Association between early changes of left atrial volume and right ventricular function after transcatheter edge-to-edge repair for mitral regurgitation
Authors: Bonelli A , Guasti S , De Sanctis G M , Spano' F M , Santambrogio G M , De Chiara B C , Belli O E , Musca F , Casadei F , Garascia A , Oreglia J A , Bruschi G , Oliva F G , Giannattasio C , Moreo A 
Published: June 2023

Abstract

Funding Acknowledgements
Type of funding sources: None.

Background
Transcatheter edge-to-edge repair (TEER) has recently become a therapeutic option for patients with severe mitral regurgitation (MR) who are unsuitable for surgery, in order to improve clinical outcomes. MR is a determinant of structural and functional changes of all cardiac chambers. The left atrium (LA) and the right ventricle (RV) play an important role in the pathogenesis of symptoms in patients affected by severe MR. Recent data suggests that reverse changes of left ventricle (LV), as well as LA and RV, are associated to reduced morbidity and mortality.

Purpose
The aim of the study is to test the association between changes of LAV and RV function early after TEER.

Methods
This is a retrospective study that enrolled patients with chronic functional severe MR, at high surgical risk, who underwent TEER between February 2015 and July 2022. We evaluated the changes of LA and RV function between baseline and before discharge and their relation with symptoms.

Results
A total of 52 patients were included (mean age 65.2 ± 10.2 years; 69% males, mean left ventricular ejection fraction [LVEF] 28.8 ± 5.7%). No differences of baseline clinical and echocardiographic characteristics were detected between the groups of patients who had LA volume (LAV) reduction (n = 31) and those who did not (n = 21), including symptoms assessed with New York Heart Association (NYHA) classification. However, the former group had a significant higher LA size (LAVI 76.6 ± 18.2 vs. 61.2 ± 17.6 mL/m2, p = 0.004). In the overall population, we observed a significant increase in tricuspid annular plane systolic excursion (TAPSE), S’ wave at Tissue Doppler and ratio between TAPSE and pulmonary artery systolic pressure (TAPSE/PASP), as well as a decrease of PASP (respectively, p = 0.034, p = 0.003, p &lt; 0.001 and p &lt; 0.001). Compared to patients who did not have LAV reduction, those who had showed a significant increase of TAPSE/PASP (from 0.40 ± 0.17 to 0.52 ± 0.21 mm/mmHg, p = 0.002), S’ wave (from 8.7 ± 1.6 to 9.4 ± 1.7 cm/s, p = 0.005) and a decrease of PASP (from 50.3 ± 14.3 to 38.9 ± 11.5 mmHg, p &lt; 0.001).
The absolute change of LAV from baseline to discharge was associated with the change of PASP (b coefficient 0.55, 95% confidence interval 0.09, 1.02, p = 0.022) and TAPSE/PASP (b coefficient −4.06, 95% confidence interval −7.78, −0.33, p = 0.033), even after adjustment for covariates (respectively, b coefficient 0.61, 95% confidence interval 0.07, 1.14, p = 0.027 and b coefficient −4.82, 95% confidence interval −9.43, −0.23, p = 0.040). Finally, NYHA class significantly improved in the group of patients whose LAV reduced (p = 0.011).

Conclusion
In this retrospective study, an association between early changes of LA structure and RV functional parameters has been described. After TEER, RV function improved, especially in patients who had LAV reduction. In the latter, we observed an improvement of NYHA functional class.