• TEER and TMVR Procedures and Favorable Outcomes on the Rise in the US

    Transcatheter edge-to-edge repair (TEER) and transcatheter mitral valve replacement (TMVR) procedures have grown drastically in the U.S. since 2014, with improving outcomes over time, according to new data from the ongoing real-world Transcatheter Valve Therapy (TVT) Registry.

    The findings from the Society of Thoracic Surgeons (STS) and American College of Cardiology (ACC) database of nearly all patients undergoing either of the procedures with an approved device in the U.S. were reported Monday online in a Journal of the American College of Cardiology  State-of-the-Art review, led by Michael Mack, MD, Baylor Scott & White Health.

    It is the first full report of transcatheter mitral valve repair and replacement since 2017 from the TVT registry, which collects data on patients undergoing mitral valve-in-valve (MViV), valve-in-ring (MViR) and valve-in-mitral annular calcification (MViMAC) procedures with U.S. Food and Drug Administration (FDA)-approved transcatheter aortic valve replacement (TAVR) devices, TEER and TMVR.

    The current review looks only at TEER and TMVR procedures, in those with mitral regurgitation and provide post-approval device surveillance, as well as potential evidence for expanded indications.

    It includes in-hospital, 30-day and available 1-year outcomes for a total 37,475 subjects who underwent one of the two mitral transcatheter procedures over a 6-year period between 2014 and March 31, 2020, of whom 33,878 had TEER and 3,597 TMVR. Outcome data that could be linked with Center for Medicare and Medicaid Services (CMS)  claims were available for patients treated on or before Dec 31. 2019, and 1-year mortality data for those treated on or before Sept. 30, 2018.

    Both procedures have one approved technology: for TEER, Abbott’s MitraClip, which was approved by the FDA for severe, symptomatic, primary mitral regurgitation with prohibitive surgical risk and covered under a National Coverage Determination (NCD) from CMS since 2014.  

    The device’s indication was expanded in 2019 to include those with moderate-to-severe or severe secondary mitral regurgitation and heart failure symptoms, although an NCD was not issued by CMS until early 2021 in this setting.

    For TMVR, the device is Edwards Lifesciences’ balloon-expandable Sapien transcatheter heart valve system, first FDA-approved in 2017 for high-risk patients with degenerated surgical mitral bioprosthesis. The approval was based partly on patients from the TVT Registry treated off-label with the system.

    The reviewers' report various ties with the device manufacturers.

    Growing use

    “We report significant annual growth in both transcatheter mitral valve repair and replacement with improving outcomes over time,” said the reviewers.

    For TEER, annual procedure volumes grew from 1,152 per year in 2014 to 10,460 per year in 2019 at 403 sites, said the reviewers, noting in particular a 50% increase between 2018 and 2019.

    “Patients undergoing TEER are site determined as prohibitive risk for surgical mitral valve repair with overall median STS predicted risk of mortality for surgical valve repair of 5.35%,” the reviewers noted, though mortality risk for surgical valve repair declined from 6.1% in 2014 to 4.9% in 2020.

    The median age of TEER patients was 80 years, with a trend toward decreasing age from initial commercial approval of TEER in 2014 (82 years) to the last year of data collection in 2020 (79 years). Site-reported incidence of frailty, however, increased during the period, from 49.8% in those undergoing TEER in 2014 to 58% in 2020.

    The majority (83.3%) had baseline New York Heart Association (NYHA) Class III (61.9%) or IV (21.4%) symptoms, while those on home oxygen comprised 11.9% of the overall cohort.

    Overall, the male-to-female ratio undergoing these procedures was 53.7% vs. 46.3%.

    TEER patients were mostly white (87%), although the percentage of Black and Hispanic or Latino patients did rise slightly during the review period (Black: 6.3% in 2014 vs. 10.8% in 2020; Hispanic or Latino: 4% in 2014 vs. 7% in 2020), increasing annually.

    “The proportion of individuals undergoing TEER who are Black (9%) matches the representation of Blacks in the overall US population age 65 and older, but for Hispanics the proportion undergoing TEER (6%) is slightly less than that of the entire US population age 65 and older (8%),” the reviewers said.

    “This is in contradistinction to TAVR, for which there appears to be greater under-representation of minority populations.”

