Bolin EH, Collins RT 2nd, Best TH, Zakaria D, Lang SM, Boushka MG, Renno MS, Heil LL, Lowery CL, Bornemeier RA.J Perinatol. 2020 May 7. doi: 10.1038/s41372-020-0677-2. Online ahead of print. PMID: 32382116
Take Home Points:
- Fetal tele-echo identified all types of CHD with a sensitivity of 74% and specificity of 97%.
- For ductal dependent lesions, sensitivity and specificity were 100%.
- With an experienced sonographer willing to travel, fetal tele-echo may be a viable option for more remote locales.
Commentary from Dr. Jared Hershenson (Greater Washington DC), section editor of Pediatric Cardiology Journal Watch: This was a study of fetal tele-echo (FTE) on 1164 fetuses in 6 satellite sites in Arkansas. The main campus is located centrally in the state, and they opened 6 offices throughout the state, many over 100-150 miles away. All studies were interpreted in real time by a fetal cardiologist as they were transmitted over a broadband IP network. Most of the studies were performed by a single sonographer with 20+ years experience. A positive study, defined as whether a postnatal echo was recommended (excluding a normal FTE in a poorly controlled diabetic mother) prompted a next available referral to the main campus with (in-person) face to face consultation with a pediatric cardiologist. FTE was not recommended in those with a high risk of carrying a fetus with an arrhythmia or structural heart disease (e.g. suspected cardiac abnormality or arrhythmia on OB ultrasound or hydrops) and these patients were initially referred to the main campus.
Table 1 shows the population characteristics. 1086 FTEs were normal and 78 abnormal. There were 15 false negative studies, but only 2 of those required cardiac intervention in the first 6 months of life. Both were perimembranous VSDs. There were 36 false positives of which the authors state were mostly small VSDs that may have closed prior to delivery. Of the 42 true positives, 18 required intervention in the first 6 months of life. This resulted in 74% sensitivity and 97% specificity. When subanalyzing ductal dependent lesions, FTE was 100% sensitive and 100% specific. With neonatal intervention within the first 6 months, FTE was 91% sensitive and 100% specific. See table 2. There was 1 patient who had a normal FTE, but subsequently developed flail TV and functional PV atresia; however since the disease developed after FTE, the case was not included in the analysis.
Per the authors, this was the largest study of FTE in terms of number of patients and sites. Previous studies have also shown good accuracy of FTE as well as community acceptance and patient preference of local FTE instead of traveling to quite distant sites. Additionally, there may be some economic benefits to patients and empowerment of local providers. The authors did not specifically discuss delivery planning based on FTE which would have been helpful given the variations in regional and state-wide hospital systems and medical transport. They showed an increase in rate of prenatal detection of CHD as well as financial benefit with implementation of the FTE program.
There were a few caveats. First 26% of abnormal FTEs were lost to follow up, which is quite high and concerning. The authors state that none of these cases were ductal dependent lesions. Additionally, the feasibility of the program most likely hinges on the experience of the sonographer; however, the studies were reviewed in real-time and theoretically, discussion and requests for more/different views could be done before the patient left. Based on the data, I would wonder if real-time review is actually necessary; this would result in even greater cost-effectiveness and financial benefit and likely be more applicable nation-wide or even world-wide.