375 research outputs found
Presente y futuro de las publicaciones médicas
El acceso a la literatura médica ha sufrido un cambio radical en los últimos años. En menos de dos décadas se ha pasado de un sistema basado en papel a un sistema de envÃo digital en red. El desarrollo de la informática, y sobre todo de internet, ha revolucionado no solo el formato de envÃo de manuscritos, sino también la rapidez con que se preparan estos (incluyendo gestores informáticos de referencias adaptables al formato diferente de cada revista). Esta revolución también ha afectado a la velocidad de acceso a la información. Las bases de datos que se generaban a principios del siglo XXI pueden considerarse «prehistóricas» comparadas con las existentes hoy. La digitalización de las historias clÃnicas y la creación de cuadernos de recogida de datos informáticos aceleran de manera exponencial la preparación y el análisis de los datos incluidos en las investigaciones. Incluso la formación de los investigadores es en la actualidad mucho más transversal, y es frecuente encontrar en los equipos de investigación expertos en estadÃstica que facilitan el análisis de los datos. Sin embargo, todos estos cambios tan importantes se quedan pequeños en comparación con el acceso existente a la información médica en general. Pese a que..
Transcatheter Valve-in-Valve and Valve-in-Ring for Treating Aortic and Mitral Surgical Prosthetic Dysfunction
AbstractBioprosthetic valve use has increased significantly. Considering their limited durability, there will remain an ongoing clinical need for repairing or replacing these prostheses in the future. The current standard of care for treating bioprosthetic valve degeneration involves redo open-heart surgery. However, repeat cardiac surgery may be associated with significant morbidity and mortality. With the rapid evolution of transcatheter heart valve therapies, the feasibility and safety of implanting a transcatheter heart valve within a failed tissue valve has been established. We review the historical perspective of transcatheter valve-in-valve therapy, as well as the main procedural challenges and clinical outcomes associated with this new less invasive treatment option
Comparison of early surgical or transcatheter aortic valve replacement versus conservative management in low-flow, low-gradient aortic stenosis sing Inverse Probability of Treatment Weighting: Results From the TOPAS Prospective Observational Cohort Study
BACKGROUND: No randomized comparison of early (ie, ≤3 months) aortic valve replacement (AVR) versus conservative management or of transcatheter AVR (TAVR) versus surgical AVR has been conducted in patients with low-flow, low-gradient
(LFLG) aortic stenosis (AS).
METHODS AND RESULTS: A total of 481 consecutive patients (75±10 years; 71% men) with LFLG AS (aortic valve area ≤0.6 cm2/
m2 and mean gradient <40 mm Hg), 72% with classic LFLG and 28% with paradoxical LFLG, were prospectively recruited in
the multicenter TOPAS (True or Pseudo Severe Aortic Stenosis) study. True-severe AS or pseudo-severe AS was adjudicated
by flow-independent criteria. During follow-up (median [IQR] 36 [11–60] months), 220 patients died. Using inverse probability
of treatment weighting to address the bias of nonrandom treatment assignment, early AVR (n=272) was associated with a
major overall survival benefit (hazard ratio [HR], 0.34 [95% CI, 0.24–0.50]; P<0.001). This benefit was observed in patients
with true-severe AS but also with pseudo-severe AS (HR, 0.38 [95% CI, 0.18–0.81]; P=0.01), and in classic (HR, 0.33 [95%
CI, 0.22–0.49]; P<0.001) and paradoxical LFLG AS (HR, 0.42 [95% CI, 0.20–0.92]; P=0.03). Compared with conservative
management in the conventional multivariate model, trans femoral TAVR was associated with the best survival (HR, 0.23 [95%
CI, 0.12–0.43]; P<0.001), followed by surgical AVR (HR, 0.36 [95% CI, 0.23–0.56]; P<0.001) and alternative-access TAVR (HR,
0.51 [95% CI, 0.31–0.82]; P=0.007). In the inverse probability of treatment weighting model, trans femoral TAVR appeared to
be superior to surgical AVR (HR [95% CI] 0.28 [0.11–0.72]; P=0.008) with regard to survival.
