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1.
Nature ; 602(7895): 129-134, 2022 02.
Artículo en Inglés | MEDLINE | ID: mdl-35082446

RESUMEN

Differentiation proceeds along a continuum of increasingly fate-restricted intermediates, referred to as canalization1,2. Canalization is essential for stabilizing cell fate, but the mechanisms that underlie robust canalization are unclear. Here we show that the BRG1/BRM-associated factor (BAF) chromatin-remodelling complex ATPase gene Brm safeguards cell identity during directed cardiogenesis of mouse embryonic stem cells. Despite the establishment of a well-differentiated precardiac mesoderm, Brm-/- cells predominantly became neural precursors, violating germ layer assignment. Trajectory inference showed a sudden acquisition of a non-mesodermal identity in Brm-/- cells. Mechanistically, the loss of Brm prevented de novo accessibility of primed cardiac enhancers while increasing the expression of neurogenic factor POU3F1, preventing the binding of the neural suppressor REST and shifting the composition of BRG1 complexes. The identity switch caused by the Brm mutation was overcome by increasing BMP4 levels during mesoderm induction. Mathematical modelling supports these observations and demonstrates that Brm deletion affects cell fate trajectory by modifying saddle-node bifurcations2. In the mouse embryo, Brm deletion exacerbated mesoderm-deleted Brg1-mutant phenotypes, severely compromising cardiogenesis, and reveals an in vivo role for Brm. Our results show that Brm is a compensable safeguard of the fidelity of mesoderm chromatin states, and support a model in which developmental canalization is not a rigid irreversible path, but a highly plastic trajectory.


Asunto(s)
Diferenciación Celular , Linaje de la Célula , Mesodermo/citología , Mesodermo/metabolismo , Miocitos Cardíacos/citología , Factores de Transcripción/metabolismo , Animales , Proteína Morfogenética Ósea 4/metabolismo , Cromatina/genética , Cromatina/metabolismo , Ensamble y Desensamble de Cromatina , ADN Helicasas/metabolismo , Embrión de Mamíferos , Epigénesis Genética , Femenino , Regulación de la Expresión Génica , Masculino , Ratones , Miocardio/metabolismo , Neurogénesis , Neuronas/citología , Neuronas/metabolismo , Proteínas Nucleares/metabolismo , Factor 6 de Transcripción de Unión a Octámeros/metabolismo , Fenotipo , Proteínas Represoras/metabolismo , Células Madre/citología , Factores de Tiempo , Factores de Transcripción/deficiencia , Factores de Transcripción/genética
2.
Science ; 373(6557)2021 08 20.
Artículo en Inglés | MEDLINE | ID: mdl-34301855

RESUMEN

Stochastic fluctuations in gene expression ("noise") are often considered detrimental, but fluctuations can also be exploited for benefit (e.g., dither). We show here that DNA base excision repair amplifies transcriptional noise to facilitate cellular reprogramming. Specifically, the DNA repair protein Apex1, which recognizes both naturally occurring and unnatural base modifications, amplifies expression noise while homeostatically maintaining mean expression levels. This amplified expression noise originates from shorter-duration, higher-intensity transcriptional bursts generated by Apex1-mediated DNA supercoiling. The remodeling of DNA topology first impedes and then accelerates transcription to maintain mean levels. This mechanism, which we refer to as "discordant transcription through repair" ("DiThR," which is pronounced "dither"), potentiates cellular reprogramming and differentiation. Our study reveals a potential functional role for transcriptional fluctuations mediated by DNA base modifications in embryonic development and disease.


Asunto(s)
Diferenciación Celular , Reprogramación Celular , Reparación del ADN , ADN-(Sitio Apurínico o Apirimidínico) Liasa/metabolismo , ADN/química , Expresión Génica , Transcripción Genética , Animales , Células Cultivadas , Simulación por Computador , ADN/genética , ADN/metabolismo , Células Madre Embrionarias , Expresión Génica/efectos de los fármacos , Idoxuridina/metabolismo , Idoxuridina/farmacología , Ratones , Modelos Genéticos , Proteína Homeótica Nanog/genética , Conformación de Ácido Nucleico , ARN Mensajero/genética , ARN Mensajero/metabolismo , Análisis de la Célula Individual , Procesos Estocásticos , Timidina Quinasa/genética , Timidina Quinasa/metabolismo , Transcripción Genética/efectos de los fármacos
3.
Proc Natl Acad Sci U S A ; 117(19): 10350-10356, 2020 05 12.
Artículo en Inglés | MEDLINE | ID: mdl-32358201

RESUMEN

Nongenetic cellular heterogeneity is associated with aging and disease. However, the origins of cell-to-cell variability are complex and the individual contributions of different factors to total phenotypic variance are still unclear. Here, we took advantage of clear phenotypic heterogeneity of circadian oscillations in clonal cell populations to investigate the underlying mechanisms of cell-to-cell variability. Using a fully automated tracking and analysis pipeline, we examined circadian period length in thousands of single cells and hundreds of clonal cell lines and found that longer circadian period is associated with increased intercellular heterogeneity. Based on our experimental results, we then estimated the contributions of heritable and nonheritable factors to this variation in circadian period length using a variance partitioning model. We found that nonheritable noise predominantly drives intercellular circadian period variation in clonal cell lines, thereby revealing a previously unrecognized link between circadian oscillations and intercellular heterogeneity. Moreover, administration of a noise-enhancing drug reversibly increased both period length and variance. These findings suggest that circadian period may be used as an indicator of cellular noise and drug screening for noise control.


