/diagnóstico por imagen , Isquemia Miocárdica/mortalidad , Pronóstico , Modelos de Riesgos Proporcionales , Tasa de Supervivencia
15.
J Am Coll Cardiol ; 27(1): 132-9, 1996 Jan.
Artículo en Inglés | MEDLINE | ID: mdl-8522686

RESUMEN

OBJECTIVES: This study sought to establish the prognostic implications of ischemic and viable myocardium identified by dobutamine echocardiography in patients with left ventricular dysfunction. BACKGROUND: Recent studies have suggested that in patients with viable myocardium identified by positron emission tomography, medical treatment is associated with recurrent cardiac events. Dobutamine echocardiography has been used to identify viable myocardium in patients with left ventricular dysfunction, but the prognostic significance of this test is undefined. METHODS: One hundred thirty-six consecutive patients (mean [+/- SD] age 67 +/- 7.9 years; 104 men) with moderate or severe left ventricular dysfunction (left ventricular ejection fraction 30 +/- 5%) undergoing dobutamine echocardiography were included in the study. Dobutamine was administered using a standard incremental protocol (5 to 40 micrograms/kg body weight per min intravenously in 3-min stages) with additional atropine (1 mg intravenously) as required. Standard body weight echocardiographic views were digitized on-line and compared using a side-by-side display. Viable myocardium was identified by enhancement of regional function at low dose (< 10 micrograms); scar was diagnosed by akinesia at rest or dyskinesia without change and ischemia as new or worsening dysfunction. One hundred thirty patients (95%) were followed up for 16 +/- 8 months after the original study for major cardiac events (cardiac death, myocardial infarction or severe unstable angina requiring late myocardial revascularization). RESULTS: No significant complications occurred during dobutamine echocardiography. Viable myocardium was detected in 26 patients (19%), ischemia in 23 (17%), both viability and ischemia in 13 (10%) and scar in 74 (54%). Of 108 patients treated medically, 46 had viable or ischemic myocardium, and 62 had scar only. There were no significant differences in age or other clinical characteristics, stress response, left ventricular dimensions and ejection fraction between the two groups. Cardiac events occurred in 26 medically treated patients (24%): 18 died of cardiac-related causes; 4 had a nonfatal myocardial infarction; and 4 had late revascularization because of unstable angina. The event rate was greater in patients with viable or ischemic myocardium than those with scar (43% vs. 8%, p = 0.01 by log-rank test). In a Cox regression model, the presence of viable or ischemic myocardium was found to predict subsequent events (relative risk 3.51, p = 0.02) independently of ejection fraction and age. CONCLUSIONS: Viable or ischemic myocardium detected at dobutamine echocardiography in patients with left ventricular dysfunction is associated with an adverse prognosis, independent of age and ejection fraction.


Asunto(s)
Cardiotónicos , Dobutamina , Ecocardiografía/métodos , Isquemia Miocárdica/diagnóstico , Disfunción Ventricular Izquierda/complicaciones , Anciano , Anciano de 80 o más Años , Angiografía Coronaria , Electrocardiografía , Prueba de Esfuerzo , Femenino , Estudios de Seguimiento , Cardiopatías/epidemiología , Cardiopatías/etiología , Hemodinámica/fisiología , Humanos , Masculino , Persona de Mediana Edad , Isquemia Miocárdica/complicaciones , Isquemia Miocárdica/fisiopatología , Pronóstico , Análisis de Regresión , Factores de Riesgo , Análisis de Supervivencia , Disfunción Ventricular Izquierda/mortalidad , Disfunción Ventricular Izquierda/fisiopatología
16.
J Am Coll Cardiol ; 37(6): 1558-64, 2001 May.
Artículo en Inglés | MEDLINE | ID: mdl-11345365

