16 Early differences in the right ventricular size and function after transcatheter therapies of tricuspid regurgitation; a meta-analysis

Introduction Transcatheter Tricuspid valve replacement (TTVR) and Edge-to-edge repair (T-TEER) are novel treatment options for the management of right-sided heart failure in patients with severe and torrential tricuspid valve regurgitation (TR). The effects of these treatment modalities on cardiac function are not fully defined. In this meta-analysis, we aimed to study the impact of the different transcatheter therapies on the right ventricular (RV) size and function. Methods We ran a systematic review on three different databases (Pubmed Central, EMBASE and Google Scholar) following the PRISMA protocol and using various combinations of the search words (tricuspid, transcatheter, replacement, repair, edge to edge, TTVR and TEER). We included studies and case series that were published in English and reported the 30-day outcomes post TTVR and/or T-TEER. We utilised the RV fractional area change (FAC) percentage and tricuspid annulus peak systolic excursion (TAPSE) to indicate the RV function. We used the RV basal diameter as a surrogate for the RV size. We ran a random model meta-analysis using SPSS 28.0 software and assessed the studies' heterogeneity using the I2 test. We used the Cohen's d test to determine the effect size of the included studies. Results Two single-arm prospective studies and one case series met our inclusion criteria for the TTVR study (number of patients=82).¹–³ The mean of the RV basal diameter improved by 7.48 mm (95% CI 5.92–9.02 mm, P<0.0001). The effect size of TTVR on RV basal diameter was large (d=-1.18, 95%CI -2.18 to -0.18, P=0.02). Nonetheless, there was a significant reduction in the mean TAPSE of 2.4 mm (95% CI 1.5–3.3 mm, P<0.0001) and mean FAC of 7.77% (95% CI 5.37–10.16%, P<0.0001) after TTVR. The meta-analysis showed a medium effect of TTVR on TAPSE (d=- 0.61, 95% CI -0.92 to -0.3, P<0.05) and a large effect on FAC (d= -1.21, 95% CI -1.55 to -0.88, P<0.05). (Figure 1) Two single-arm prospective studies met our inclusion criteria for the T-TEER study (number of patients= 420) [4,5]. The was a non-significant reduction in the TAPSE post T-TEER of 0.55 mm (95%CI -0.05–1.15 mm, P=0.07). The effect of T-TEER on TAPSE was non-significant (d=- 0.04, 95% CI -0.16 to 0.09, P=0.56). (Figure 2). There was no significant heterogeneity in the TTVR and T-TEER studies. Lurz et al.[5] reported a significant reduction in the mean RV end-diastolic diameter post T-TEER of 3.5 mm (P<0.0001) with a non-significant decrease in the mean RV FAC of 0.5% (P=0.59). We could not find other studies reporting these variables to run a meta-analysis. We propose that the worse RV function after TTVR than T-TEER is caused by the greater preload mismatch in cases that underwent TTVR. TTVR can significantly reduce TR severity, causing a more substantial preload mismatch compared to T-TEER [6]. Conclusion Despite the reduction in RV size by both TTVR and T-TEER, TTVR was associated with a more significant early reduction in the standard measurements of RV function than T-TEER at 30 days. Such difference between the two techniques could be secondary to the characteristics of the procedure or the characteristics of the studied population. Further prospective randomised controlled trials are needed better to study both procedures' impact on the RV function. References Kodali S, Hahn RT, George I, et al. Transfemoral tricuspid valve replacement in patients with tricuspid regurgitation: TRISCEND study 30-day results. JACC Cardiovasc Interv. 2022;15:471–80. 10.1016/J.JCIN.2022.01.016 Fam NP, von Bardeleben RS, Hensey M, et al. Transfemoral transcatheter tricuspid valve replacement with the EVOQUE system: a multicenter, observational, first-in-human experience. JACC Cardiovasc Interv. 2021;14:501–11. 10.1016/J.JCIN.2020.11.045 Hahn RT, George I, Kodali SK, et al. Early single-site experience with transcatheter tricuspid valve replacement. JACC Cardiovasc Imaging 2019;12:416–29. 10. Conflict of Interest None