Early Feasibility Study of a Transcatheter Tricuspid Valve Annuloplasty: SCOUT Trial 30-Day Results.

BACKGROUND: The SCOUT (Percutaneous Tricuspid Valve Annuloplasty System for Symptomatic Chronic Functional Tricuspid Regurgitation) trial is a prospective, single-arm, multicenter, early feasibility study of a novel transcatheter device to plicate the tricuspid annulus (TA) and reduce tricuspid regurgitation (TR). OBJECTIVES: This study tested the feasibility and safety of a novel transcatheter device and assessed its early performance and functional outcomes. METHODS: Between November 2015 and June 2016, 15 patients with New York Heart Association (NYHA) functional class ≥II and moderate or greater functional TR were enrolled. Primary performance and safety endpoint outcomes were technically successful at 30 days with no reintervention. Echocardiographic measurements (TA diameter, effective regurgitant orifice area [EROA], left ventricular stroke volume [LVSV]) and quality-of-life (QoL) measurements (NYHA functional class, Minnesota Living with Heart Failure Questionnaire [MLHFQ], and 6-min walk test [6MWT]) were performed at baseline and 30 days. RESULTS: All patients (mean 73.2 ± 6.9 years of age, 87% female) underwent successful device implantation with no deaths, strokes, bleeding, tamponade, or valve reintervention. Technical success rate at 30 days was 80%, with 3 single-pledget annular detachments without reintervention. In the remaining 12 patients, there were significant reductions in TA (12.3 ± 3.1 cm2 to 11.3 ± 2.7 cm2, respectively; p = 0.019) and EROA (0.51 ± 0.18 cm2 vs. 0.32 ± 0.18 cm2, respectively; p = 0.020), with significant increase in LVSV (63.6 ± 17.9 ml vs. 71.5 ± 25.7 ml, respectively; p = 0.021). In the intention-to-treat cohort, there were significant improvements in NYHA functional class (≥1 class, p = 0.001), MLHFQ (47.4 ± 17.6 to 20.9 ± 14.8; p < 0.001), and 6MWT (245.2 ± 110.1 to 298.0 m ± 107.6 m; p = 0.008). CONCLUSIONS: The 30-day results of the SCOUT trial confirmed the safety of the novel transcatheter device, which reduced TA and EROA, increased LVSV, and improved QoL. (Early Feasibility of the Mitralign Percutaneous Tricuspid Valve Annuloplasty System (PTVAS) Also Known as TriAlign [SCOUT]; NCT02574650.).