Transcatheter Aortic Valve Implantation: Challenges and potential solutions

Datum: 31 mei 2016

Locatie: UAntwerp - Campus Drie Eiken - Building Q - Promotiezaal - Universiteitsplein 1 - 2610 WILRIJK

Tijdstip: 16.30 uur

Promovendus: Valérie Collas

Promotor: Prof J. Bosmans & Prof C. Vrints

Korte beschrijving: PhD defence Valérie Collas - Faculty of Medicine and Health Sciences



Abstract

Transcatheter aortic valve implantation (TAVI) has been proven to be a reasonable alternative to surgical aortic valve replacement for the treatment of severe, symptomatic aortic valve stenosis in elderly high risk patients. The aim of this thesis is to evaluate the most important limitations of TAVI, such as the occurrence of aortic regurgitation (AR) and conduction disturbances post TAVI, non-ideal transfemoral access and patient selection.

To evaluate AR post TAVI, the mechanism(s) of post TAVI AR based on baseline anatomical and morphological characteristics are measured and quantified on computed tomography scan analysis and compared according to the occurrence of significant AR post TAVI on angiography and echocardiography. The most accurate method to assess AR post TAVI is evaluated based on the capability to discriminate good and bad prognosis. Virtual implantation software to predict AR post TAVI is validated.

Conduction disturbances post TAVI are evaluated by the implantation depth, the incidence of new conduction disturbances, and the need for and indications of permanent pacemaker implantation within the first month after TAVI, using the new Accutrak CoreValve delivery system, compared to the previous generation in a consecutive “real world” patient population.

Increasing numbers of patients without ideal femoral access are referred to the heart team. The first series of 20 patients undergoing TAVI via brachiocephalic artery access are reported. 

Surgical risk scores could be helpful in patient selection, but do not take TAVI-related risk factors into account, are not based on elderly patients (75 years and older) and are in general not accurate enough to predict prognosis after TAVI. Therefore, recently proposed risk scores for the prediction of mortality up to one year after TAVI, using a self-expandable valve (CoreValve) are validated. The potential role of red cell distribution width, a relative simple and inexpensive parameter in predicting outcome after TAVI is analysed.

Geriatric parameters of patients with severe, symptomatic aortic valve stenosis are evaluated through multidimensional geriatric assessment. The aim is to evaluate objective multidimensional geriatric assessment to heart team decision for the treatment selection of elderly patients with symptomatic severe aortic valve stenosis.