Diagnostic performance of “Superb Microvascular Imaging” in fetal heart exploration during first trimester of pregnancy in a high-risk population for cardiac malformations fetuses

Abstract

To evaluate the diagnostic performance of Superb Micro vascular Imaging (SMI) at 11–14 weeks of gestation in an early extended fetal heart examination in a high-risk population of fetal cardiac malformations. We present a moncocentric study in a referral unit of fetal medicine in a university hospital in Lyon, from September 2020 to March 2022. Only transabdominal fetal echocardiography was performed with an Aplio i800 US system, Canon Medical Systems, Tokyo, Japan, in routine care, during the first trimester screening, in a high risk population of fetal heart malformations. Extended cardiac examination was performed using six views (four chamber, pulmonary veins, left outflow, right outflow, three vessel trachea, aorta in sagittal view) with B mode, Color Doppler and SMI. All the pregnancies, which were continued, had second trimester heart scan. In total, 142 fetuses were scanned at 11 to 14 weeks gestation. In total, 100% were performed in transabdominal examination. Congenital heart diseases (CHD) were identified in 31 (23%): 11 to 11 + 6 weeks (8.5%), 12 to 12 + 6 weeks (36.6%) 13 to 14 weeks (54.9%). Ninety-two percent of all views were obtained with SMI, 63% in color doppler ( P < 0.001) and 40% in B Mode ( P < 0.001). When adding SMI to the examination, we obtained a complete 6-views examination for 80.3% up to 90.8% with 5 views out of 6 ( P < 0.001); in comparison, those scores were respectively of 23.5% and 45.6% using only B mode and color doppler ( P < 0.001). In total, 106 (75%) normal scans were confirmed at the second trimester control. In detection of CHD, sensitivity and specificity were high (100%). In diagnostic concordance, sensitivity was 92%, specificity 99%, positive predictive value 83% and negative predictive value 99% ( Fig. 1 ). SMI is a complementary mode with B-Mode and Color Doppler to improve early detection of congenital heart disease in this high-risk population, with transabdominal examination.