Changes in Biventricular Cardiac Mechanics After Transcatheter Edge-to-Edge Repair for Severe Tricuspid Regurgitation

Transcatheter edge-to-edge repair (TEER) is an established therapy for severe tricuspid regurgitation (TR). Invasive pressure-volume (PV) analysis is the gold standard for characterizing ventricular function and ventricular-vascular interactions. The effects of tricuspid TEER on biventricular PV relationships are unknown.

The authors aimed to assess postprocedural changes in right (RV) and left ventricular (LV: 1) end-systolic and end-diastolic pressures and volumes; 2) ventricular-arterial coupling, expressed as end-systolic elastance (E_es) to effective arterial elastance (E_a) ratio; and 3) metabolic demand, represented by PV area (PVA).

We used a conductance catheter to determine RV and LV PV relationships before and after tricuspid TEER. Pre- and postprocedural changes in cardiac mechanics were compared using the paired-samples t-test or Wilcoxon signed rank test.

Among the twenty-two patients (mean age 80 ± 6 years, 46% female, median LV ejection fraction of 52 [IQR 44-55]%) with severe TR, tricuspid TEER resulted in significant TR reduction and lower RV volumes (end-diastolic volume from 114.8 ± 32.2 to 102.0 ± 26.8 mL, P < 0.001). RV afterload increased (E_a: 0.55 [0.47-0.81] mm Hg/mL to 0.85 [0.65-1.27] mm Hg/mL, P < 0.001) as did RV contractility (E_es: from 0.46 [0.33-1.06] to 0.82 [0.55-2.07] mm Hg/mL, P < 0.001), with a stable RV E_es/E_a, preserved stroke volume, RV end-diastolic pressure, PVA, and stroke work-to-PVA ratio. LV end-diastolic volume increased, (108.0 ± 31.8-114.0 ± 32.2 mL, P < 0.001), whereas LV pressures, contractility, E_es/E_a, PVA, and stroke work-to-PVA remained unchanged.

TR reduction with tricuspid TEER generated immediate RV volume unloading, increased RV afterload, and enhanced RV contractility, maintaining forward stroke volume and increasing LV preload.