Echocardiographic Outcomes Following Left Ventricular Assist Device or Mitral Valve Repair in Severe Left Ventricular Dilatation with Mitral Regurgitation

Abstract

Purpose Mitral regurgitation (MR) is a predictor of poor outcomes in patients with severe left ventricular dysfunction (LV) and options for repairing the valve have yielded conflicting results. We compared one-year echocardiographic and clinical outcomes of patients with grade 3-4MR and severe LV dilatation (end-diastolic dimension [LVEDD] above 65mm) undergoing either left ventricular assist device (LVAD) insertion alone or mitral valve repair (surgical minimally invasive repair or transcatheter edge-to-edge repair). Methods This is a single-center, retrospective, observational cohort study of patients with grade 3-4MR and severe LV dilatation who underwent either LVAD or MVR between 2008-2018. Baseline and post-operative transthoracic echocardiograms were analysed for LV-ejection fraction (EF), LV EDD and MR. Functional class, re-hospitalisation, cardiovascular morbidity and mortality was obtained. Results Fifty-two patients (27 LVAD; 25 MVR; 44 men) with grade 3-4MR and pre-existing LV systolic dysfunction (47 [90%] NYHA class III-IV) underwent either LVAD or MVR. There was no significant between group difference in NYHA class, however LVAD patients were younger (49±14 vs 60±17years; P=0.01) with lower LVEF baseline (21±7% vs 29±12%, P=0.01). MVR patients had more severe pre-operative MR (P=0.01). Less than 2+ (mild-moderate) MR was achieved in 84% of LVAD patients with a reduction in LVEDD (Pre-76±7mm/68±8mm; Post- 69mm±11mm/62±12mm; P=0.01). Less than 2+ MR was achieved in 77% of MVR patients with a corresponding reduction in LVEDD (Pre- 71±7mm/53±12mm; Post- 68mm±8mm/51±11mm;P=0.01). 82% of LVAD patients (P=0.01) and 100% of MVR patients (P=0.01) reported mild or no symptoms at 12-month follow-up. There was no significant difference between groups in re-hospitalisation rates, and all cause cardiovascular morbidity and mortality at one year (P=0.29). Conclusion Patients undergoing isolated LVAD insertion have an improvement in MR severity comparable to patients with end-stage MR undergoing MVR. Unloading of the LV by LVAD with consequent reduction in left ventricular end-diastolic and end-systolic dimensions is associated with a significant improvement in MR. This may explain the lack of additional benefit of MVR in LVAD patients shown in large registries.