Asunto(s)
Relojes Circadianos , Ritmo Circadiano , Modelos Biológicos , Células Madre Embrionarias de Ratones/metabolismo , Proteínas Circadianas Period/metabolismo , Análisis de la Célula Individual/métodos , Animales , Células Cultivadas , Mediciones Luminiscentes , Ratones , Células Madre Embrionarias de Ratones/citología , Proteínas Circadianas Period/genética , Procesos Estocásticos
4.
Echocardiography ; 36(6): 1181-1190, 2019 Jun.
Artículo en Inglés | MEDLINE | ID: mdl-31087463

RESUMEN

PURPOSE: Phase-contrast cardiovascular magnetic resonance (PC-CMR) quantification of intracardiac shunt (measuring the pulmonary to systemic flow ratio, Qp/Qs) is typically determined by measuring flow through planes perpendicular the pulmonary trunk (PA) and ascending aorta (Ao). This method is subject to error from presence of background velocity offsets and requires two scan acquisitions. We evaluated an alternate PC-CMR technique for quantifying Qp/Qs using a single modified plane that encompasses both the PA and Ao. MATERIAL AND METHODS: In 53 patients evaluated for intracardiac shunting, PC-CMR measurement in the individual Ao and PA planes and also in a single-acquisition plane was obtained and Qp/Qs calculated by each method. Bland-Altman analysis was performed to evaluate the agreement between the two methods. RESULTS: The 95% confidence limits of agreement ranged from -0.52 to +0.34 indicating good agreement between the two methods. There was excellent agreement on the clinically relevant threshold value of Qp/Qs ratio of 1.5 (representing criteria for surgical correction of shunt). CONCLUSIONS: Qp/Qs determined from the single-acquisition approach agrees well with that of the individual PA and Ao method and offers potential improved accuracy (due to background velocity offset).


Asunto(s)
Aorta/diagnóstico por imagen , Defectos del Tabique Interatrial/diagnóstico por imagen , Imagen por Resonancia Magnética/métodos , Arteria Pulmonar/diagnóstico por imagen , Circulación Pulmonar/fisiología , Adulto , Aorta/fisiopatología , Femenino , Defectos del Tabique Interatrial/fisiopatología , Humanos , Masculino , Persona de Mediana Edad , Arteria Pulmonar/fisiopatología , Reproducibilidad de los Resultados , Sensibilidad y Especificidad , Adulto Joven
5.
Cell Syst ; 7(4): 384-397.e6, 2018 10 24.
Artículo en Inglés | MEDLINE | ID: mdl-30243562

RESUMEN

Transcription is an episodic process characterized by probabilistic bursts, but how the transcriptional noise from these bursts is modulated by cellular physiology remains unclear. Using simulations and single-molecule RNA counting, we examined how cellular processes influence cell-to-cell variability (noise). The results show that RNA noise is higher in the cytoplasm than the nucleus in ∼85% of genes across diverse promoters, genomic loci, and cell types (human and mouse). Measurements show further amplification of RNA noise in the cytoplasm, fitting a model of biphasic mRNA conversion between translation- and degradation-competent states. This multi-state translation-degradation of mRNA also causes substantial noise amplification in protein levels, ultimately accounting for ∼74% of intrinsic protein variability in cell populations. Overall, the results demonstrate how noise from transcriptional bursts is intrinsically amplified by mRNA processing, leading to a large super-Poissonian variability in protein levels.


Asunto(s)
Variación Biológica Poblacional , Modelos Teóricos , Procesamiento Postranscripcional del ARN , ARN Mensajero/genética , Animales , Citoplasma/metabolismo , Células Madre Embrionarias/metabolismo , Células HEK293 , Humanos , Células Jurkat , Ratones , ARN Mensajero/metabolismo , Imagen Individual de Molécula , Análisis de la Célula Individual , Activación Transcripcional
6.
Circ Heart Fail ; 8(4): 694-701, 2015 Jul.
Artículo en Inglés | MEDLINE | ID: mdl-26038535

RESUMEN

BACKGROUND: According to the 2004 Surgeon General's Report on Health Consequences of Smoking, after >15 years of abstinence, the cardiovascular risk of former smokers becomes similar to that of never-smokers. Whether this health benefit of smoking cessation varies by amount and duration of prior smoking remains unclear. METHODS AND RESULTS: Of the 4482 adults ≥65 years without prevalent heart failure (HF) in the Cardiovascular Health Study, 2556 were never-smokers, 629 current smokers, and 1297 former smokers with >15 years of cessation, of whom 312 were heavy smokers (highest quartile; ≥32 pack-years). Age-sex-race-adjusted hazard ratios (aHR) and 95% confidence intervals (CI) for centrally adjudicated incident HF and mortality during 13 years of follow-up were estimated using Cox regression models. Compared with never-smokers, former smokers as a group had similar risk for incident HF (aHR, 0.99; 95% CI, 0.85-1.16) and all-cause mortality (aHR, 1.08; 95% CI, 0.96-1.20), but former heavy smokers had higher risk for both HF (aHR, 1.45; 95% CI, 1.15-1.83) and mortality (aHR, 1.38; 95% CI, 1.17-1.64). However, when compared with current smokers, former heavy smokers had lower risk of death (aHR, 0.64; 95% CI, 0.53-0.77), but not of HF (aHR, 0.97; 95% CI, 0.74-1.28). CONCLUSIONS: After >15 years of smoking cessation, the risk of HF and death for most former smokers becomes similar to that of never-smokers. Although this benefit of smoking cessation is not extended to those with ≥32 pack-years of prior smoking, they have lower risk of death relative to current smokers.


