Your browser doesn't support javascript.
loading
Mostrar: 20 | 50 | 100
Resultados 1 - 20 de 26
Filtrar
Más filtros

Banco de datos
País/Región como asunto
Tipo del documento
Intervalo de año de publicación
1.
J Med Internet Res ; 23(5): e22959, 2021 05 25.
Artículo en Inglés | MEDLINE | ID: mdl-33999834

RESUMEN

Artificial intelligence-driven voice technology deployed on mobile phones and smart speakers has the potential to improve patient management and organizational workflow. Voice chatbots have been already implemented in health care-leveraging innovative telehealth solutions during the COVID-19 pandemic. They allow for automatic acute care triaging and chronic disease management, including remote monitoring, preventive care, patient intake, and referral assistance. This paper focuses on the current clinical needs and applications of artificial intelligence-driven voice chatbots to drive operational effectiveness and improve patient experience and outcomes.


Asunto(s)
Inteligencia Artificial , COVID-19 , Comunicación , Atención a la Salud/métodos , Software de Reconocimiento del Habla , Telemedicina/métodos , Voz , Teléfono Celular , Enfermedad Crónica/terapia , Cuidados Críticos/métodos , Humanos , Pandemias , Derivación y Consulta , Triaje
2.
Nature ; 464(7288): 601-5, 2010 Mar 25.
Artículo en Inglés | MEDLINE | ID: mdl-20336144

RESUMEN

Recent studies indicate that mammals, including humans, maintain some capacity to renew cardiomyocytes throughout postnatal life. Yet, there is little or no significant cardiac muscle regeneration after an injury such as acute myocardial infarction. By contrast, zebrafish efficiently regenerate lost cardiac muscle, providing a model for understanding how natural heart regeneration may be blocked or enhanced. In the absence of lineage-tracing technology applicable to adult zebrafish, the cellular origins of newly regenerated cardiac muscle have remained unclear. Using new genetic fate-mapping approaches, here we identify a population of cardiomyocytes that become activated after resection of the ventricular apex and contribute prominently to cardiac muscle regeneration. Through the use of a transgenic reporter strain, we found that cardiomyocytes throughout the subepicardial ventricular layer trigger expression of the embryonic cardiogenesis gene gata4 within a week of trauma, before expression localizes to proliferating cardiomyocytes surrounding and within the injury site. Cre-recombinase-based lineage-tracing of cells expressing gata4 before evident regeneration, or of cells expressing the contractile gene cmlc2 before injury, each labelled most cardiac muscle in the ensuing regenerate. By optical voltage mapping of surface myocardium in whole ventricles, we found that electrical conduction is re-established between existing and regenerated cardiomyocytes between 2 and 4 weeks post-injury. After injury and prolonged fibroblast growth factor receptor inhibition to arrest cardiac regeneration and enable scar formation, experimental release of the signalling block led to gata4 expression and morphological improvement of the injured ventricular wall without loss of scar tissue. Our results indicate that electrically coupled cardiac muscle regenerates after resection injury, primarily through activation and expansion of cardiomyocyte populations. These findings have implications for promoting regeneration of the injured human heart.


Asunto(s)
Factores de Transcripción GATA/genética , Factores de Transcripción GATA/metabolismo , Corazón/fisiología , Miocitos Cardíacos/citología , Miocitos Cardíacos/metabolismo , Regeneración/fisiología , Proteínas de Pez Cebra/genética , Proteínas de Pez Cebra/metabolismo , Pez Cebra/fisiología , Animales , Animales Modificados Genéticamente , Proliferación Celular , Conductividad Eléctrica , Regulación de la Expresión Génica , Regeneración/genética , Pez Cebra/genética , Pez Cebra/metabolismo
3.
Curr Heart Fail Rep ; 11(1): 64-9, 2014 Mar.
Artículo en Inglés | MEDLINE | ID: mdl-24363021

RESUMEN

Cardiac resynchronization therapy (CRT) improves measures of systolic function and clinical status. However, its effect on diastolic function is not well established. Commonly used parameters of diastolic function are measured from echocardiography, using pulse wave and tissue Doppler technologies, as well as timing and deformation data. Review of the existing studies that address the relationship between diastolic function and CRT shows conflicting data, but general trends can be deduced. Baseline elevated filling pressure appears to identify patients most likely to derive improvement in that particular parameter. Intrinsic relaxation does not appear to be significantly impacted by CRT. Generally, changes in diastolic properties after CRT appear to be linked to changes in systolic function. Specific therapy aimed at diastolic asynchrony is lacking, partly due to an unclear relationship between diastolic asynchrony and diastolic dysfunction, and the inability to specifically impact diastolic timing with a systolic intervention such as CRT.