RESUMEN

OBJECTIVES: The goal of this study was to determine the value of thallium201 single photon emission computed tomography (SPECT) imaging for prediction of all-cause mortality when considered along with functional capacity and heart rate recovery. BACKGROUND: Myocardial perfusion defects identified by thallium201 SPECT imaging are predictive of cardiac events. Functional capacity and heart rate recovery are exercise measures that also have prognostic implications. METHODS: We followed 7,163 consecutive adults referred for symptom-limited exercise thallium SPECT (mean age 60 +/- 10, 25% women) for 6.7 years. Using information theory, we identified a probable best model relating nuclear findings to outcome to calculate a prognostic nuclear score. RESULTS: There were 855 deaths. Intermediate- and high-risk prognostic nuclear scores were noted in 28% and 10% of patients. Compared with those with low-risk scans, patients with an intermediate-risk score were at increased risk for death (14% vs. 9%, hazard ratio: 1.67, 95% confidence interval [CI]: 1.44 to 1.95, p < 0.0001), while those with high-risk scores were at greater risk (24%, hazard ratio: 2.98, 95% CI: 2.49 to 3.56, p < 0.0001). In multivariable analyses that adjusted for clinical characteristics, functional capacity and heart rate recovery, an intermediate-risk nuclear score remained predictive of death (adjusted hazard ratio: 1.50, 95% CI: 1.28 to 1.76, p < 0.0001), as did a high-risk score (adjusted hazard ratio: 2.76, 95% CI: 2.13 to 2.56, p < 0.0001). Impaired functional capacity and decreased heart rate recovery provided additional prognostic information. CONCLUSIONS: Myocardial perfusion defects detected by thallium SPECT imaging are independently predictive of long-term all-cause death, even after accounting for exercise capacity, heart rate recovery and other potential confounders.


Asunto(s)
Causas de Muerte , Enfermedad Coronaria/diagnóstico por imagen , Enfermedad Coronaria/mortalidad , Prueba de Esfuerzo/normas , Frecuencia Cardíaca , Radioisótopos de Talio , Tomografía Computarizada de Emisión de Fotón Único/normas , Actividades Cotidianas , Anciano , Factores de Confusión Epidemiológicos , Enfermedad Coronaria/fisiopatología , Prueba de Esfuerzo/métodos , Femenino , Estudios de Seguimiento , Humanos , Teoría de la Información , Masculino , Persona de Mediana Edad , Análisis Multivariante , Valor Predictivo de las Pruebas , Pronóstico , Modelos de Riesgos Proporcionales , Factores de Riesgo , Análisis de Supervivencia , Tomografía Computarizada de Emisión de Fotón Único/métodos
17.
J Am Coll Cardiol ; 30(3): 641-8, 1997 Sep.
Artículo en Inglés | MEDLINE | ID: mdl-9283520

RESUMEN

OBJECTIVES: We sought to determine the relative influence of estimated functional capacity and thallium-201 (Tl-201) single-photon emission computed tomographic (SPECT) findings on prediction of short-term all-cause and cardiac-related mortality. BACKGROUND: Decreased functional capacity and abnormal Tl-201 SPECT findings are predictive of increased cardiovascular risk and mortality. However, the relative importance of these variables as predictors of all-cause mortality is not well established. METHODS: Analyses were based on 3,400 consecutive adults undergoing symptom-limited exercise Tl-201 SPECT testing at the Cleveland Clinic Foundation between September 1990 and December 1993; none had previous invasive procedures, heart failure or valve disease. Estimated functional capacity, classified by age and gender, and thallium perfusion defects, expressed as a stress extent thallium score on a 12-segment scale, were analyzed to determine their relative prognostic importance during 2 years of follow-up. RESULTS: Of 3,400 patients, 108 (3.2%) died during follow-up; 32 deaths were identified as cardiac related. On univariable analysis, estimated functional capacity was a strong predictor of death, with 62 (57%) deaths occurring in patients achieving < 6 metabolic equivalents (METs) (log-rank chi-square 86, p < 0.0001). On multivariable analysis, the strongest independent predictors of all-cause mortality were fair or poor functional capacity (adjusted relative risk [RR] 3.96, 95% confidence interval [CI] 2.36 to 6.64, chi-square 27, p < 0.0001) and age (adjusted RR for 10 years 2.25, 95% CI 1.80 to 2.80, chi-square 27, p < 0.0001). The presence of SPECT thallium perfusion defects was a less powerful predictor of death (for each two additional segments with defects, adjusted RR 1.21, 95% CI 1.03 to 1.43, chi-square 5, p = 0.02). Cardiac mortality was predicted by both fair or poor functional capacity (adjusted RR 4.37, 95% CI 1.59 to 12.00, chi-square 8, p = 0.004) and by stress extent thallium score (adjusted RR 1.62, 95% CI 1.25 to 2.11, chi-square 13, p = 0.0003). CONCLUSIONS: In this clinically low risk group, estimated functional capacity was a strong and overwhelmingly important independent predictor of all-cause mortality among patients undergoing exercise Tl-201 SPECT testing. The extent of myocardial perfusion defects was of comparable importance for the prediction of cardiac mortality.