CONCLUSIONS: In this large prospective observational study of LFLG AS, early AVR appeared to confer a major survival benefit
in both classic and paradoxical LFLG AS. This benefit seems to extend to the subgroup with pseudo-severe AS. Our findings
suggest that TAVR using femoral access might be the best strategy in these patients
Interatrial Shunting for Treating Acute and Chronic Left Heart Failure
The creation of an interatrial shunt has emerged as a new therapy to decompress the left atrium in patients with acute and chronic left heart failure (HF). Current data support the safety of this therapy, and promising preliminary efficacy results have been reported in patients who are refractory to optimal medical/device therapy. This article aims to provide an updated overview and clinical perspective on interatrial shunting for treating different HF conditions, and highlights the potential challenges and future directions of this therapy
The physiological burden of the 6-minute walk test compared with cardiopulmonary exercise stress test in patients with severe aortic atenosis
Background
Management of aortic stenosis (AS) relies on symptoms. Exercise testing is recommended for asymptomatic patients with significant AS but is often experienced as forbidding and/or technically unrealistic for patients who are often frail, deconditioned, and intimidated by the exercise test. We compared the physiological burden assessed with gas exchange assessments to gauge and respiratory exchange ratio (RER) of a 6-minute walk test (6MWT) to a cardiopulmonary exercise stress test (CPET) in patients with severe AS. peak oxygen utilization
Methods
Adults with equivocal symptoms and severe AS (1-aortic valve area [AVA] ≤ 1.0 cm2 or AVA index ≤ 0.6 cm2/m2, 2-peak aortic jet velocity ≥ 4.0 m/sec, 3-mean transvalvular pressure gradient ≥ 40 mm Hg by rest or dobutamine stress echocardiography, or 4-aortic valve calcification ≥ 1200 in women or ≥ 2000 AU in men) were studied. All participants completed both a 6MWT and symptom-limited progressive bicycle exercise testing. Breath-by-breath gas analysis and 12-lead electrocardiography were completed during 6MWT and CPET. Results: Eleven patients were studied. Patients walked on average 330 ± 75 m during the 6MWT and achieved a maximal workload of 48 ± 14 watts during the CPET. During the 6MWT, peak maximal oxygen uptake (O2peak) was 12.8 ± 2.5 vs 10.8 ± 4.2 mL/kg/min during the CPET. Respiratory exchange ratio exceeded 1.1 in both the 6MWT and CPET indicating similarly high exertion. Compared with the CPET, a larger proportion of the 6MWT was performed at a high intensity level (78% ± 28% vs 33% ± 24% at > 85% V̇O2peak; P = 0.004).
Conclusions
The 6MWT with breath-by-breath gas analysis was well tolerated and able to achieve a physiological intense RER and O2peak that are similar to symptom-limited CPET in patients with severe AS.Introduction
La prise en charge de la sténose aortique (SA) dépend des symptômes. L’épreuve d’effort est recommandée aux patients asymptomatiques qui ont une SA significative, mais elle est souvent perçue comme dangereuse et/ou théoriquement irréaliste chez ces patients qui sont souvent fragiles, en mauvaise forme et craintifs par l’épreuve d’effort. Nous avons comparé le fardeau physiologique calculé par la consommation maximale de l’oxygène (O2max) et le quotient respiratoire (QR) d’un test de marche de 6 minutes (TM6) et d'une épreuve d’effort maximal chez des patients avec une SA sévère.
Méthodes
Tous les patients présentaient une SA symptomatique et sévère (1-aire valvulaire aortique [AVA] ≤ 1,0 cm2 ouAVA ≤ 0,6 cm2/m2, 2-une vélocité maximale du flux aortique ≥ 4,0 m/sec, 3-un gradient de pression transvalvulaire moyen ≥ 40 mmHg au repos ou à l’échocardiographie à l’effort sous dobutamine ou 4-une calcification valvulaire aortique (AU) ≥ 1200 chez les femmes ou ≥ 2000 AU chez les hommes). Les participants ont effectué un TM6 et une ’épreuve d’effort maximal de type rampe sur vélo. L’analyse des échanges gazeux respiration par respiration et un électrocardiogramme à 12 dérivations ont été effectués durant le TM6 et l'épreuve d'effort maximal.
Résultats
Un total de 11 patients ont participé à l'étude. Les patients ont marché en moyenne 330 ± 75 m durant le TM6 et ont atteint une charge de travail maximale de 48 ± 14 watts durant l’épreuve d'effort maximal. Durant le TM6, le O2max était de 12,8 ± 2,5 vs 10,8 ± 4,2 ml/kg/min durant l’épreuve d'effort maximal. Le QR était supérieur à 1,1 au TM6 ainsi qu'à l’épreuve d'effort maximal. Comparativement à l’épreuve d'effort maximal, un pourcentage plus important au TM6 a été réalisée à une intensité élevée (78 % ± 28 % vs 33 % ± 24 % à > 85 % V̇O2max; P = 0,004).
Conclusions
Le TM6 avec mesure directe des échanges gazeux était bien toléré et susceptible d’atteindre des valeurs physiologiques d'intensité élevée pour le QR et le O2max. Les valeurs atteintes au TM6 étaient semblables à celles de l'épreuve d'effort maximal chez les patients avec une SA sévère
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