Role of the mitral valve in left ventricular assist device pathophysiology

Abstract

Functional mitral regurgitation (MR) in the setting of heart failure results from progressive dilatation of the left ventricle (LV) and mitral annulus. This leads to leaflet tethering with posterior displacement. Contrary to common assumptions, MR often does not resolve with LVAD decompression of the LV alone. The negative impact of significant (moderate-severe) mitral regurgitation in the LVAD setting is becoming better recognized in terms of its harmful effect on right heart function, pulmonary vascular resistance and hospital readmissions. However, controversies remain regarding the threshold for intervention and management. At present, there are no consensus indications for the repair of significant mitral regurgitation at the time of LVAD implantation due to the conflicting data regarding potential adverse effects of MR on clinical outcomes. In this review, we summarize the current understanding of MR pathophysiology in patients supported with LVAD and potential future management strategies.

Concomitant triple-valve repair with durable left ventricular assist device implantation in severe right ventricle dysfunction

“…Competent valves that promote unidirectional blood flow will reduce upstream pressure transmission and promote native cardiac ejection in parallel to LVAD output. 2 …”

“… 1 Recently, significant mitral regurgitation (MR) after LVAD implant has been shown to raise pulmonary pressures and worsen right ventricle (RV) function. 2 It is controversial whether tricuspid regurgitation (TR) is simply a marker of RV dysfunction or has an influence on RV output. 3 Therefore, concomitant valvular repair may maximize the benefits of mechanical support.…”

“…Comprehensive valve optimization ( Figure 1 ) can reduce hospital readmissions, improve symptoms, and benefit survival. 1 , 2

Figure 1 Illustration of aortic, mitral, and tricuspid valve repair in the setting of left ventricular assist device implantation.

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Left ventricular assist device implantation and concomitant mitral valve surgery: A systematic review and meta‐analysis

“…In CF‐LVAD recipients, etiology of MR is commonly functional secondary to left ventricular remodeling resulting in dilatation of the mitral annulus and disruption to leaflet coaptation 7 . Following CF‐LVAD implantation and resultant left ventricular unloading, mitral valve (MV) morphology is typically restored such that residual MR is no longer significant 8 .…”

“…6 In CF-LVAD recipients, etiology of MR is commonly functional secondary to left ventricular remodeling resulting in dilatation of the mitral annulus and disruption to leaflet coaptation. 7 Following CF-LVAD implantation and resultant left ventricular unloading, mitral valve (MV) morphology is typically restored such that residual MR is no longer significant. 8 Furthermore, surgically intervening upon left-sided valvular pathology during CF-LVAD implantation has been associated with worse postoperative outcomes, 9 enhanced surgical complexity, and increased time spent upon cardiopulmonary bypass.…”