Your browser doesn't support javascript.
loading
Mostrar: 20 | 50 | 100
Resultados 1 - 20 de 193
Filtrar
1.
Aliment Pharmacol Ther ; 47(11): 1453-1463, 2018 06.
Artículo en Inglés | MEDLINE | ID: mdl-29667211

RESUMEN

AIM: To evaluate GI safety of celecoxib compared with 2 nonselective (ns) NSAIDs, as a secondary objective of a large trial examining multiorgan safety. METHODS: This randomised, double-blind controlled trial analysed 24 081 patients. Osteoarthritis or rheumatoid arthritis patients, needing ongoing NSAID treatment, were randomised to receive celecoxib 100-200 mg b.d., ibuprofen 600-800 mg t.d.s. or naproxen 375-500 mg b.d. plus esomeprazole, and low-dose aspirin or corticosteroids if already prescribed. Clinically significant GI events (CSGIE-bleeding, obstruction, perforation events from stomach downwards or symptomatic ulcers) and iron deficiency anaemia (IDA) were adjudicated blindly. RESULTS: Mean treatment and follow-up durations were 20.3 and 34.1 months. While on treatment or 30 days after, CSGIE occurred in 0.34%, 0.74% and 0.66% taking celecoxib, ibuprofen and naproxen. Hazard ratios (HR) were 0.43 (95% CI 0.27-0.68, P = 0.0003) celecoxib vs ibuprofen and 0.51 (0.32-0.81, P = 0.004) vs naproxen. There was also less IDA on celecoxib: HR 0.43 (0.27-0.68, P = 0.0003) vs ibuprofen; 0.40 (0.25-0.62, P < 0.0001) vs naproxen. Even taken with low-dose aspirin, fewer CSGIE occurred on celecoxib than ibuprofen (HR 0.52 [0.29-0.94], P = 0.03), and less IDA vs naproxen (0.42 [0.23-0.77, P = 0.005]). Corticosteroid use increased total GI events and CSGIE. H. pylori serological status had no influence. CONCLUSIONS: Arthritis patients taking NSAIDs plus esomeprazole have infrequent clinically significant gastrointestinal events. Co-prescribed with esomeprazole, celecoxib has better overall GI safety than ibuprofen or naproxen at these doses, despite treatment with low-dose aspirin or corticosteroids.


Asunto(s)
Antiinflamatorios no Esteroideos/administración & dosificación , Artritis Reumatoide/tratamiento farmacológico , Celecoxib/administración & dosificación , Enfermedades Gastrointestinales/inducido químicamente , Ibuprofeno/administración & dosificación , Naproxeno/administración & dosificación , Osteoartritis/tratamiento farmacológico , Adulto , Anciano , Antiinflamatorios no Esteroideos/efectos adversos , Antiulcerosos/administración & dosificación , Antiulcerosos/efectos adversos , Artritis Reumatoide/diagnóstico , Artritis Reumatoide/epidemiología , Aspirina/administración & dosificación , Aspirina/efectos adversos , Celecoxib/efectos adversos , Método Doble Ciego , Quimioterapia Combinada , Esomeprazol/administración & dosificación , Esomeprazol/efectos adversos , Femenino , Enfermedades Gastrointestinales/diagnóstico , Enfermedades Gastrointestinales/epidemiología , Humanos , Ibuprofeno/efectos adversos , Masculino , Persona de Mediana Edad , Naproxeno/efectos adversos , Osteoartritis/diagnóstico , Osteoartritis/epidemiología , Resultado del Tratamiento
2.
Osteoporos Int ; 25(2): 737-45, 2014 Feb.
Artículo en Inglés | MEDLINE | ID: mdl-24322476

RESUMEN

UNLABELLED: We explored the cardiac safety of the osteoporosis treatment strontium ranelate in the UK Clinical Practice Research Datalink. While known cardiovascular risk factors like obesity and smoking were associated with increased cardiac risk, use of strontium ranelate was not associated with any increase in myocardial infarction or cardiovascular death. INTRODUCTION: It has been suggested that strontium ranelate may increase risk for cardiac events in postmenopausal osteoporosis. We set out to explore the cardiac safety of strontium ranelate in the Clinical Practice Research Datalink (CPRD) and linked datasets. METHODS: We performed a nested case-control study. Primary outcomes were first definite myocardial infarction, hospitalisation with myocardial infarction, and cardiovascular death. Cases and matched controls were nested in a cohort of women treated for osteoporosis. The association with exposure to strontium ranelate was analysed by multivariate conditional logistic regression. RESULTS: Of the 112,445 women with treated postmenopausal osteoporosis, 6,487 received strontium ranelate. Annual incidence rates for first definite myocardial infarction (1,352 cases), myocardial infarction with hospitalisation (1,465 cases), and cardiovascular death (3,619 cases) were 3.24, 6.13, and 14.66 per 1,000 patient-years, respectively. Obesity, smoking, and cardiovascular treatments were associated with significant increases in risk for cardiac events. Current or past use of strontium ranelate was not associated with increased risk for first definite myocardial infarction (odds ratio [OR] 1.05, 95 % confidence interval [CI] 0.68-1.61 and OR 1.12, 95 % CI 0.79-1.58, respectively), hospitalisation with myocardial infarction (OR 0.84, 95 % CI 0.54-1.30 and OR 1.17, 95 % CI 0.83-1.66), or cardiovascular death (OR 0.96, 95 % CI 0.76-1.21 and OR 1.16, 95 % CI 0.94-1.43) versus patients who had never used strontium ranelate. CONCLUSIONS: Analysis in the CPRD did not find evidence for a higher risk for cardiac events associated with the use of strontium ranelate in postmenopausal osteoporosis.


