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TAVR in failing transcatheter valves feasibility dependent on aortic root anatomy
NEW ORLEANS — Transcatheter aortic valve replacement in failing transcatheter valves may not be feasible in approximately 20% of patients, and the feasibility appears to depend on aortic root anatomy, according to research presented at the American College of Cardiology Scientific Session.
“With both low-risk randomized trials being presented at the ACC Scientific Session, and TAVR being expanded to younger patients, the durability and feasibility of reintervention after TAVR becomes increasingly relevant. We know that TAVR in prior failing surgical aortic valve (TAV-in-SAV) is mostly feasible and TAVR in prior transcatheter aortic valve (TAV-in-TAV) has been performed in isolated case reports. There have also been discussions about whether feasibility of TAV-in-TAV would be more favorable in balloon-expandable over self-expanding valves,” Gilbert H.L. Tang, MD, MSc, MBA, from Mount Sinai Medical Center in New York, wrote in an email to Cardiology Today’s Intervention.
“Given the prevalence of Sapien 3 valve (Edwards Lifesciences) being used in the United States, we wanted to determine the feasibility of TAV-in-TAV with the assumption that future reintervention would happen when the Sapien 3 valve fails.”
Importance of root anatomy
For their study, Tang and colleagues evaluated aortograms after initial TAVR with the Sapien 3 valve to assess the risk for coronary obstruction should TAV-in-TAV be performed.
The analysis included 551 aortograms obtained at two centers during the study period.
The researchers classified aortic roots into three types based on sinotubular junction diameter and sinus height relative to the transcatheter valve diameter and height:
- Type 1 root was defined as sinotubular junction diameter greater than the transcatheter valve diameter and sinus height greater than the transcatheter valve height.
- Type 2 root was defined as sinotubular junction diameter less than or equal to the transcatheter valve diameter and sinus height greater than the transcatheter valve height.
- Type 3 was defined as sinotubular junction diameter greater than or equal to the transcatheter valve diameter and sinus height less than the transcatheter valve height.
TAV-in-TAV was considered not feasible if the valve-to-sinus distance and/or valve-to-sinus height were 2 mm or less.
Results showed that TAV-in-TAV was not feasible in 21.4% of cases, including 0% in type 1 roots, 36.5% in type 2 roots and 54.8% in type 3 roots (P < .001 across all sizes).
“We were surprised that type 3 root occurred in 30% of our study cohort, and in more than 50% of them TAV-in-TAV would be not be feasible,” Tang said. “This is an important finding, and we need to pay more attention in patients with type 3 root to see if surgery may be better suited in these patients since TAV-in-SAV may be feasible but maybe not TAV-in-TAV.”
Additionally, the researchers found that TAV-in-TAV was 100% feasible in those with 20-mm valves. However, it was 19.1% feasible in 23-mm valves, 22.8% in 26-mm valves and 23.9% in 29-mm valves.
“Contrary to belief that TAV-in-TAV in all Sapien 3 valves would be feasible, our study showed that 20% would not be, due to the risk of left main coronary obstruction from the Sapien 3 leaflets pushed against the valve frame,” Tang said. “Our study also shows that we can classify the aortic root anatomy into three types, and depending on the aortic root type, TAV-in-TAV after prior Sapien 3 TAVR would be less feasible in type 2 and 3 roots. Although there are currently only two commercially available transcatheter valves available to perform TAVR, it would be important to evaluate the aortic root anatomy prior to selecting the TAVR device to evaluate the feasibility of TAV-in-TAV in certain patients, such as younger patients where future valve reintervention may occur.”
Future directions
Tang also said future research would be helpful in placing these findings in context.
“We would ideally like to evaluate the post-TAVR CT to better characterize the valve frame-to-coronary distance among the three root types to correlate with our aortogram findings. We are also investigating whether we can better control the TAVR device orientation to make it coronary reaccess friendly, given that there is currently no predictable way to orient the TAVR device in the same way as surgical valves do. The native leaflets being in the way facing the coronary orifices also complicate the ability to perform coronary reaccess after TAVR, which is another important topic to study in lower-risk, younger patients who may have moderate CAD that may progress after TAVR,” Tang told Cardiology Today’s Intervention.
The study was also published in the Journal of the American College of Cardiology. – by Melissa Foster
Reference:
Tang GHL. Abstract 1256-058. Presented at: American College of Cardiology Scientific Session; March 16-18, 2019; New Orleans.
Tang GHL, et al. J Am Coll Cardiol. 2019;doi:10.1016/S0735-1097(19)31946-1.
Disclosures: Tang reports he is a physician proctor for Edwards Lifesciences and Medtronic. Please see the study for all other authors’ relevant financial disclosures.