Right ventricular reverse remodelling and pulmonary pressure changes post-TTVR for tricuspid regurgitation

Introduction

Transcatheter Tricuspid Valve Replacement (TTVR) is a minimally invasive treatment for severe tricuspid regurgitation (TR). While significant improvement in quality-of-life post-intervention has been demonstrated, the post-procedural changes in right ventricular (RV) morphology and physiology are poorly understood.

Purpose

To determine RV morphological changes post-intervention and their association with changes in cardiac function and pulmonary pressures. Secondary aim was to explore associations between changes in the latter 2.

Methods

This is a single-centre observational analysis of patients who underwent TTVR for symptomatic ≥ severe TR at a specialist referral centre from June 2024 to September 2025. Routine 2-dimensional transthoracic echocardiography (TTE) at timepoints: pre-procedure, <48hrs, 1-3 and 5-9 months was used. Associations in TTE-measured RV size, function, PASP and cardiac output (CO) were analysed using univariate Pearson’s or Kendall’s Tau correlation coefficient as appropriate, and temporal changes in parameters with paired t-tests.

Results

19 patients underwent TTVR: 12 (63%) female, mean age 82 years (IQR 79-84). Pre-intervention, 26% had severe, 26% massive and 47% torrential TR. Post-intervention all patients had ≤mild-moderate TR, with 100% procedural success and no conversion to surgery.

Significant RV reverse remodelling was seen by 5-9 months (Fig. 1). Decrease in RV base diameter trended towards significance at 1-3 months (p=0.114). RV mid diameter significantly declined from baseline by 5-9 months (p=0.002). Similarly, a significant decline in RV end diastolic area (EDA) at 1–3 months was seen (p=0.036). RV end systolic area (ESA) increased significantly at 1-3 months (p=0.034), later decreasing; however, baseline to 5-9 months slightly increased without significance (p=0.143). RV length shows similar trends.

A significant decline in RV function was seen by 5-9 months: TAPSE (p<0.001), RV S’ (p=0.005), FAC (p<0.001) and global RV function (p=0.005). Forward CO significantly increased from baseline (p=0.023). PASP saw a significant decline (p=0.05).

Baseline PASP and RV-PA coupling (TAPSE/PASP) correlated with early RV reverse remodelling at 1-3 months (Tables 1 and 2), but not at 5-9 months. Curiously, there was no clear relationship between measures of RV function and output, and between RV output and RV-PA coupling.

Conclusion

This study shows significant changes in RV structure and function, forward CO and PASP post-TTVR. The changes in RV morphology, especially RV ESA and length, along with the corresponding changes in RV function, forward output and PASP, suggest two phases of reverse remodelling: initial unloading of the RV overload, followed by a later phase – perhaps myocardial muscle fibre shortening. A continuous decline in metrics of RV function was observed, while forward CO increased. Baseline PASP correlated with the extent of early reverse remodelling.For image description, please refer to the figure legend and surrounding text.For image description, please refer to the figure legend and surrounding text.