    Meanwhile, TMVR procedures overall grew from 84 per year to 1,120 per year at 301 centers.

    Those undergoing TMVR were also deemed to be at high risk for surgical mitral valve replacement, with an overall STS-predicted surgical mortality risk of 10%, decreasing slightly to 8.6% in 2020.

    The median age of TMVR patients was 75 years, remaining “fairly consistent” annually. Unlike TEER, women were the predominant sex undergoing TMVR, accounting for 60% of overall procedures.

    Again, white patients were the recipients of the vast majority of procedures (84%), with the number of Black (11% in 2020) and Hispanic or Latino (6% in 2020) patients again increasing during the study period.

    Most (83.85%) had either NYHA Class III (56.2%) or IV (27.6%) symptoms prior to TMVR, and 15.5% of the overall cohort were on home oxygen.

    Transseptal access was used in the majority of TMVR cases (70.9%), followed by the transapical route (17.0%), but there was a reversal in the preferred approach over the study period, from a 76% transapical vs. 16.7% transseptal balance in 2014, to a 3.8% transapical vs. 83.3% transseptal by 2020.

    Decreasing risk

    Over the period, 30-day mortality rates fell from 5.6% to 4.1% for TEER and 1-year mortality dropped from 27.4% to 22%.

    For TEER, complications within 30 days were infrequent overall, at 4.5% overall (excluding approximately 10% of patients with missing data.

    Still, 30-day rates were more than twice the reported in-hospital mortality, which in turn declined “slightly but significantly” from 2.9% in 2014 to 2.1% in 2020, with a consistently low stroke rate below 1%.

    “There were no yearly trends of note in many complications with stable and low overall rates of life threatening/disabling bleeding (1.3%), major vascular access site complications (0.4%), and new atrial fibrillation (2.13%),” said the reviewers.

    The 1-year mortality rate for TEER was 23.1% overall, dropping from 27% in 2014 to 21% in 2018 (p = 0.0017).

    As in TEER, TMVR risk trends decreased over the review period.

    Excluding the 8.8% with missing data, 30-day mortality was 7.8% overall, dropping annually from 11.1% in 2014 to 6.2% by 2019.

    “During the off-label period of 2014-2017 30-day mortality ranged from 5.7 to 9.1% and after approval the mortality dropped in 2018 and 2019 to 4.1% and 3.9% respectively,” the reviewers added.

    “Of note is that the 30-day mortality was lower for MViV (4.7%) than for MViR (9.4%) and MViMAC (20.3%),” the reviewers said, adding that – despite trending lower – 30-day mortality remained “substantial” for MViMAC (17.6%) in 2019.

    “Complications within 30-days occurred mainly during the index admission rather than during a readmission episode,” they added.

    During index procedural TMVR admissions, 4.1% of patients suffered cardiac arrest, and 5.5% of patients died.

    Stroke rates remained similar (1.7% overall), as did mitral valve re-intervention (1.8%), post-procedural atrial fibrillation (5.0%), new dialysis requirement (3.3%), acute kidney injury (4.9%, inclusive of all stages), vascular complications (2.0%), or major/disabling bleed (12.8%).

    Conversion to open-heart surgery (1.2% overall) fell from 2.4% in 2014 to 0.4% in 2020, left ventricular outflow tract obstruction occurred in 1.9% of cases overall, peaking at 3.1% in 2016 “but decreasing gradually since then,” and hospital length of stay fell from a median of 7 days to 2 days over the study period.

    However, 1-year mortality did not show a “discernable change over time,” hitting 22.5% overall.

    Experience is growing rapidly in terms of both procedural volume and the number of centers offering transcatheter mitral therapies,” the reviewers summarized.

    “The annual mitral procedural volumes have increased almost tenfold from a combined TEER and TMVR volume of 1,236 in 2014 to 11,580 at 403 centers in 2019.”

    They added: “With the growth of transcatheter mitral valve repair and replacement and improved outcomes for both procedures, substantial variations in effectiveness and safety of these technologies are apparent.”

     

    Source:

    Mack M, Carroll JD, Thourani V, et al. Transcatheter Mitral Valve Therapy in the United States: STS-ACC TVT Registry: State-of-the-Art Review. J Am Coll Cardiol 2021 Oct 25. (Article in press)

    Image Credit: ibreakstock – stock.adobe.com

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