Magnetic resonance in patients with cardiovascular devices. SEC-GT CRMTC/SEC-Heart Rhythm Association/SERAM/SEICAT consensus document.

Magnetic resonance has become a first-line imaging modality in various clinical scenarios. The number of patients with different cardiovascular devices, including cardiac implantable electronic devices, has increased exponentially. Although there have been reports of risks associated with exposure to magnetic resonance in these patients, the clinical evidence now supports the safety of performing these studies under specific conditions and following recommendations to minimize possible risks. This document was written by the Working Group on Cardiac Magnetic Resonance Imaging and Cardiac Computed Tomography of the Spanish Society of Cardiology (SEC-GT CRMTC), the Heart Rhythm Association of the Spanish Society of Cardiology (SEC-Heart Rhythm Association), the Spanish Society of Medical Radiology (SERAM), and the Spanish Society of Cardiothoracic Imaging (SEICAT). The document reviews the clinical evidence available in this field and establishes a series of recommendations so that patients with cardiovascular devices can safely access this diagnostic tool.

Valvulopatía mitral y tricuspídea: diagnóstico y tratamiento. Posicionamiento conjunto de la Sección de Valvulopatías y las Asociaciones de Imagen, Cardiología Clínica y Cardiología Intervencionista de la SEC / Mitral and tricuspid valve disease: diagnosis and management. Consensus document of the Section on Valvular Heart Disease and the Cardiovascular Imaging, Clinical Cardiology, and Interventional Cardiology Associations of the Spanish Society of Cardiology

El diagnóstico y el tratamiento de la valvulopatía mitral y tricuspídea han sufrido unos cambios extraordinarios en los últimos años. La irrupción de las intervenciones percutáneas y la generalización de las nuevas técnicas de imagen han modificado las recomendaciones para el diagnóstico y el tratamiento de estas afecciones. La ingente cantidad de publicaciones y estudios en este campo obliga a una continua actualización de nuestros protocolos. La publicación de la guía de la Sociedad Europea de Cardiología de 2021 sobre el tratamiento de las valvulopatías no cubre algunos aspectos novedosos de estos tratamientos y, además, el número de intervenciones realizadas en los países de nuestro entorno es muy variable, lo que exige una adecuación de las recomendaciones al contexto local. Además, es indispensable un resumen de toda esta información para que se pueda generalizar su uso. Por estos motivos, se considera necesario el posicionamiento común de la Asociación de Cardiología Intervencionista, la Asociación de Imagen Cardiaca, la Asociación de Cardiología Clínica y la Sección de Valvulopatías y Patología Aórtica de la Sociedad Española de Cardiología para el diagnóstico y el tratamiento de la valvulopatía mitral y tricuspídea (AU)

The diagnosis and management of mitral and tricuspid valve disease have undergone major changes in the last few years. The expansion of transcatheter interventions and widespread use of new imaging techniques have altered the recommendations for the diagnosis and treatment of these diseases. Because of the exponential growth in the number of publications and clinical trials in this field, there is a strong need for continuous updating of local protocols. The recently published 2021 European Society of Cardiology guidelines for the management of valvular heart disease did not include some of the new data on these new therapies and, moreover, the number of mitral and tricuspid interventions varies widely across Europe. Therefore, all this information must be summarized to facilitate its use in each specific country. Consequently, we present the consensus document of the Section on Valvular Disease, Cardiovascular Imaging, Clinical Cardiology, and Interventional Cardiology Associations of the Spanish Society of Cardiology for the diagnosis and management of mitral and tricuspid valve disease (AU)

Ice front blocking of ocean heat transport to an Antarctic ice shelf.

Mass loss from the Antarctic Ice Sheet to the ocean has increased in recent decades, largely because the thinning of its floating ice shelves has allowed the outflow of grounded ice to accelerate1,2. Enhanced basal melting of the ice shelves is thought to be the ultimate driver of change2,3, motivating a recent focus on the processes that control ocean heat transport onto and across the seabed of the Antarctic continental shelf towards the ice4-6. However, the shoreward heat flux typically far exceeds that required to match observed melt rates2,7,8, suggesting that other critical controls exist. Here we show that the depth-independent (barotropic) component of the heat flow towards an ice shelf is blocked by the marked step shape of the ice front, and that only the depth-varying (baroclinic) component, which is typically much smaller, can enter the sub-ice cavity. Our results arise from direct observations of the Getz Ice Shelf system and laboratory experiments on a rotating platform. A similar blocking of the barotropic component may occur in other areas with comparable ice-bathymetry configurations, which may explain why changes in the density structure of the water column have been found to be a better indicator of basal melt rate variability than the heat transported onto the continental shelf9. Representing the step topography of the ice front accurately in models is thus important for simulating ocean heat fluxes and induced melt rates.

The effect of tissue-segmented attenuation maps on PET quantification with a special focus on large arteries. / Efecto de la segmentación por tejidos en los mapas de atenuación sobre la cuantificación PET con especial hincapié en grandes arterias.