Asunto(s)
Prueba de Esfuerzo , Tolerancia al Ejercicio , Mortalidad , Tomografía Computarizada de Emisión de Fotón Único , Adulto , Enfermedad Coronaria/diagnóstico , Enfermedad Coronaria/diagnóstico por imagen , Enfermedad Coronaria/fisiopatología , Femenino , Cardiopatías/mortalidad , Humanos , Masculino , Persona de Mediana Edad , Análisis Multivariante , Pronóstico , Modelos de Riesgos Proporcionales , Estudios Prospectivos , Radioisótopos de Talio
18.
J Am Coll Cardiol ; 32(5): 1366-70, 1998 Nov.
Artículo en Inglés | MEDLINE | ID: mdl-9809949

RESUMEN

OBJECTIVES: This study sought to determine whether the duration of pretreatment with the adenosine diphosphate receptor antagonist ticlopidine prior to intracoronary stenting is associated with the incidence of procedure-related non-Q-wave myocardial infarctions (MIs). BACKGROUND: Dual antiplatelet therapy with ticlopidine and aspirin is routinely used with stenting, although ticlopidine is commonly not begun until the day of the procedure. Periprocedural MIs are at least partially platelet-dependent events. As the maximal platelet inhibitory effects of this drug take 2 to 3 days to be realized, we hypothesized that longer treatment prior to stenting would be associated with lower rates of procedure-related MIs. METHODS: We reviewed outcomes in 175 consecutive patients treated with ticlopidine prior to stenting at the Cleveland Clinic Foundation. Those patients with an elevation in creatine kinase above our laboratory normal (>210 IU/L) with > or =4% MB fraction on routine evaluation were defined as having a non-Q-wave MI. RESULTS. There were 28 patients (16%) who had a non-Q-wave MI. Longer duration of ticlopidine pretreatment was strongly associated with a lower incidence of procedure-related non-Q-wave MIs (duration of pretreatment <1 day, 29% had MI; 1 to 2 days, 14%; > or =3 days, 5%; chi-square for trend=9.6; p=0.002). Ticlopidine pretreatment of > or =3 days was associated with a significant reduction in the risk of non-Q-wave MI (unadjusted odds ratio 0.18, 95% confidence interval=0.04 to 0.78, p=0.01) compared with pretreatment of <3 days. CONCLUSIONS: Among patients undergoing intracoronary stenting, beginning ticlopidine therapy several days prior to the procedure is associated with a reduced risk of procedural non-Q-wave MIs.


Asunto(s)
Implantación de Prótesis Vascular/efectos adversos , Infarto del Miocardio/prevención & control , Inhibidores de Agregación Plaquetaria/uso terapéutico , Cuidados Preoperatorios , Stents/efectos adversos , Ticlopidina/uso terapéutico , Enfermedad Coronaria/cirugía , Quimioterapia Combinada , Femenino , Estudios de Seguimiento , Humanos , Incidencia , Masculino , Persona de Mediana Edad , Infarto del Miocardio/epidemiología , Infarto del Miocardio/etiología , Oportunidad Relativa , Estudios Prospectivos , Factores de Riesgo , Factores de Tiempo
19.
J Am Coll Cardiol ; 33(3): 661-9, 1999 Mar.
Artículo en Inglés | MEDLINE | ID: mdl-10080466

