[Echocardiographic characteristics and prognostic evaluation of Ebstein anomaly in fetuses]

Objective: To investigate the prenatal echocardiographic features of fetuses diagnosed with Ebstein anomaly (EA), identify prognostic factors affect the fetal and neonatal mortality, and evaluate the clinical value of the Simpson Andrews Sharland prognostic score (SAS prognostic score). Methods: A retrospective cohort study was conducted on 37 fetuses diagnosed with EA via prenatal and postnatal echocardiography at Guangdong Provincial People's Hospital from June 2012 to June 2024. The echocardiographic features of EA patients were summarized. According to the patients' survival statuses during the fetal and neonatal periods, they were divided into survival group and death group for a comparative analysis of key echocardiographic parameters, as well as SAS prognostic score. Also, receiver operator characteristic (ROC) curve was employed to assess the predictive abilities of various indicators. Finally, based on the medium-and long-term prognostic outcomes of EA cases, the predictive value of the SAS system was evaluated. The t test, Mann-Whitney U test, and Fisher exact test were used for group comparison. Results: Regarding the 37 EA cases, the gestational age at the initial diagnosis was (29±4) weeks. All of EA fetuses exhibited echocardiographic characterized by tricuspid regurgitation (TR) originating below the native tricuspid annulus with the severity varied, accompanied by manifestations such as right atrial enlargement. Of all cases, 5 cases (14%) died prenatally, and 32 cases (86%) were born alive. Postnatally, 4 cases died preoperatively, 1 case died postoperatively, and 27 cases survived. Compared with the survival group, the death group had a significantly higher average SAS prognostic score (6.9±1.1 vs. 2.0±1.5, t=9.17, P<0.001), right atrium (RA) to left atrium (LA) transverse diameter ratio (2.0±0.5 vs. 1.3±0.2, t=4.87, P=0.001) and TR area to RA area ratio (0.8±0.2 vs. 0.4±0.2,t=5.27,P<0.001). According to the ROC analysis, the optimal predictive value indicators are RA to LA transverse diameter ratio (AUC=0.93, 95%CI 0.81-1.00) and the TR area-to-RA area ratio (AUC=0.93, 95%CI 0.85-1.00); the optimal cut-point values were 1.5 and 0.5, respectively. Of 32 born alive cases, 21 cases (66%) didn't undergo surgery, 2 cases (6%) underwent bidirectional Glenn surgery, and one case (3%) underwent tricuspid valvuloplasty. All 17 cases with SAS score≤2 survived, while all 9 cases with SAS score≥6 died. Among the 11 cases with a score from 3 to 5, 8 cases achieved a biventricular outcome. Conclusions: The typical echocardiographic feature of EA fetuses is that the originating point of TR is below the native tricuspid annulus and the severity can vary. The SAS score is essential for tiered prognosis. When the SAS is 3-5, dynamic monitoring for TR and RA enlargement should be employed to help guide prenatal intervention and reduce fetal and neonatal mortality.