Pronóstico hospitalario de la endocarditis infecciosa izquierda : importancia de la cirugía urgente

Tesis doctoral formada por los trabajos centrados en el estudio de los factores pronósticos de la endocarditis infecciosa izquierda : 1 Pronóstico hospitalario de la endocarditis infecciosa izquierda. El riesgo de eventos puede ser cuantificado precozmente en base a un sencillo modelo de variables fácilmente obtenidas en las primeras 72 horas del ingreso : - insuficiencia cardíaca.- Complicaciones perianulares.- Estafilococo aureus.2 Pronóstico hospitalario de la endocarditis infecciosa izquierda que precisa cirugía urgente : - La principal causa de cirugía urgente es la insuficiencia cardíaca que no se asocia a una mayor mortalidad.- La infección persistente y la insuficiencia renal son los factores asociados a una mayor mortalidad.3 Pronóstico hospitalario de la endocarditis protésica que precisa cirugía urgente :- La principal causa de cirugía urgente es la insuficiencia cardiaca que no se asocia a una mayor mortalidad.- La presencia de complicaciones y los signos de falta de control de la infección, son los predictores de mortalidad hospitalari

Timing of Intervention in Asymptomatic Patients with Aortic Stenosis

Aortic stenosis is a very common disease. Current guidelines recommend intervention mainly in symptomatic patients; aortic valve replacement can be considered in asymptomatic patients under specific conditions, but the evidence supporting these indications is poor. Continuous advances in both surgical and percutaneous techniques have substantially decreased rates of perioperative complications and mortality; with this in mind, many authors suggest that earlier intervention in patients with severe aortic stenosis, when they are still asymptomatic, may be indicated. This paper summarises what is known about the natural history of severe aortic stenosis and the scientific evidence available about the optimal timing for aortic valve replacement

Groupwise Non-Rigid Registration with Deep Learning: An Affordable Solution Applied to 2D Cardiac Cine MRI Reconstruction

Groupwise image (GW) registration is customarily used for subsequent processing in medical imaging. However, it is computationally expensive due to repeated calculation of transformations and gradients. In this paper, we propose a deep learning (DL) architecture that achieves GW elastic registration of a 2D dynamic sequence on an affordable average GPU. Our solution, referred to as dGW, is a simplified version of the well-known U-net. In our GW solution, the image that the other images are registered to, referred to in the paper as template image, is iteratively obtained together with the registered images. Design and evaluation have been carried out using 2D cine cardiac MR slices from 2 databases respectively consisting of 89 and 41 subjects. The first database was used for training and validation with 66.6–33.3% split. The second one was used for validation (50%) and testing (50%). Additional network hyperparameters, which are—in essence—those that control the transformation smoothness degree, are obtained by means of a forward selection procedure. Our results show a 9-fold runtime reduction with respect to an optimization-based implementation; in addition, making use of the well-known structural similarity (SSIM) index we have obtained significative differences with dGW with respect to an alternative DL solution based on Voxelmorph

Multi-Stencil Streamline Fast Marching: a general 3D Framework to determine Myocardial Thickness and Transmurality in Late Enhancement Images

We propose a fully three-dimensional methodology for the computation of myocardial non-viable tissue transmurality in contrast enhanced magnetic resonance images. The outcome is a continuous map defined within the myocardium where not only current state-of-the-art measures of transmurality can be calculated, but also information on the location of non-viable tissue is preserved. The computation is done by means of a partial differential equation framework we have called Multi- Stencil Streamline Fast Marching (MSSFM). Using it, the myocardial and scarred tissue thickness is simultaneously computed. Experimental results show that the proposed 3D method allows for the computation of transmurality in myocardial regions where current 2D methods are not able to as conceived, and it also provides more robust and accurate results in situations where the assumptions on which current 2D methods are based —i.e., there is a visible endocardial contour and its corresponding epicardial points lie on the same slice—, are not met