Asunto(s)
Insuficiencia Cardíaca/mortalidad , Cese del Hábito de Fumar , Prevención del Hábito de Fumar , Fumar/mortalidad , Anciano , Anciano de 80 o más Años , Distribución de Chi-Cuadrado , Femenino , Insuficiencia Cardíaca/diagnóstico , Insuficiencia Cardíaca/etiología , Humanos , Incidencia , Masculino , Análisis Multivariante , Pronóstico , Modelos de Riesgos Proporcionales , Estudios Prospectivos , Medición de Riesgo , Factores de Riesgo , Fumar/efectos adversos , Factores de Tiempo , Estados Unidos/epidemiología
7.
J Cardiovasc Magn Reson ; 16: 70, 2014 Sep 26.
Artículo en Inglés | MEDLINE | ID: mdl-25316384

RESUMEN

BACKGROUND: Torsion shear angle φ is an important measure of left ventricular (LV) systolic and diastolic functions. Here we provide a novel index utilizing LV normalized torsion shear angle φ ^ volume V ^ loop to assess LV diastolic functional properties. We defined the area within φ ^ V ^ loop as torsion hysteresis area, and hypothesized that it may be an important global parameter of diastolic function. We evaluated the φ ^ changes to increased V ^ during early diastole - d φ ^ / d V ^ as a potential measure of LV suction. METHODS: Sixty resistant hypertension patients (HTN), forty control volunteers were studied using cardiovascular magnetic resonance with tissue tagging. Volumetric and torsional parameters were evaluated. RESULTS: HTN demonstrated concentric remodeling with preserved ejection fraction. HTN had significantly decreased normalized early filling rate, early diastolic mitral annulus velocity and E/A (1.33 ± 1.13 vs. 2.19 ± 1.07, P < 0.0001) vs. control. Torsion hysteresis area was greater (0.11 ± 0.07 vs. 0.079 ± 0.045, P < 0.001) and peak - d φ ^ / d V ^ at early diastole was higher (10.46 ± 8.51 vs. 6.29 ± 3.85, P = 0.002) than control. Torsion hysteresis area was significantly correlated with E/A (r = -0.23, P = 0.025). Thirteen HTN patients had both E/A ratio < 1.12 (Control mean E/A-1SD) and torsion hysteresis area > 0.12 (Control mean torsion hysteresis area + 1SD). CONCLUSIONS: Torsion hysteresis area and peak early diastolic - d φ ^ / d V ^ were significantly increased in hypertensive concentric remodeling. The φ ^ V ^ loop takes into account the active and passive recoil processes of LV diastolic and systolic phases, therefore provides a new global description of LV diastolic function.


Asunto(s)
Diástole , Hipertensión/complicaciones , Imagen por Resonancia Cinemagnética , Disfunción Ventricular Izquierda/diagnóstico , Función Ventricular Izquierda , Adulto , Anciano , Fenómenos Biomecánicos , Estudios de Casos y Controles , Femenino , Humanos , Masculino , Persona de Mediana Edad , Valor Predictivo de las Pruebas , Estudios Prospectivos , Torsión Mecánica , Disfunción Ventricular Izquierda/etiología , Disfunción Ventricular Izquierda/fisiopatología , Remodelación Ventricular
8.
J Gerontol A Biol Sci Med Sci ; 69(2): 223-30, 2014 Feb.
Artículo en Inglés | MEDLINE | ID: mdl-23846416

RESUMEN

OBJECTIVES: To examine the association of orthostatic hypotension with incident heart failure (HF) in older adults. METHODS: Of the 5,273 community-dwelling adults aged 65 years and older free of baseline prevalent HF in the Cardiovascular Health Study, 937 (18%) had orthostatic hypotension, defined as ≥20 mmHg drop in systolic or ≥10 mmHg drop in diastolic blood pressure from supine to standing position at 3 minutes. Of the 937, 184 (20%) had symptoms of dizziness upon standing and were considered to have symptomatic orthostatic hypotension. Propensity scores for orthostatic hypotension were estimated for each of the 5,273 participants and were used to assemble a cohort of 3,510 participants (883 participants with and 2,627 participants without orthostatic hypotension) who were balanced on 40 baseline characteristics. Cox regression models were used to estimate the association of orthostatic hypotension with centrally adjudicated incident HF and other outcomes during 13 years of follow-up. RESULTS: Participants (n = 3,510) had a mean (±standard deviation) age of 74 (±6) years, 58% were women, and 15% nonwhite. Incident HF occurred in 25% and 21% of matched participants with and without orthostatic hypotension, respectively (hazard ratio, 1.24; 95% confidence interval, 1.06-1.45; p = .007). Among matched participants, hazard ratios for incident HF associated with symptomatic (n = 173) and asymptomatic (n = 710) orthostatic hypotension were 1.57 (95% confidence interval, 1.16-2.11; p = .003) and 1.17 (95% confidence interval, 0.99-1.39; p = .069), respectively. CONCLUSIONS: Community-dwelling older adults with orthostatic hypotension have higher independent risk of developing new-onset HF, which appeared to be more pronounced in those with symptomatic orthostatic hypotension.


Asunto(s)
Insuficiencia Cardíaca/epidemiología , Hipotensión Ortostática/complicaciones , Características de la Residencia , Anciano , Anciano de 80 o más Años , Estudios de Casos y Controles , Estudios de Cohortes , Femenino , Estado de Salud , Insuficiencia Cardíaca/diagnóstico , Humanos , Hipotensión Ortostática/diagnóstico , Incidencia , Masculino , Factores de Riesgo , Factores Socioeconómicos
9.
Am J Med ; 126(10): 887-93, 2013 Oct.
Artículo en Inglés | MEDLINE | ID: mdl-24054956

