Valve in valve transcatheter aortic valve implantation (ViV-TAVI) versus redo-Surgical aortic valve replacement (redo-SAVR): A systematic review and meta-analysis

In recent times, there has been a considerable increase in the use of aortic bioprostheses (vs. mechanical prostheses) for treating aortic valve disease, and this tendency is likely to continue in the near future. However, the occurrence of structural valve degeneration, limiting valve durability, remains an important drawback of surgical and transcatheter bioprostheses. In this paper, we provide an overview of bioprosthetic valve durability, focusing on the definition, incidence, mechanisms, predictive factors, and management of structural degeneration of aortic bioprostheses.

Patients undergoing repeat heart valve operations are a diverse population. We assessed risk factors for operative mortality in patients undergoing a first heart valve reoperation. A retrospective review of hospital records was performed for 671 patients who underwent first repeat heart valve operations between 1969 and 1998. Univariable and multivariable analyses were performed. Operative mortality was 8.6%. Mortality fell each decade to 4.8% in the most recent period (adjusted chi(2) for linear trend P <.0005). Mortality increased from 3.0% for reoperation for a failed repair or reoperation at a new valve site to 10.6% for prosthetic valve dysfunction or periprosthetic leak and to 29.4% for endocarditis or valve thrombosis. Concomitant coronary artery bypass grafting was associated with a mortality of 15.4% compared with 8.2% when it was not required. Mortality for aortic valve replacement was 6.4%, mitral valve replacement 7.4%, aortic and mitral valve replacement 11.5%, tricuspid valve replacement 25.6%, periprosthetic leak repair 9.1%, and isolated valve repair 2.2%. Among 336 patients requiring replacement of prosthetic valves, mortality was 26.1% for replacement of a mechanical valve compared with 8.6% for replacement of a tissue valve (P <.0005). Multivariable analyses identified year of reoperation, age, coronary artery bypass grafting, indication, and replacement of a mechanical valve rather than a tissue valve as significant explanatory variables for operative mortality. Heart valve reoperations can be performed with an acceptable operative mortality. However, we have identified several categories of patients in whom reoperation carries an increased risk.

Transcatheter aortic valve implantation (TAVI) has become the standard of care for inoperable patients, and the preferred treatment option for high-risk patients with severe aortic stenosis. Given that this therapy was intended for elderly patients with limited life expectancy, long-term durability has not been in the focus. Now that TAVI is increasingly being used in patients with intermediate-risk and lower-risk profiles, device durability has gained importance. The available mid-term results for TAVI are promising; however, little is known about the fate of TAVI devices beyond 5 years. The experience with long-term durability of surgical valves shows that ≥10-year follow-up is required to ensure reliable durability data. In this Review, we discuss the existing studies of TAVI durability, highlight differences between surgical and transcatheter treatment of aortic stenosis that might influence durability, and present a clinical solution for failed prostheses. Furthermore, we suggest how device durability might influence the future selection of patients for TAVI.