Comparing TAVI Devices: Much Overlap, Some Nuances to Guide Care

Adverse outcome rates are low and comparable between current transcatheter heart valve (THV) types in real-world use, a subanalysis of the OBSERVANT II study shows. Yet the researchers say some differences do stand out, illustrating that the devices each possess distinctive characteristics.

The analysis considered five valves: Evolut R and Evolut PRO (Medtronic), Sapien 3 (Edwards Lifesciences), Acurate neo (Boston Scientific), and Portico (Abbott).

“To date, transcatheter aortic valve comparisons have been mostly limited to two-arm-design studies, which [focus] attention on the potential benefits of the use of specific [devices] over others,” Giuliano Costa, MD (A.O.U. Policlinico “G. Rodolico – San Marco” and University of Catania, Italy), and colleagues note in their paper, which was published recently in Circulation: Cardiovascular Interventions.

Marco Barbanti, MB (A.O.U. Policlinico “G. Rodolico – San Marco” and University of Catania), the study’s corresponding author, told TCTMD that most of their findings are “in line with previous observations” showing equivalent outcomes.

Here, the key takeaway “is that the current TAVI devices carry some unique features that should always be taken into consideration to apply more-tailored patient selection,” he said in an e-mail. “I believe that the times are mature enough for a prospective study [that] compares a highly tailored THV type selection versus the standard approach. Such a study, he said, should assess endpoints like paravalvular leak (PVL), patient-prosthesis mismatch, and conduction disturbances, which in OBSERVANT II varied somewhat among the devices.

Until the arrival of such data, TAVI centers should make sure they are “able to offer their patients at least two different iterations of TAVI devices with different features, in order to choose the best TAVI platform in each individual anatomy. This means that TAVI volume must be high enough to allow operators to reach a good expertise,” he advised. “Overall, all TAVI devices guarantee favorable acute and midterm outcomes, which will be further improved with next-generation devices that have been already adopted in clinical practice.”

Permanent Pacemaker, PVL Differences

Costa, Barbanti, and colleagues compared outcomes among 2,728 patients (median age 83; median EuroSCORE II 5.1%) treated with the various second- and third-generation TAVI devices between December 2016 and September 2018. The most commonly used THV was Evolut R, in 41%, followed by Sapien 3 (28%), Evolut PRO (12%), Acurate neo (11%), and Portico (8%). TAVI was done via a transfemoral approach in 91.4% of cases, and preprocedural CT was performed in 88.7%.

The primary endpoint, a composite of all-cause death, stroke, and rehospitalization for heart failure at 1 year, was similar among the five valves.

After the procedure, patients treated with Sapien 3 were less likely to have moderate-to-severe PVL but had higher transprosthetic gradients than those given other THVs. In-hospital outcomes were mostly similar across devices, apart from lower rates of new-onset left bundle branch block (LBBB) and permanent pacemaker (PPM) implantation with Sapien 3 and Acurate neo. By 1 year, Sapien 3 patients still were less likely to have PPM, while the PPM rate was highest with Portico.

Outcomes by Valve Type

“We were surprised to see the rates of paravalvular regurgitation, particularly in self-expanding valves, which were slightly higher compared with clinical trials. This can be explained by the higher complexity of anatomies treated in a real-world setting,” Barbanti noted.

Also important is that moderate-to-severe PVL after TAVI seems to matter more for 1-year prognosis than does increased transprosthetic gradient, he said, adding that this needs to be confirmed over longer-term follow-up. Barbanti added that the OBSERVANT II study, by linking with an administrative database, offers the ability to continue gathering data, and that the researchers intend to offer an extended look once this information becomes available.

Look Beyond 1 Year

In the years since the study period, the field has continued to produce new device iterations, including Evolut PRO+ (Medtronic), Sapien 3 Ultra (Edwards Lifesciences), Acurate neo2 (Boston Scientific), and Navitor (Abbott). These, the researchers note in their paper, carry “different refinements in valve design and delivery system, aimed to mitigate residual paravalvular regurgitation and facilitate valve deployment, and therefore to significantly improve patients’ outcomes.”

Andrew Tully, MD (Emory University, Atlanta, GA), and colleagues, writing in an accompanying editorial, suggest that advances in TAVI have lowered risk to the point that these data from OBSERVANT II leave many open questions.

“With accelerating implantation in low-risk patients, the 1-year metric is too narrow, and future investigations ought to provide clarity on projected outcomes two, even three decades into the future,” they write.

They agree that as of now, any differences that do exist appear to be subtle. However, “these slight discrepancies in risk over the long term may have meaningful consequences and must be taken into consideration in a patient-specific approach,” the editorialists note.

A longer horizon is particularly important for younger patients who “expect a therapy whose outcomes aim ambitiously beyond death, stroke, and rehospitalization, especially at 1 year. They expect to be free of dire outcomes far into the future,” Tully et al say. “In the short term, they expect noticeable improvements in cardiovascular performance and freedom from medical intervention and surveillance. Such patients prefer to avoid extra medication over their lifetime, especially anticoagulation.

“In an era where payor reimbursement and patient satisfaction are demanding shared decision-making, future studies guiding lifetime valve management should focus on patient-centered outcomes. TAVR is progressing swiftly; future studies must be bolder,” they conclude.