44 Long term echocardiographic follow up post transcatheter aortic valve implantation (TAVI) to assess for structural valve deterioration (SVD) and bioprosthetic valve failure (BVF): a single centre prospective study

Background The clinical application of transcatheter aortic valve implantation (TAVI) for patients with severe symptomatic aortic stenosis (AS) has increased exponentially over the past decade. It is currently indicated in AS patients who cannot undergo surgical replacement or are at high risk for surgery. Recent evidence has also shown equivalent outcomes to surgery in intermediate risk cohorts. Additionally there are trials underway to assess the use of TAVI in low risk patient cohorts, including younger patients. However, an important consideration prior to widespread TAVI use in this low risk, younger patients is the long-term durability of transcatheter valves, as these patients are expected to have a longer life expectancy. Whilst there is a robust body of knowledge on durability of surgical aortic bioprostheses, long term data on the incidence of structural valve deterioration (SVD) (figure 1) and bioprosthetic valve dysfunction ( BVF) of TAVI beyond 5 years remains limited and thus further data is needed. The primary aim of this prospective study is to evaluate the incidence of SVD and BVF in our TAVI cohort at 5 years, utilizing recently released standardized definitions. The information obtained from this study will contribute to the ongoing need for more information on the durability of TAVI implants. Objectives Primary aims: 1)Incidence of morphological and/or haemodynamic structural valve deterioration ( SVD) in our TAVI cohort at 5 years; 2)Incidence of bioprosthetic valve dysfunction (as defined by valve related death, need for repeat intervention and severe haemodynamic SVF) in our TAVI cohort at 5 years Secondary aims: 1)5 year survival analysis on our patient cohort who have undergone TAVI; 2)Patient quality of life (SF 35) and symptom (NYHA) at 5 years post TAVI. Methods From Feb 2009 to April 2013, n=78 patients with a minimal theoretical five-year follow-up were included. At Royal Perth Hospital procedural, clinical and echocardiographic follow-up was analysed from baseline and 5 years post procedure. TAVI prosthesis were evaluated for durability by standardised definitions. Results Mean age and Euro-SCORE were 84 and 23% respectively. At 5 years 40(51%) patients of the total n=78, were deceased. 6.5%-SVD. 2.6%-severe SVD. <1%-Biological Valve Failure(BVF). The incidence of SVD and BVF beyond 5 years was in keeping with global registry reports to date on the issue. Median 5 year survival was 4.8 years with QOL and symptom(NYHA) analysis at 5 years ongoing. Conclusions/Implications This ongoing study to date exhibits SVD to be a low frequency occurrence beyond 5 years post TAVI in keeping with international data in the area. The information obtained from this study will fill an important knowledge gap on long term (5 years) durability of TAVI implantation, as manifested by structural valve deterioration (SVD) and bioprosthetic valve dysfunction (BVF). This will have implications on the future use of TAVI in low risk, younger patients who are expected to have longer life expectancy. Additionally recent studies on bioprosthesis durability have utilized different definitions for SVD/BVF which makes comparison of information difficult between studies. This study will contribute to the body of knowledge on SVD/BVF utilizing the recent standardized definitions set out by the ESC consensus paper.