TAVI surgical explantations are risky and on the rise: STS data bears a warning
The disturbing signals seen in a comparison of revision procedures carry a message for interventionists and surgeons.
BOSTON, MA—The number of TAVI patients who end up needing SAVR later for a failing TAVI valve is growing faster than many cardiologists realize. Additionally, a new analysis warns that the risk of death during this second procedure is significantly higher than that seen in patients whose initial valve implantation was surgical, followed by a second SAVR device.
Speaking to the press ahead of his late-breaking clinical science presentation here at TCT 2022, Robert B. Hawkins, MD (University of Michigan, Ann Arbor), pointed out that explanting a TAVI device to implant a new surgical valve is a very different procedure than a single SAVR or a repeat SAVR.
“It’s not the same operation,” he said. “It’s very different.”
Surgeons and interventionists should be aware that a TAVI in TAVI will not be the solution for many patients, that the number of TAVI explants is steadily increasing, and that the complex procedure to remove a TAVI device to implant a surgical valve is foreign to the vast majority of surgeons.
Patients, Hawkins added, need to know this at the time of their first procedures.
SAVR After TAVI
Hawkins and colleagues searched the Society of Thoracic Surgeons (STS) Participant User Files database from 2011 to 2021 looking for all cases of aortic valve replacement, excluding all non-bioprosthetic valves and all patients for whom STS risk score details were missing. The patients were then separated into groups based on their subsequent procedures.
A total of 14,826 patients who had first SAVR underwent subsequent SAVR, 544 patients initially treated with TAVI underwent subsequent SAVR, and a total of 318 patients had SAVR, then valve-in-valve TAVI, followed by of a second SAVR.
Looking first at volumes and trends, Hawkins showed that repeat valve surgery procedures have been relatively stable over the past 5 years, while the number of repeat TAVI and SAVR after TAVI has steadily increased. By 2026, Hawkins noted, the number of surgical TAVI valve explantations is expected to reach 500 per year.
In an overall unadjusted comparison between groups, TAVI-SAVR patients – unsurprisingly – were more likely to be older, with more comorbid conditions and more prior PCI than SAVR-SAVR patients.
But strikingly, overall complication rates were significantly higher in TAVI-SAVR patients, with operative mortality reaching 17%, compared to 12% in SAVR-TAVI-SAVR patients and 9% in SAVR-SAVR patients (P
[T]its risk should be disclosed to patients and considered in lifelong management plans for aortic stenosis. Robert B. Hawkins
Recognizing that these groups are “not the same to begin with,” Hawkins and colleagues performed hierarchical regression modeling using the STS risk score. Here, TAVI-SAVR patients faced a 1.5 times higher mortality risk than SAVR-SAVR patients, as well as an increased risk of combined morbidity-mortality.
Drilling further to consider only patients undergoing isolated aortic valve replacement, a risk-adjusted analysis indicated that the odds ratio of mortality in TAVI-SAVR versus SAVR-SAVR patients increased to 1.7. Following additional propensity score matching of only isolated patients who underwent aortic valve replacement, TAVI-SAVR patients had higher operative mortality than SAVR-SAVR patients (11.3% versus 6.7% ), higher rescue failure (32% versus 16%), higher rates of kidney failure, and longer ICU stays.
“TAVR explantation remains a low-volume, but escalating operation with increased risk compared to repeat SAVR,” Hawkins concluded. “Consideration should be given to centralizing these cases in high-volume centers of excellence and requires further study.”
Additionally, he insisted, “this risk must be disclosed to patients and factored into lifelong management plans for aortic stenosis. For patients who are likely to survive their first valve replacement and who are not TAVR-in-TAVR candidates, a surgical first approach should be strongly considered.
Surgeons, too, must bear some of the blame, he continued. “As surgeons, we must also design our operations for future valves and valves, with aggressive use of root enlargement and internally mounted tissue valves must be considered.”