Asunto(s)
Terapia de Resincronización Cardíaca , Insuficiencia Cardíaca/fisiopatología , Insuficiencia Cardíaca/terapia , Diástole/fisiología , Humanos , Pronóstico , Sístole/fisiología
5.
ASAIO J ; 69(3): 278-283, 2023 03 01.
Artículo en Inglés | MEDLINE | ID: mdl-36731068

RESUMEN

The aim of this investigation was to characterize the hemostatic status of heart failure patients with implanted left ventricular assist devices (LVADs) to propose a mechanism associated with bleeding. Patients (n = 300) from 23 US hospitals were enrolled in the PREVENtion of HeartMate II Pump Thrombosis through Clinical Management (PREVENT) study. A biobank was established with serum and plasma samples prospectively collected from a cohort of 175 patients preimplant baseline (BL) and 3 months (3M) postimplant. Outcomes were collected for 6 months. Thrombin (prothrombin fragment 1.2 [F1.2], functional thrombin generation [TG]) and fibrinolytic activity (D-dimer, plasminogen activator inhibitor-1 [PAI-1]), but not contact activation (complement C5a), were elevated in heart failure patients at BL. F1.2, TG, and PAI-1 levels decreased 3M after LVAD implantation ( p < 0.01) but did not revert to normal in all patients; conversely, D-dimer increased BL to 3M ( p < 0.01). Compared with patients without events, thrombin activity (F1.2) was increased in patients with late bleeding (3-4 months postimplant) ( p = 0.06) and in those with late gastrointestinal (GI) bleeding ( p = 0.01). Patients with 3M F1.2 levels above the cohort mean had a higher incidence of bleeding ( p < 0.001) and GI bleeding ( p < 0.001) compared with those with below mean F1.2. Patients experiencing multiple bleeding events were more likely to have 3M F1.2 greater than the cohort mean. Despite anticoagulation with aspirin and warfarin, LVAD implanted patients exhibit hemostatic activation. Excess thrombin formation, particularly shown by increased F1.2, was demonstrated in association with bleeding in LVAD implanted patients.


Asunto(s)
Insuficiencia Cardíaca , Corazón Auxiliar , Hemostáticos , Humanos , Trombina , Inhibidor 1 de Activador Plasminogénico , Corazón Auxiliar/efectos adversos , Hemorragia Gastrointestinal/etiología , Insuficiencia Cardíaca/cirugía , Insuficiencia Cardíaca/etiología
6.
ASAIO J ; 69(8): 742-748, 2023 08 01.
Artículo en Inglés | MEDLINE | ID: mdl-37134003

RESUMEN

The purpose of this study was to describe the changes in plasma levels of angiogenic and inflammatory biomarkers, specifically Ang-2 and TNF-α, in patients receiving HeartMate II (HMII) left ventricular assist device (LVAD) and correlate them with nonsurgical bleeding. It has been shown that angiopoietin-2 (Ang-2) and tissue necrosis factor-α (TNF-α) may be linked to bleeding in LVAD patients. This study utilized biobanked samples prospectively collected from the PREVENT study, a prospective, multicenter, single-arm, nonrandomized study of patients implanted with HMII. Paired serum samples were obtained in 140 patients before implantation and at 90 days postimplantation. Baseline demographics were as follows: age 57 ± 13 years, 41% had ischemic etiology, 82% male, and 75% destination therapy indication. In the 17 patients with baseline elevation of both TNF-α and Ang-2, 10 (60%) experienced a significant bleeding event within 180 days postimplant compared with 37 of 98 (38%) patients with Ang-2 and TNF-α below the mean ( p = 0.02). The hazard ratio for a bleeding event was 2.3 (95% CI: 1.2-4.6) in patients with elevated levels of both TNF-α and Ang-2. In the PREVENT multicenter study, patients with elevations in serum Angiopoietin-2 and TNF-α at baseline before LVAD implantation demonstrated increased bleeding events after LVAD implantation.


