Abstract 10569: Risk Factors for Adverse Outcome in Prenatally Diagnosed Heterotaxy Syndrome in the Current Era

Abstract

Introduction: Fetuses with heterotaxy syndrome (HS) and congenital heart disease continue to have worse outcomes compared to other lesions. We sought to explore differences between asplenia and polysplenia subtypes and to identify risk factors for poor outcome in the current era. Methods: All cases of fetal HS seen at our center between 1/2005 and 3/2018 were included in this study. Prenatal echocardiographic parameters and clinical outcomes were recorded. Findings were compared between the asplenia and polysplenia subtypes via Chi-square or Fisher’s exact analysis. Univariate logistic regression was utilized to identify prenatal variables predictive of fetal demise. Postnatal survival was examined with Kaplan-Meier curves and univariate Cox proportional hazards models. Results: The cohort consisted of 155 subjects: 86 with asplenia and 69 with polysplenia. There were 36 with biventricular (2V) and 119 with univentricular (1V) physiology. Asplenia subjects were more likely to have 1V physiology, common atrioventricular canal (CAVC), conotruncal anomaly, and pulmonary venous obstruction (all p<0.001). Polysplenia subjects were more likely to have systemic venous anomalies (p<0.001), complete heart block (CHB, p<0.001), ventricular dysfunction (p=.005), and hydrops (p=0.03). There were 105 subjects born alive, 7 fetal demises, 40 terminations, and 3 lost to follow-up prior to birth. Postnatal follow-up data were available for 96/105 (91%) subjects with median follow-up of 5.5 years (IQR 1.2-10.5). Estimated 5-year survival was 72% (95% CI 62-80) for the entire cohort and there was no difference in overall postnatal survival between polysplenia and asplenia subtypes (p=0.24). CHB and ventricular dysfunction were significant risk factors for both fetal demise and postnatal death. Pulmonary venous obstruction and CAVC were additional risk factors for postnatal death. Conclusions: Fetuses with HS continue to have high rates of postnatal mortality, particularly if CHB, ventricular dysfunction, or pulmonary venous obstruction are identified. CHB and ventricular dysfunction are also significant risk factors for fetal demise. Further research is needed to improve management of CHB and pulmonary venous obstruction in this high-risk group.