Asunto(s)
Conservadores de la Densidad Ósea/efectos adversos , Infarto del Miocardio/inducido químicamente , Osteoporosis Posmenopáusica/tratamiento farmacológico , Tiofenos/efectos adversos , Anciano , Anciano de 80 o más Años , Conservadores de la Densidad Ósea/uso terapéutico , Estudios de Casos y Controles , Bases de Datos Factuales , Femenino , Hospitalización/estadística & datos numéricos , Humanos , Persona de Mediana Edad , Infarto del Miocardio/epidemiología , Osteoporosis Posmenopáusica/epidemiología , Tiofenos/uso terapéutico , Reino Unido/epidemiología
3.
Int J Cardiol ; 170(2): 182-8, 2013 Dec 10.
Artículo en Inglés | MEDLINE | ID: mdl-24225201

RESUMEN

BACKGROUND: Heart failure (HF) and chronic obstructive pulmonary disease (COPD) frequently coexist, with undefined prognostic and therapeutic implications. We investigated clinical profile and outcomes of patients with chronic HF and COPD, notably the efficacy and safety of ivabradine, a heart rate-reducing agent. METHODS: 6505 ambulatory patients, in sinus rhythm, heart rate ≥ 70 bpm and stable systolic HF were randomised to placebo or ivabradine (2.5 to 7.5mg bid). Multivariate Cox model analyses were performed to compare the COPD (n=730) and non-COPD subgroups, and the ivabradine and placebo treatment effects. RESULTS: COPD patients were older and had a poorer risk profile. Beta-blockers were prescribed to 69% of COPD patients and 92% of non-COPD patients. The primary endpoint (PEP) and its component, hospitalisation for worsening HF, were more frequent in COPD patients (HRs f, 1.22 [p=0.006]; and 1.34 [p<0.001]) respectively, but relative risk was reduced similarly by ivabradine in both COPD (14%, and 17%) and non-COPD (18% and 27%) patients (p interaction=0.82, and 0.53, respectively). Similar effect was noted also for cardiovascular death. Adverse events were more common in COPD patients, but similar in treatment subgroups. Bradycardia occurred more frequently in ivabradine subgroups, with similar incidence in patients with or without COPD. CONCLUSIONS: The association of COPD and HF results in a worse prognosis, and COPD represents a barrier to optimisation of beta-blocker therapy. Ivabradine is similarly effective and safe in chronic HF patients with or without COPD, and can be safely combined with beta-blockers in COPD.


Asunto(s)
Antagonistas Adrenérgicos beta/administración & dosificación , Benzazepinas/administración & dosificación , Insuficiencia Cardíaca Sistólica/tratamiento farmacológico , Insuficiencia Cardíaca Sistólica/mortalidad , Frecuencia Cardíaca/efectos de los fármacos , Enfermedad Pulmonar Obstructiva Crónica/mortalidad , Antagonistas Adrenérgicos beta/efectos adversos , Anciano , Benzazepinas/efectos adversos , Cardiotónicos/administración & dosificación , Cardiotónicos/efectos adversos , Enfermedad Crónica , Femenino , Insuficiencia Cardíaca Sistólica/complicaciones , Humanos , Incidencia , Ivabradina , Masculino , Persona de Mediana Edad , Análisis Multivariante , Placebos , Pronóstico , Modelos de Riesgos Proporcionales , Enfermedad Pulmonar Obstructiva Crónica/complicaciones , Factores de Riesgo , Resultado del Tratamiento
4.
Cardiology ; 115(2): 114-9, 2010.
Artículo en Inglés | MEDLINE | ID: mdl-19907174

RESUMEN

BACKGROUND: Anxiety and insomnia are associated with cardiovascular (CV) symptoms. We assessed whether the relation between anxiety and CV symptoms is modulated by insomnia. METHODS: Independently living women (n = 1,440; mean age = 59.36 +/- 6.53 years) were recruited by cluster sampling technique. We obtained data on demographic characteristics, health beliefs, access to health care, CV symptoms, sleep, stress and anxiety levels. RESULTS: Overall, 56% of the sample reported insomnia; 46% reported CV symptoms, and 54% were highly anxious. There was a greater likelihood for highly anxious women and those experiencing insomnia to report CV symptoms (r(s) = 0.31* and r(s) = 0.32*, respectively). In logistic regression analysis, the adjusted odds ratios for reporting CV symptoms were 1.39 for patients with insomnia and 2.79 for those with anxiety. With control for insomnia, we observed a 3-fold reduction in the magnitude of the association between anxiety and CV symptoms (r(p) = 0.09*). Stepwise adjustments for sociodemographic factors, CV risk markers, and factors anchoring health beliefs and access to health care showed lesser impact on the relationships. With simultaneous control for those covariates, the correlation was r(p) = 0.13*; * p < 0.01. CONCLUSION: The association of CV symptoms with anxiety is partly accounted for by insomnia.


