‘Spectacular results’ with next-gen TEER device for MR reduction, complications: EXPAND G4
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Key takeaways:
- At 1 year, a transcatheter edge-to-edge repair device reduced mitral regurgitation to mild or less in 92.6% of patients.
- Patients saw improvements in functional status and measures of quality of life.
SAN FRANCISCO — A fourth-generation mitral valve transcatheter edge-to-edge repair system was associated with durable reduction in mitral regurgitation severity to mild or less for most patients, including those with complex anatomy.
In an analysis of 1-year, real-world outcomes from the EXPAND G4 study, researchers also reported that rates of all-cause mortality and HF hospitalization were the lowest reported among a mixed population of patients with primary and secondary mitral regurgitation (MR) treated with the MitraClip G4 system (Abbott). Patients reported marked improvement in quality-of-life measures and demonstrated improved functional status.
Data from EXPAND G4 were presented at TCT 2023 and simultaneously published in JACC: Cardiovascular Interventions.
“The 1-year outcomes of the EXPAND G4 trial confirm the durability, safety and effectiveness of the G4 system in more than 1,000 primary and secondary MR [patients],” Ralph Stephan von Bardeleben, MD, head of the Center of Structural Heart Disease Interventions and the Heart Valve Center in Mainz, Germany, said during a press conference. “[Data show] the highest MR reduction and lowest mortality in a real-world dataset. It allows for tailored treatment for a broad variety of diseases ... setting excellent standards for [this] repair technique that is also extremely safe.”
Significant MR reductions, durable outcomes
For the ongoing single-arm study, researchers analyzed data from 1,164 adults with primary and secondary MR who underwent mitral valve transcatheter edge-to-edge repair (M-TEER) in the U.S., Europe, Canada, Middle East and Japan from 2020 to 2022. One-year outcomes included MR severity, HF hospitalization, all-cause mortality, functional capacity and quality of life measured via Kansas City Cardiomyopathy Questionnaire (KCCQ).
At 1 year, there was a durable reduction in MR to mild or less for 92.6% of patients and to none or trace in 44.2% (P < .0001 vs. baseline). Researchers saw a slightly higher rate in MR reduction for secondary MR patients (95.3%) compared with primary MR patients (88.1%).
The positive outcomes in MR reduction were accompanied by left ventricular reverse remodeling, von Bardeleben said.
“This [reduction] is the highest that has been reported so far ... and it was durable,” von Bardeleben said.
Major adverse events were favorable through 1 year, with MI, surgical reintervention or single-leaflet device attachment in less than 2% of patients. One-year Kaplan-Meier estimates for all-cause mortality and HF hospitalization were 12.3% and 16.9%, respectively.
“The all-cause mortality [data] shows you that this is an extremely safe device,” von Bardeleben said. “We have an under 3% mortality at 60 days and less than 5% mortality in all groups at 120 days — one of the lowest reported mortality rates.”
Researchers also reported significant improvements in functional capacity, with 82% of patients improving to NYHA functional class I or II (P < .0001 vs. baseline) and quality of life, with a mean 18.5-point improvement in KCCQ score (P < .0001).
The EXPAND G4 data show a significant increase in survival and MR reduction compared with MitraClip trials conducted just a decade ago, von Bardeleben said, when 1-year mortality was as high as 23% for a mixed primary and secondary MR population and MR reduction to mild or less was 37%.
“We also see device iteration making it simpler to achieve similar results, but, of course, it was not 100%,” von Bardeleben said during a Q&A session after the press conference. “In the complex cases, [MR reduction to mild or less] was closer to 80%. But still, these are spectacular results with low mortality and a low complication rate.”
Results represent ‘major achievement’
Compared with past registries and previous device iterations, the EXPAND G4 1-year results are among the best reported to date in a population not eligible for surgery, Fabien Praz, MD, and Daryoush Samim, MD, both interventional cardiologists at Bern University Hospital, Switzerland, wrote in a related editorial published in JACC: Cardiovascular Interventions.
“For the sake of comparison, the 1-year mortality in EXPAND amounted to 12.5% for primary MR and 17.7% for secondary MR, and was higher in the interventional group of COAPT,” Praz and Samim wrote. “Remarkably, all other reported individual safety events had an incidence of < 2% at 1 year. In addition, quality-of-life metrics improved by a mean of 18.5 points according to the KCCQ score. Such outstanding results represent a major achievement not only for a therapy that seems to have reached its technical maturity, but also for the participating centers and the considerable experience accumulated as members of a valve team.”
Praz and Samim said more evidence is needed to understand which patients and anatomies will benefit most from transcatheter MV implantation over M-TEER.
References:
- Praz F, et al. JACC Interv. 2023;doi:10.1016/j.jcin.2023.09.035.
- Von Bardeleben RS, et al. JACC Interv. 2023;doi:10.1016/j.jcin.2023.09.029.
Perspective
Back to TopThese data show operators are increasingly better at performing this procedure. The device has also improved. As a result, we are able to handle a broader range of patients with mitral valve disease with TEER and see excellent results. That said, we do need to look at the data carefully in terms of what the operator experience is. There is a learning curve for this device. Unlike TAVR, where the learning curve is relatively short, the learning curve for this is much longer. Yet, the number of TEER cases an individual operator is going to perform with this device is likely lower compared with TAVR cases. It takes more time to be able to reproduce the results we see here in this study. If these are high-volume operators at high-experience sites, these data may not be applicable to all centers performing these procedures.
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Von Bardeleben RS, et al. Late-breaking clinical science: Session I, in collaboration with the Journal of the American College of Cardiology. Presented at: TCT Scientific Symposium; Oct. 23-26, 2023; San Francisco (hybrid meeting).
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