Persistent mitral regurgitation after left ventricular assist device: a clinical conundrum

Abstract

Aims Persistent mitral valve regurgitation (MR) after continuous flow left ventricular assist device implantation (cfLVAD) is associated with pulmonary hypertension and right ventricular failure with variable effects on survival across published studies. The aim of this study is to determine the incidence and predictors of persistent MR at 6-month follow-up after cfLVAD implantation and its impact on survival, haemodynamics, right ventricular function, and morbidity. Methods and results We performed a retrospective review of all adult cfLVAD recipients from January 2012 to June 2017 at a single tertiary university hospital with follow-up until April 2019. Primary outcome was to compare survival between patients with no-to-mild compared with persistent moderate-to-severe MR at 6 months. Secondary outcomes included right heart failure (RHF), length of stay, re-hospitalizations, and composite of death, transplant, and pump exchange during the length of follow-up. Final analytic sample was 111 patients. The incidence of persistent moderate or severe MR at 6 months was 26%. Significant predictors of persistent MR at 6 months were left atrium dimension and volume. The group with persistent moderate-to-severe MR at 6 months had higher incidence of RHF at 6 months (45% vs. 25%, P = 0.04). There was no difference in survival at 1 year between the groups (no-to-mild MR 85.5%, moderate-to-severe MR 87.9%, Wilcoxon P-value = 0.63). There was no difference in re-hospitalizations, length of stay, composite of death, transplant, or pump exchange during the length of follow-up between the comparison groups. Conclusions Persistent moderate-to-severe MR after cfLVAD implantation is present in one fourth of patients and is associated with increased incidence of RHF, higher mean pulmonary pressure, and pulmonary capillary wedge pressure with no effect on 1 year survival. Increased left atrium size was associated with persistent moderate-to-severe MR at 6 months.

Role of the mitral valve in left ventricular assist device pathophysiology

“…These patients are more likely to have persistent MR after LVAD implant due to persistent mitral annular dilatation and poor leaflet coaptation. This is consistent with findings by our group and others that larger LV dimensions represent a more advanced stage of heart failure that is associated with persistent residual MR after LVAD ( 30 , 97 ). Since severe MR resolves without intervention in about 62–80% of patients, using biomarkers (e.g., inflammation) to identify those likely to have SMR and would benefit from concomitant mitral valve repair can help avoid unnecessary surgical interventions with inherent risks ( 20 , 98 ).…”

Tricuspid surgery at the time of LVAD implant: A critique

“…There are strong theoretical arguments for the surgical correction of TR, but the physiological studies upon which the intervention is premised also demonstrate the over-riding importance of preload and afterload in determining RV stroke volume and ventricular performance. Nearly one fourth of our patients have moderate to severe MR after isolated cfLVAD and this persistent RV afterload is associated with an increased incidence of right heart failure (RAP > 14 mmHg, cardiac index <2.2 L/min/m 2 , and need for inotropic support at 6 months), higher mean pulmonary artery pressures, and elevated pulmonary capillary wedge pressure ( 24 ). There were no differences in LVAD parameters between the MR severity groups and significant residual MR did not predict functional TR after isolated LVAD despite the MR severity dependent association with progressive RV dysfunction.…”

Prognostic value of mitral regurgitation in patients undergoing left ventricular assist device deployment: A systematic review and meta‐analysis

“…Of these, 340 relevant articles were read in full and assessed according to our inclusion and exclusion criteria. Following critical appraisal, a total of 19 studies [7][8][9][11][12][13][14][15][16][17][18][19][20][21][22][23][24][25][26] incorporating a total of 11 873 patients were included. The studies described outcomes of patients undergoing LVAD implantation with either MR grade 0-I (8819 patients) or II-III (3096 patients).…”