Asunto(s)
Ansiedad/epidemiología , Enfermedades Cardiovasculares/epidemiología , Trastornos del Inicio y del Mantenimiento del Sueño/epidemiología , Anciano , Ansiedad/complicaciones , Enfermedades Cardiovasculares/etiología , Enfermedades Cardiovasculares/psicología , Femenino , Humanos , Modelos Logísticos , Persona de Mediana Edad , New York/epidemiología , Estudios Prospectivos , Trastornos del Inicio y del Mantenimiento del Sueño/complicaciones , Trastornos del Inicio y del Mantenimiento del Sueño/psicología
5.
Am J Cardiol ; 85(2): 193-8, 2000 Jan 15.
Artículo en Inglés | MEDLINE | ID: mdl-10955376

RESUMEN

Patients with mitral valve prolapse (MVP) may develop severe mitral regurgitation (MR) and require valve surgery. Preliminary data suggest that high body weight and blood pressure might add to the irreversible factors of older age and male gender in increasing risk of these complications. Fifty-four patients with severe MR due to MVP were compared with 117 control subjects with uncomplicated MVP to elucidate factors independently associated with severe MR: the need for valve surgery and the cumulative risk of requiring mitral valve surgery. Patients with severe MR were older (p<0.00005), more overweight (p = 0.002), had higher systolic (p = 0.0003) and diastolic (p = 0.007) blood pressures, and were more likely to have hypertension (p = 0.0001) and to be men (p<0.001). In both groups, men had higher blood pressure and relative body weight than women. In multivariate analysis, older age was most strongly associated with MR; higher body mass index, hypertension, and gender were independent predictors of severe MR in analyses that excluded age. Among the 54 patients with severe MR, the 32 (59%) who underwent mitral valve surgery during 11 years of follow-up were older, more overweight, and more likely to be hypertensive than those not requiring surgery. Among patients undergoing mitral valve surgery in 3 centers, mitral prolapse was the etiology in 25%, 67% of whom were men. Using these data and national statistics, we estimate that the gender-specific cumulative risk for requiring valvular surgery for severe MR in subjects with MVP is 0.8% in women and 2.6% in men before age 65, and 1.4% and 5.5% by age 75. Thus, subjects with MVP who are older, more overweight, and hypertensive are at greater risk for severe MR and valve surgery. Higher blood pressure and relative weight in men with MVP appear to contribute to the gender difference in risk for severe MR.


Asunto(s)
Insuficiencia de la Válvula Mitral/etiología , Insuficiencia de la Válvula Mitral/cirugía , Prolapso de la Válvula Mitral/complicaciones , Adolescente , Adulto , Anciano , Estudios de Casos y Controles , Progresión de la Enfermedad , Femenino , Estudios de Seguimiento , Humanos , Masculino , Persona de Mediana Edad , Insuficiencia de la Válvula Mitral/epidemiología , Análisis Multivariante , Factores de Riesgo , Índice de Severidad de la Enfermedad
6.
Cardiology ; 93(1-2): 37-42, 2000.
Artículo en Inglés | MEDLINE | ID: mdl-10894905

RESUMEN

Among patients with chronic nonischemic mitral regurgitation (MR), high short-term mortality risk can be identified by left (LV) and/or right ventricular (RV) ejection fraction (EF) criteria (LVEF 20%, MVR significantly improved survival versus medical treatment (rest: p < 0.0001, exercise: p = 0.0003). In high risk MR patients, MVR improves survival; preoperative RV performance can define subgroups with different long-term postoperative survival.


Asunto(s)
Implantación de Prótesis de Válvulas Cardíacas , Insuficiencia de la Válvula Mitral/fisiopatología , Volumen Sistólico/fisiología , Función Ventricular/fisiología , Enfermedad Crónica , Angiografía Coronaria , Ecocardiografía , Femenino , Humanos , Masculino , Persona de Mediana Edad , Insuficiencia de la Válvula Mitral/diagnóstico , Insuficiencia de la Válvula Mitral/mortalidad , Insuficiencia de la Válvula Mitral/cirugía , Periodo Posoperatorio , Estudios Prospectivos , Ventriculografía con Radionúclidos , Factores de Riesgo , Tasa de Supervivencia , Resultado del Tratamiento
7.
Am J Ther ; 7(4): 237-43, 2000 Aug.
Artículo en Inglés | MEDLINE | ID: mdl-11486157

RESUMEN

Extensive primary fibrosis precedes heart failure and death in experimental chronic aortic regurgitation. To seek the molecular basis for this observation, this study analyzed the RNA pool for genes that are up-or downregulated in aortic regurgitation fibroblasts. Differential display reverse transcriptase polymerase chain reaction was used to compare RNA extracted from cardiac fibroblasts isolated from three healthy New Zealand white rabbits and from three with aortic regurgitation. Using two base anchoring oligo d(T) primers (T11VN) together with arbitrary upstream primers, numerous differences in normal versus aortic regurgitation gene expression were apparent on differential display reverse transcriptase polymerase chain reaction. The aortic regurgitation cell cultures showed numerous differentially up-and downregulated genes compared with cell cultures of normal cardiac fibroblasts. The results showed that pathologic fibrosis in chronic experimental aortic regurgitation is associated with abnormal cardiac fibroblast gene expression, which may be pathogenic for the fibrous lesion.


