Persistent Functional Mitral Regurgitation 1 Year after Left Ventricular Assist Device Implantation: Prognostic Impact and Preoperative Echocardiographic Features

Objectives: Functional mitral regurgitation (FMR) is a common feature of cardiac remodeling in advanced heart failure. Despite mechanical unloading after left ventricular assist device (LVAD) implantation, uncorrected FMR persists in up to 30% of LVAD recipients. Nevertheless, preoperative echocardiographic features resulting in persistent MR after LVAD implantation and its prognostic impact remain unknown.

Methods: A total of 94 consecutive patients underwent continuous-flow LVAD implantation at our institution between 2015 and 2019, whereof 47 patients showed moderate to severe FMR prior to LVAD implantation. One year after LVAD implantation, 10 patients showed persistent MR (MR group), in contrast to 23 patients with less than moderate MR (Control group). Apart from clinical baseline and follow-up parameters, preoperative echocardiographic features, functional exercise capacity 1 year after LVAD implantation and overall survival rates were retrospectively analyzed.

Result: Predominantly male patients with a mean age of 53 years were mainly treated with the Medtronic HVAD device (76%). Baseline characteristics including the severity of LV and RV dysfunction (LVEF: 19%, TAPSE: 14 mm MR group vs. LVEF: 19%, TAPSE: 16 mm Control group) were comparable between both the study groups. There was no difference regarding preoperative LV dilatation (LVEDD 78 mm vs. LVEDD 75 mm; p = 0.67). We found significantly increased parameters of mitral leaflet-tethering prior to LVAD implantation within the MR group (tenting height: 11.5 vs. 7.5 mm; p = 0.03; tenting area: 244 vs. 178 mm²; p = 0.04). Tethering of the anterior mitral leaflet was particularly increased in the MR group (tethering angle: 35.6 vs. 28.2 degrees; p = 0.02). Twelve months after LVAD implantation, patients within the MR group showed a significantly reduced exercise capacity (6-minute walk test: 293 vs. 439 m; p = 0.04). Additionally, a significant reduction of natriuretic peptide could only be shown in patients without persistent MR. Overall survival was significantly impaired in the MR group in comparison to the Control group (40 vs. 91%; p = 0.002).

Conclusion: LVAD recipients with persistent MR despite mechanical unloading showed significant echocardiographic signs of mitral leaflet tethering prior to LVAD implantation. Furthermore, persistent MR 12 months after LVAD implantation was associated with a reduced exercise capacity and an impaired overall survival. If correction of preoperative MR improves post implant survival needs to be shown in future studies.

Publication History

Article published online:
19 February 2021