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

Objectives: 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.

Methods: 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. Secondary endpoints were TTE parameters and NYHA class.

Results: 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 15 mm in MR-group vs. LVEF 21%, TAPSE 15 mm 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 (12/34 = 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 1-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). Twelve 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).

Conclusion: 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.