[Development, techniques, and utility of experimental animal models of thoracic and abdominal aortic aneurysms]. / Desarrollo, técnicas y utilidad de modelos animales experimentales de aneurismas aórticos torácicos y abdominales.

Aneurysms are clinical entities that can develop and affect human aorta; and although in most cases they have an asymptomatic course, these pathological dilatations can lead to a lethal outcome when rupture occurs, thus the establishment of predictors is crucial for death prevention. Essential events that take place in the vessel wall have been identified and described, such as inflammation, proteolysis, smooth muscle cell apoptosis, angiogenesis, and vascular remodeling. Porcine and ovine models have been useful for the development and evaluation of endovascular devices of the aorta. However, since the worldwide introduction and adoption of these minimally invasive techniques for aneurysm repair, there is lesser availability of diseased aortic tissue for molecular, cellular, and histopathological analysis, therefore over the last three decades it has been proposed various small species models that have allowed the focal induction of these lesions for the study of physiopathological mechanisms and possible useful biomarkers as diagnostic and therapeutic targets. The present review article presents and discusses the animal models available as their applications, characteristics, advantages, and limitations for the development of preclinical studies, and their importance in the comprehension of this pathology in humans.

Los aneurismas son una de las entidades clínicas que pueden desarrollarse y afectar la aorta humana. Aunque en la mayoría de los casos tienen un carácter asintomático, estas dilataciones patológicas pueden resultar letales cuando se presentan con ruptura, por lo que el reconocimiento de factores predictores de esta complicación es crucial para evitar muertes. Fisiopatológicamente se han identificado eventos esenciales que ocurren en la pared del vaso, como inflamación, proteólisis, apoptosis del músculo liso, angiogénesis y remodelación. Las grandes especies como porcinos y ovinos han sido de utilidad para el desarrollo y evaluación del desempeño de dispositivos endovasculares en la aorta, así como la remodelación; con el advenimiento y disposición de estas técnicas mínimamente invasivas para su reparación existe una menor disponibilidad de tejido aórtico para el análisis molecular, celular e histopatológico, por lo que en las últimas tres décadas se han propuesto e introducido distintos modelos que han permitido, mediante la inducción focal de estas lesiones, el estudio de los mecanismos fisiopatológicos y posibles biomarcadores de utilidad como dianas diagnósticas y terapéuticas. El presente artículo de revisión aborda tipos de modelos animales disponibles, así como sus aplicaciones, consideraciones, ventajas y limitaciones para el desarrollo de estudios preclínicos y su importancia en el entendimiento de esta patología en la especie humana.

Clinical Characteristics and Outcomes in Adults With Moderate-to-Severe Complexity Congenital Heart Disease Undergoing Palliation or Surgical Repair.

Background: Congenital heart disease (CHD) survival rate has improved dramatically due to advances in diagnostic and therapeutic techniques. However, concerning the unrepaired CHD population of moderate and severe complexity, the data regarding risk predictors and surgical outcomes are scarce. Our aim was to describe the surgical results and predictors of in-hospital outcomes in adult patients with moderate-to-severe complexity CHD that were not repaired in childhood. Methods: We conducted a retrospective cohort study that included 49 adult patients with moderate-to-complex CHD who were treated in a single medical centre. Clinical and echocardiographic variables were obtained on admission, after surgical procedures and during follow-up. Results: Most of the patients were female (66%). Left ventricular ejection fraction and right ventricular outflow tract fractional shortening were within the normal range. The median pulmonary artery systolic pressure was 37 (27-55) mm Hg. The median time was 118 (80-181) minutes for extracorporeal circulation and 76 (49-121) minutes for aortic cross-clamping. The most frequent complication was postoperative complete atrioventricular block (12.2%). In-hospital survival rate was 87.7%. The development of low cardiac output syndrome with predominant right ventricle failure in the postoperative period was the most important predictor of in-hospital death (P = 0.03). Conclusions: Deciding to treat adults with CHD is challenging in moderate and severe unrepaired cases. Adequate clinical, functional, and imaging evaluation is essential to determine each patient's suitability for surgical management and to achieve the best clinical outcome for this population.

