Longitudinal changes in right ventricular mechanics after tricuspid transcatheter edge-to-edge repair

Background Severe tricuspid regurgitation (TR) causes chronic right ventricular (RV) volume overload, increased myocardial work, impaired RV-pulmonary arterial (RVPA) coupling, and progressive RV dysfunction. Tricuspid transcatheter edge-to-edge repair (T-TEER) acutely reduces RV volume loading, followed by longer-term ventricular remodelling. Right ventricular pressure-volume (PV) loop analysis characterises these changes in RV mechanics. Aims To characterise longitudinal changes in RV mechanics over 12 months following T-TEER using PV loop analysis. Methods RV pressure and volume waveforms were integrated to construct PV loops at baseline, post-T-TEER, and at 12-month follow-up. Stroke work (SW), potential energy (PE; wasted work), and pressure-volume area (total mechanical work (TW) and surrogate of myocardial oxygen demand) were quantified. End systolic elastance (Ees) as a measure of RV contractility, effective arterial elastance (Ea), as a measure of afterload and RVPA coupling (Ees/Ea) were derived. Longitudinal analyses were performed in patients with complete 12-month follow-up, with paired comparisons performed between baseline and post-procedure, and post-procedure and 12 months. Results Thirty-three patients had complete 12-month follow-up. Compared with baseline, T-TEER was associated with a significant immediate reduction in right ventricular myocardial work, with decreases in SW (-443 ± 260 mmHg·mL, p <0.001) and total mechanical work (-693 ± 491 mmHg·mL, p < 0.001). RVPA coupling decreased significantly early after intervention (0.91 ± 0.36 vs 0.62 ± 0.28; p < 0.001), while RV contractility increased (Ees: +0.07 ± 0.08 mmHg/mL, p <0.001). From post-procedure to 12 months, further reductions in myocardial work were observed. SW continued to decline (-169 ± 168 mmHg·mL, p = 0.04), as did total work (-439 ± 286 mmHg·mL, p = 0.012). RVPA coupling was stable over time (RVPAc: 0.62 ± 0.28 post-procedure vs 0.62 ± 0.26 at 12 months; p = 0.94), and RV contractility also remained stable (Ees: -0.03 ± 0.12 mmHg/mL, p = 0.37). Conclusion T-TEER produces sustained improvements in RV mechanical efficiency, with early unloading followed by longer-term remodelling reflected in PV loop-derived metrics. Pressure-volume analysis provides mechanistic insight into RV adaptation after T-TEER and may offer a valuable framework for assessing therapeutic response.