RESUMEN

BACKGROUND: The prevalence of atrial fibrillation substantially increases after 70 years of age. However, the effect of rate-control versus rhythm-control strategies on outcomes in these patients remains unclear. METHODS: In the randomized Atrial Fibrillation Follow-up Investigation of Rhythm Management (AFFIRM) trial, 4060 patients (mean age 70 years, range 49-80 years) with paroxysmal and persistent atrial fibrillation were randomized to rate-control versus rhythm-control strategies. Of these, 2248 were 70-80 years, of whom 1118 were in the rate-control group. Propensity scores for rate-control strategy were estimated for each of the 2248 patients and were used to assemble a cohort of 937 pairs of patients receiving rate-control versus rhythm-control strategies, balanced on 45 baseline characteristics. RESULTS: Matched patients had a mean age of 75 years; 45% were women, 7% were nonwhite, and 47% had prior hospitalizations due to arrhythmias. During 3.4 years of mean follow-up, all-cause mortality occurred in 18% and 23% of matched patients in the rate-control and rhythm-control groups, respectively (hazard ratio [HR] associated with rate control, 0.77; 95% confidence interval [CI], 0.63-0.94; P = .010). HRs (95% CIs) for cardiovascular and noncardiovascular mortality associated with rate control were 0.88 (0.65-1.18) and 0.62 (0.46-0.84), respectively. All-cause hospitalization occurred in 61% and 68% of rate-control and rhythm-control patients, respectively (HR 0.76; 95% CI, 0.68-0.86). HRs (95% CIs) for cardiovascular and noncardiovascular hospitalization were 0.66 (0.56-0.77) and 1.07 (0.91-1.27), respectively. CONCLUSION: In septuagenarian patients with atrial fibrillation, compared with rhythm-control, a rate-control strategy was associated with significantly lower mortality and hospitalization.


Asunto(s)
Antiarrítmicos/uso terapéutico , Fibrilación Atrial/tratamiento farmacológico , Cardioversión Eléctrica , Frecuencia Cardíaca/efectos de los fármacos , Anciano , Anciano de 80 o más Años , Antiarrítmicos/farmacología , Fibrilación Atrial/mortalidad , Fibrilación Atrial/terapia , Estudios de Cohortes , Femenino , Hospitalización/estadística & datos numéricos , Humanos , Masculino , Puntaje de Propensión , Modelos de Riesgos Proporcionales , Resultado del Tratamiento
10.
Int J Cardiol ; 168(4): 3616-22, 2013 Oct 09.
Artículo en Inglés | MEDLINE | ID: mdl-23731526

RESUMEN

BACKGROUND: Whether prediabetes is an independent risk factor for incident heart failure (HF) in non-diabetic older adults remains unclear. METHODS: Of the 4602 Cardiovascular Health Study participants, age≥65 years, without baseline HF and diabetes, 2157 had prediabetes, defined as fasting plasma glucose (FPG) 100-125 mg/dL. Propensity scores for prediabetes, estimated for each of the 4602 participants, were used to assemble a cohort of 1421 pairs of individuals with and without prediabetes, balanced on 44 baseline characteristics. RESULTS: Participants had a mean age of 73 years, 57% were women, and 13% African American. Incident HF occurred in 18% and 20% of matched participants with and without prediabetes, respectively (hazard ratio {HR} associated with prediabetes, 0.90; 95% confidence interval {CI}, 0.76-1.07; p=0.239). Unadjusted and multivariable-adjusted HRs (95% CIs) for incident HF associated with prediabetes among 4602 pre-match participants were 1.22 (95% CI, 1.07-1.40; p=0.003) and 0.98 (95% CI, 0.85-1.14; p=0.826), respectively. Among matched individuals, prediabetes had no independent association with incident acute myocardial infarction (HR, 1.02; 95% CI, 0.81-1.28; p=0.875), angina pectoris (HR, 0.93; 95% CI, 0.77-1.12; p=0.451), stroke (HR, 0.86; 95% CI, 0.70-1.06; p=0.151) or all-cause mortality (HR, 0.99; 95% CI, 0.88-1.11; p=0.840). CONCLUSIONS: We found no evidence that prediabetes is an independent risk factor for incident HF, other cardiovascular events or mortality in community-dwelling older adults. These findings question the wisdom of routine screening for prediabetes in older adults and targeted interventions to prevent adverse outcomes in older adults with prediabetes.


Asunto(s)
Insuficiencia Cardíaca/diagnóstico , Insuficiencia Cardíaca/mortalidad , Vigilancia de la Población , Estado Prediabético/diagnóstico , Estado Prediabético/mortalidad , Anciano , Anciano de 80 o más Años , Estudios de Cohortes , Femenino , Estudios de Seguimiento , Humanos , Incidencia , Estudios Longitudinales , Masculino , Vigilancia de la Población/métodos , Factores de Riesgo
11.
Int J Cardiol ; 163(1): 61-7, 2013 Feb 10.
Artículo en Inglés | MEDLINE | ID: mdl-21704392

RESUMEN

BACKGROUND: Right ventricular ejection fraction (RVEF) < 20% is an independent predictor of poor outcomes in patients with advanced chronic systolic heart failure (HF). The aim of this study was to examine if the adverse effect of abnormally reduced RVEF varies by the receipt of beta-blockers. METHODS: In the Beta-Blocker Evaluation of Survival Trial (BEST), 2708 patients with chronic advanced HF and left ventricular ejection fraction < 35%, receiving standard background therapy with renin-angiotensin inhibition, digoxin, and diuretics, were randomized to receive bucindolol or placebo. Of these 2008 had data on baseline RVEF, and 14% (146/1017) and 13% (125/991) of the patients receiving bucindolol and placebo respectively had RVEF < 20%. RESULTS: Among patients in the placebo group, all-cause mortality occurred in 33% and 43% of patients with RVEF ≥ 20% and < 20% respectively (unadjusted hazard ratios {HR}, 1.33; 95% confidence intervals {CI}, 0.99-1.78; p = 0.055 and adjusted HR, 0.99; 95% CI, 0.71-1.37; p = 0.934). Among those receiving bucindolol, all-cause mortality occurred in 28% and 49% of patients with RVEF ≥ 20% and < 20% respectively (unadjusted HR, 2.15; 95% CI, 1.65-2.80; p < 0.001 and adjusted HR, 1.50; 95% CI, 1.08-2.07; p = 0.016). These differences were statistically significant (unadjusted and adjusted p for interaction, 0.016 and 0.053 respectively). CONCLUSIONS: In ambulatory patients with chronic advanced systolic HF receiving renin-angiotensin inhibition, digoxin, and diuretics, RVEF < 20% had no intrinsic association with mortality. However, in those receiving additional therapy with bucindolol, RVEF < 20% had a significant independent association with increased risk of mortality.