Contexte: Grâce aux avancées réalisées en matière de techniques diagnostiques et thérapeutiques, la survie des patients atteints d'une cardiopathie congénitale s'est considérablement améliorée. Cependant, en ce qui concerne les personnes atteintes d'une cardiopathie congénitale non corrigée présentant une complexité modérée ou extrême, les données portant sur les facteurs de risque prédictifs ainsi que sur les résultats chirurgicaux sont rares. Notre objectif était de décrire les résultats chirurgicaux ainsi que les facteurs prédictifs des résultats obtenus en milieu hospitalier chez les patients adultes atteints d'une cardiopathie congénitale présentant une complexité modérée ou extrême qui n'a pas été corrigée pendant l'enfance. Méthodologie: Nous avons mené une étude de cohorte rétrospective comprenant 49 patients adultes atteints d'une cardiopathie congénitale modérée ou complexe qui ont reçu leurs traitements dans un seul centre médical. Les variables cliniques et échocardiographiques ont été obtenues au moment de l'admission, après les interventions chirurgicales et pendant la période de suivi. Résultats: Les patients étaient en majorité des femmes (66 %). La fraction d'éjection du ventricule gauche ainsi que la fraction de raccourcissement de la voie d'éjection ventriculaire droite sont demeurées dans les limites de la normale. La pression systolique médiane de l'artère pulmonaire a été de 37 mmHg (27-55 mmHg). Le temps médian écoulé pour la circulation extracorporelle a été de 118 minutes (80-181 minutes) et pour le clampage de la crosse aortique, de 76 minutes (49-121 minutes). Le bloc auriculo-ventriculaire postopératoire complet a été la complication la plus fréquente (12,2 %). Le taux de survie en milieu hospitalier a été de 87,7 %. Le développement du syndrome du faible débit cardiaque accompagné d'une insuffisance prédominante du ventricule droit durant la période postopératoire a constitué le principal facteur prédictif de décès à l'hôpital (p = 0,03). Conclusion: Il est difficile de traiter les adultes qui présentent une cardiopathie congénitale modérée ou sévère non corrigée. Il est essentiel que les évaluations cliniques, fonctionnelles et par imagerie soient réalisées de façon adéquate pour déterminer si une prise en charge chirurgicale convient aux patients et pour garantir les meilleurs résultats cliniques chez ces derniers.

Acute Mitral Regurgitation Due to Chordae Tendineae Rupture: A Rare Presentation of Cardiac Amyloidosis.

BACKGROUND In cardiac amyloidosis (CA), misfolded proteins deposit in the extracellular space of cardiac tissue. These deposits classically cause restrictive cardiomyopathy with diastolic dysfunction. Although there are at least 30 proteins known to cause amyloid aggregates, 2 main types make up most diagnosed cases: light chain amyloidosis (AL) and transthyretin amyloidosis (ATTR). Since CA is considered a rare condition, it is often underdiagnosed or recognized in the advanced stages. Once amyloid deposits involve the heart tissue, they are associated with a worse outcome and higher mortality rates, especially in patients presenting symptoms of heart failure. CASE REPORT We report a case of a 22-year-old man presenting with acute severe mitral regurgitation, secondary to posterior mitral leaflet chordae tendineae rupture (CTR). Surgical mitral valve replacement with a mechanical prosthesis was performed, and cardiac tissue biopsy samples were obtained. After surgery, the patient improved significantly but suddenly presented with hemodynamic deterioration, until he died due to severe hemodynamic compromise and multiorgan failure. Although the etiology of the CTR was not established before surgical intervention, the histopathological analysis suggested CA. CONCLUSIONS CA diagnosis can be complex, especially in a 22-year-old-man with atypical clinical and imaging manifestations. In this patient, other differential diagnoses were considered, since CA presenting in a young patient is a rare phenomenon and acute mitral regurgitation secondary to CTR presents more frequently in other heart conditions. Furthermore, rapid postoperative deterioration resulted in the patient's death before biopsy samples were available because suspicion of amyloidosis had not been raised until that point.