Stiffening of arteries is one of the first measurable changes associated with cardiovascular diseases. Arterial stiffening impacts the hemodynamic stress applied to multiple organs and is associated with catastrophic events such as plaque rupture, vessel dissection and rupture. Stiffening of the thoracic aorta (TA) is of particular concern because it increases the load on the heart and systemic vasculature. The TA is naturally a very elastic artery constructed to withstand the large fluid and tissue stresses created by the left ventricle, allowing it to absorb and redistribute blood flow energy throughout the cardiac cycle. Aneurysm of the TA cause pathological stiffening increasing the risk of catastrophic dissection and rupture. TA aneurysms (TAA) are the most common indication for cardiac surgery, however identifying patients for surgery can be challenging due to the risks associated with this massively invasive procedure. Current surgical guidelines are based on the diameter of the TA as a surrogate for stiffness due to a lack of reliable in vivo mechanical biomarkers. The International Registry of Acute Aortic Dissections (IRAD) has shown diameter is a poor predictor of TA aneurysm risk. Following the established guidelines becomes questionable in many patients due to patient wish, family history, co-morbidities, age, repeated surgeries and increased surgical risk. In this talk I will present work our group has conducted to identify biomechanical properties of TAA and preliminary studies using non-invasive speckle tracking echocardiography to provide clinicians with validated biomarkers of TAA stiffness. The goal is to help identify patients below the diameter guidelines that are at higher-risk due to poor mechanical properties and ones above the guidelines that are low-risk with well-functioning TA biomechanics.
Dr. Leask is a Professor in the Department of Chemical Engineering and Associate Chair of Facility Planning at McGill University. He holds a Quebec Government teaching chair and is a Researcher at the Montreal Heart Institute and McGill University Health Center. He has a Bachelor’s (1994) and Master’s (1997) from the University of Waterloo in Mechanical Engineering. Prof. Leask was granted a Doctoral degree in 2002 from the University of Toronto from the Institute of Biomaterials and Biomedical Engineering. After completing a post-doctoral fellowship at the Toronto Hospital in clinical pathology, he joined the Department of Chemical Engineering at McGill. His research focus is the mechanobiology of cardiovascular diseases and the application of engineering principles to improve treatment options.