Transcatheter-edge-to-edge-repair of functional mitral regurgitation in advanced HFrEF: the impact of intrinsic left ventricular performance on the degree of MR reduction and clinical outcome

Abstract

Abstract Background Transcatheter-edge-to-edge-repair (TEER) of functional mitral regurgitation (FMR) reduces rehospitalisation and all-cause mortality in patients with HFrEF/HFmrEF. Not conclusively clarified is the interaction of pre-interventional intrinsic left ventricular (LV) function with TEER success and clinical outcome. By using the gold standard of LV contractility analysis, the invasive pressure-volume loop technique, we examined the interaction of pre-and post-interventional intrinsic LV performance with the degree of MR reduction and all-cause mortality after TEER in patients with advanced HFrEF. Methods In a prospective study of 71 patients with advanced HFrEF (median EF 26%, 22-31%) and severe FMR, we quantified different intrinsic parameters of LV performance by PV-loop analysis (single beat analysis) pre-and post-interventionally. Results In 83% of the patients a MR reduction to grad < 2 could be achieved (hospital discharge). In the ROC analysis, the best cut-off to separate medium-term survival from all-cause mortality (median FU 2.9 years) was a post-interventional regurgitation fraction (RF) < 20% (AUC 0.72, p<0.001, sensitivity 83%, specificity 60%) and a R-volume (RV) < 18ml (AUC 0,7, p=0.002, sensitivity 67%, specificity 72%). The PV-loop-derived intrinsic LV contractility (LV-endsystolic elastance, Ees), LV afterload (arterial elastance, Ea), LV-Ao-coupling (Ees/Ea), LV-mechanical efficacy (ME), PV-loop area (PVA), stroke work, Tau; end-diastolic elastance (Eed), LVEF, LVEDV, and LVESV, pre- and post-TEER, were not predictive for the extent of MR reduction acutely, after 6 months FU, and for all-cause mortality. In multivariate cox-regression analysis, only a post-interventional RF<20% (HR 0.36, p=0.017) or RV<18ml (HR 0.32, p=0.005) and the pre-interventional LV-contractile reserve (LV-CR: post-extra-systolic augmentation of LV-Ees) remained independent predictors of all-cause mortality. In a second model, we included the degree of LV-remodeling (LV-R: LVESV reduction from hospital discharge to 6 months) in the model. In addition to pre-interventional LV-CR, and RF<20%, the LV-R remains independent predictive for all-cause mortality. Conclusion In our peri-mitral-TEER LV-PV-loop study, only the extent of MR reduction and the pre-interventional LV-CR, but not the intrinsic LV performance at rest, determine the medium-term survival of patients with advanced HFrEF and FMR. TEER-mediated MR reduction itself seems not be determined by the LV performance.