Transcatheter end-to-end repair (M-TEER) for primary mitral regurgitation can be performed safely in centers with a low volume of surgical mitral valve repair, but new data suggest that surgical It has been suggested that hospitals with more experience in M-TEER can achieve better M-TEER outcomes with a single surgery. Year.

There was no difference in the risk of in-hospital and 30-day mortality when M-TEER was performed in small, medium, and high-volume surgery centers, but that equivalence was not maintained after 1 year. It was.

“In the short term, there is not much of a relationship between a center’s complex mitral valve surgical volume and M-TEER performance,” said senior investigator Sreekanth Vemulapalli, MD, Duke University Medical Center, Durham, North Carolina. told TCTMD. “It’s the one-year results that really matter, and that’s where we see the association between complex mitral valve surgery volume and M-TEER performance in terms of mortality and heart failure hospitalizations.”

The big question is how to adjust for discordant early and late outcomes between low-volume and high-volume centers, Vemulapalli said.

“At these centers that perform a high volume of complex mitral valve surgery, either there is some kind of better postoperative care or long-term follow-up, or there are differences in patient selection that are not captured by simple patient statistics. “You either do it,” he said. “Centers that perform more complex surgeries may be intervening with M-TEER at an earlier stage of the disease.”

For example, M-TEER at these centers may be performed in patients with a more preserved left ventricular ejection fraction or less structural damage to the myocardium. In fact, Vemulapalli noted that his median LVEF for patients treated at high-volume surgical centers tends to be slightly higher than for patients treated at low- and medium-volume surgical centers. (57% vs 55% vs 55% respectively).

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A new study recently published is Circulation: cardiovascular interventionsThe paper, by lead author Paul Grayburn, M.D., Baylor Scott & White Research Institute, Plano, Texas, includes a study of primary patients treated at 500 hospitals affiliated with the American College of Cardiology/Association of Thoracic Surgeons. 41,834 patients with mitral regurgitation (MR) were included in the (ACC/STS) TVT Registry and STS Adult Cardiac Surgery Database.

Vemulapalli told TCTMD that this analysis differs from previous studies that compare results based on operator/facility volume. Instead, it is important to understand the “treatment system” for the treatment of primary MR. He noted that national coverage decisions by the U.S. Centers for Medicare and Medicaid Services require that the M-TEER program require on-site cardiac surgeries (20 or more mitral valve surgeries per year, at least 10 of which He pointed out that repairs (must be done) are necessary.

“That was one of the rationales for considering this question,” he said. “The other thing is the underlying idea of ​​a valve center of excellence. The question is, is there any relationship between his mitral valve surgery performance and his M-TEER performance?”

Of the 500 surgical sites, 66.4% were low volume (less than 25 mitral valve repairs per year), 20.4% were medium volume (25 to 49 mitral valve repairs), and 13.2% were high volume (50 mitral valve repairs per year). mitral valve repair). . Surgical mitral valve repair was defined as leaflet resection or prosthesis with or without annuloplasty.

The success rate of M-TEER was 54.6% and did not differ by hospital surgical volume. The in-hospital or 30-day mortality rate with M-TEER was 3.5%, and this rate did not differ between centers with different surgical volumes (3.4% and 3.4% for low, medium, and high volume, respectively). , and 3.9%). surgical site). After adjusting for clinical and demographic data, the relationship between surgical volume and early mortality by M-TEER was not statistically significant (P = 0.552).

The readmission rate for heart failure (HF) at 30 days was 2.8%, and there was no difference by surgical volume. The 1-year readmission rate was 9.4% overall, but this was significantly lower at high-volume repair centers (9.2%, 10.8%, and 8.6% at low-volume, medium-volume, and high-volume repair sites). In restricted cubic spline analysis, the relationship between his HF readmission after 1 year and surgical volume was statistically significant (P = 0.015).

Regarding mortality after 1 year, the overall mortality rate for M-TEER was 15.0%. After adjustment, the restricted cubic spline analysis for mortality was statistically significant, and in a high-volume surgical center he had lower 1-year mortality (P = 0.027).

Results are more pronounced with secondary MR?

As for whether M-TEER should be moved to hospitals that also perform high-volume mitral valve repair surgeries, Vemulapalli said patient access needs to be balanced, and the absolute magnitude of the difference in outcomes at 1 year is He pointed out that it is relatively large. small.

“We’re talking about a few percentage points in terms of mortality and hospitalization rates,” he said. “Right now, if it were me, I would be willing to travel to go to the center with the absolute lowest readmission and mortality rates. But balancing access is a personal decision at the patient level. .”

Still, Vemulapalli believes these new data support the Valve Center of Excellence concept. “There appears to be a difference both in selection and in subsequent care,” he said, noting better outcomes in high-volume surgical settings.

Importantly, our analysis focuses only on first-order MR, so it is difficult to extrapolate the results to second-order MR. Vemulapalli noted that secondary MR requires a variety of subspecialists, including a good heart failure team with advanced therapies.

“The whole ecosystem around care is different,” he said. “Furthermore, the level of evidence for surgical intervention in secondary MR is very different than in primary MR. That being said, if similar studies were done for secondary MR, the same, but more I suspect that it may be found to a large extent. Given that what we have seen here is related to patient selection and postoperative care, in my opinion most secondary It will be even more important in patients with severe myocardial disease, as well as in patients with sexual MR.”