Serial changes in right ventricular function after mitral valve surgery: retrospective analysis of a prospective cohort

Background: Despite the clinical relevance of right ventricular (RV) function assessed on echocardiography, its predictive utility for patients receiving mitral valve surgery remains uncertain. The primary objectives of this study were to characterize RV function before and after valvular surgery and to establish the diagnostic value of this assessment. Methods: Echocardiograms were collected prospectively from patients undergoing mitral valve surgery between 2020 and 2023. Subsequently, a retrospective analysis of preoperative and postoperative echocardiographic parameters was performed to evaluate RV function, including tricuspid annular plane systolic excursion (TAPSE), tricuspid annular systolic velocity (S'TDI), RV fractional area change (FAC), RV free wall longitudinal strain (RVFWLS), RV global longitudinal strain (RVGLS), and three-dimensional RV ejection fraction (3D RVEF). The study included 115 patients with mitral valve surgery. Serial echocardiographic evaluations were performed at four time points: preoperatively, 1 week postoperatively, 6 months postoperatively, and 1 year postoperatively. Serial changes in echocardiographic parameters (TAPSE, FAC, S'TDI, RVFWLS, and 3D‑RVEF) were analyzed via repeated‑measures analysis of variance (ANOVA). Receiver operating characteristic (ROC) curves and DeLong tests were used to evaluate and compare diagnostic performance. Reproducibility for RVFWLS, RVGLS, and 3D‑RVEF was assessed according to intraclass correlation coefficients (ICCs) and Bland-Altman plots in a random subset of 20 observations. Results: The principal findings were as follows: (I) RV systolic function demonstrated a statistically significant reduction postoperatively as compared to the preoperative baseline level (P<0.0001). (II) One year after operation, TAPSE and S'TDI remained significantly lower than their corresponding preoperative values, with mean changes of -0.34 mm [95% confidence interval (CI): -0.55 to -0.14; P=0.0003] and 1.48 cm/s (95% CI: 0.45 to 2.52; P=0.0024), respectively. In contrast, RVFWLS and 3D RVEF recovered to levels comparable to those at baseline, with mean changes of 0.29% (95% CI: -2.19% to 2.77%; P>0.05) and -3.04% (95% CI: -9.98% to 3.91%; P>0.05), respectively. (III) According to the DeLong test, RVFWLS demonstrated the highest diagnostic accuracy for RV systolic dysfunction (area under the curve =0.771), significantly outperforming conventional parameters (FAC, TAPSE, and S'TDI; all P values <0.001). (IV) RVFWLS exhibited stronger diagnostic agreement with the reference standard (3D RVEF) in identifying impaired RV systolic function, as indicated by the reclassification rate (31%), as compared to conventional parameters (57-64%). Conclusions: RVFWLS may serve as a novel indicator for assessing RV systolic function both preoperatively and postoperatively in patients with mitral regurgitation (MR).