OBJECTIVES: Accuracy on quantitative PET image analysis relies on the correct application of attenuation correction which is one of the major challenges for PET/MRI that remains to be solved. The purpose of this study is to evaluate the effect of MRI-based attenuation maps and the use of flexible coils on the quantitative accuracy of PET images with a special focus on large arteries. MATERIALS AND METHODS: PET/CT data from eight oncologic patients was used. PET data was reconstructed using attenuation maps with different level of detail emulating several approaches available on current PET/MRI scanners. PET images obtained with CT-based and MRI-based attenuation maps were compared to evaluate the quantitative biases obtained. The quantitative effect produced by flexible MRI receiver coils on the attenuation maps was also studied. RESULTS: The use of simpler attenuation maps produced increased biases between PET data reconstructed with CT-based and MRI-based attenuation maps for fat, non-fat soft-tissues and bone. Biases in lung were very high due to the large heterogeneity and inter-patient variability of the lung. The quantification on large arteries had small deviations except for the case when flexible coils were used. The TBR provided smaller biases in all cases as it cancelled out the similar deviations obtained for arteries and reference veins. CONCLUSIONS: Simplified attenuation maps used on PET/MRI significantly increase the quantitative variability of PET images especially on lungs and bones. The quantification of PET images acquired with PET/MRI scanners applied to studies of atherosclerosis has small deviations, especially when the TBR is considered.

The suppression of Antarctic bottom water formation by melting ice shelves in Prydz Bay.

A fourth production region for the globally important Antarctic bottom water has been attributed to dense shelf water formation in the Cape Darnley Polynya, adjoining Prydz Bay in East Antarctica. Here we show new observations from CTD-instrumented elephant seals in 2011-2013 that provide the first complete assessment of dense shelf water formation in Prydz Bay. After a complex evolution involving opposing contributions from three polynyas (positive) and two ice shelves (negative), dense shelf water (salinity 34.65-34.7) is exported through Prydz Channel. This provides a distinct, relatively fresh contribution to Cape Darnley bottom water. Elsewhere, dense water formation is hindered by the freshwater input from the Amery and West Ice Shelves into the Prydz Bay Gyre. This study highlights the susceptibility of Antarctic bottom water to increased freshwater input from the enhanced melting of ice shelves, and ultimately the potential collapse of Antarctic bottom water formation in a warming climate.

Bmi1 limits dilated cardiomyopathy and heart failure by inhibiting cardiac senescence.

Dilated cardiomyopathy (DCM) is the most frequent cause of heart failure and the leading indication for heart transplantation. Here we show that epigenetic regulator and central transcriptional instructor in adult stem cells, Bmi1, protects against DCM by repressing cardiac senescence. Cardiac-specific Bmi1 deletion induces the development of DCM, which progresses to lung congestion and heart failure. In contrast, Bmi1 overexpression in the heart protects from hypertrophic stimuli. Transcriptome analysis of mouse and human DCM samples indicates that p16(INK4a) derepression, accompanied by a senescence-associated secretory phenotype (SASP), is linked to severely impaired ventricular dimensions and contractility. Genetic reduction of p16(INK4a) levels reverses the pathology of Bmi1-deficient hearts. In parabiosis assays, the paracrine senescence response underlying the DCM phenotype does not transmit to healthy mice. As senescence is implicated in tissue repair and the loss of regenerative potential in aging tissues, these findings suggest a source for cardiac rejuvenation.

The Progression and Early detection of Subclinical Atherosclerosis (PESA) study: rationale and design.

BACKGROUND: The presence of subclinical atherosclerosis is a likely predictor of cardiovascular events; however, factors associated with the early stages and progression of atherosclerosis are poorly defined. OBJECTIVE: The PESA study examines the presence of subclinical atherosclerosis by means of noninvasive imaging and prospectively analyzes the determinants associated with its development and progression in a middle-aged population. METHODS: The PESA study is an observational, longitudinal and prospective cohort study in a target population of 4000 healthy subjects (40-54 years old, 35% women) based in Madrid (Spain). Recruitment began in June 2010 and will be completed by the end of 2013. Baseline examination consists of (1) assessment for cardiovascular risk factors (including lifestyle and psychosocial factors); (2) screening for subclinical atherosclerosis using 2D/3D ultrasound in carotid, abdominal aorta and iliofemoral arteries, and coronary artery calcium score (CACS) by computed tomography; and (3) blood sampling for determination of traditional risk factors, advanced "omics" and biobanking. In addition, a subgroup of 1300 participants with evidence of atherosclerosis on 2D/3D ultrasound or CACS will undergo a combined (18)F-fluorodeoxyglucose-positron emission tomography/magnetic resonance imaging ((18)FDG PET/MRI) study of carotid and iliofemoral arteries. Follow-up at 3 and 6 years will include a repetition of baseline measurements, except for the (18)FDG PET/MRI study, which will be repeated at 6 years. CONCLUSIONS: The PESA study is expected to identify new imaging and biological factors associated with the presence and progression of atherosclerosis in asymptomatic people and will help to establish a more personalized management of medical care.

[Guidelines of the Spanish Society of Cardiology on magnetic resonance]. / Guías de práctica clínica de la Sociedad Española de Cardiología en resonancia magnética.

A wide perspective of the cardiac applications of magnetic resonance is presented in this report, including technical aspects of the practice, recommendations on the appropriate training of medical personnel for the practice of examination and also, an extensively commented review of the accepted clinical indications for the practice of a cardiac magnetic resonance imaging study at present.

Blood flow patterns in the thoracic aorta studied with three-directional MR velocity mapping: the effects of age and coronary artery disease.

The objective was to investigate how the blood flows in the thoracic aorta, with special emphasis on flow reversal and flow into the coronary arteries. Three-directional MR velocity mapping was used to map multidirectional flow velocities in the aorta in 14 normal subjects and 14 patients with coronary artery disease. Dynamic flow vector maps and through-plane velocity maps were used. The flow reversed in all subjects in the upper ascending aorta and usually also in the distal aortic arch. Retrograde flow became antegrade again at various levels in the ascending aorta and in the coronary sinuses. Seven flow characteristics were investigated that, lumped together, were significantly different (P = .0005) in normal subjects compared with patients and in normal subjects 70 years of age and older compared with those younger than 70 years of age.