Asunto(s)
Insuficiencia de la Válvula Aórtica/genética , Regulación de la Expresión Génica/genética , Miocardio/citología , ARN/biosíntesis , Animales , Insuficiencia de la Válvula Aórtica/metabolismo , Northern Blotting , Separación Celular , Células Cultivadas , ADN Complementario , Fibroblastos/metabolismo , Miocardio/metabolismo , ARN/aislamiento & purificación , Conejos , Reacción en Cadena de la Polimerasa de Transcriptasa Inversa
8.
Circulation ; 100(9): 924-32, 1999 Aug 31.
Artículo en Inglés | MEDLINE | ID: mdl-10468522

RESUMEN

BACKGROUND: Previous data indicate that left ventricular ejection fraction (LVEF) provides prognostic information among patients with coronary artery disease (CAD), but the value of such testing specifically for defining benefits of coronary artery bypass grafting (CABG) may relate to severity of exercise-inducible ischemia measured noninvasively before surgery. METHODS AND RESULTS: To determine the independent prognostic importance of preoperative ischemia severity for predicting outcomes of CABG among patients with extensive CAD, we monitored 167 stable patients with angiographically documented 3-vessel CAD (average follow-up of 9 years in event-free patients) who previously had undergone rest and exercise radionuclide cineangiography. Their course was correlated with data obtained during initial radionuclide testing, coronary arteriography, and clinical evaluation at study entry. Fifty-two patients received medical treatment only, and 115 underwent CABG (44 early [

Asunto(s)
Puente de Arteria Coronaria , Enfermedad Coronaria/fisiopatología , Enfermedad Coronaria/cirugía , Ejercicio Físico , Volumen Sistólico , Anciano , Análisis de Varianza , Presión Sanguínea , Cineangiografía , Factores de Confusión Epidemiológicos , Angiografía Coronaria , Enfermedad Coronaria/diagnóstico por imagen , Enfermedad Coronaria/patología , Femenino , Estudios de Seguimiento , Frecuencia Cardíaca , Humanos , Masculino , Persona de Mediana Edad , Pronóstico , Ventriculografía con Radionúclidos , Índice de Severidad de la Enfermedad
11.
Cardiovasc Pathol ; 8(1): 1-6, 1999.
Artículo en Inglés | MEDLINE | ID: mdl-10722242

RESUMEN

Intercellular conduction in the working myocardium of the mammalian heart is mediated by gap junctions composed of connexin43 or 45. Recently, it has been shown that myocardial connexin expression is malleable and may be altered with disease. To better understand myocardial conduction in left ventricular hypertrophy resulting from volume overload, we used indirect immunofluorescence microscopy to examine cardiac connexin43 expression in 10 New Zealand white rabbits with surgically induced aortic regurgitation (AR) and in 10 age-matched sham-operated controls. Animals were sacrificed at approximately 1 month or > or =2.5 years after operation. All AR animals developed eccentric hypertrophy; none evidenced heart failure. The heart-to-body weight ratios for the 1 month AR and control groups were 2.9+/-0.8 vs 1.8+/-0.2 g/kg (p < or = 0.01) while ratios for the > or =2.5 year AR and control groups were 2.4+/-0.3 vs 1.9+/-0.3 (p < or = 0.05). No significant differences in posterior wall thickness were found among any of the groups. Although the overall pattern of connexin43-like immunoreactivity was similar for all four groups, staining in the I month AR animals tended to be less than that of age-matched controls; staining was increased in the > or =2.5 year AR animals and was greater than control (p < 0.05), in which staining did not change with animal age. This disease duration-related increase differs from the long-term decrease in connexin43 expression associated with other forms of heart disease and suggests that alterations in connexin expression may play a role in the rhythm abnormalities commonly seen in AR.


Asunto(s)
Insuficiencia de la Válvula Aórtica/complicaciones , Conexina 43/metabolismo , Hipertrofia Ventricular Izquierda/metabolismo , Miocardio/metabolismo , Animales , Modelos Animales de Enfermedad , Técnica del Anticuerpo Fluorescente Indirecta , Hipertrofia Ventricular Izquierda/etiología , Hipertrofia Ventricular Izquierda/patología , Procesamiento de Imagen Asistido por Computador , Miocardio/patología , Tamaño de los Órganos , Conejos
12.
Cardiology ; 90(2): 101-9, 1998 Oct.
Artículo en Inglés | MEDLINE | ID: mdl-9778546

RESUMEN

Myocardial fibrosis and myocyte degeneration have been reported in patients with chronic aortic regurgitation (AR), and may be related to the pathophysiology of congestive heart failure (CHF) in this disease. To define the relationship between myocardial histopathologic variations and CHF in chronic AR, we performed gross and microscopic evaluations of postmortem tissue from a rabbit model of chronic AR manifesting left ventricular (LV) responses to AR similar to those in humans. Moderate-to-severe chronic AR (echocardiographic regurgitant fraction = 52 +/- 13%) was induced by closed-chest aortic valve perforation in 11 New Zealand White rabbits; 5 control rabbits were sham operated. Six of the 11 AR rabbits died 1.5 +/- 0.8 years (range 0.6-2.8 years) after AR induction; all 6 had gross and histologic anatomic evidence of CHF at necropsy. The remaining 5 AR rabbits survived until sacrifice at 2.9 +/- 0.1 years of AR; none had pathologic evidence of CHF. Cardiac hypertrophy and the extent of LV fibrosis and myocyte necrosis all were greatest among the 6 AR CHF rabbits. No inflammatory response was apparent in any animal. Moderate-to-severe chronic experimental AR frequently results in CHF which is strongly associated with myocardial fibrosis and necrosis, without evidence of inflammation. These histopathologic variations may be pathophysiologically related to CHF development.


