{
  "abstract": "Introduction Fetal critical aortic stenosis with evolving hypoplastic left heart syndrome (CAS-eHLHS) causes biomechanical and functional aberrations, leading to a high risk of progression to hypoplastic left heart syndrome (HLHS) at birth. Fetal aortic valvuloplasty (FAV) can resolve the flow obstruction, and past studies suggest an ability to reduce risk of the progression, to result in a biventricular (BV) circulation at birth which has survival benefits. However, many fetuses fitting the current selection criteria do not respond sufficiently to the intervention, and are still born with a functionally single ventricle (SV) circulation. Our current selection criteria for FAV may thus not be optimal.Purpose we investigated whether biomechanics parameters, back-computed from image-based simulations, can more robustly predict the birth outcome of FAV on CAS-eHLHS cases, compared to routine echo measurements.Methods and Results Finite element biomechanics simulations were performed on 9 CAS-eHLHS cases undergoing FAV, and 6 healthy controls. The back-computed biomechanics parameters and a wide range of echo measurements were gauged for their ability to distinguish between cases with BV and UV birth outcomes. A biomechanics parameter, peak systolic myocardial stress, showed a uniquely large effect (Cohen’s D) in distinguishing between BV and SV cohorts.Next, we tested if this parameter improves prediction of FAV SV versus BV birth outcomes. We first used our simulations to derive an empirical equation for quick and easy computation of the parameter from routine echo measurements, and then performed ROC analysis on a retrospective cohort of 37 CAS-eHLHS cases. We find that the peak myocardial stress outperformed all other parameters in predicting SV versus BV birth outcome, suggesting a robust prognosis capability.Finally, we tested the use of the parameter to refine FAV patient selection. For CAS-eHLHS cases fitting the current selection criteria, we modelled the outcomes if an additional criterion of peak myocardial stress < 17.4 kPa is used to rule out cases, and tested on a cohort of 27 FAV cases not used for model training. This led to 6 out of 27 cases being ruled out, an increase in BV birth rate from 63% to 81%, and a decrease in fetal death rate from 11% to 4.5%.Abstract 2-060 Figure 1(A) Our finite element model, reconstructed from 4D fetal echo images. (B) Peak myocardial stress has the largest Cohen’s D effect size to distinguishing between CAS-eHLHS cohort with BV birth outcome versus that with SV outcome. (C) ROC analysis shows that peak myocardial stress has the highest area under the curve in a ROC analysis to predict SV versus BV birth outcomeConclusion We observed that the biomechanic parameter, peak myocardial stress, has robust predictive capability of FAV birth outcomes. When incorporated into the patient selection process, it enables more suitable patients to be selected for FAV, reducing mortality risks from adverse response to FAV, and increasing chances of positive outcomes of avoiding SV births.",
  "authors": [
    {
      "affiliations": [
        "Department of Bioengineering, Imperial College London, London, UK"
      ],
      "name": "Laura Green"
    },
    {
      "affiliations": [
        "Department of Bioengineering, Imperial College London, London, UK"
      ],
      "name": "Wei Xuan Chan"
    },
    {
      "affiliations": [
        "Department of Pediatric Cardiology, Kepler University Hospital, Linz, Austria"
      ],
      "name": "Andreas Tulzer"
    },
    {
      "affiliations": [
        "Department of Pediatric Cardiology, Kepler University Hospital, Linz, Austria"
      ],
      "name": "Gerald Tulzer"
    },
    {
      "affiliations": [
        "Department of Bioengineering, Imperial College London, London, UK"
      ],
      "name": "Choon Hwai Yap"
    }
  ],
  "title": "2-060 Biomechanics parameter improves outcome prediction and patient selection for fetal aortic valvuloplasty",
  "uid": "2c10368b-428c-5113-9e31-ff981a30ad0d"
}