Etiologies and Impact of Exclusion Rates for Transcatheter Mitral and Tricuspid Valve Structural Heart Clinical Trials at a High-Volume Quaternary Care Hospital

Abstract

There are various devices under clinical investigation for transcatheter mitral valve intervention and transcatheter tricuspid valve intervention (TTVI); however, the exclusion rates remain high. We aimed to investigate the exclusion rates for transcatheter mitral valve repair (TMVr), transcatheter mitral valve replacement (TMVR), transcatheter tricuspid valve repair (TTVr), and transcatheter tricuspid valve replacement (TTVR). There were 129 patients who were referred to St. Francis Hospital & Heart Center valve clinic and completed screening between January 2021 and July 2022. The causes for exclusion were classified into 4 categories: patient withdrawal, anatomic unsuitability, clinical criteria, and medical futility. In 129 patients, the exclusion rates for TMVr, TMVR, TTVr, and TTVR were 81%, 85%, 91%, and 87%, respectively. Patient withdrawal and medical futility were leading etiologies for exclusion, followed by anatomic unsuitability. TMVr had the highest rate of patient withdrawal (64%) and the lowest anatomic unsuitability (5%) because of short posterior leaflet length. Replacement interventions have a higher anatomic unsuitability (33%) than repair interventions (17%) (p = 0.04). Most exclusions of anatomic unsuitability were because of mitral stenosis or small annulus size for TMVR and large annulus size for TTVR. A total of 50% of exclusions from TTVr were because of the presence of pacemaker/defibrillator leads. In patients excluded from their respective trials, patients being referred for TMVr had the highest recurrent hospitalization and repair group had a higher mortality (p <0.01 and p = 0.01, respectively). In conclusion, the exclusion rates for transcatheter mitral valve intervention and TTVI trials remain high because of various reasons, limiting patient enrollment and treatment. This supports the need for further device improvement or exploring alternative means of therapy.

Keywords: exclusion rates; transcatheter mitral valve intervention; transcatheter tricuspid valve intervention.