Haese, C. E. | bioRxiv Science

bioRxiv2026

Transcatheter Edge-to-Edge Repair Increases Annular Forces in In Vitro Whole Heart Preparations

BackgroundTricuspid transcatheter edge-to-edge repair (TEER) can induce an acute annuloplasty effect. While this has a therapeutic benefit, the mechanisms driving the reduction in annular size remain unclear. ObjectivesWe quantify the annular force induced by TEER in vitro in whole porcine heart preparations. We explore the impact of clipping different leaflet pairs on the TEER-induced annular forces. MethodsWe performed 49 interventions in 13 porcine hearts using a MitraClip XT. The clip was implanted between either the anterior-septal (AS), anterior-posterior (AP), or posterior-septal (SP) leaflet pairs. We also considered two-clip interventions between the combination of the AS-AP, AS-PS, or AP-PS leaflet pairs. For each intervention, we measured the right ventricular pressure, transvalvular flow rate, and force at eight locations around the annulus. ResultsTEER induced significant inward-pulling forces on the annulus. The maximum force was induced following an AS-PS two-clip intervention. A single AS clip induced the largest force among the one-clip interventions. Furthermore, the AP and AS-AP interventions induced the smallest annular forces. ConclusionsThe magnitude of the TEER-induced force depends on the intervention and number of clips implanted.

bioengineering↗

bioRxiv2025

Understanding the Mechanisms Behind the Annuloplasty Effect in Tricuspid Valve TEER: A Computational Study

BackgroundAn annuloplasty effect has been observed following tricuspid transcatheter edge-to-edge repair (TEER) and has been shown to have a therapeutic benefit. However, the mechanisms underlying the annuloplasty effect remain unknown. ObjectivesWe investigate the impact of TEER-induced annular forces on the annuloplasty effect. Additionally, we explored the impact of clip size, clip orientation, leaflet pair, and leaflet site on TEER-induced annular forces. MethodsWe simulated 36 TEER repairs in finite element models of three human tricuspid valves. We used either a NTW or XTW TriClip. The clip was placed between either the anterior-septal or anterior-posterior leaflet pairs, in either the central or near-annulus site. For each scenario, we quantified the reduction in annular area, septal-lateral (SL) diameter, and anterior-posterior (AP) diameter. We also report the total annular force, orientation of maximum annular force, total papillary muscle force, leaflet stress, and coaptation area ratio following TEER. ResultsTEER induced annular forces, which strongly predicted the annuloplasty effect as measured by reduction in annular area and SL diameter. The maximum annular force aligned with the orientation of the clip. Furthermore, XTW clips induced more annular force and leaflet stress than NTW clips. A central anterior-posterior site induced more force than a near-annulus anterior-posterior site, but showed no difference from an anterior-septal pair. ConclusionsTEER procedural parameters, such as clip size and site, strongly influence the magnitude of induced annular forces, which, in turn, correlate with the degree of annuloplasty effect.

bioengineering↗