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

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