Transcatheter annuloplasty with the K-Clip system for tricuspid regurgitation: one-year results from the TriStar study.

Background: Despite the fact that morbidity and mortality rates significantly increase with tricuspid regurgitation (TR) severity, limited treatment options are available for treating severe TR.

Aims: The single-arm, multicentre, prospective Confirmatory Clinical Study of Treating Tricuspid Regurgitation With K-Clip TM Transcatheter Annuloplasty System (TriStar) evaluated the 1-year outcomes of the novel transcatheter K-Clip annuloplasty system in treating secondary TR.

Methods: Between May 2022 and October 2022, patients with ≥severe secondary TR despite optimal medical therapy at 11 centres in China were deemed candidates for transcatheter tricuspid repair by the local Heart Team and a multidisciplinary screening committee. Echocardiographic parameters, clinical and quality-of-life measures, and major adverse events were collected at 1 year.

Results: Ninety-six patients were enrolled (mean age 72.6±7.0 years, 60.4% female, mean TRI-SCORE 5.4±2.1). The technical success rate was 97.9%. At 1 year, echocardiographic follow-up showed an average reduction in the annular septolateral diameter of 11.3% (41.9 mm vs 37.1 mm; p<0.01), compared with baseline, with marked right ventricular remodelling. A total of 82.5% of patients had ≤moderate TR, and 97.7% had a ≥1 grade reduction. Patients experienced significant clinical improvements in New York Heart Association Functional Class I/II (32.6% to 96.5%; p<0.001), the 6-minute walk distance increased by 31.9±71.8 m (p<0.001), and the overall Kansas City Cardiomyopathy Questionnaire score increased by 7.6±17.7 points (p<0.001). Neither cardiovascular death nor reintervention were recorded at the 30-day or 1-year follow-up, while severe bleeding requiring further treatment was noted in 5 patients at 1 year. The Kaplan-Meier estimates of survival and freedom from heart failure rehospitalisation were 97.8% and 95.1%, respectively, at 1 year.

Conclusions: The 1-year experience using the K-Clip tricuspid annuloplasty system demonstrated high survival and low rehospitalisation rates with durable TR reduction and clinical benefits in functional status and quality-of-life outcomes.