Four-dimensional automated quantitative echocardiography assessment of right heart remodeling in patients with functional tricuspid regurgitation.

Background: Functional tricuspid regurgitation (FTR) has a pathophysiological connection with right heart remodeling. Given the increasing focus on right atrial remodeling in recent years, a comprehensive study of all aspects of right heart remodeling is crucial for understanding the progression and treatment of FTR. In the scientific literature, there is a lack of comprehensive exploration of right atrial remodeling in patients with FTR, and no reports on the potential correlation between the degree of this remodeling and the severity of tricuspid regurgitation (TR) have been published. This study aimed to evaluate the relationship between right heart parameters measured by four-dimensional (4D) automated quantitative echocardiography and the severity of TR in patients with FTR.

Methods: In this prospective case-control study, 100 patients diagnosed with FTR by echocardiography at The First Affiliated Hospital of Guangxi Medical University from February 2022 to March 2023 were prospectively and consecutively selected as the case group, comprising 50 patients with mild FTR and 50 patients with moderate or severe FTR. Additionally, 30 healthy participants served as the control group. Routine echocardiography was employed to obtain two-dimensional (2D) and three-dimensional (3D) images, which was followed by 4D automated quantitative echocardiograph assessment. Analysis of variance (ANOVA) or Kruskal-Wallis tests were used to compare differences between groups, Pearson correlation coefficient analysis was used to discern the relationship between parameters and TR volume, multivariate linear regression was used to identify factors associated with TR volume, and logistic regression was employed to predict the severity of FTR.

Results: The case group consisted of 50 patients with mild FTR (26 males, 52%; age range, 31-78 years; mean age ± SD: 58±11.4 years) and 50 patients with moderate-to-severe FTR (21 males, 42%; age range, 29-87 years; mean age ± SD: 60±13.0 years). Additionally, 30 healthy participants (13 males, 43%; age range, 19-81 years; mean age ± SD: 58±13.3 years) constituted the control group. Patients with moderate-to-severe FTR had significant right heart dilatation and functional decline. The TR volume was highly correlated with right atrium minimum volume (RAVmin; r=0.864; P<0.001), and linear regression showed that the RAVmin was independently correlated with the severity of TR in patients (β=0.820; P<0.001). There were several predictive variables that were significantly associated with increased FTR severity, including right atrial reservoir strain [RASr; odds ratio (OR) =0.702; 95% confidence interval (CI): 0.575-0.857; P=0.001], right atrial conduit strain (RAScd; OR =1.308; 95% CI: 1.098-1.558; P=0.003), and right atrial reservoir circumferential strain (RASr-c; OR =0.823; 95% CI: 0.684-0.990; P=0.04).

Conclusions: 4D automated quantitative echocardiography allows for the dynamic assessment of right heart volume and function. To determine the development of FTR, RA dilation appears to be more significant than right ventricular dilation. The RASr, RAScd, and RASr-c are directly correlated with FTR severity.