African American-Caucasian American differences in aortic valve replacement in patients with severe aortic stenosis.

Background: Among patients with severe aortic stenosis (AS), there are limited data on aortic valve replacement (AVR), reasons for nonreceipt and mortality by race.

Methods: Utilizing the Duke Echocardiography Laboratory Database, we analyzed data from 110,711 patients who underwent echocardiography at Duke University Medical Center between 1999 and 2013. We identified 1,111 patients with severe AS who met ≥1 of 3 criteria for AVR: ejection fraction ≤50%, diagnosis of heart failure, or need for coronary artery bypass surgery.

Racial and Ethnic Differences in Treatment and Outcomes of Severe Aortic Stenosis: A Review.

Aortic stenosis (AS) is among the most common valvular heart diseases encountered in the United States. In this review the authors examine differences between racial and ethnic groups in the epidemiology and management of severe AS, explore potential explanations for these findings, and discuss the implications for improving the delivery of care to racially and ethnically diverse populations. Underrepresented racial and ethnic groups experience a paradoxically lower prevalence or incidence of AS relative to white subjects, despite having a higher prevalence of traditional risk factors.

Regional imbalanced activation of the calcineurin/BAD apoptotic pathway and the PI3K/Akt survival pathway after myocardial infarction.

Background: The underlying molecular mechanisms of the remodeling after myocardial infarction (MI) remain unclear. The purpose of this study was to investigate the role of a survival pathway (PI3K/Akt) and an apoptosis pathway (calcineurin/BAD) in the remodeling after MI in a large animal model.

Methods: Ten Dorset hybrid sheep underwent 25% MI in the left ventricle (LV, n=10).

Functional and biocompatibility performances of an integrated Maglev pump-oxygenator.

To provide respiratory support for patients with lung failure, a novel compact integrated pump-oxygenator is being developed. The functional and biocompatibility performances of this device are presented. The pump-oxygenator is designed by combining a magnetically levitated pump/rotor with a uniquely configured hollow fiber membrane bundle to create an assembly free, ultracompact, all-in-one system.

Regional remodeling strain and its association with myocardial apoptosis after myocardial infarction in an ovine model.

Objective: Progressive left ventricular remodeling after myocardial infarction has been viewed as an important contributor to progressive heart failure. The objective of this study was to investigate the relationship between myocardial apoptosis and strain during progressive cardiac remodeling.

Methods: Before creation of an anterolateral left ventricular infarction by ligation of diagonal arteries, 16 sonomicrometry transducers were placed in the left ventricular free wall of 8 sheep to assess regional deformation in the infarct, adjacent, and normally perfused remote myocardial regions over 8 weeks' duration.

Beating heart direct left atrial access balloon cryoablation: safety and efficacy of pulmonary vein isolation in an ovine model.

Objective: : Clinical experience with endocardial cryoablation for the surgical treatment of atrial fibrillation has demonstrated safety and efficacy. Direct access to the left atrium via a thoracoscopic or pericardial approach with a balloon-tipped cryoablation catheter might facilitate endocardial cryoablation on the beating heart. We investigated the ability of a novel cryoballoon to produce endocardial pulmonary vein ostial cryolesions on the beating heart in a large-animal model.

Early in vivo experience with the pediatric Jarvik 2000 heart.

The need for smaller, more efficient ventricular assist devices that can be used in a more chronic setting have led to exploration of mechanical circulatory support in the pediatric population. The pediatric Jarvik 2000 heart (child size), under development, was implanted in six juvenile sheep and studied for both acute fit and chronic performance evaluation. Daily hemodynamic measurements of cardiac output and pump output at varying pump speeds were taken.

Strain-related regional alterations of calcium-handling proteins in myocardial remodeling.

Background: Cardiac remodeling has been shown to have deleterious effects at both the global and local levels. The objective of this study is to investigate the role of strain in the initiation of structural and functional changes of myocardial tissue and its relation to alteration of calcium-handling proteins during cardiac remodeling after myocardial infarction.

Methods: Sixteen sonomicrometry transducers were placed in the left ventricular free wall of 9 sheep to measure the regional strain in the infarct, adjacent, and remote myocardial regions.