Acute Impact of Transcatheter Edge-to-Edge Repair of Tricuspid Regurgitation on Right Ventricular Hemodynamics

J.-C. Reil (Bad Oeynhausen)¹, P. Steendijk (2333 ZA)², V. Sequeira (Würzburg)³, J. Bormann (Bad Oeynhausen)¹, A. Klinke (Bad Oeynhausen)¹, G.-H. Reil (Oldenburg)⁴, K. Friedrichs (Bad Oeynhausen)⁵, V. Rudolph (Bad Oeynhausen)^1
1Herz- und Diabeteszentrum NRW Allgemeine und Interventionelle Kardiologie/Angiologie Bad Oeynhausen, Deutschland; ²LUMC Leiden 2333 ZA, Niederlande; ³Universitätsklinikum Würzburg Deutsches Zentrum für Herzinsuffizienz Würzburg, Deutschland; ⁴Klinikum Oldenburg AöR Klinik für Kardiologie Oldenburg, Deutschland; ⁵Herz- und Diabeteszentrum NRW Klinik für Kardiologie Bad Oeynhausen, Deutschland

Background: Tricuspid transcatheter edge-to-edge repair (T-TEER) is an established therapy for high-grade tricuspid regurgitation (TR), but its acute impact on right ventricular (RV) mechanics remains incompletely understood.

Objective: The aim of the study was to quantify the acute hemodynamic effects of T-TEER on right ventricle (RV) function using invasive pressure-volume analysis.

Methods: Nine patients with severe TR (grade III–IV) underwent simultaneous invasive and echocardiographic assessment of RV function. A 7-electrode conductance catheter positioned in the RV continuously recorded pressure-volume (PV) signals, calibrated against 3D echocardiographic RV volumes. Steady-state RV PV loops and RV echocardiography were obtained pre- and post-procedure. Hemodynamic indices included: RV end-diastolic volume (RVEDV) and end-diastolic pressure (RVEDP) as preload markers; end-systolic elastance (Ees) as contractility; stroke work (SW) and pressure–volume area (PVA) as measures of external and total mechanical energy; and forward stroke volume derived as effective output excluding regurgitant flow.

Results: T-TEER significantly reduced regurgitant volume (16 [11–26] vs. 9 [4–13] mL, p=0.004). Forward stroke volume increased significantly (41 [34–48] vs. 51 [43–57] ml, p=0.004), despite unchanged RV afterload and contractility (Ees 0.33 [0.24–0.53] vs. 0.32 [0.25–0.72] mmHg/mL, p=0.30). Stroke work and pressure–volume area were preserved, indicating stable myocardial energy expenditure. Preload decreased (EDV 145 [113–171] vs. 131 [104–137] mL, p=0.01; RVEDP 9 [6–11] vs. 7 [4–9] mmHg, p=0.03), reflecting substantial RV unloading. Conventional echocardiographic indices (TAPSE, RV strain) declined post-procedure, whereas echo-derived dP/dt_max and dP/dt_max/RVSP matched well with invasive contractility data.

Conclusion: Successful T-TEER is accompanied by economization of myocardial work through redirection of blood flow into the pulmonary circulation. Forward stroke volume increased while contractility and stroke work remained unchanged. Preload was significantly reduced, both in terms of volume and pressure, indicating an improved preload reserve. This enhanced reserve facilitates utilization of the Frank–Starling mechanism under stress conditions and helps explaining the improved clinical status observed after successful T-TEER.