Asunto(s)
Insuficiencia Cardíaca , Corazón Auxiliar , Humanos , Masculino , Adulto , Persona de Mediana Edad , Anciano , Femenino , Factor de Necrosis Tumoral alfa , Angiopoyetina 2 , Estudios Prospectivos , Corazón Auxiliar/efectos adversos , Tromboplastina , Hemorragia/etiología , Necrosis/complicaciones , Insuficiencia Cardíaca/cirugía , Insuficiencia Cardíaca/complicaciones , Estudios Retrospectivos
7.
J Heart Lung Transplant ; 42(1): 33-39, 2023 01.
Artículo en Inglés | MEDLINE | ID: mdl-36347767

RESUMEN

BACKGROUND: Continuous flow left ventricular assist devices have improved outcomes in patients with end-stage heart failure that require mechanical circulatory support. Current devices have an adverse event profile that has hindered widespread application. The EVAHEART®2 left ventricular assist device (EVA2) has design features such as large blood gaps, lower pump speeds and an inflow cannula that does not protrude into the left ventricle that may mitigate the adverse events currently seen with other continuous flow devices. METHODS: A prospective, multi-center randomized non-inferiority study, COMPETENCE Trial, is underway to assess non-inferiority of the EVA2 to the HeartMate 3 LVAS when used for the treatment of refractory advanced heart failure. The primary end-point is a composite of the individual primary outcomes: Survival to cardiac transplant or device explant for recovery; Free from disabling stroke; Free from severe Right Heart Failure after implantation of original device. Randomization is in a 2:1 (EVA2:HM3) ratio. RESULTS: The first patient was enrolled into the COMPETENCE Trial in December of 2020, and 25 subjects (16 EVA2 and 9 HM3) are currently enrolled. Enrollment of a safety cohort is projected to be completed by third quarter of 2022 at which time an interim analysis will be performed. Short-term cohort (92 EVA2 subjects) and long-term cohort is expected to be completed by the end of 2023 and 2024, respectively. CONCLUSIONS: The design features of the EVA2 such as a novel inflow cannula and large blood gaps may improve clinical outcomes but require further study. The ongoing COMPETENCE trial is designed to determine if the EVA2 is non-inferior to the HM3.


Asunto(s)
Insuficiencia Cardíaca , Trasplante de Corazón , Corazón Auxiliar , Humanos , Corazón Auxiliar/efectos adversos , Estudios Prospectivos , Insuficiencia Cardíaca/cirugía , Ventrículos Cardíacos , Resultado del Tratamiento
8.
ASAIO J ; 68(2): 220-225, 2022 02 01.
Artículo en Inglés | MEDLINE | ID: mdl-33927084

RESUMEN

The impact of preoperative end-diastolic left ventricular dimension (preLVEDD) on long-term outcomes with centrifugal continuous-flow left ventricular assist device (CF-LVAD) is not well established. Accordingly, we performed an analysis of the Interagency Registry for Mechanically Assisted Circulatory Support (INTERMACS) registry to study this relationship. All patients with centrifugal CF-LVAD in the INTERMACS registry from June 2006 to December 2017 were screened. The final study group consisted of 3,304 patients. After a median follow-up of 9.0 months (interquartile range [IQR], 4.2-18.8 months), 2,596 (79%) patients were alive. After adjusting for significant covariates, increased preLVEDD was associated with lower mortality (hazard ratio [HR], 0.91; 95% confidence interval [CI], 0.84-0.98; p = 0.01), stroke (HR, 0.85; 95% CI, 0.77-0.93; p < 0.001), and gastrointestinal bleeding (HR, 0.88; 95% CI, 0.80-0.97; p = 0.01), although there were more arrhythmias (HR, 1.14; 95% CI, 1.05-1.24; p = 0.003). Our study suggests that preLVEDD is an independent predictor of mortality and adverse events in patients treated with centrifugal CF-LVAD. preLVEDD should be considered an important preimplant variable for risk stratification when considering a CF-LVAD.