RESUMEN

OBJECTIVES: The study aim was to determine observational differences in costs of care by the coronary disease diagnostic test modality. BACKGROUND: A number of diagnostic strategies are available with few data to compare the cost implications of the initial test choice. METHODS: We prospectively enrolled 11,372 consecutive stable angina patients who were referred for stress myocardial perfusion tomography or cardiac catheterization. Stress imaging patients were matched by their pretest clinical risk of coronary disease to a series of patients referred to cardiac catheterization. Composite 3-year costs of care were compared for two patients management strategies: 1) direct cardiac catheterization (aggressive) and 2) initial stress myocardial perfusion tomography and selective catheterization of high risk patients (conservative). Analysis of variance techniques were used to compare costs, adjusting for treatment propensity and pretest risk. RESULTS: Observational comparisons of aggressive as compared with conservative testing strategies reveal that costs of care were higher for direct cardiac catheterization in all clinical risk subsets (range: $2,878 to $4,579), as compared with stress myocardial perfusion imaging plus selective catheterization (range: $2,387 to $3,010, p < 0.0001). Coronary revascularization rates were higher for low, intermediate and high risk direct catheterization patients as compared with the initial stress perfusion imaging cohort (13% to 50%, p < 0.0001); cardiac death or myocardial infarction rates were similar (p > 0.20). CONCLUSIONS: Observational assessments reveal that stable chest pain patients who undergo a more aggressive diagnostic strategy have higher diagnostic costs and greater rates of intervention and follow-up costs. Cost differences may reflect a diminished necessity for resource consumption for patients with normal test results.


Asunto(s)
Angina de Pecho/diagnóstico , Cateterismo Cardíaco/economía , Tomografía Computarizada de Emisión de Fotón Único/economía , Angina de Pecho/economía , Costos y Análisis de Costo , Electrocardiografía , Prueba de Esfuerzo/economía , Femenino , Estudios de Seguimiento , Humanos , Masculino , Persona de Mediana Edad , Valor Predictivo de las Pruebas , Probabilidad , Estudios Prospectivos , Sistema de Registros , Sensibilidad y Especificidad
20.
Hypertension ; 25(6): 1155-60, 1995 Jun.
Artículo en Inglés | MEDLINE | ID: mdl-7768556

RESUMEN

Increased left atrial size has been identified as a precursor of atrial fibrillation and of stroke once atrial fibrillation is manifest. Conflicting data exist regarding the effect of high blood pressure on left atrial size. Our objective was to evaluate the association of contemporary and long-term measures of blood pressure with echocardiographically determined left atrial size in a large, population-based cohort. The study sample consisted of 1849 male and 2152 female participants of the Framingham Heart Study and Framingham Offspring Study. All analyses were sex specific. In correlation analyses, systolic and pulse pressures were identified as statistically significant determinants of left atrial size after adjustment for age and body mass index, although the magnitudes of these relations were very modest (partial r < or = .10). Multivariable linear regression models showed the relative contributions of the pressure variables to the prediction of left atrial size to be substantially less than those of age and, in particular, body mass index. Furthermore, inclusion of left ventricular mass in these multivariable models eliminated or attenuated the associations of the pressure variables with left atrial size. In logistic analyses, increasing levels of the pressure variables were significantly predictive of left atrial enlargement. Subjects with 8-year average systolic pressure of 140 mm Hg or higher were twice as likely to have left atrial enlargement as those with values of 110 mm Hg or lower. Overall, in this population-based study sample, increased levels of systolic and pulse pressures (but not diastolic or mean arterial pressures) were significantly associated with increased left atrial size.(ABSTRACT TRUNCATED AT 250 WORDS)


Asunto(s)
Presión Sanguínea , Cardiomegalia/etiología , Adulto , Anciano , Anciano de 80 o más Años , Envejecimiento/fisiología , Índice de Masa Corporal , Estudios de Cohortes , Femenino , Humanos , Masculino , Persona de Mediana Edad , Obesidad/complicaciones , Análisis de Regresión
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