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

Tricuspid transcatheter edge-to-edge repair is an established therapy for high-grade tricuspid regurgitation, but its acute impact on right ventricular (RV) mechanics remains incompletely understood. The aim of the study was to quantify the acute hemodynamic effects of tricuspid transcatheter edge-to-edge repair on RV function using invasive pressure-volume analysis.

Nine patients with severe tricuspid regurgitation (grades III-IV) underwent simultaneous invasive and echocardiographic assessment of RV function. A 7-electrode conductance catheter positioned in the RV continuously recorded pressure-volume signals, calibrated against 3-dimensional echocardiographic RV volumes. Steady-state RV pressure-volume loops and RV echocardiography were obtained before and after the procedure.

Tricuspid transcatheter edge-to-edge repair significantly reduced regurgitant volume. Forward stroke volume increased significantly (41 [34-48] versus 51 [43-57] mL, P=0.004), despite unchanged RV afterload and contractility (end-systolic elastance, 0.33 [0.24-0.53] versus 0.32 [0.25-0.72] mm Hg/mL, P=0.30). Stroke work was preserved. Preload decreased (RV end-diastolic volume, 145 [113-171] versus 131 [104-137] mL, P=0.01; RV end-diastolic pressure, 9 [6-11] versus 7 [4-9] mm Hg, P=0.03), reflecting substantial RV unloading.

Successful tricuspid transcatheter edge-to-edge repair 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, indicating an improved preload reserve.