Asunto(s)
Antagonistas Adrenérgicos beta/uso terapéutico , Insuficiencia Cardíaca Sistólica/tratamiento farmacológico , Insuficiencia Cardíaca Sistólica/mortalidad , Volumen Sistólico/fisiología , Función Ventricular Derecha/fisiología , Antagonistas Adrenérgicos beta/efectos adversos , Antagonistas Adrenérgicos beta/farmacología , Anciano , Enfermedad Crónica , Femenino , Insuficiencia Cardíaca Sistólica/fisiopatología , Humanos , Masculino , Persona de Mediana Edad , Propanolaminas/efectos adversos , Propanolaminas/uso terapéutico , Volumen Sistólico/efectos de los fármacos , Resultado del Tratamiento , Función Ventricular Derecha/efectos de los fármacos
12.
Int J Cardiol ; 166(1): 230-5, 2013 Jun 05.
Artículo en Inglés | MEDLINE | ID: mdl-22119116

RESUMEN

BACKGROUND: Heart failure (HF) is the leading cause of hospitalization for Medicare beneficiaries. Nearly half of all HF patients have diastolic HF or HF with preserved ejection fraction (HF-PEF). Because these patients were excluded from major randomized clinical trials of neurohormonal blockade in HF there is little evidence about their role in HF-PEF. METHODS: The aims of the American Recovery & Reinvestment Act-funded National Heart, Lung, and Blood Institute-sponsored "Neurohormonal Blockade and Outcomes in Diastolic Heart Failure" are to study the long-term effects of angiotensin-converting enzyme inhibitors, angiotensin receptor blockers, beta-blockers, and aldosterone antagonists in four separate propensity-matched populations of HF-PEF patients in the OPTIMIZE-HF (Organized Program to Initiate Life-Saving Treatment in Hospitalized Patients with Heart Failure) registry. Of the 48,612 OPTIMIZE-HF hospitalizations occurring during 2003-2004 in 259 U.S. hospitals, 20,839 were due to HF-PEF (EF ≥40%). For mortality and hospitalization we used Medicare national claims data through December 31, 2008. RESULTS: Using a two-step (hospital-level and hospitalization-level) probabilistic linking approach, we assembled a cohort of 11,997 HF-PEF patients from 238 OPTIMIZE-HF hospitals. These patients had a mean age of 75 years, mean EF of 55%, were 62% women, 15% African American, and were comparable with community-based HF-PEF cohorts in key baseline characteristics. CONCLUSIONS: The assembled Medicare-linked OPTIMIZE-HF cohort of Medicare beneficiaries with HF-PEF with long-term outcomes data will provide unique opportunities to study clinical effectivenss of various neurohormonal antagonists with outcomes in HF-PEF using propensity-matched designs that allow outcome-blinded assembly of balanced cohorts, a key feature of randomized clinical trials.


Asunto(s)
Bases de Datos Factuales , Insuficiencia Cardíaca Diastólica/tratamiento farmacológico , Antagonistas de Hormonas/uso terapéutico , Medicare , Inhibición Neural/fisiología , Sistema de Registros , Anciano , Anciano de 80 o más Años , Estudios de Cohortes , Femenino , Insuficiencia Cardíaca Diastólica/sangre , Insuficiencia Cardíaca Diastólica/epidemiología , Humanos , Masculino , Persona de Mediana Edad , Neurotransmisores/antagonistas & inhibidores , Neurotransmisores/sangre , Resultado del Tratamiento , Estados Unidos/epidemiología
13.
JACC Cardiovasc Imaging ; 5(3): 273-81, 2012 Mar.
Artículo en Inglés | MEDLINE | ID: mdl-22421172

RESUMEN

OBJECTIVES: The goal of this study was to define the mechanism of preserved ejection fraction (EF) despite depressed myocardial strains in hypertension (HTN). BACKGROUND: Concentric left ventricular (LV) remodeling in HTN may have normal or supranormal EF despite depressed myocardial strains. The reason for such discordance is not clear. The aim of this study was to comprehensively evaluate the LV mechanics in a well-defined HTN population to define underlying reasons for such a paradox. METHODS: Sixty-seven patients with resistant HTN and 45 healthy control subjects were studied by cardiac magnetic resonance imaging and tissue tagging with 3-dimensional analysis. Amplitude and directional vector of longitudinal (Ell), circumferential (Ecc), and principal strain for maximal shortening (E3) were computed at basal, mid, and distal LV levels, respectively. LV torsion, defined as the rotation angle of apex relative to base, and LV twist, which accounts for the effects of differential LV remodeling on torsion for comparison among the 2 groups, were also calculated. RESULTS: LV mass index and LV mass/LV end-diastolic volume ratio were significantly higher in the HTN group compared with controls, consistent with concentric LV remodeling. Ell and Ecc were significantly decreased in amplitude with altered directional vector in HTN compared with controls. However, the amplitude of E3 was similar in the 2 groups. Torsion and twist were significantly higher in HTN, which was mainly due to increase in apical rotation. The HTN group demonstrated significantly increased LV wall thickening compared with controls that resulted in greater LVEF in the HTN group compared with controls (70% vs. 65%, p < 0.001, respectively). CONCLUSIONS: In compensated LV remodeling secondary to HTN, there is increased LV wall thickening with preserved E3 and increased torsion compared with normal controls. This, therefore, contributes to supranormal LVEF in HTN despite depressed longitudinal and circumferential strains.