Asunto(s)
Insuficiencia Cardíaca , Corazón Auxiliar , Accidente Cerebrovascular , Insuficiencia Cardíaca/cirugía , Ventrículos Cardíacos/diagnóstico por imagen , Ventrículos Cardíacos/cirugía , Corazón Auxiliar/efectos adversos , Humanos , Sistema de Registros , Estudios Retrospectivos , Resultado del Tratamiento
9.
Am J Cardiol ; 177: 61-68, 2022 08 15.
Artículo en Inglés | MEDLINE | ID: mdl-35697544

RESUMEN

The impact of substance abuse, including alcohol abuse or illicit drug use, on outcomes after left ventricular assist device (LVAD) implantation, has not been fully elucidated. Accordingly, to test the hypothesis that such a history would be associated with worse outcomes, we analyzed the Interagency Registry for Mechanically Assisted Circulatory Support registry. All patients from the Interagency Registry for Mechanically Assisted Circulatory Support registry who received a continuous-flow LVAD from June 2006 to December 2017 were included. The median follow-up duration was 12.9 months (interquartile range, 5.3 to 17.5). The final study group consisted of 15,069 patients, of which 1,184 (7.9%) had a history of alcohol abuse and 1,139 (7.6%) had a history of illicit drug use. The overall mortality rates in the alcohol, illicit drug, and control groups were 25%, 21%, and 29%, respectively. Cox regression analysis showed that having a history of alcohol abuse (hazard ratio, 0.97, 95% confidence interval, 0.84 to 1.13, p = 0.72) or illicit drug use (hazard ratio, 1.02, 95% confidence interval, 0.86 to 1.21, p = 0.81) was not significantly associated with increased risk of all-cause mortality when compared with general LVAD population. On the contrary, after adjusting for other covariates, a history of alcohol abuse or illicit drug use was significantly associated with increased device malfunction/pump thrombosis, device-related infection, or all-cause hospitalization (all p <0.05). Furthermore, After LVAD implantation, these patients had a lower quality of life assessed by the Kansas City Cardiomyopathy Questionnaire compared with those who did not. In conclusion, our findings suggest that patients with a history of alcohol abuse or illicit drug use are at risk for adverse device-related events with a lower quality of life after continuous-flow LVAD implantation compared with the general LVAD population.


Asunto(s)
Alcoholismo , Insuficiencia Cardíaca , Corazón Auxiliar , Drogas Ilícitas , Alcoholismo/complicaciones , Alcoholismo/epidemiología , Insuficiencia Cardíaca/epidemiología , Insuficiencia Cardíaca/etiología , Insuficiencia Cardíaca/terapia , Corazón Auxiliar/efectos adversos , Humanos , Calidad de Vida , Sistema de Registros , Estudios Retrospectivos , Resultado del Tratamiento
11.
Heart Fail Clin ; 7(4): 457-66, 2011 Oct.
Artículo en Inglés | MEDLINE | ID: mdl-21925429

RESUMEN

Recent advances in mechanically assisted circulation, including refinement of patient selection criteria and enhancements in device design, have been associated with improvements in survival, functionality and quality of life as well as reductions in adverse events. Novel and innovative trial design, methodology and endpoints have been utilized in the development of the cumulative database supporting the role of ventricular assist devices for the management of patients with advanced heart failure. The rapid and significant improvements in patient-centric outcomes support the expansion of this technology into less moribund populations where the potential benefits may be even more robust.


Asunto(s)
Circulación Asistida/instrumentación , Ensayos Clínicos como Asunto , Insuficiencia Cardíaca/terapia , Selección de Paciente , Diseño de Equipo , Humanos , Resultado del Tratamiento
12.
J Am Soc Echocardiogr ; 33(11): 1357-1362.e2, 2020 11.
Artículo en Inglés | MEDLINE | ID: mdl-32828622

