Hemodynamic implications of transcatheter tricuspid valve repair in HFpEF Patients - HERACLES-HFpEF

Abstract

Abstract Background Patients with severe tricuspid regurgitation (TR) and heart failure with preserved ejection fraction (HFpEF) have been suggested to respond favourably to transcatheter edge-to-edge tricuspid valve repair (TEER), but the mechanisms remain poorly understood. Purpose The aim of this study was to investigate the pathophysiological implications of TV-TEER in patient with HFpEF and severe TR. Methods This was a prospective interventional single arm trial that included 20 HFpEF patients with invasive evidence of increased filling pressures (i.e. left-ventricular enddiastolic pressure [LVEDP] >15 mmHg and preserved ejection fraction i.e. LVEF ≥50%) at a single centre. All patients received transthoracic echocardiography and cardiac magnetic resonance imaging (MRI) immediately before and 1-month after TV-TEER. During the TV-TEER procedure LV pressure-volume loops were recorded by using a conductance catheter (Figure 1A). The primary outcome was the periprocedural change in the ratio of LVEDP to left-ventricular end-diastolic volume (LVEDV) as surrogate for preload independent diastolic function. The secondary outcomes included single-beat estimated end-diastolic pressure volume-relationships (EDPVRs), and LV distending pressure (calculated as LVEDP-mean right atrial pressure) as well as changes at 1-month in LVEDV and right ventricular EDV (RVEDV) as surrogates for ventricular interdependence. Results Between 02/2021 to 12/2022 20 patients (median age 78, IQR 72 to 83 years, 65% ♀) were included in the prospective HERACLES-HFpEF trial. All patients successfully underwent TV-TEER with a median TR grade reduction of 2 (IQR 2 to 1) on a five-grade scaling. Despite a periprocedural increase in LVEDV (p<0.001), LVEDP remained stable after successful TV-TEER (p=0.12). This led to a significant reduction of the primary endpoint LVEDP/LVEDV (p=0.001, Figure 1B). Load independent diastolic function improved with a rightward shift of the EDPVR (Figure 1C). LV distending pressure increased implying stronger LV distension in the restricted pericardial space. At one-month follow-up MRI (available for 17 patients) LVEDV increased (∆ median +5 ml, p=0.017), while RVEDV decreased (∆ median -17 ml, p=0.031). Interestingly, there was a significant inverse correlation between the change of LVEDV and RVEDV, again implying more favourable LV to RV interaction (Figure 1C). Conclusion TV-TEER in HFpEF patients leads to an immediate periprocedural increase in LV volume at maintained filling pressures. The improved diastolic function is possibly attributable to a more favourable LV to RV interaction where RV volumes are reduced to allow for the LV to better distend in the limited pericardial space. TV-TEER might pose a potential therapy for a subgroup of HFpEF patients with severe TR, meriting validation in prospective endpoint driven clinical trials.Figure 1