New imaging technique to improve the study of heart valve disease in mice

Vrushali Guruji (left) and Prof. Craig Simmons (right) are lead and corresponding author of this research, respectively.

Researchers from the Institute of Biomedical Engineering (BME) at the University of Toronto and the Translational Biology and Engineering Program in the Ted Rogers Centre for Heart Research have developed an ultrasound imaging protocol that promises to transform how congenital heart valve diseases are studied in mice. This new technique allows scientists to identify structural abnormalities in the aortic valve of juvenile mice as young as four weeks old, paving the way for more efficient, cost-effective, and humane research practices.

These findings were published in the latest issue of American Journal of Physiology – Heart and Circulatory Physiology, with the journal cover art designed and drawn by Vrushali Guruji, a PhD student in Dr. Craig Simmons’ lab and the lead author of the paper.

Congenital aortic valve malformations, in particular bicuspid aortic valves (BAVs), are important to study as they are associated with heart failure and rupture of the aorta. Mice are useful models to study BAVs, but only a small fraction of mice have BAVs, making it challenging to efficiently select the right subjects for in-depth studies.

To overcome this challenge, the researchers established a high frequency ultrasound imaging protocol that can detect aortic valve malformations in young mice. The study involved imaging 50 specially bred mice at both 4 and 8 weeks of age.

The ultrasound parameters that were linked to aortic valve abnormalities in the young mice were validated through anatomical and histological examinations, which revealed abnormalities like thickened aortic valve cusps and BAVs.

By implementing this protocol, researchers can now screen for aortic valve malformations in juvenile mice. This advancement not only reduces the number of animals needed for research but also enhances the precision and ethical standards of longitudinal studies on congenital heart valve diseases and their acquired complications. 

“This novel imaging technique is a game-changer for studying congenital heart valve diseases,” said Guruji. “It allows us to diagnose and focus on the mice with specific valve abnormalities, ensuring that our ongoing longitudinal studies of BAV-associated complications are both efficient and ethically sound.”

The adoption of this protocol by other researchers is expected to accelerate the understanding of congenital heart diseases, which will aid in the development of potential treatments for millions of at-risk patients.