Transcatheter Aortic Valve Implantation/Replacement
Structural heart disease minimally invasive interventions represent a new branch of percutaneous treatments covering a wide range of congenital and acquired diseases that were previously treated surgically or simply not addressed.
Transcatheter aortic valve implantation/replacement (TAVI/TAVR) is rapidly becoming a mature technology. This minimally invasive surgical procedure repairs the valve without removing the old, damaged valve. Instead, it wedges a replacement valve into the aortic valve’s place. Usually, valve replacement requires an open heart procedure with a “sternotomy.”, in which the chest is surgically separated (open) for the procedure. The TAVR or TAVI procedures can be done through very small openings that leave all the chest bones in place. Watch an animation of TAVI/TAVR.
Long-Term Data is Needed on TAVI/TAVR
One problem has been that the data on the long-term durability of TAVI/TAVR valves has been sparse and it has been difficult to justify the higher cost of this minimally invasive procedure compared to open surgery. However, recent results published from NOTION trial of low-risk patients and the UK TAVI Registry suggest that valve deterioration and failure rates beyond 5 years are low. There is no signal that these valves deteriorate more frequently or more erratically than surgical valves overall and there appear to be no differences in device hemodynamics between surgical and transcatheter valves.
A systematic review by Chakos et al., 2017 analyzing the outcomes on 13,857 patients has demonstrated acceptable long-term survival results for TAVI/TAVR procedures in the elderly population. The next few years will be important turning points for the TAVI/TAVR field as longer follow-up time is achieved. Data beyond 10 years after treatment will be an important endpoint since experience from the surgical field shows that valve deterioration increases significantly beyond this time point.
The Challenge to Obtain Long-Term Follow Up
One challenge is to mitigate for the loss of patients since many of the patients treated will not survive to 10 years or longer due to comorbidities and other non-valve-related issues. Another challenge will be to demonstrate durability since the long-term data will not include newer device iterations which will make comparisons uneven.
Device manufacturers need to make a serious investment and effort to address the need for extended follow-up since this will be required to assess long-term outcomes before its application is extended into wider population groups.
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