Tulzer A, Arzt W, Gitter R, Sames-Dolzer E, Kreuzer M, Mair R, Tulzer G.Ultrasound Obstet Gynecol. 2022 May;59(5):633-641. doi: 10.1002/uog.24792. Epub 2022 Apr 11.PMID: 34605096
Take Home Points:
- Preprocedural right ventricular (RV) to left ventricular (LV) length ratio in combination with mitral valve regurgitation maximum velocity (MR-Vmax) predicted with high sensitivity and specificity biventricular (BV) outcome after successful fetal aortic valvuloplasty (FAV) in fetuses with critical aortic stenosis and evolving hypoplastic left heart syndrome.
- Postnatal BV circulation may be achieved in fetuses undergoing FAV at earlier gestational ages, with smaller LV structures, if the LV still generates adequate pressure as estimated by MR-Vmax.
- RV/LV length ratio is an easy-to-use alternative to Z-scores of cardiac measurements for the prediction of postnatal circulation before FAV in daily clinical practice. Improved prediction of BV circulation allows better parental counseling.
Commentary from Dr. Manoj Gupta (New York City, NY, USA), chief section editor of Pediatric & Fetal Cardiology Journal Watch.
Patients with prenatally diagnosed critical aortic stenosis (CAS) and evolving hypoplastic left heart syndrome (eHLHS) are at significant risk of morbidity and mortality. Several studies have reported an improved biventricular (BV) outcome rate in these patients after fetal intervention, with the advantage of long-term survival.
All patients with CAS and eHLHS who underwent FAV at their center between December 2001 and September 2020 were included. The indication for FAV was the patient meeting the criteria for eHLHS. The initial criteria included a LV long-axis Z-score of>– 3.0; however, this criterion to a LV long-axis Z-score of>– 1.0 in the more recent study period (from 2014).
Flowchart showing outcome of fetuses with critical aortic stenosis (CAS) and evolving hypoplastic left heart syndrome (eHLHS) that underwent fetal aortic valvuloplasty (FAV). *Including one patient after hybrid repair. †Including five patients with biventricular (BV) to univentricular (UV) conversion. IUD, intrauterine death.
Predictors of BV outcome
In both analyses, the best prediction for BV outcome without signs of PAH at 1 year of age could be achieved by a combination of RV/LV length ratio and MR-Vmax at different cut-offs. The CART for the prediction of BV outcome without PAH at 1 year after live birth following technically successful FAV performed after 2010 had a sensitivity of 96.97% (95% CI, 84.24 – 99.92%), specificity of 94.44% (95% CI, 72.71 – 99.86%), PPV of 96.97%(95% CI, 84.24 – 99.92%) and NPV of 94.44% (95% CI,72.71 – 99.86%).
The highest probability for a BV outcome in this group was reached for fetuses with a RV/LV length ratio of <1.094 (96.4%) and fetuses with a RV/LV length ratio≥1.094 to<1.135 combined with a MR-Vmax of ≥3.14 m/s (100%). Fetuses with a RV/LV length ratio of≥1.135 combined with a MR-Vmax of≥3.14 m/s had a low probability of 20% for a BV outcome, while none of the fetuses with RV/LV length ratio of≥1.094 combined with a MR-Vmax of<3.14 m/s had BV circulation at 1 year of age.
In fetuses with CAS and eHLHS, FAV can be performed with a high success rate and an acceptable risk, but an experienced multidisciplinary team with a high volume of interventions is imperative. Almost all newborns required interventional or surgical procedures in the neonatal or infant period, resulting in significant morbidity and mortality in the first year after birth. A combination of RV/LV length ratio and LV pressure estimates before FAV predicted BV outcome at 1 year of age with high sensitivity and specificity. Different cut-offs of RV/LV length ratio and MR-Vmax were required in fetuses younger than 28+0 weeks. A prospective controlled study is warranted to confirm these findings and to assess if FAV truly improves BV outcome rates.