Valve durability after transcatheter aortic valve implantation

Area of Science:

• Cardiology
• Biomedical Engineering
• Interventional Cardiology

Background:

• Severe symptomatic aortic stenosis requires treatment, with Transcatheter Aortic Valve Implantation (TAVI) being a minimally invasive option.
• While TAVI shows excellent short-term (5-year) outcomes, the long-term durability of the bioprosthetic valves remains largely unknown.
• TAVI valves are susceptible to structural valve deterioration (SVD) and non-SVD, similar to surgical bioprosthetic valves, but with unique degeneration mechanisms.

Purpose of the Study:

• To review the current understanding of long-term durability for Transcatheter Aortic Valve Implantation (TAVI) devices.
• To identify mechanisms of TAVI valve degeneration, including both structural and non-structural factors.
• To compare TAVI valve durability with traditional surgical bioprosthetic valves and provide recommendations for clinical practice.

Main Methods:

• Literature review of TAVI trials and meta-analyses focusing on valve durability and structural valve deterioration (SVD).
• Analysis of reported mechanisms contributing to TAVI valve degeneration, such as leaflet calcification, tear, thrombosis, and stent issues.
• Comparison of long-term SVD rates between TAVI and surgical bioprosthetic aortic valves.

Main Results:

• TAVI valves are prone to degeneration through SVD (e.g., leaflet calcification, tear) and non-SVD (e.g., thrombosis, endocarditis).
• Meta-analyses estimate SVD at approximately 7% at 5 years for TAVI valves.
• Traditional surgical bioprosthetic valves show clinically relevant SVD of 6.6% at 10 years, indicating potentially better long-term durability.

Conclusions:

• The long-term durability of TAVI valves is not yet well-defined, posing a challenge for patient selection and management.
• While TAVI technology is improving, its use in younger patients, who may require longer-term valve function, should be approached with caution.
• Further research and standardized definitions for SVD are needed to accurately assess and predict TAVI valve longevity.