The importance of pulsatility in modern mechanical circulatory support devices

2019 Health Professional Scholarship

Years funded: 2020-2022

One of the cornerstones of modern cardiovascular intervention is the use of mechanical circulatory support. Mechanical circulatory support exists as devices which are implanted either in the short term or in the long term to supplement, or even take over the function of the cardiovascular system. This technology has allowed us to do everything from conduct intricate heart operations to keeping patients alive that would have otherwise died a mere 10-15 years ago. For example, in patients with refractory heart failure, left sided ventricular assist devices are being increasingly utilised to bridge these patients till an appropriate transplant is organised.

This is particularly important for Australians, as up to 10% of individuals aged over 65 have some degree of heart failure. With time it is expected that, partly due to an ageing population, this number will increase. One of the main issues which limits wider utilisation of ventricular assist devices is the associated morbidity and limited quality of life for these patients as well as the heavy cost burden on the healthcare system. Example of morbidity includes stroke, pump thrombosis and gastrointestinal bleeding.

It has been postulated that the nature of blood flow (continuous flow) in modern mechanical circulatory support devices may be a contributor to these effects. My PhD will focus on assessing the importance of pulsatility in modern mechanical assist devices. This will be conducted by assessing the current patient cohort, using data from mock circulatory loops as well as data from a new total artificial heart device which utilises a pulsatile flow. My hypothesis is that absence of pulsatility in modern ventricular assist devices exposes patients to a greater degree of stroke, gastrointestinal bleed and a myriad of other problems. By conducting this project, we aim to prove these findings with the ultimate end goal being to guide and improve future design of mechanical assist devices.