Experimental Investigation of the Effect of a MitraClip on Left Ventricular Flow Dynamics.

Abstract

Purpose: The MitraClip device has emerged as an effective treatment option for patients with mitral regurgitation. However, implementing a MitraClip alters the mitral valve structure and left ventricular flow dynamics. In this study, we experimentally investigate the effects of the MitraClip and the resulting twin pulsed jets on flow dynamics within the left ventricle.

Methods: A custom-made left heart pulse duplicator was utilized, considering three different configurations: (1) a healthy mitral valve; (2) a regurgitant mitral valve; and (3) a repaired mitral valve with a MitraClip device. The flow field within the left ventricle was examined using time-resolved particle image velocimetry across different planes. Of particular interest was the analysis of flow structures, viscous energy dissipation and the accumulation of viscous shear stresses in the left ventricle.

Results: The results indicate that mitral valve regurgitation increases both viscous energy dissipation and the accumulation of viscous shear stresses in the left ventricle along with a 45% increase in peak velocity compared to the case with a normal mitral valve. Moreover, while mitral valve repair with a MitraClip alters the flow dynamics in the left ventricle, generating twin pulsed jets, it effectively reduces viscous energy dissipation (by 25 and 36% in the lateral and side planes, respectively) and shear stress accumulation compared to the regurgitant valve. However, these improvements do not fully restore the levels observed in a healthy mitral valve.

Conclusion: MitraClip mitigates the adverse effects of mitral regurgitation by restoring key hemodynamic parameters closer to healthy levels, highlighting its potential as a promising treatment.