EP09.62: Atrial distensibility predicting prognosis of fetal single ventricle associated with atrioventricular valve regurgitation

Atrial distensibility (AD) reflects severity of atrioventricular valve regurgitation (AVVR) or heart failure in adults. Otherwise, reliable marker that can assess fetal heart failure or AVVR has not been established. AD in fetus with single ventricle (SV group) and normal heart (normal group) was studied from January 2013 to December 2023. Severity of AVVR was classified into none, mild, and moderate-severe based on vena contracta. AD was measured by tracing atrial area in a four-chamber view and compared between both groups. The primary endpoints were complex outcome of intrauterine fetal death, neonatal death, and AVVR repair within 3 months. Impact, as a predictive indicator for prognosis of atrial distensibility, was studied. Patients with chromosomal anomalies were excluded. In the SV group (n = 59), right/left ventricle was 46/13 patients. AVVR grade in SV group was 48 and 11 patients in the none-mild and moderate-severe groups, respectively. Moderate-severe group showed significantly reduced AD (RA; 0.63 ± 0.19, LA; 0.77 ± 0.19, SV none-mild; 0.59 ± 0.24, SV moderate-severe; 0.31 ± 0.17). Eight patients in the SV group showed primary endpoints, of which five were in the moderate-severe group. In the moderate-severe group, AD was significantly low in patients with endpoints compared to those without (with endpoints; 0.19 ± 0.075 vs without endpoint; 0.40 ± 0.17, p = 0.03). Prognosis of endpoint with AUC ROC of AD was 0.90, showing significantly better than other indicators (fraction of area change in ventricle, cardio-thoracic area ratio, Tei index). In fetal SV patients, reduced AD is a useful predictor for the severity and prognosis of AVVR.