RESUMEN

BACKGROUND: The aim of this study was to examine the relationship between baseline left ventricular (LV) geometry and outcomes after transcatheter aortic valve replacement (TAVR). METHODS: Patients undergoing TAVR (n = 206) had baseline LV geometry classified as (1) concentric hypertrophy, (2) eccentric hypertrophy, (3) concentric remodeling, or (4) normal. Descriptive statistics, Kaplan-Meier time-to-event analysis, and Cox regression were performed. RESULTS: Distribution of baseline LV geometry differed between male and female patients (χ2 = 16.83, P = .001) but not at 1 month (χ2 = 2.56, P = .47) or 1 year (χ2 = 5.68, P = .13). After TAVR, a majority of patients with concentric hypertrophy evolved to concentric remodeling. Survival differed across LV geometry groups at 1 year (χ2[3] = 8.108, P = .044, log-rank test) and at 6.5 years (χ2[3] = 9.023, P = .029, log-rank test). Compared with patients with concentric hypertrophy, patients with normal geometry (hazard ratio, 2.25; 95% CI, 1.12-4.54; P = .023) and concentric remodeling (hazard ratio, 1.89; 95% CI, 1.12-3.17; P = .016) had higher rates of all-cause mortality. CONCLUSIONS: Baseline concentric hypertrophy confers a survival advantage after TAVR. Although baseline patterns of LV geometry appear gender specific (with women demonstrating more concentric hypertrophy), this difference resolves after TAVR.


Asunto(s)
Estenosis de la Válvula Aórtica , Reemplazo de la Válvula Aórtica Transcatéter , Válvula Aórtica/cirugía , Estenosis de la Válvula Aórtica/diagnóstico , Estenosis de la Válvula Aórtica/cirugía , Femenino , Humanos , Hipertrofia Ventricular Izquierda/diagnóstico por imagen , Masculino , Factores de Riesgo , Factores Sexuales , Función Ventricular Izquierda , Remodelación Ventricular
13.
J Am Soc Echocardiogr ; 32(9): 1067-1074.e1, 2019 09.
Artículo en Inglés | MEDLINE | ID: mdl-31278049

RESUMEN

BACKGROUND: Left ventricular filling pressure (LVFP) has been demonstrated to be a major predictor of poor cardiovascular outcomes. However, estimation of LVFP in patients with aortic stenosis is limited by the high prevalence of significant mitral annular calcification. The aim of this study was to investigate the effect of transcatheter aortic valve replacement on LVFP and the relationship of LVFP to mortality and hospitalization. METHODS: This was a single-center, retrospective study of 140 consecutive patients in sinus rhythm with significant mitral annular calcification who underwent transcatheter aortic valve replacement for severe aortic stenosis from May 2011 to June 2015. Mean follow-up duration was 3.06 ± 1.48 years (minimum, 2.4 years; maximum, 6.5 years). Diastolic function was assessed using recently proposed criteria for those with significant mitral annular calcification. High LVFP was defined as a mitral E/A ratio > 1.8 or a ratio of 0.8 to 1.8 and isovolumic relaxation time < 80 msec. RESULTS: At baseline, the proportion of patients with high LVFP was 40.7%, similar to 1 month (39.7%) (P = .86). However, the proportion of patients with high LVFP was significantly decreased at 1 year compared with those at baseline (26.9% vs 40.7%, P = .02). Multivariate analysis showed that high LVFP at baseline significantly increased risk for all-cause mortality compared with patients with normal LVFP (hazard ratio, 2.84; 95% confidence interval, 1.33-6.05; P = .007). CONCLUSIONS: High baseline LVFP was associated with a significantly increased all-cause mortality, and LVFP does not improve in the short term but only at 1 year after transcatheter aortic valve replacement.


Asunto(s)
Estenosis de la Válvula Aórtica/cirugía , Ventrículos Cardíacos/fisiopatología , Estenosis de la Válvula Mitral/etiología , Válvula Mitral/diagnóstico por imagen , Reemplazo de la Válvula Aórtica Transcatéter/métodos , Función Ventricular Izquierda/fisiología , Presión Ventricular/fisiología , Anciano de 80 o más Años , Estenosis de la Válvula Aórtica/complicaciones , Estenosis de la Válvula Aórtica/mortalidad , Calcinosis/complicaciones , Calcinosis/diagnóstico , Calcinosis/fisiopatología , Causas de Muerte/tendencias , Diástole , Ecocardiografía Doppler , Femenino , Estudios de Seguimiento , Ventrículos Cardíacos/diagnóstico por imagen , Humanos , Masculino , Estenosis de la Válvula Mitral/diagnóstico , Estenosis de la Válvula Mitral/mortalidad , Estenosis de la Válvula Mitral/fisiopatología , Estudios Retrospectivos , Tasa de Supervivencia/tendencias , Factores de Tiempo , Resultado del Tratamiento , Estados Unidos/epidemiología
15.
J Am Coll Cardiol ; 69(11): 1399-1406, 2017 Mar 21.
Artículo en Inglés | MEDLINE | ID: mdl-27654854

