Long-arm Clip for Transcatheter Edge-to-Edge Treatment of Mitral and Tricuspid Regurgitation – Ex-Vivo Beating Heart Study

Abstract

ABSTRACT Background: A longer-arm clip design for transcatheter edge-to-edge repair of mitral and tricuspid valves could be beneficial in treating complex valve pathologies. Its hemodynamic effects and usability are unknown. This study aims to assess its new design in an ex-vivo beating heart model. Methods: The long-arm clip was implanted in porcine left (n = 14) and right (n = 6) hearts with induced degenerative mitral regurgitation and functional tricuspid regurgitation, respectively. Hemodynamic conditions were assessed at baseline, pathology and post-treatment. Usability and grasping quality were evaluated during simulated treatment. Results: Mitral valve treatment significantly increased cardiac output (p < 0.001) and decreased mean left atrial pressure during ventricular systole (p = 0.001) with respect to pathological conditions. Tricuspid treatment with grasping involving septal leaflet significantly increased cardiac output (posterior-septal grasping: p = 0.006; anterior-septal grasping: p = 0.04). There was no significant increase of transvalvular gradient pressure nor tissue damage. Conclusion: Long-arm clip treatment was feasible in porcine hearts, it effectively reduced regurgitation and did not significantly increase the transvalvular pressure gradient. Abbreviations: MV, mitral valve; DMR, degenerative mitral regurgitation; FTR, functional tricuspid regurgitation; TV, tricuspid valve; XTR Clip, long-arm clip; P2, posterior middle scallop of mitral valve; MRF, mitral regurgitation fraction; A-P, medial grasping of anterior and posterior leaflets; A-S, medial grasping of anterior and septal leaflets; P-S, medial grasping of posterior and septal leaflets; COs, systemic cardiac output; COp, pulmonary cardiac output; AoP, mean aortic pressure; PAP, mean pulmonary artery pressure; LAP, mean left atrial pressure; LAPsyst, mean left atrial pressure during ventricular systole; Δpm, mean diastolic pressure gradient across mitral valve; Δpt, mean diastolic pressure gradient across tricuspid valve; APd, mid-systole mitral antero-posterior distance; CI, confidence interval