Transcatheter Aortic Valves: A Finite Element Study of Leaflet Stress Distribution in the In Vivo Environment

The aortic valve is responsible for controlling the unidirectional flow of blood within the heart during the cardiac cycle [1]. Aortic stenosis reduces the opening area of the valve, impeding blood flow and can lead to increased strain on the heart muscle, onset of early fatigue and heart failure. The disease is prevalent in the elderly population and is predicted to affect 88.5 million people by 2050 [2]. Open heart surgery to replace stenotic valves with either bioprosthetic or mechanical surgical valves is the current gold standard of care. However 30% of patients presenting with stenosis are refused this highly invasive surgery because of high postoperative mortality rates in elderly patients or those with pre-existing illnesses [2]. Transcatheter Aortic Valves (TAV) are an alternative to conventional heart valve surgery [2, 3–4], which use minimally invasive techniques to replace stenotic valves. TAV’s consist of tissue leaflets on a self or balloon expandable percutaneous valve stent which is deployed via a transfemoral or transapical based approach. Owing to the fact that the first CE certification of a TAV (Edwards SAPIEN) was only in 2010 and received FDA approval for clinical trials in 2011, the long term performance of implanted TAV’s is as of yet unknown.