RESUMEN

BACKGROUND: The oral vasopressin-2 receptor antagonist tolvaptan causes aquaresis in patients with volume overload, potentially facilitating decongestion and improving the clinical course of patients with acute heart failure (AHF). OBJECTIVES: The TACTICS-HF (Targeting Acute Congestion with Tolvaptan in Congestive Heart Failure) study was conducted to address the acute use of tolvaptan to improve congestion in AHF. METHODS: The TACTICS-HF study randomized patients (n = 257) within 24 h of AHF presentation in a prospective, double blind, placebo-controlled trial. Patients were eligible regardless of ejection fraction, and were randomized to either 30 mg of tolvaptan or placebo given at 0, 24, and 48 h, with a fixed-dose furosemide regimen as background therapy. The primary endpoint was the proportion of patients considered responders at 24 h. Secondary endpoints included symptom improvement, changes in renal function, and clinical events. RESULTS: Dyspnea relief by Likert scale was similar between groups at 8 h (25% moderately or markedly improved with tolvaptan vs. 28% placebo; p = 0.59) and at 24 h (50% tolvaptan vs. 47% placebo; p = 0.80). Need for rescue therapy was also similar at 24 h (21% tolvaptan, 18% placebo; p = 0.57). The proportion defined as responders at 24 h (primary study endpoint) was 16% for tolvaptan and 20% for placebo (p = 0.32). Tolvaptan resulted in greater weight loss and net fluid loss compared with placebo, but tolvaptan-treated patients were more likely to experience worsening renal function during treatment. There were no differences in in-hospital or post-discharge clinical outcomes. CONCLUSIONS: In patients hospitalized with AHF, dyspnea, and congestion, the addition of tolvaptan to a standardized furosemide regimen did not improve the number of responders at 24 h, despite greater weight loss and fluid loss. (Targeting Acute Congestion With Tolvaptan in Congestive Heart Failure [TACTICS-HF]; NCT01644331).


Asunto(s)
Antagonistas de los Receptores de Hormonas Antidiuréticas/uso terapéutico , Benzazepinas/uso terapéutico , Insuficiencia Cardíaca/tratamiento farmacológico , Anciano , Método Doble Ciego , Disnea/tratamiento farmacológico , Femenino , Humanos , Pruebas de Función Renal , Masculino , Persona de Mediana Edad , Estudios Prospectivos , Tolvaptán
16.
J Heart Lung Transplant ; 36(1): 1-12, 2017 01.
Artículo en Inglés | MEDLINE | ID: mdl-27865732

RESUMEN

BACKGROUND: Recommended structured clinical practices including implant technique, anti-coagulation strategy, and pump speed management (PREVENT [PREVENtion of HeartMate II Pump Thrombosis Through Clinical Management] recommendations) were developed to address risk of early (<3 months) pump thrombosis (PT) risk with HeartMate II (HMII; St. Jude Medical, Inc. [Thoratec Corporation], Pleasanton, CA). We prospectively assessed the HMII PT rate in the current era when participating centers adhered to the PREVENT recommendations. METHODS: PREVENT was a prospective, multi-center, single-arm, non-randomized study of 300 patients implanted with HMII at 24 participating sites. Confirmed PT (any suspected PT confirmed visually and/or adjudicated by an independent assessor) was evaluated at 3 months (primary end-point) and at 6 months after implantation. RESULTS: The population included 83% men (age 57 years ± 13), 78% destination therapy, and 83% Interagency Registry for Mechanically Assisted Circulatory Support (INTERMACS) Profile 1-3. Primary end-point analysis showed a confirmed PT of 2.9% at 3 months and 4.8% at 6 months. Adherence to key recommendations included 78% to surgical recommendations, 95% to heparin bridging, and 79% to pump speeds ≥9,000 RPMs (92% >8,600 RPMs). Full adherence to implant techniques, heparin bridging, and pump speeds ≥9,000 RPMs resulted in a significantly lower risk of PT (1.9% vs 8.9%; p < 0.01) and lower composite risk of suspected thrombosis, hemolysis, and ischemic stroke (5.7% vs 17.7%; p < 0.01) at 6 months. CONCLUSIONS: Adoption of all components of a structured surgical implant technique and clinical management strategy (PREVENT recommendations) is associated with low rates of confirmed PT.


