Prognostic Impact of Functional Mitral Regurgitation at the Time of Left Ventricular Assist Device Implantation

Abstract

Due to LV remodeling functional mitral regurgitation (FMR) is a common feature of heart failure resulting in an impaired outcome. Nevertheless, the prognostic impact of uncorrected FMR at the time of LVAD implantation remains controversial. Between 2015 and 2018 77 consecutive patients underwent continuous-flow LVAD implantation at our institution. According to preoperative TTE 34 patients (44.2%) showed moderate to severe MR (MR-group), whereas 43 patients (55.8%) showed less than moderate MR (less-MR-group). Baseline and follow-up data were retrospectively analyzed. Primary endpoints were death, stroke, pump-thrombosis, major bleeding and right heart failure (RHF) after 1 year. Predominantly male patients (84.4%) with a mean age of 54 years were mainly treated with the Medtronic HVAD device (95%). Baseline characteristics and the severity of LV and RV dysfunction (LVEF 20%, TAPSE 15mm in MR-group vs. LVEF 21%, TAPSE 15mm in less-MR-group) were comparable between both study groups. There were no differences regarding the surgical access (predominantly full sternotomy 79.2%) and concomitant aortic valve replacement procedures (14.7% in MR-group vs. 13.9% in less-MR-group; p=0.93). Tricuspid valve repair (12% in MR-group vs. 0% in less-MR-group; p=0.02) and the implantation of a temporary RVAD was more frequent in the MR-group (35% in MR-group vs. 21% in less-MR-group; p=0.16). Postoperative RHF within the first postoperative year occurred more frequently in the MR-group (12/43 35,3% vs. 5/43 11,6%; p=0.01). The overall survival during follow up (24.9 months) was 52.9% (n=18) in the MR-group vs. 51.2 % (n=22) in the less-MR-group (p=0.63), whereas one-year event-free survival was 35.3% in the MR-group compared to 44.2% in the less-MR-group (p=0.43). 12 months after LVAD implantation 22% of patients in the less-MR-group were classified as NYHA III in comparison to 71% of patients in the MR-group (p<0.001). 12 months after LVAD implantation MR>1 was shown in 33.3% of patients in the MR-group in comparison to 7.4% in the less-MR-group (p=0.02). Preoperative uncorrected FMR at the time of LVAD implantation did not affect overall survival, although it was associated with increased rates of temporary RVAD implantation as well as postoperative RHF; furthermore, it was associated with higher postoperative NYHA class.