Asunto(s)
Hipertensión/fisiopatología , Contracción Miocárdica , Volumen Sistólico , Función Ventricular Izquierda , Remodelación Ventricular , Adaptación Fisiológica , Adulto , Anciano , Alabama , Antihipertensivos/uso terapéutico , Fenómenos Biomecánicos , Estudios de Casos y Controles , Resistencia a Medicamentos , Femenino , Humanos , Hipertensión/diagnóstico , Hipertensión/tratamiento farmacológico , Modelos Lineales , Imagen por Resonancia Magnética , Masculino , Persona de Mediana Edad , Análisis Multivariante , Estudios Prospectivos , Torsión Mecánica
14.
Recent Pat Cardiovasc Drug Discov ; 7(1): 53-8, 2012 Apr.
Artículo en Inglés | MEDLINE | ID: mdl-22250920

RESUMEN

Heart failure (HF) is a common clinical syndrome characterized by high morbidity and frequent hospitalizations. HF is an independent and major risk factor for venous thromboembolism (VTE) and VTE occurring in patients with HF carries a worse prognosis. The present review will focus on short and long term role of anti-coagulants in prevention of venous thrombosis in HF patients. We will also be discussing the recently investigated and patented anti-coagulants which could have a role in this specific population.


Asunto(s)
Anticoagulantes/uso terapéutico , Insuficiencia Cardíaca/complicaciones , Tromboembolia Venosa/prevención & control , Insuficiencia Cardíaca/sangre , Humanos , Ensayos Clínicos Controlados Aleatorios como Asunto , Factores de Riesgo , Tromboembolia Venosa/sangre , Tromboembolia Venosa/etiología
15.
Am J Cardiol ; 109(3): 370-7, 2012 Feb 01.
Artículo en Inglés | MEDLINE | ID: mdl-22118824

RESUMEN

Anticoagulation has been shown to decrease ischemic stroke in atrial fibrillation (AF). However, concerns remain regarding their safety and efficacy in those ≥70 years of age who constitute most patients with AF. Of the 4,060 patients (mean age 65 years, range 49 to 80) in the Atrial Fibrillation Follow-up Investigation of Rhythm Management (AFFIRM) trial, 2,248 (55% of 4,060) were 70 to 80 years of age, 1,901 of whom were receiving warfarin. Propensity score for warfarin use, estimated for each of the 2,248 patients, was used to match 227 of the 347 patients not on warfarin (in 1:1, 1:2, or 1:3 sets) to 616 patients on warfarin who were balanced in 45 baseline characteristics. All-cause mortality occurred in 18% and 33% of matched patients receiving and not receiving warfarin, respectively, during up to 6 years (mean 3.4) of follow-up (hazard ratio [HR] when warfarin use was compared to its nonuse 0.58, 95% confidence interval [CI] 0.43 to 0.77, p <0.001). All-cause hospitalization occurred in 64% and 67% of matched patients receiving and not receiving warfarin, respectively (HR associated with warfarin use 0.93, 95% CI 0.77 to 1.12, p = 0.423). Ischemic stroke occurred in 4% and 8% of matched patients receiving and not receiving warfarin, respectively (HR associated with warfarin use 0.57, 95% CI 0.31 to 1.04, p = 0.068). Major bleeding occurred in 7% and 10% of matched patients receiving and not receiving warfarin, respectively (HR associated with warfarin use 0.73, 95% CI 0.44 to 1.22, p = 0.229). In conclusion, warfarin use was associated with decreased mortality in septuagenarian patients with AF but had no association with hospitalization or major bleeding.


Asunto(s)
Fibrilación Atrial/complicaciones , Accidente Cerebrovascular/epidemiología , Warfarina/administración & dosificación , Distribución por Edad , Factores de Edad , Anciano , Anciano de 80 o más Años , Anticoagulantes/administración & dosificación , Fibrilación Atrial/tratamiento farmacológico , Fibrilación Atrial/epidemiología , Relación Dosis-Respuesta a Droga , Femenino , Estudios de Seguimiento , Humanos , Incidencia , Masculino , Persona de Mediana Edad , Estudios Prospectivos , Quebec/epidemiología , Factores de Riesgo , Accidente Cerebrovascular/etiología , Accidente Cerebrovascular/prevención & control , Tasa de Supervivencia/tendencias , Factores de Tiempo , Resultado del Tratamiento , Estados Unidos/epidemiología
16.
Can J Cardiol ; 28(3): 354-9, 2012 May.
Artículo en Inglés | MEDLINE | ID: mdl-21982425