Asunto(s)
Manejo de la Enfermedad , Insuficiencia Cardíaca/terapia , Corazón Auxiliar/efectos adversos , Complicaciones Posoperatorias/prevención & control , Mejoramiento de la Calidad , Prevención Secundaria/métodos , Trombosis/prevención & control , Femenino , Estudios de Seguimiento , Insuficiencia Cardíaca/mortalidad , Humanos , Incidencia , Masculino , Persona de Mediana Edad , Complicaciones Posoperatorias/epidemiología , Estudios Prospectivos , Sistema de Registros , Factores de Riesgo , Tasa de Supervivencia/tendencias , Trombosis/epidemiología , Estados Unidos/epidemiología
17.
Circ Res ; 94(2): 184-93, 2004 Feb 06.
Artículo en Inglés | MEDLINE | ID: mdl-14615292

RESUMEN

Posttranslational modification of target substrates underlies biological processes through activation/inactivation of signaling cascades. To concurrently identify the phosphoprotein substrates associated with cardiac beta-adrenergic signaling, the mouse myocyte phosphoproteome was analyzed using 2-D gel electrophoresis in combination with 32P autoradiography. Phosphoprotein spots, detected by silver staining, were identified using MALDI-TOF mass spectrometry in conjunction with computer-assisted protein spot matching. Stimulation with isoproterenol (1 micromol/L for 5 minutes) was associated with maximal increases in myocyte contractile parameters, and significant stimulation of the phosphorylation of troponin I (190+/-23%) and succinyl CoA synthetase (160+/-16%), whereas the phosphorylation of pyruvate dehydrogenase (48+/-10%), NADH-ubiquinone oxidoreductase (46+/-6%), heat shock protein 27 (18+/-3%), alphaB-crystallin (20+/-3%), and an unidentified 26-kDa protein (29+/-7%) was significantly decreased, compared with unstimulated cells (100%). After sustained (30 minutes) stimulation with isoproterenol, only the alterations in the phosphorylation levels of troponin I and NADH-ubiquinone oxidoreductase were maintained and de novo phosphorylation of a phosphoprotein (approximately 20 kDa and pI 5.5) was observed. The tryptic peptide fragments of this phosphoprotein were sequenced using postsource decay mass spectrometry, and the protein was subsequently cloned and designated as p20, based on its high sequence homology with rat and human skeletal p20. The mouse cardiac p20 contains the conserved domain sequences for heat shock proteins, and the RRAS consensus sequence for cAMP-PKA substrates. LC-MS/MS phosphorylation mapping confirmed phosphorylation of Ser16 in p20 on beta-agonist stimulation. Adenoviral gene transfer of p20 was associated with significant increases in contractility and Ca transient peak in adult rat cardiomyocytes, suggesting an important role of p20 in cardiac function. These findings suggest that cardiomyocytes undergo significant posttranslational modification via phosphorylation in a multitude of proteins to dynamically fine-tune cardiac responses to beta-adrenergic signaling.


Asunto(s)
Agonistas Adrenérgicos beta/farmacología , Proteínas de Choque Térmico/aislamiento & purificación , Isoproterenol/farmacología , Proteínas Musculares/aislamiento & purificación , Miocitos Cardíacos/efectos de los fármacos , Procesamiento Proteico-Postraduccional/efectos de los fármacos , Secuencia de Aminoácidos , Animales , Señalización del Calcio , Tamaño de la Célula/efectos de los fármacos , Clonación Molecular , Electroforesis en Gel Bidimensional , Proteínas de Choque Térmico/química , Proteínas de Choque Térmico/genética , Proteínas de Choque Térmico/fisiología , Humanos , Masculino , Ratones , Datos de Secuencia Molecular , Proteínas Musculares/química , Proteínas Musculares/genética , Proteínas Musculares/fisiología , Contracción Miocárdica , Miocitos Cardíacos/metabolismo , Miocitos Cardíacos/ultraestructura , Fragmentos de Péptidos/química , Fosforilación/efectos de los fármacos , Proteómica , Ratas , Alineación de Secuencia , Homología de Secuencia de Aminoácido , Espectrometría de Masa por Láser de Matriz Asistida de Ionización Desorción
18.
FASEB J ; 18(14): 1725-7, 2004 Nov.
Artículo en Inglés | MEDLINE | ID: mdl-15358683

