Balloon-Expandable Redo TAVI Shows Promise in Real-world Cohort

Among older patients with failed transcatheter aortic valves, redo TAVI with a balloon-expandable valve effectively treats transcatheter valve stenosis or regurgitation with minimal complications, on par with what is seen in native TAVI procedures, according to registry data.

Past research on redo TAVI is limited to smaller registry studies, including the Redo Registry and EXPLANT-OR-REDO TAVI, with outdated valve technology.

“Our study results will guide the treatment of failed transcatheter heart valves,” write lead author Raj Makkar, MD (Cedars-Sinai Medical Center, Los Angeles, CA), and colleagues. “Redo TAVR with balloon-expandable transcatheter valves might be a reasonable option for the treatment of failed transcatheter valves in selected patients who are deemed appropriate for redo TAVR by their heart teams.”

“I am very, very encouraged by the data,” Kendra Grubb, MD (Emory University, Atlanta, GA), who was not involved with the study, told TCTMD. “It's clear that the heart teams are doing a good job in prescreening patients and minimizing the risk of the redo TAVR. You didn't see a lot of coronary obstructions and you didn't see conversions to surgery or early deaths.”

This might translate to increased success with these procedures in the future “because I do think that we are going to see more and more failed TAVR valves as the patient population that we are implanting is younger,” she continued. “If we can learn how to do redo TAVR on the older, sicker patients, then hopefully those lessons will carry over to our younger patients and our lower-risk patients.”

The study was published online last week in the Lancet.

Redo TAVI Effective

For the study, Makkar and colleagues included 350,591 consecutive patients from the Society of Thoracic Surgeons/American College of Cardiology Transcatheter Valve Therapy Registry who underwent TAVI with balloon-expandable valves between November 2011 and December 2022.

Of the 1,320 patients undergoing redo TAVI, the mean age was 78 years, 42.3% were female, and the mean predicted surgical risk of 30-day mortality was 8.1%. The median time to redo TAVI was 28.7 months, although this increased from 8 months in 2012-2016 to 49 months in 2022.

In an analysis of 1,320 propensity-matched pairs, those undergoing redo TAVI reported low rates of coronary compression or obstruction (0.3%), intraprocedural death (0.6%), and conversion to open heart surgery (0.5%) similar to those seen in native-valve TAVI.

Additionally, the researchers found no differences between the redo and native TAVI populations in rates of the coprimary endpoints of death at 30 days (4.7% vs 4.0%; HR 1.19; 95% CI 0.82-1.83) or 1 year (17.5% vs 19.0%; HR 0.94; 95% CI 0.77-1.16) and stroke at 30 days (2.0% vs 1.9%; HR 1.06; 95% CI 0.61-1.83) or 1 year (3.2% vs 3.5%; HR 0.94; 95% CI 0.60-1.49).

Aortic valve gradients were reduced at 1 year for all patients compared with baseline, but they were higher for those undergoing redo compared with native TAVI (15 vs 12 mm Hg; P < 0.0001). Additionally, the rates of moderate or severe aortic regurgitation at 1 year were similar in the two groups (1.8% vs 3.3%; P = 0.18).

Redo TAVI was associated with similar improvements in quality of life. For instance, there was no difference in the proportion of redo or native TAVI patients who were considered NYHA class III or IV at both 30 days and 1 year. Also, while the mean Kansas City Cardiomyopathy Questionnaire overall summary score was higher after native TAVI than redo procedures, this metric showed sustained improvement over time for all patients at both 30 days and 1 year.

Finally, the incidence of death or stroke after redo TAVI did not seem related to the timing of redo TAVI or index transcatheter valve type, but rather baseline surgical risk.

Notably, the authors acknowledge that “the patient population might represent a select cohort of patients who were either high risk for surgery or anatomically more favorable for redo TAVR.”

Limitations, Future Directions

Commenting on the study for TCTMD, John Webb, MD (St. Paul's Hospital, Vancouver, Canada), agreed that its biggest limitation is “that these are very selected patients.” Much remains unanswered about redo TAVI in patients with small annuli or those with long expected life spans, he added.

“We would hope that TAVR valves would last an average of 10 years, but in these patients, the average time that the valve lasted was just 2-and-a-half years,” Webb said. “So this says something about this patient population. It's difficult to apply it to patients who have late failure.”

Nevertheless, Webb said the results are in line with what has been seen before but are enhanced by a larger population, “more-rigorous” methodology, and real-world design.

Because the study doesn’t provide any information about late outcomes, “we don't really know if this is an ideal long-term strategy for patients, [but] it is certainly a reasonable short-term or midterm strategy for patients,” Webb added. “At this time, this doesn't prove equivalence to surgery but it probably does represent a preferred strategy in most patients who have failure of transcatheter valves as opposed to explanting the valves.”

Grubb noted the “huge improvement” in valve durability over the course of the study, and called that a “good sign.”

She continued: “There is still a lot we need to learn, but so far, what this suggests is that in this real-world cohort of patients, the heart teams are doing a great job, and that has to be emphasized in terms of selecting patients and safely doing the operation.”

However, Grubb did express concern at the proportion of patients left with residual gradients after redo TAVI (18.4% had mean transaortic gradients of at least 20 mm Hg at discharge). “Is that a signal that these valves are going to fail even sooner? Well, that is still for us to learn, but it is certainly something we should keep an eye on and figure out which combinations of valves will give these patients the best lifetime management,” she said.

Ultimately, the biggest limitation of the study is that the data lack the granularity to be able to provide “the true denominator, which is how many patients came with failed TAVRs that were turned down,” Grubb said.

Going forward, she would like to see other valves studied so that “we can truly decide what is the best second valve for these patients.” After that, a looming open question is: “How do we plan from the first valve what the second valve is?” This might involve CT imaging, advanced planning, or even simulation technology, according to Grubb.

“Certainly, technology will change as we go forward, but this gives us an early signal that we are going to be able to offer TAV-in-TAV safely,” she said.