Asunto(s)
Insuficiencia de la Válvula Aórtica/complicaciones , Fibrosis Endomiocárdica/etiología , Atrios Cardíacos/patología , Insuficiencia Cardíaca/etiología , Ventrículos Cardíacos/patología , Animales , Insuficiencia de la Válvula Aórtica/patología , Insuficiencia de la Válvula Aórtica/fisiopatología , Enfermedad Crónica , Modelos Animales de Enfermedad , Ecocardiografía , Fibrosis Endomiocárdica/patología , Fibrosis Endomiocárdica/fisiopatología , Atrios Cardíacos/diagnóstico por imagen , Atrios Cardíacos/fisiopatología , Insuficiencia Cardíaca/patología , Insuficiencia Cardíaca/fisiopatología , Ventrículos Cardíacos/diagnóstico por imagen , Ventrículos Cardíacos/fisiopatología , Contracción Miocárdica , Fotomicrografía , Conejos , Función Ventricular Izquierda
13.
Hypertension ; 31(4): 937-42, 1998 Apr.
Artículo en Inglés | MEDLINE | ID: mdl-9535418

RESUMEN

Identification of left ventricular hypertrophy (LVH) using 12-lead ECG criteria based primarily on QRS amplitudes has been limited by poor sensitivity at acceptable levels of specificity. Because the product of QRS voltage and duration, as an approximation of the time-voltage area of the QRS complex, can improve accuracy of the 12-lead ECG for LVH, we examined the diagnostic value of true time-voltage area measurements of QRS complexes from the standard 12-lead ECG. Standard 12-lead ECGs and echocardiograms were obtained in 175 control subjects without LVH and in 74 patients with regurgitant valvular heart disease and LVH defined by echocardiographic criteria (indexed LV mass >110 g/m2 in women and >125 g/m2 in men). Standard voltage criteria, voltage-duration products (voltage multiplied by QRS duration), and true time-voltage areas of the QRS were calculated for Sokolow-Lyon criteria (SV1 +RV(5/6)) and the 12-lead sum of voltage criteria. Test sensitivities were compared using gender-specific partitions with matched specificity of 98% in the 175 subjects without LVH. Measurement of the time-voltage area significantly improved sensitivity for both criteria. The 76% sensitivity of the 12-lead sum area and 65% sensitivity of Sokolow-Lyon area were significantly greater than the 54% sensitivity of the approximation of QRS area provided by each voltage-duration product (P<.001 and P=.021) and than the 46% and 43% sensitivities of the respective simple voltage criteria (each P<.001). Comparison of receiver operating characteristic curves confirmed the superior overall performance of time-voltage area criteria compared with both voltage-duration products and simple voltage criteria. These results suggest that use of time-voltage areas can dramatically improve identification of LVH by 12-lead ECG. Further study of this approach is needed to identify optimal criteria for LVH based on the time-voltage area measurements from the 12-lead ECG.


Asunto(s)
Hipertrofia Ventricular Izquierda/fisiopatología , Ecocardiografía , Electrocardiografía , Femenino , Humanos , Hipertrofia Ventricular Izquierda/diagnóstico , Hipertrofia Ventricular Izquierda/diagnóstico por imagen , Masculino , Persona de Mediana Edad , Sensibilidad y Especificidad , Factores Sexuales
14.
Circulation ; 97(6): 525-34, 1998 Feb 17.
Artículo en Inglés | MEDLINE | ID: mdl-9494022

RESUMEN

BACKGROUND: Optimal criteria for valve replacement are unclear in asymptomatic/minimally symptomatic patients with aortic regurgitation (AR) and normal left ventricular (LV) performance at rest. Moreover, previous studies have not assessed the prognostic capacity of load-adjusted LV performance ("contractility") variables, which may be fundamentally related to clinical state. Therefore, 18 years ago, we set out to test prospectively the hypothesis that objective noninvasive measures of LV size and performance and, specifically, of load-adjusted variables, assessed at rest and during exercise (ex), could predict the development of currently accepted indications for operation for AR. METHODS AND RESULTS: Clinical variables and measures of LV size, performance, and end-systolic wall stress (ESS) were assessed annually in 104 patients by radionuclide cineangiography at rest and maximal ex and by echocardiography at rest; ESS was derived during ex. During an average 7.3-year follow-up among patients who had not been operated on, 39 of 104 patients either died suddenly (n = 4) or developed operable symptoms only (n = 22) or subnormal LV performance with or without symptoms (n = 13) (progression rate=6.2%/y). By multivariate Cox model analysis, change (delta) in LV ejection fraction (EF) from rest to ex, normalized for deltaESS from rest to ex (deltaLVEF-deltaESS index), was the strongest predictor of progression to any end point or to sudden cardiac death alone. Unadjusted deltaLVEF was almost as efficient. Symptom status modified prediction on the basis of the deltaLVEF-deltaESS index. The population tercile at highest risk by deltaLVEF-deltaESS progressed to end points at a rate of 13.3%/y, and the lowest-risk tercile progressed at 1.8%/y. CONCLUSIONS: Currently accepted symptom and LV performance indications for valve replacement, as well as sudden cardiac death, can be predicted in asymptomatic/minimally symptomatic patients with AR by load-adjusted deltaLVEF-deltaESS index, which includes data obtained during exercise.