RESUMEN

BACKGROUND: In the Beta-Blocker Evaluation of Survival Trial (BEST), systolic blood pressure (SBP) ≤ 120 mm Hg was an independent predictor of poor prognosis in ambulatory patients with chronic systolic heart failure (HF). Because SBP is an important predictor of response to ß-blocker therapy, the BEST protocol prespecified a post hoc analysis to determine whether the effect of bucindolol varied by baseline SBP. METHODS: In the BEST, 2706 patients with chronic systolic (left ventricular ejection fraction < 35%) HF and New York Heart Association class III (92%) or IV (8%) symptoms and receiving standard background therapy were randomized to receive either bucindolol (n = 1354) or placebo (n = 1354). Of these, 1751 had SBP ≤ 120 mm Hg, and 955 had SBP > 120 mm Hg at baseline. RESULTS: Among patients with SBP > 120 mm Hg, all-cause mortality occurred in 28% and 22% of patients receiving placebo and bucindolol, respectively (hazard ratio when bucindolol was compared with placebo, 0.77; 95% confidence interval [CI], 0.59-0.99; P = 0.039). In contrast, among those with SBP ≤ 120 mm Hg, 36% and 35% of patients in the placebo and bucindolol groups died, respectively (hazard ratio, 0.95; 95% CI, 0.81-1.12; P = 0.541). Hazard ratios (95% CIs; P values) for HF hospitalization associated with bucindolol use were 0.70 (0.56-0.89; P = 0.003) and 0.82 (0.71-0.95; P = 0.008) for patients with SBP > 120 and ≤ 120 mm Hg, respectively. CONCLUSION: Bucindolol, a nonselective ß-blocker with weak α(2)-blocking properties, significantly reduced HF hospitalization in systolic HF patients regardless of baseline SBP. However, bucindolol reduced mortality only in those with SBP > 120 mm Hg.


Asunto(s)
Antagonistas Adrenérgicos beta/administración & dosificación , Insuficiencia Cardíaca Sistólica/tratamiento farmacológico , Hipertensión/tratamiento farmacológico , Propanolaminas/administración & dosificación , Factores de Edad , Anciano , Determinación de la Presión Sanguínea , Distribución de Chi-Cuadrado , Relación Dosis-Respuesta a Droga , Esquema de Medicación , Femenino , Estudios de Seguimiento , Insuficiencia Cardíaca Sistólica/etiología , Insuficiencia Cardíaca Sistólica/mortalidad , Hospitalización/estadística & datos numéricos , Humanos , Hipertensión/complicaciones , Hipertensión/diagnóstico , Estimación de Kaplan-Meier , Masculino , Persona de Mediana Edad , Modelos de Riesgos Proporcionales , Valores de Referencia , Medición de Riesgo , Índice de Severidad de la Enfermedad , Factores Sexuales , Volumen Sistólico/efectos de los fármacos , Tasa de Supervivencia , Resultado del Tratamiento
17.
Int J Cardiol ; 154(2): 128-33, 2012 Jan 26.
Artículo en Inglés | MEDLINE | ID: mdl-20947188

RESUMEN

BACKGROUND: Older age is an independent predictor of all-cause mortality in patients with mild to moderate heart failure (HF). Whether older age is also an independent predictor of mortality in patients with more advanced HF is unknown. METHODS: Of the 2707 Beta-Blocker Evaluation of Survival Trial (BEST) participants with ambulatory chronic HF (New York Heart Association class III/IV and left ventricular ejection fraction <35%), 1091 were elderly (≥ 65 years). Propensity scores for older age, estimated for each of the 2707 patients, were used to assemble a cohort of 603 pairs of younger and older patients, balanced on 66 baseline characteristics. RESULTS: All-cause mortality occurred in 33% and 36% of younger and older matched patients respectively during 4 years of follow-up (hazard ratio {HR} associated with age ≥ 65 years, 1.05; 95% confidence interval {CI}, 0.87-1.27; P=0.614). HF hospitalization occurred in 38% and 40% of younger and older matched patients respectively (HR, 1.01; 95% CI, 0.84-1.21; P=0.951). Among 603 pairs of unmatched and unbalanced patients, all-cause mortality occurred in 28% and 36% of younger and older patients respectively (HR, 1.34; 95% CI, 1.10-1.64; P=0.004) and HF hospitalization occurred in 34% and 40% of younger and older unmatched patients respectively (HR, 1.24; 95% CI, 1.03-1.50; P=0.024). CONCLUSION: Significant bivariate associations suggest that older age is a useful marker of poor outcomes in patients with advanced chronic systolic HF. However, lack of significant independent associations suggests that older age per se has no intrinsic effect on outcomes in these patients.


Asunto(s)
Insuficiencia Cardíaca Sistólica/mortalidad , Hospitalización/estadística & datos numéricos , Antagonistas Adrenérgicos beta/uso terapéutico , Negro o Afroamericano/estadística & datos numéricos , Distribución por Edad , Anciano , Enfermedad Crónica , Estudios de Cohortes , Comorbilidad , Femenino , Estudios de Seguimiento , Insuficiencia Cardíaca Sistólica/tratamiento farmacológico , Insuficiencia Cardíaca Sistólica/etnología , Humanos , Masculino , Persona de Mediana Edad , Valor Predictivo de las Pruebas , Modelos de Riesgos Proporcionales , Estudios Retrospectivos , Factores de Riesgo
18.
Ann Med ; 44(3): 253-61, 2012 May.
Artículo en Inglés | MEDLINE | ID: mdl-21254894

RESUMEN

BACKGROUND: Little is known about the association of rheumatic heart disease (RHD) with incident heart failure (HF) among older adults. DESIGN: Cardiovascular Health Study, a prospective cohort study. METHODS: Of the 4,751 community-dwelling adults ≥ 65 years, free of prevalent HF at baseline, 140 had RHD, defined as self-reported physician-diagnosed RHD along with echocardiographic evidence of left-sided valvular disease. Propensity scores for RHD, estimated for each of the 4,751 participants, were used to assemble a cohort of 720, in which 124 and 596 participants with and without RHD, respectively, were balanced on 62 baseline characteristics. RESULTS: Incident HF developed in 33% and 22% of matched participants with and without RHD, respectively, during 13 years of follow-up (hazard ratio when RHD was compared to no-RHD 1.60; 95% confidence interval 1.13-2.28; P = 0.008). Pre-match unadjusted, multivariable-adjusted, and propensity-adjusted hazard ratios (95% confidence intervals) for RHD-associated incident heart failure were 2.04 (1.54-2.71; P < 0.001), 1.32 (1.02-1.70; P = 0.034), and 1.55 (1.14-2.11; P = 0.005), respectively. RHD was not associated with all-cause mortality (HR 1.09; 95% CI 0.82-1.45; P = 0.568). CONCLUSION: RHD is an independent risk factor for incident HF among community-dwelling older adults free of HF, but has no association with mortality.


