Venous Flow Variation Predicts Preoperative Pulmonary Venous Obstruction in Children with Total Anomalous Pulmonary Venous Connection

The Role of Fetal Echocardiography in Predicting Postnatal Pulmonary Venous Obstruction in Neonates with TAPVR: A Single Center Experience

Total anomalous pulmonary venous return (TAPVR) is a high risk and rare cardiac malformation with a low prenatal detection rate and predicting obstruction in these cases is difficult. We sought to investigate fetal echocardiographic parameters associated with postnatal pulmonary venous obstruction (PPVO). We performed a retrospective review of 26 patients with TAPVR who had a fetal echocardiogram from 2010 to 2021. Blinded readers analyzed the fetal Doppler features of the pulmonary veins (PV) and vertical veins (VV) at final fetal assessment. Of the 26 patients, 17 (65%) were prenatally diagnosed and overall 10 (38.5%) developed PPVO. All patients had additional associated congenital heart disease. Compared to patients without PPVO, patients with PPVO had a lower VV variability index (VI) (0.51 (0.17-0.79) vs 1.43 (0.54-2.58); p = 0.003), a higher likelihood of having an abnormal VV or PV Doppler pattern (p = 0.042, p = 0.015), a higher VV minimum velocity (0.435 m/s (0.17-1.05) vs 0.14 m/s (- 0.16 to 0.35) p = 0.001) and a higher VV mean velocity (0.641 m/s (0.31-1.15) vs 0.321 m/s (0.19-0.5); p = 0.009). A fetal VV VI of ≤ 0.8 was associated with PPVO (100% sensitivity, 86% specificity). Our data show that some fetal PV and VV Doppler indices are significantly different between those that develop PPVO and those who do not, with the most significant difference seen in the VV variability index and VV minimum velocity. Prenatal predictors of PPVO have the potential to influence prenatal counseling, perinatal care, surgical timing, and outcomes associated with this critical diagnosis.

Fetal Doppler Echocardiographic Assessment Predicts Severe Postnatal Obstruction in Total Anomalous Pulmonary Venous Connection

BACKGROUND

Obstructed total anomalous pulmonary venous connection (TAPVC) is a form of critical congenital heart disease that usually requires urgent postnatal intervention. Knowing which patients have severe obstruction can aid delivery planning. The authors previously developed a novel quantitative metric of pulmonary venous flow, the pulmonary venous variability index (PVVI). The aim of this study was to test the hypothesis that fetal PVVI and vertical vein Doppler velocities are associated with severe pulmonary vein obstruction postnatally.

METHODS

A retrospective cohort study of neonates with prenatally diagnosed TAPVC was performed. Patients who underwent fetal echocardiography at the Children's Hospital of Philadelphia with Doppler interrogation of the vertical vein were included for analysis. Twenty-nine patients met criteria (21 with heterotaxy, 18 with supracardiac TAPVC). The latest gestation fetal echocardiogram was used. Severe pulmonary vein obstruction was defined as preoperative death or urgent surgery or catheter-based intervention (first day of life). Measurements of PVVI, defined as (maximum velocity - minimum velocity)/mean velocity, were made offline. Wilcoxon rank sum models were used to assess the associations of severe obstruction and PVVI and maximum, mean, and minimum velocities.

RESULTS

The mean gestational age at the latest fetal echocardiographic examination was 35 weeks (range, 30-39 weeks). Twelve of the 29 patients (41%) met criteria for severe pulmonary vein obstruction. Lower PVVI was associated with greater risk for severe pulmonary venous obstruction (P = .008). The maximum, mean, and minimum velocities in the vertical vein were all significantly associated with severe pulmonary venous obstruction (P = .03, P = .03, and P = .007, respectively). Qualitative assessment of obstruction was not significantly associated with the outcome. Interobserver reliability for all vertical vein Doppler metrics was high (intraclass correlation coefficient > 0.9).

CONCLUSIONS

Fetal PVVI and maximum, mean, and minimum velocities are associated with severe postnatal pulmonary vein obstruction in TAPVC. Accurate prediction of obstructed TAPVC could allow safer delivery planning. Further research with larger sample sizes is needed to identify the ideal cutoff values for these Doppler measures.

Peripheral Blood Transcripts Predict Preoperative Obstructive Total Anomalous Pulmonary Venous Connection

The lack of accessible noninvasive tools to examine the molecular alterations limits our understanding of the causes of total anomalous pulmonary venous connection (TAPVC), as well as the identification of effective operational strategies. Here, we consecutively enrolled peripheral leukocyte transcripts of 26 preoperative obstructive and 22 non-obstructive patients with TAPVC. Two-hundred and fifty six differentially expressed mRNA and 27 differentially expressed long noncoding RNA transcripts were dysregulated. The up-regulated mRNA was enriched in the hydrogen peroxide catabolic process, response to mechanical stimulus, neutrophil degranulation, hemostasis, response to bacterium, and the NABA CORE MATRISOME pathway, all of which are associated with the development of fibrosis. Furthermore, we constructed predictive models using multiple machine-learning algorithms and tested the performance in the validation set. The mRNA NR3C2 and lncRNA MEG3 were screened based on multiple iterations. The random forest prediction model can predict preoperative obstruction patients in the validation set with high accuracy (area under curve = 1; sensitivity = 1). These data highlight the potential of peripheral leukocyte transcripts to evaluate obstructive-related pathophysiological alterations, leading to precision healthcare solutions that could improve patient survival after surgery. It also provides a novel direction for the study of preoperative obstructive TAPVC.