Ramipril After Transcatheter Aortic Valve Implantation in Patients Without Reduced Ejection Fraction: The RASTAVI Randomized Clinical Trial

Background: Patients with aortic stenosis may continue to have an increased risk of heart failure, arrhythmias, and death after successful transcatheter aortic valve implantation. Renin-angiotensin system inhibitors may be beneficial in this setting. We aimed to explore whether ramipril improves the outcomes of patients with aortic stenosis after transcatheter aortic valve implantation. Methods and Results: PROBE (Prospective Randomized Open, Blinded Endpoint) was a multicenter trial comparing ramipril with standard care (control) following successful transcatheter aortic valve implantation in patients with left ventricular ejection fraction >40%. The primary end point was the composite of cardiac mortality, heart failure readmission, and stroke at 1-year follow-up. Secondary end points included left ventricular remodeling and fibrosis. A total of 186 patients with median age 83 years (range 79-86), 58.1% women, and EuroSCORE-II 3.75% (range 3.08-4.97) were randomized to receive either ramipril (n=94) or standard treatment (n=92). There were no significant baseline, procedural, or in-hospital differences. The primary end point occurred in 10.6% in the ramipril group versus 12% in the control group (P=0.776), with no differences in cardiac mortality (ramipril 1.1% versus control group 2.2%, P=0.619) but lower rate of heart failure readmissions in the ramipril group (3.2% versus 10.9%, P=0.040). Cardiac magnetic resonance analysis demonstrated better remodeling in the ramipril compared with the control group, with greater reduction in end-systolic and end-diastolic left ventricular volumes, but nonsignificant differences were found in the percentage of myocardial fibrosis. Conclusions: Ramipril administration after transcatheter aortic valve implantation in patients with preserved left ventricular function did not meet the primary end point but was associated with a reduction in heart failure re-admissions at 1-year follow-up

Groupwise Non-Rigid Registration with Deep Learning: An Affordable Solution Applied to 2D Cardiac Cine MRI Reconstruction

Groupwise image (GW) registration is customarily used for subsequent processing in medical imaging. However, it is computationally expensive due to repeated calculation of transformations and gradients. In this paper, we propose a deep learning (DL) architecture that achieves GW elastic registration of a 2D dynamic sequence on an affordable average GPU. Our solution, referred to as dGW, is a simplified version of the well-known U-net. In our GW solution, the image that the other images are registered to, referred to in the paper as template image, is iteratively obtained together with the registered images. Design and evaluation have been carried out using 2D cine cardiac MR slices from 2 databases respectively consisting of 89 and 41 subjects. The first database was used for training and validation with 66.6–33.3% split. The second one was used for validation (50%) and testing (50%). Additional network hyperparameters, which are—in essence—those that control the transformation smoothness degree, are obtained by means of a forward selection procedure. Our results show a 9-fold runtime reduction with respect to an optimization-based implementation; in addition, making use of the well-known structural similarity (SSIM) index we have obtained significative differences with dGW with respect to an alternative DL solution based on Voxelmorph

Vortical Features for Myocardial Rotation Assessment in Hypertrophic Cardiomyopathy using Cardiac Tagged Magnetic Resonance

Left ventricular rotational motion is a feature of normal and diseased cardiac function. However, classical torsion and twist measures rely on the definition of a rotational axis which may not exist. This paper re- views global and local rotation descriptors of myocardial motion and introduces new curl-based (vortical) features built from tensorial magnitudes, intended to provide better comprehension about fibrotic tissue characteristics mechanical properties. Fifty-six cardiomyopathy patients and twenty-two healthy volun- teers have been studied using tagged magnetic resonance by means of harmonic phase analysis. Rotation descriptors are built, with no assumption about a regular geometrical model, from different approaches. The extracted vortical features have been tested by means of a sequential cardiomyopathy classification procedure; they have proven useful for the regional characterization of the left ventricular function by showing great separability not only between pathologic and healthy patients but also, and specifically, between heterogeneous phenotypes within cardiomyopathies