Right ventricular pressure–strain–volume loop–derived myocardial work as a marker of contractility before and after transcatheter tricuspid valve intervention

Background Comprehensive assessment of right ventricular (RV) function is pivotal in patients with severe tricuspid regurgitation (TR) undergoing tricuspid transcatheter edge-to-edge repair (T-TEER). However, conventional echocardiographic parameters, including three-dimensional echocardiography (3DE) and speckle-tracking-derived markers, are inherently load-dependent and may not adequately reflect RV contractile reserve, particularly under the markedly altered loading conditions associated with severe TR and following T-TEER. Pressure-strain-volume (PSV) loop-derived myocardial work integrates preload, afterload, and chamber geometry within a unified hemodynamic framework and, therefore, may better reflect load-independent indices of RV contractility. Aims Accordingly, we aimed to determine whether RV PSV loop–derived myocardial work correlates with pressure-volume (PV) loop indices of contractility, and to assess acute changes in RV mechanics in patients undergoing T-TEER. Methods In 50 patients undergoing T-TEER, RV pressure waveforms were acquired intraprocedurally, immediately before and after device implantation, with simultaneous 3DE for RV volumes, to generate RV PV loops and to derive end-systolic elastance (Ees). Conventional echocardiographic metrics, such as tricuspid annular plane systolic excursion (TAPSE) and ejection fraction (EF), were also obtained. Then, to obtain RV pressure-strain (PS) loops and global myocardial constructive work (GCW), RV pressure and 3DE-derived RV longitudinal strain tracings were combined. We further adjusted GCW to instantaneous RV volumes (GCWv) and constructed PSV loops. (Figure) Results Among the 50 patients with severe TR, T-TEER resulted in significantly lower RV volumes (end-diastolic volume from 183±59 to 143±51 mL, p<0.001), RV EF (from 48±10 to 36±10%, p<0.001, and TAPSE (from 18±4 to 16±5 mm, p=0.002). Conversely, RV contractility derived from PV loop analysis significantly increased after the procedure (Ees: from 0.38 [0.29-0.47] to 0.46 [0.36-0.55] mmHg/mL, p=0.008). While PS loop-derived GCW (from 615 [439-881] to 549 [394-756] mmHg%, p=0.007) showed significantly lower values after T-TEER, values of PSV loop-derived volume-adjusted GCWv (from 180 [106-275] to 180 [92-256] mmHg%/mL, p=0.295) remained similar after the procedure. Importantly, although TAPSE (r=0.21, p=0.049), RVEF (r=0.29, p=0.004), and GCW (r=0.37, p<0.001) correlated modestly with Ees, volume-adjusted GCWv (r=0.62, p<0.001) showed a stronger correlation with RV contractility. Conclusions In the setting of acute RV unloading following successful T-TEER, pressure-volume loop-derived Ees demonstrated improved contractility. Using our novel PSV loop approach, volume-adjusted global constructive work showed a stronger association with contractility and more accurately captured intrinsic RV mechanics than conventional, load-dependent echocardiographic indices.