Tricuspid Valve Replacement Finds Surer Footing With TRISCEND II’s 1-Year Report

The Evoque transcatheter tricuspid valve replacement (TTVR) system continued to show significant benefits 1 year after implant, according to an update from the TRISCEND II trial.

Among study participants with symptomatic, severe tricuspid regurgitation (TR), those randomized to TTVR, in lieu of medical therapy alone, had significantly better 1-year outcomes per win ratio analysis on a hierarchical composite primary endpoint indicating clinical and symptom benefits (win ratio 2.02, 95% CI 1.56-2.62).

TTVR also led to “near elimination” of the TR, as 99.1% of people had moderate or less TR (and 95.3% mild or less) at the 1-year mark, according to Susheel Kodali, MD, of Columbia University Irving Medical Center/New York-Presbyterian Hospital in New York City, and colleagues.

The caveat was safety: more severe bleeding (15.4% vs 5.3%, P=0.003) and new permanent pacemakers (17.4% vs 2.3%, P<0.001) emerged after TTVR.

Kodali presented the TRISCEND II trial results at the Transcatheter Cardiovascular Therapeutics (TCT) meeting. The full manuscript was simultaneously published in the New England Journal of Medicine.

The device in question, the Evoque, had been FDA approved in February on the basis of the initial 6-month results from TRISCEND II. The approved indication is specifically for the improvement of health status in severe TR due to the lack of a proven reduction in hard outcomes such as mortality.

At TCT, Kodali noted that TRISCEND II is not powered to detect a difference in mortality in the first place.

However, TTVR was at least numerically favored across the individual components of the primary endpoint, the Kaplan-Meier estimates being:

• All-cause mortality: 12.6% vs 15.2% with medical therapy alone
• Heart failure hospitalization: 20.9% vs 26.1%
• Subsequent tricuspid valve intervention: 1.1% vs 5.6%
• Improvement in the Kansas City Cardiomyopathy Questionnaire overall summary (KCCQ-OS) score of at least 10 points: 66.4% vs 36.5%
• Drop in at least one New York Heart Association (NYHA) class: 78.9% vs 24.0%
• Increase in 6-minute walk distance by at least 30 m: 47.6% vs 31.8%

Looking more closely at quality of life, each time point of the trial favored the TTVR in the KCCQ-OS scale. Health status was especially improved by TTVR in people with torrential or massive TR on subgroup analysis, according to the TRISCEND II co-presenter Suzanne Arnold, MD, MHA, of Saint Luke’s Health System in Kansas City, Missouri, during the same session at TCT. That quality of life report was published separately in the Journal of the American College of Cardiology.

Session discussant Neil Fam, MD, of St. Michael’s Hospital in Toronto, highlighted the large improvements in quality of life resulting from Evoque TTVR. “The results of this trial are really a home run for patients suffering from TR,” he told the audience, likening the benefit to what is seen with transcatheter aortic valve replacement.

In TR, the tricuspid valve leaflets do not close completely during systole, causing blood to regurgitate from the right ventricle into the right atrium. Due to a typically older, sicker profile, affected patients have historically had few treatment options outside high-risk surgery.

Experts have long shared concerns about the shaky foundations of the burgeoning tricuspid intervention field despite the unmet need of patients.

After Evoque was FDA approved, the approval for another TR intervention device swiftly followed in April. Like Evoque, the TriClip G4 transcatheter edge-to-edge repair device is similarly indicated for improving quality of life and functional status — both criticized for being subjective endpoints.

During a TCT press conference, panelist Roxana Mehran, MD, of Mount Sinai Health System in New York City, commented on the perceived lowering of the bar for tricuspid valve technologies. She pointed out in particular TRISCEND II’s reliance on a non-traditional win ratio analysis on subjective measures.

Kodali said “we all want a sham-controlled trial” but it is just not feasible currently.

And despite the open-label design of TRISCEND II, Arnold reasoned that the placebo effect is likely not the sole driver of TTVR’s results, given the large magnitude of KCCQ score changes and continued improvement from 1 month to 6 months.

“We have to separate our thought process about left-sided vs right-sided disease,” said Clyde Yancy, MD, MSc, of Northwestern Medicine in Chicago. Given that less is known about the recovery and plasticity of the right ventricle, and that patients with severe TR tend to have other comorbidities such as atrial arrhythmias and liver disease, he spoke out against applying the exact same bar to right- vs left-side interventions.

At least TRISCEND II sets the expectations for future trials, as new technologies will have to match or improve on the safety signals seen here, commented Juan Granada, MD, president and CEO of the Cardiovascular Research Foundation hosting TCT. “We need to be realistic about expectations.”

TRISCEND II was an international trial that included 400 patients with severe symptomatic TR. Exclusion criteria included very low ejection fraction, severely depressed right ventricular systolic function, prior heart transplantation, anatomy that precluded proper device delivery, and severe kidney disease.

Participants were randomized 2:1 to TTVR or medical therapy alone from 2021 to 2023.

The two groups were comparable at baseline; mean age was just over 79 years and 75% were women. Study authors characterized the cohort as broadly representative of the severe TR population in clinical practice. Around 30% of the group had torrential TR, the most severe category, according to the investigators. Nearly 95% of patients had atrial fibrillation and the mean Society of Thoracic Surgeons mortality score for mitral replacement was 9.7%. Around 20% had ascites. Nearly 40% had an existing pacemaker or implantable cardioverter-defibrillator.

Kodali reported that 95.4% of the TTVR arm had the study valve implanted successfully, all percutaneously via the transfemoral approach. The procedure time was 98 minutes and device time 56.5 minutes. Conversions to surgery reached 1.2% in the cohort.

Among the trial’s limitations were the crossovers allowed from medical therapy to TTVR around the 1-year mark that confounds long-term follow-up.

Annual follow-up is nevertheless planned out to 5 years, according to the study authors.

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