Asunto(s)
Insuficiencia de la Válvula Aórtica/fisiopatología , Insuficiencia de la Válvula Aórtica/cirugía , Implantación de Prótesis de Válvulas Cardíacas , Función Ventricular Izquierda , Insuficiencia de la Válvula Aórtica/patología , Enfermedad Crónica , Muerte Súbita Cardíaca/etiología , Progresión de la Enfermedad , Prueba de Esfuerzo , Estudios de Seguimiento , Ventrículos Cardíacos/patología , Humanos , Análisis Multivariante , Modelos de Riesgos Proporcionales , Estudios Prospectivos
15.
Am J Ther ; 5(3): 139-46, 1998 May.
Artículo en Inglés | MEDLINE | ID: mdl-10099051

RESUMEN

Myocardial fibrosis and abnormal myocardial collagen content are common in many forms of pathological cardiac hypertrophy, including that mediated by pressure overload. Recently, in an experimental animal model of chronic aortic regurgitation (AR), we found a strong relation between myocardial fibrosis and congestive heart failure development. To determine if these fibrotic lesions are composed of collagen, as they are in pressure overload, and to determine if potential preventive therapies should be developed similarly in both diseases, we assessed left ventricular collagen content at three time points after AR induction. Moderate to severe AR was induced in 19 New Zealand White rabbits by inserting a catheter through the carotid artery to perforate the aortic valve leaflets. Animals were killed (1) when they showed echocardiographically discernible systolic dysfunction or (2) if normal cardiac function continued, either early (1 month) or late (>3 years) after operation. Fourteen age-matched, sham-operated controls and seven normal unoperated rabbits also were studied. Collagen concentrations were determined biochemically by hydroxyproline measurement. Fibrosis was measured histologically using Mason's trichrome stain and the fibrous collagen-specific stain, Picro-Sirius Red. Our results show an age-related increase in left ventricular collagen concentration with no specific increase among animals with evidence of fibrosis. We conclude that, unlike pressure overload, volume overload produces fibrotic lesions not composed predominantly of excess collagen and that the therapy needed to prevent fibrosis may be different in these conditions. Further study is needed to define the chemical characteristics of the fibrous lesions and the pathophysiological importance of this finding.


Asunto(s)
Insuficiencia de la Válvula Aórtica/complicaciones , Cardiomegalia/etiología , Cardiomegalia/patología , Colágeno/análisis , Modelos Animales de Enfermedad , Miocardio/química , Factores de Edad , Animales , Peso Corporal , Cardiomegalia/diagnóstico por imagen , Cardiomegalia/fisiopatología , Enfermedad Crónica , Colágeno/ultraestructura , Ecocardiografía , Fibrosis , Miocardio/ultraestructura , Tamaño de los Órganos , Conejos , Índice de Severidad de la Enfermedad , Factores de Tiempo
16.
Am J Ther ; 5(6): 369-75, 1998 Nov.
Artículo en Inglés | MEDLINE | ID: mdl-10099079

RESUMEN

Vesnarinone, a quinoline derivative with modest positive inotropic action, has been shown in several studies to benefit patients with clinical congestive heart failure. The cellular basis of its clinical benefit is not known, although the drug has several pharmacologic effects demonstrated both in isolated cardiac myocytes and in other noncardiac cell types. To investigate the possibility that the clinical benefit of vesnarinone is based, at least in part, on the inhibition of pathologic myocardial fibrosis, we examined its effects on cultured cardiac fibroblasts isolated from both normal and aortic regurgitant New Zealand White rabbit hearts. As in people, rabbits with moderate-to-severe aortic regurgitation often develop congestive heart failure that, at necropsy, is characterized by exuberant myocardial fibrosis. A dose-response curve was constructed with vesnarinone concentrations ranging from 10(-4 ) to 10(-9 ) mol/L. Cellular survival was decreased by exposure to nanomolar concentrations of drug but not at the higher doses tested. Fibroblasts isolated from normal hearts responded maximally at 10(-7 ) mol/L vesnarinone, whereas fibroblasts from aortic regurgitant hearts responded maximally at 10(-8 ) mol/L. These concentrations of drug are more than an order of magnitude lower than those believed to be associated with clinical benefit from earlier studies. Our results indicate that vesnarinone can suppress cardiac fibroblast proliferation and suggest that this action may be useful in therapies designed to prevent congestive heart failure in aortic regurgitation.


