TEER May Be Option for Primary MR and ‘Red Zone’ Anatomy

NEW YORK, NY—Both transcatheter edge-to-edge repair (TEER) and transcatheter mitral valve replacement (TMVR) appear to be acceptable treatment options for patients with primary mitral regurgitation (MR) and challenging “red zone” anatomy, an observational study suggests.

Certain anatomical features, like calcification and small mitral valves, have been proposed to point to TMVR as a better choice over TEER, and these data provide insights into patients with these characteristics.

Though TMVR was associated with a greater reduction in regurgitation compared with TEER, that came at the cost of more periprocedural complications, including major access-site complications, major bleeding, and acute kidney injury, Sebastian Ludwig, MD (University Heart & Vascular Center Hamburg, Germany), reported last week at New York Valves 2024, previously known as the TVT meeting.

All-cause mortality in the first 2 years occurred at a higher rate with TMVR, mostly driven by an excess of deaths in the first 3 months, but functional outcomes were similarly improved with either procedure.

Ludwig reported that mean gradient was about 4 mm Hg after either TMVR or TEER, which “shows that we can actually treat many patients with TEER even with complex anatomy.”

On the other hand, “I think it all comes down to three major requirements that need to be fulfilled for TMVR to have a chance to at last become a therapy that we can apply in more patients or apply for all patients,” Ludwig said, pointing to the need to improve anatomical patient eligibility, reduce periprocedural complications, and move away from transapical access.

Treating Those With Complex Anatomies

TEER is a safe, effective, and increasingly used option for the treatment of MR, but its procedural success is dependent on anatomic suitability, Ludwig noted. A classification scheme published in a state-of-the-art review in EuroIntervention last year includes a list of “red zone” anatomic criteria that render TEER challenging and thus favor replacement. This includes features like calcification, a mitral valve area < 3 cm2, a deep regurgitant cleft, multiple/wide jets, and others.

Questions remain, however, as to whether TEER or TMVR is preferred in these tricky scenarios, Ludwig indicated. TEER may have the edge in terms of safety, although it’s dependent on anatomy and leaves some residual MR. On the other hand, TMVR is less dependent on anatomy and provides a more predictable and complete reduction in MR, albeit at the cost of more procedural complications.

To compare the two approaches, Ludwig and his colleagues used data from two international registries: the CHOICE-MI registry of TMVR with dedicated devices and the PRIME-MR registry of TEER for primary MR. After propensity-score matching, the investigators compared results of the two procedures in 141 pairs of patients with primary MR and red zone anatomical features, mostly mitral annular calcification (82%) and small valve area (51%). For TMVR, transapical access was used in 82% of cases, with transfemoral/transseptal used for the rest.

The baseline characteristics of the TMVR and TEER groups were well matched, indicating a typical elderly cohort with elevated surgical risk (mean age about 80 years; 57% men). Some of the echocardiographic parameters were not balanced, however, with TMVR patients having a larger effective regurgitant orifice area (0.4 vs 0.3 cm²), regurgitant volume (61.6 vs 45.0 mL), and mean mitral valve pressure gradient (3.9 vs 3.0 mm Hg).

Procedural outcomes were similar, with a technical success of about 92% in both groups. There were low rates of mortality (1.4% with TMVR and none with TEER) and device embolization (0.7% with TMVR and none with TEER).

Periprocedural outcomes at 30 days favored TEER. TMVR was associated with higher rates of major access-site complications (8.8% vs 0; P = 0.002), major bleeding (8.3% vs 1.6%; P = 0.031), and stage 2/3 acute kidney injury (18.8% vs 0; P < 0.001).

TMVR, however, provided a greater sustained reduction in MR. At discharge, the proportion of patients with MR grade 1+ or less was 93% following TMVR and 68% following TEER. Similar differences were observed at 1 year (91% vs 55%) and 2 years (87% vs 61%; P < 0.001 for all).

Yet those improvements did not translate into a difference in functional outcomes. The proportion of patients with NYHA class I/II disease at 1 year was 74% after TMVR and 92% after TEER (P = 0.12); there was still no significant difference at 2 years (70.5% vs 68.9%; P = 0.58).

Despite delivering similar functional outcomes, TEER was associated with a lower rate of all-cause mortality through 2 years (30.9% vs 36.4%; P = 0.019). A landmark analysis demonstrated that the gap was mostly attributed to a greater risk in the 90 days following TMVR, with an additional analysis by access type suggesting that use of the transapical route is particularly problematic.

Increasing Treatment Options

Discussing the results after Ludwig’s presentation, Isaac George, MD (NewYork-Presbyterian/Columbia University Irving Medical Center, New York, NY), said the study is “conceptually important, and it really sets the stage for what TMVR pivotal trials will look like.” He noted that results were excellent in both groups, which “really is testimony to the field and the technology.”

Citing the fact that TMVR provided a greater reduction in MR but not better functional outcomes, George asked Ludwig whether moderate MR is an acceptable outcome after TEER.

“I personally don’t think that moderate MR is a goal that we should aim for,” Ludwig responded. “I think there’s good evidence that even moderate residual MR is associated with inferior outcome. . . . We have to ask ourselves why there’s no difference in functional outcome and also no improvement in long-term mortality even though we reduced MR efficiently with TMVR.”

To TCTMD, George said that “sometimes we think we need to achieve really, really low MR to make people feel better, but clearly in these high-risk anatomies maybe leaving a little bit of leak isn’t so bad, especially when the procedural issues of a higher-risk procedure may mitigate that gain from the MR reduction. So it’s really something to think about—the trade-off between MR reduction and procedural risk.”

Moving forward, this study “does go to show us that what we’re studying right now is probably not going to be good enough in terms of TMVR,” George said. “We need to not go transapical and we need to have better procedural results in terms of risk.”

He pointed out that the TMVR devices used in the current study are likely not going to be the same ones used 5 years from now, and that the field will be moving away from transapical access, which—in the aortic stenosis literature—has been shown to be independently associated with increased mortality.

“So when we’re evaluating how well one therapy fixes the primary problem,” George continued, “we’re . . . confounded by the fact that we have this access issue that we need to kind of understand, and that really makes interpretation of the data challenging in that regard.”

Overall, George said, “I am confident that this is a step forward. It shows that we’re getting options for these challenging anatomy patients. . . . In some patients, maybe a TEER is a better option, and you accept some leak, and in some patients, maybe you chase after a better MR reduction [with TMVR]. And I think with newer devices, we’re going to see these TMVR results really be excellent and I think there’s a good chance that TMVR, with a better approach and better devices that are coming out now and are already now in trials, will be a better option for these challenging patients.”