RESUMEN

Depressed sarcoplasmic reticulum (SR) Ca-cycling is a hallmark of human and experimental heart failure. Strategies to improve this impairment by either increasing SERCA2a levels or decreasing phospholamban (PLN) activity have been suggested as promising therapeutic targets. Indeed, ablation of PLN gene in mice was associated with greatly enhanced cardiac Ca-cycling and performance. Intriguingly, this hyperdynamic cardiac function was maintained throughout the lifetime of the mouse without observable pathological consequences. To determine the cellular alterations in the expression or modification of myocardial proteins, which are associated with the enhanced cardiac contractility, we performed a proteomics-based analysis of PLN knockout (PLN-KO) hearts in comparison to isogenic wild-types. By use of 2-dimensional gel electrophoresis (2-DE), approximately 3300 distinct protein spots were detected in either wild-type or PLN-KO ventricles. Protein spots observed to be altered between PLN-KO and wild-type hearts were subjected to tryptic peptide mass fingerprinting for identification by MALDI-TOF mass spectrometry in combination with LC/MS/MS analysis. In addition, two-dimensional 32P-autoradiography was performed to analyze the phosphorylation profiles of PLN-KO cardiomyocytes. We identified alterations in the expression level of more than 100 ventricular proteins, along with changes in phosphorylation status of important regulatory proteins in the PLN-KO. These protein changes were observed mainly in two subcellular compartments: the cardiac contractile apparatus, and metabolism/energetics. Our findings suggest that numerous alterations in protein expression and phosphorylation state occurred upon ablation of PLN and that a complex functional relationship among proteins involved in calcium handling, myofibrils, and energy production may exist to coordinately maintain the hyperdynamic cardiac contractile performance of the PLN-KO mouse in the long term.


Asunto(s)
Proteínas de Unión al Calcio/genética , Calcio/metabolismo , Contracción Miocárdica , Miocardio/metabolismo , Proteoma/metabolismo , Retículo Sarcoplasmático/metabolismo , Animales , Electroforesis en Gel Bidimensional , Espectrometría de Masas , Ratones , Ratones Noqueados , Procesamiento Proteico-Postraduccional , Proteómica
20.
Circ Heart Fail ; 8(5): 997-1005, 2015 Sep.
Artículo en Inglés | MEDLINE | ID: mdl-26374918

RESUMEN

Congestion is a primary reason for hospitalization in patients with acute heart failure (AHF). Despite inpatient diuretics and vasodilators targeting decongestion, persistent congestion is present in many AHF patients at discharge and more severe congestion is associated with increased morbidity and mortality. Moreover, hospitalized AHF patients may have renal insufficiency, hyponatremia, or an inadequate response to traditional diuretic therapy despite dose escalation. Current alternative treatment strategies to relieve congestion, such as ultrafiltration, may also result in renal dysfunction to a greater extent than medical therapy in certain AHF populations. Truly novel approaches to volume management would be advantageous to improve dyspnea and clinical outcomes while minimizing the risks of worsening renal function and electrolyte abnormalities. One effective new strategy may be utilization of aquaretic vasopressin antagonists. A member of this class, the oral vasopressin-2 receptor antagonist tolvaptan, provides benefits related to decongestion and symptom relief in AHF patients. Tolvaptan may allow for less intensification of loop diuretic therapy and a lower incidence of worsening renal function during decongestion. In this article, we summarize evidence for decongestion benefits with tolvaptan in AHF and describe the design of the Targeting Acute Congestion With Tolvaptan in Congestive Heart Failure Study (TACTICS) and Study to Evaluate Challenging Responses to Therapy in Congestive Heart Failure (SECRET of CHF) trials.


Asunto(s)
Benzazepinas/uso terapéutico , Ensayos Clínicos como Asunto , Manejo de la Enfermedad , Insuficiencia Cardíaca/tratamiento farmacológico , Hospitalización , Enfermedad Aguda , Antagonistas de los Receptores de Hormonas Antidiuréticas/uso terapéutico , Humanos , Tolvaptán
SELECCIÓN DE REFERENCIAS
DETALLE DE LA BÚSQUEDA