Association of right ventricular mechanics with the severity of tricuspid regurgitation and mortality in patients with left-sided cardiac diseases: a propensity score-matched 3D echocardiography study
Authors: Fabian A , Ferencz A , Tolvaj M , Lakatos B K , Tokodi M , Ladanyi Z S , Shiida K , Ujvari A , Demenyi B , Veres B , Schwertner W , Assabiny A , Kosztin A , Merkely B , Kovacs A 
Published: June 2023

Abstract

Funding Acknowledgements
Type of funding sources: Public grant(s) – National budget only. Main funding source(s): Supported by the ÚNKP-22-3-II New National Excellence Program of the Ministry for Culture and Innovation from the source of the National Research, Development and Innovation Fund.

Introduction
The development of secondary tricuspid regurgitation (TR) is associated with poor outcomes in patients with left-sided cardiac diseases. Data are scarce concerning the right ventricular (RV) morphological and functional remodeling in patients with left-sided heart diseases in relation to the severity of TR.

Purpose
Accordingly, we aimed to characterize RV remodeling in patients with left-sided cardiac diseases with and without significant TR using three-dimensional (3D) echocardiography.

Methods
We retrospectively identified 357 patients with a wide variety of left-sided cardiac diseases and we graded TR severity according to current guidelines. To account for the heterogeneity of our cohort, we performed propensity-score matching using relevant clinical variables (age, sex, etiology of left-sided cardiac disease, left [LV] and right ventricular [RV] ejection fraction [EF]), and then we compared 134 patients with significant TR (sTR) with a matched cohort of 134 patients without significant TR (nsTR) (Figure 1). All patients underwent clinically indicated 3D transthoracic echocardiography, and 3D EFs were measured. To characterize RV mechanical patterns, the ReVISION method was used to quantify the contribution of the longitudinal (LEF), radial (REF), and anteroposterior (AEF) motion components to total RV EF. The primary endpoint was all-cause mortality, and patients were followed up for a median of 39 months.

Results
During the follow-up period, 48 patients (17.9%) met the primary endpoint. The propensity-matched groups did not differ in terms of LV and RV EFs. In patients with significant TR, values of AEF were significantly lower (sTR vs. nsTR; 17±7 vs.19±7 %, p&lt;0.05), whereas LEF and REF did not show a difference in the two matched groups. Using univariable Cox regression analysis, both AEF (HR, 0.93 [95% CI 0.89–0.97], p = 0.001) and the presence of significant TR (HR, 2.75 [95% CI 1.48–5.14], p = 0.001) were found to be significant predictors of all-cause mortality. By receiver operating characteristics analysis, we defined an optimal cut-off value of 20.9% for AEF, which was then used to dichotomize our patient population (Figure 2A). Patients with AEF values below the 20.9% cut-off had more than a three-fold risk of all-cause mortality (HR, 3.03 [95% CI 1.42–6.47], p = 0.004) compared to patients with AEF values above the cut-off (Figure 2B). Furthermore, we assessed the relationship between regurgitant volume describing the extent of TR, and AEF, which showed a significant inverse correlation (r=-0.37; p&lt;0.001).

Conclusions
Three-dimensional echocardiography enabled a more precise assessment of RV mechanics. In patients with left-sided heart diseases with TR, the deterioration of the RV anteroposterior motion component was significantly associated with both the severity of TR and all-cause mortality.