Do not preach to the choir
Speaking to TCTMD, study co-author Shinichi Fukuhara, MD (University of Michigan Ann Arbor, MI), said that they had been very intentional in submitting these data at the TCT 2022 meeting, rather than at a surgical meeting, as they want the interventionists to be aware of the number of cases in which a TAVI-in-TAVI is simply not an option. Fukuhara estimated that the number of people ineligible for a new TAVI could be on the order of 50% of patients. Hawkins called it “an area that desperately needs more research”, adding: “We just don’t have a good way of knowing at this time who will or will not be a candidate, but there is certainly a significant number of people who will not be candidates for TAVR-in-TAVR.
For now, surgical explantation of a TAVI valve is a complicated and risky procedure that many surgeons are unfamiliar with.
Indeed, in the formal discussion following Hawkins’ last-minute presentation, moderator Michael Reardon, MD (Houston Methodist, TX), noted that these investigators are American leaders in this proceeding, joking that Fukuhara was on a mission to “eliminate all valve TAVRs in the state of Michigan.
“You’ve done a lot now,” Reardon continued, “but on average, across the country, the average number of TAVR removals by surgeons is one, and they’re often done by surgeons who have never really implanted with a TAVR valve or seen a TAVR valve.
Hawkins, in response, noted that a low volume of explantation procedures resulting in a slight increase in operative mortality and “failed salvage” is only part of the problem. “Many of these patients with failing TAVR valves don’t have surgery either,” he said. “They are palliative. And so really what we’re looking at is the margins of these failed TAVRs and what happens to them.
Suzanne V. Arnold, MD (Saint Luke’s Mid America Heart Institute/University of Missouri-Kansas City), speaking at the press conference, noted that patients who received transcatheter valves between 2011 and 2015 were very different from most patients undergoing TAVI today, transcatheter devices were only approved by the U.S. Food and Drug Administration for highest-risk patients and many had already been deemed too high risk for surgery at the time. time of their TAVI.
“I’m concerned about being able to account for all these differences between patients who were only allowed to have a TAVR during this time with just an STS risk score, because there’s so much more, in the characteristics of the patient, the patient’s risk than an STS risk score,” she said.
Addressing this point with TCTMD, Hawkins and Fukuhara suggested that the richness of data collected in the STS score is richer than many interventionists realize, and their results should not be ignored simply because they are not not randomized — at least 60 different factors were used to match patients, Fukuhara noted.
That said, Hawkins added, the situation will only get more complicated as more low-risk patients undergo TAVI procedures. “As we move into the low-risk categories, palliative care isn’t really an option anymore, so I think that’s going to become more and more important . . . and I think there’s a learning curve .
On the other hand, noted Tsuyoshi Kaneko, MD (Brigham And Women’s Hospital, Boston, MA), one of the last-minute responders, the fact that many of these patients were likely at high surgical risk for their first procedures would also have an impact on their subsequent mortality risk. “As the risk decreases, can we reduce this mortality? And does it come with greater experience – operator experience, institutional experience, or societal experience? I think that will be the key to see,” he said.
Lessons for all
For surgeons, Hawkins suggested, “it’s important to really understand biventricular anatomy. We found that TTE systematically underestimated the posterior part [paravalvular leak] and we underestimate the load on the LV, resulting in RV failure and failed rescue. So I think it’s a learning curve and most centers will be on that learning curve for at least a decade because of how little they do.
For interventionists who are always excited to be able to “innovate to solve this problem,” Hawkins said, this data should give them pause.
“It will always be an answer and that’s very optimistic,” he said, but pointed to new valve-in-valve data presented in the same last-minute session showing risk as an example. higher mortality in patients undergoing a bioprosthetic valve. fracture to accommodate a TAVI device. “What we’re seeing is that whether it’s BASILICA or fracture, the results aren’t as good as the people who pioneered and are experts in this are claiming.”