Asunto(s)
Insuficiencia de la Válvula Aórtica/patología , Cardiotónicos/farmacología , Corazón/efectos de los fármacos , Quinolinas/farmacología , Animales , Insuficiencia de la Válvula Aórtica/complicaciones , Supervivencia Celular/efectos de los fármacos , Células Cultivadas , Relación Dosis-Respuesta a Droga , Fibroblastos/efectos de los fármacos , Insuficiencia Cardíaca/prevención & control , Pirazinas , Conejos
17.
Cardiology ; 88(6): 518-25, 1997.
Artículo en Inglés | MEDLINE | ID: mdl-9397305

RESUMEN

We recently demonstrated dynamic alterations in protein turnover 3 days and 1 month after surgical induction of aortic regurgitation (AR). To characterize protein synthesis and degradation during the long-term plateau phase, we performed [3H]-leucine infusion 2.5 years after induction of AR in 10 New Zealand White rabbits and 12 sham-operated controls. Protein fractional synthesis rates were obtained by analyses of plasma and protein hydrolysates, growth rates from protein concentration and heart weight measurements, and degradation rates by subtraction of growth from synthesis rates. AR (regurgitant fraction 25 +/- 11%) caused a 57% increase in left ventricular (LV) weight in comparison with controls (7.4 +/- 1.7 vs. 4.7 +/- 0.6 g, p < 0.001) and no evidence of heart failure. Although concentrations of total cardiac protein, myosin heavy chain and actin were similar, the enlarged AR hearts had increased amounts of total cardiac protein (1,009 +/- 312 vs. 682 +/- 120 mg/LV, p < 0.05), myosin heavy chain (148 +/- 91 vs. 81 +/- 29 mg/LV, p < 0.05), and actin (73 +/- 42 vs. 44 +/- 16 mg/LV, p < 0.06). Individual protein fractional synthesis and degradation rates were closely balanced. However, myosin fractional synthesis rates were 152% (p < 0.01) greater than those of total cardiac protein in AR animals, while only 52% (p < 0.05) greater in controls (AR vs. controls, p = 0.05). Variations in actin turnover between AR and control animals did not attain statistical significance. Myosin and actin fractional synthesis rates correlated closely in AR rabbits (R = 0.81, p < 0.02), but not among controls (R = 0.41, NS). Thus, selective alterations in myofibrillar protein turnover contribute to the maintenance of increased myofibrillar protein content in the 'compensatory' LV hypertrophy of chronic AR.


Asunto(s)
Actinas/metabolismo , Insuficiencia de la Válvula Aórtica/metabolismo , Miocardio/metabolismo , Miosinas/metabolismo , Animales , Insuficiencia de la Válvula Aórtica/diagnóstico por imagen , Insuficiencia de la Válvula Aórtica/patología , Enfermedad Crónica , Densitometría , Modelos Animales de Enfermedad , Ecocardiografía Doppler , Electroforesis en Gel de Poliacrilamida , Estudios de Seguimiento , Corazón/crecimiento & desarrollo , Leucina , Miocardio/patología , Tamaño de los Órganos , Conejos
18.
Am J Cardiol ; 79(11): 1482-7, 1997 Jun 01.
Artículo en Inglés | MEDLINE | ID: mdl-9185637

RESUMEN

We examined the relation of the standard deviation of the 5-minute mean RR intervals over 24 hours (SDANN), a measure of ultra-low frequency heart rate variability (HRV) (<0.0033 Hz), and other measures of HRV to clinical outcome events in 50 asymptomatic or minimally symptomatic patients with chronic severe aortic regurgitation (AR) who underwent ambulatory electrocardiography as part of a prospective study of the natural history of regurgitant valvular diseases. At entry, all patients were in sinus rhythm and had New York Heart Association functional class I or minimal II congestive heart failure, with left ventricular (LV) ejection fraction > or = 45% and LV end-diastolic dimension > or = 5.5 cm in women and > or = 5.9 cm in men. End points were defined as progression to aortic valve replacement (n = 19) or sudden cardiac death (n = 1) during the mean follow-up period of 8.1 +/- 3.8 years. With the median SDANN of 145 ms as a partition value, the average annual risk of end-point events in patients with low SDANN was significantly greater than the event rate in patients with high SDANN (11%/year vs 2%/year, p <0.0003). In multivariate analysis, reduced SDANN was associated with end-point events independent of LV function, LV end-systolic dimension, and symptom status (p = 0.001). We conclude that reduced ultra-low frequency HRV measured as SDANN is strongly related to progression to valve surgery in asymptomatic and minimally symptomatic patients with chronic AR.


