Right atrial dynamics in patients with tricuspid regurgitation undergoing intervention

Abstract Background Tricuspid regurgitation (TR) is a rising healthcare issue, affecting over 1.6 million people in the US alone. Severe or worse TR is associated with poor clinical outcomes. Transcatheter tricuspid intervention (TTVI) has revolutionized the approach to patients with TR, showing significant improvement in quality of life and symptomatic status. However, TTVI efficacy seems to differ based on the specific TR phenotype, whereby right ventricular (RV) and right atrial (RA) geometry and function play a major role in modifying response to therapy. Although evidence on RV function is increasingly available, very little is known about RA dynamics in this setting. Purpose This study aims to assess RA function and remodelling in patients undergoing different types of TTVI for the treatment of severe TR. Methods A retrospective analysis was conducted on transthoracic ultrasounds (TTE) of 82 patients who underwent different types of TTVI between May 2019 and October 2024. TTE assessments were conducted at baseline (within 30-days prior to intervention), and within 30-days post-intervention. Focus of this analysis was on RA dynamics, which was assessed by means of RA conduit, contraction and reservoir strain, and remodelling, stratified according to the type of interventions as well as baseline TR grade. Results Of the 82 included patients, 41 received annuloplasty and 41 underwent transcatheter edge-to-edge repair (T-TEER). Mean age was 81 years, 51.2% of patients were female and 93% had a previous diagnosis of atrial fibrillation. RA conduit strain significantly increased following intervention, and even more so in patients starting with worse TR grade (Mean ± Standard Deviation – SD; -9.30 ± 5.05 vs -7.06 ± 5.13, p = 0.014; Figure, Panels A and D). Although RA reservoir showed overall no significant change, it did correlate with TR severity, with higher TR grades exhibiting greater improvements, independently of the intervention type (11.9 ± 5.75 vs 10.39 ± 7.02, p = 0.1; Figure, Panels B and E). The absolute change in RA contraction strain was not significant (Figure, Panels C and F). Additionally, TTVI was associated with a significant reduction in RA volume (125.82 ± 65.64 vs 113.67 ± 50.39, p 0.005). Conclusions The increase in RA conduit strain post-TTVI represents the reduction in RV filling pressures derived from the abolition of the regurgitation. The decrease in RA volume coupled with an improvement in RA reservoir strain, specifically in higher TR grade patients, indicate both RA structural and functional improvements. These findings highlight RA strain as a potential key parameter for assessing both procedural success and post-intervention RA functional recovery.