Asunto(s)
Insuficiencia Cardíaca/etiología , Cardiopatía Reumática/complicaciones , Anciano , Anciano de 80 o más Años , Femenino , Estudios de Seguimiento , Insuficiencia Cardíaca/epidemiología , Humanos , Incidencia , Estimación de Kaplan-Meier , Modelos Logísticos , Masculino , Puntaje de Propensión , Modelos de Riesgos Proporcionales , Estudios Prospectivos , Riesgo , Factores de Riesgo
19.
Int J Cardiol ; 155(1): 120-5, 2012 Feb 23.
Artículo en Inglés | MEDLINE | ID: mdl-21664707

RESUMEN

BACKGROUND: Reduced right ventricular ejection fraction (RVEF) is associated with poor outcomes in patients with chronic systolic heart failure (HF). Although most HF patients are older adults, little is known about the relationship between low RVEF and outcomes in older adults with systolic HF. METHODS: Of the 2008 Beta-Blocker Evaluation of Survival Trial (BEST) participants with systolic HF (left ventricular ejection fraction ≤ 35%) 822 were ≥ 65 years and had data on baseline RVEF estimated by gated-equilibrium radionuclide ventriculography. Using RVEF ≥ 40% (n = 308) as reference, we examined association of RVEF 30-39% (n = 214), 20-29% (n = 206) and <20% (n = 94) with outcomes using Cox regression models. RESULTS: All-cause mortality occurred in 36%, 40%, 39% and 56% of patients with RVEF ≥ 40%, 30-39%, 20-29% and <20% respectively. Compared with RVEF ≥ 40%, unadjusted hazard ratios (HR) and 95% confidence intervals (CI) for all-cause mortality associated with RVEF 30-39%, 20-29% and <20% were 1.19 (0.90-1.57; P = 0.220), 1.13 (0.84-1.51; P = 0.423) and 1.97 (1.43-2.73; P<0.001) respectively. Respective multivariable-adjusted HR's (95% CI's) for all-cause mortality were 1.19 (0.88-1.60; P = 0.261), 1.00 (0.73-1.39; P = 0.982) and 1.70 (1.14-2.53; P = 0.009). Adjusted HR's (95% CI's) associated with RVEF <20% (versus ≥ 40%) for cardiovascular mortality and HF mortality were 1.79 (1.17-2.76; P = 0.008) and 1.97 (1.02-3.83; P = 0.045) respectively. RVEF had no independent association with sudden cardiac death, all-cause or HF hospitalization. CONCLUSIONS: Abnormally low RVEF is a significant independent predictor of mortality, but not of HF hospitalization, in older adults with systolic HF.


Asunto(s)
Insuficiencia Cardíaca Sistólica/mortalidad , Insuficiencia Cardíaca Sistólica/fisiopatología , Hospitalización , Volumen Sistólico , Función Ventricular Derecha , Factores de Edad , Anciano , Femenino , Insuficiencia Cardíaca Sistólica/tratamiento farmacológico , Humanos , Masculino , Valor Predictivo de las Pruebas , Propanolaminas/uso terapéutico
20.
J Card Fail ; 17(12): 1035-40, 2011 Dec.
Artículo en Inglés | MEDLINE | ID: mdl-22123368

RESUMEN

BACKGROUND: Heart failure (HF) patients often depend on driving for access to specialty care. We analyzed a public-use copy of the Cardiovascular Health Study (CHS) data to determine if HF is a risk factor for driving cessation and to identify other risk factors for driving cessation among those with HF. METHODS AND RESULTS: Of the 5,383 community-dwelling drivers aged ≥65 years (mean age 73 years, 55% women, 13% African American), 839 had HF: 246 had baseline prevalent HF and 593 developed incident HF before driving cessation during 9 years of follow-up. Incident driving cessation occurred at rates of 3,980 and 3,709 per 10,000 person-years of follow-up for those with and without HF, respectively (unadjusted hazard ratio [HR] associated with HF as a time-varying variable: 2.13, 95% confidence interval [CI] 1.83-2.47; P < .001). This association remained unchanged after multivariable risk adjustment (HR 1.43, 95% CI 1.21-1.68; P < .001). Among the 839 older drivers with HF, independent predictors for incident driving cessation were age ≥75 years (HR 1.99, 95% CI 1.44-2.73; P < .001), female gender (HR 1.93, 95% CI 1.37-2.74; P < .001), difficulty walking half a mile (HR 1.47 (1.04-2.08); P = .028), vision problems (HR 1.47, 95% CI 1.07-2.02; P = .018), and stroke as a time-varying covariate (HR 1.96, 95% CI 1.38-2.79; P < .001). CONCLUSIONS: HF is an independent risk factor for incident driving cessation among community-dwelling older drivers. Several patient characteristics predicted driving cessation in older HF patients, which may be targets for interventions to prevent driving cessation among these patients.


Asunto(s)
Conducción de Automóvil/psicología , Insuficiencia Cardíaca , Características de la Residencia , Factores de Edad , Anciano , Envejecimiento/fisiología , Envejecimiento/psicología , Intervalos de Confianza , Femenino , Estado de Salud , Humanos , Masculino , Prevalencia , Estudios Prospectivos , Psicometría , Factores de Riesgo , Autoinforme , Trastornos de la Visión
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