Asunto(s)
Insuficiencia de la Válvula Aórtica/fisiopatología , Frecuencia Cardíaca , Adulto , Anciano , Insuficiencia de la Válvula Aórtica/diagnóstico por imagen , Enfermedad Crónica , Cineangiografía , Electrocardiografía Ambulatoria , Femenino , Humanos , Masculino , Persona de Mediana Edad , Estudios Prospectivos , Cintigrafía , Volumen Sistólico , Análisis de Supervivencia
19.
Am J Cardiol ; 79(8): 1070-4, 1997 Apr 15.
Artículo en Inglés | MEDLINE | ID: mdl-9114766

RESUMEN

We have recently shown that a subgroup of asymptomatic hypertensive patients exhibit subnormal left ventricular (LV) midwall fiber shortening at rest and that this finding predicts morbidity and mortality independently of age, blood pressure (BP), or the presence of LV hypertrophy. However, it is unknown whether abnormal midwall fractional shortening predicts either subnormal LV functional reserve or extracardiac damage in asymptomatic hypertensive patients. Accordingly, we compared radionuclide cineangiographic LV ejection fraction at rest and maximum exercise as well as clinical findings between 89 patients with normal and 16 patients with subnormal midwall fractional shortening by echocardiogram. Patients with low midwall fractional shortening were similar in gender, age, and systolic BP to those with normal shortening but had higher mean diastolic BP and body mass indexes (both p < 0.05). The 2 groups also had similar resting ejection fraction (56 +/- 9% vs 55 +/- 15%, with normal or subnormal shortening, respectively, p = NS). Patients with subnormal midwall fractional shortening had higher LV mass and tended to have higher urinary protein excretion and serum creatinine levels. Subnormal LV ejection fraction with exercise (< 54%) was observed in 13 of 89 patients (15%) with normal midwall fractional shortening but in 7 of 16 patients (44%) with subnormal shortening (p < 0.05). Multiple linear regression analysis revealed that midwall fractional shortening independently predicted exercise performance (p < 0.001). Thus, subnormal midwall fractional shortening predicts depressed LV fractional reserve in asymptomatic hypertensive patients and may contribute to identification of patients with extracardiac target-organ damage.


Asunto(s)
Prueba de Esfuerzo , Hipertensión/fisiopatología , Contracción Miocárdica , Disfunción Ventricular Izquierda/fisiopatología , Adulto , Cineangiografía , Ecocardiografía , Femenino , Hemodinámica , Humanos , Hipertensión/complicaciones , Hipertensión/diagnóstico por imagen , Masculino , Persona de Mediana Edad , Análisis Multivariante , Valor Predictivo de las Pruebas , Cintigrafía , Disfunción Ventricular Izquierda/diagnóstico por imagen , Disfunción Ventricular Izquierda/etiología
20.
J Nucl Cardiol ; 4(1 Pt 1): 25-32, 1997.
Artículo en Inglés | MEDLINE | ID: mdl-9138836

RESUMEN

BACKGROUND: Fiber dropout and myocyte necrosis precede heart failure in experimental aortic regurgitation (AR). The current study aimed to determine whether this process can be detected by noninvasive scintigraphic imaging. METHODS AND RESULTS: 111In-labeled antimyosin antibody Fab fragment (1 to 1.5 mCi) (Myoscint) was administered to each of 34 New Zealand White rabbits: 11 early (3 to 5 weeks) after surgical AR induction; 9 late (98 to 128 weeks) after AR induction; 5 normal and 3 sham-operated age-matched with early AR; and 3 normal and 3 sham-operated age-matched with late AR. Echocardiographic fractional shortening was indistinguishable among control, early AR, and late AR groups. In vivo gamma camera imaging 24 and 48 hours after isotope administration, post-mortem heart activity determination (percentage injected dose per gram), and autoradiography were performed. At 24 and 48 hours, heart-to-lung counts-per-pixel ratios from in vivo images were greater (p < 0.05) in the late AR rabbits than in each of the three other groups. No significant differences were found when early AR and older or younger control rabbits were compared. Heart activity (percentage injected dose per gram) in late AR rabbits trended toward higher values than in age-matched control rabbits (p = 0.057), but in early AR it was indistinguishable from that in the corresponding control (p = 0.413, difference not significant). The autoradiographic endocardial/epicardial activity ratio in late AR rabbits was greater than in control and early AR rabbits (1.27 +/- 0.13 vs 1.06 +/- 0.09 and vs 1.13 +/- 0.10, respectively, p < 0.02). CONCLUSIONS: Whereas isotope uptake in late AR rabbits differed from that in control and early AR rabbits, systolic function was indistinguishable. Thus 111In-labeled antimyosin antibody imaging may permit noninvasive detection of AR-induced myocardial damage before functional deterioration.


Asunto(s)
Anticuerpos Monoclonales , Insuficiencia de la Válvula Aórtica/diagnóstico por imagen , Radioisótopos de Indio , Miosinas , Compuestos Organometálicos , Radiofármacos , Animales , Insuficiencia de la Válvula Aórtica/metabolismo , Insuficiencia de la Válvula Aórtica/patología , Autorradiografía , Gasto Cardíaco Bajo/patología , Estudios de Casos y Controles , Ecocardiografía Doppler , Endocardio/diagnóstico por imagen , Endocardio/metabolismo , Endocardio/patología , Estudios de Seguimiento , Corazón/diagnóstico por imagen , Radioisótopos de Indio/farmacocinética , Pulmón/diagnóstico por imagen , Pulmón/metabolismo , Pulmón/patología , Fibras Musculares Esqueléticas/patología , Miocardio/metabolismo , Miocardio/patología , Miosinas/farmacocinética , Necrosis , Pericardio/diagnóstico por imagen , Pericardio/metabolismo , Pericardio/patología , Conejos , Cintigrafía , Radiofármacos/farmacocinética , Sístole
SELECCIÓN DE REFERENCIAS
DETALLE DE LA BÚSQUEDA