Cardiac ultrasound based screening for chronic pulmonary hypertension in extremely preterm and extremely low birth weight infants

Prospective data collection of the clinician performed cardiac ultrasound (CCPU) findings for chronic pulmonary hypertension (cPHT) on infants born less than 29 weeks or less than 1000g. CCPU based parameters for assessment of cPHT involves: Fractional area change of the right ventricle (FAC), Trans Annular Plane Systolic Excursion (TAPSE) of the tricuspid valve, tissue doppler imaging of the right, left and interventricular wall, peak tricuspid regurgitation(TR), left ventricular study, pulmonary artery acceleration time/right ventricle ejection time (PAAT/RVET), peak pulmonary valve regurgitation, interventricular ventricular septal flattening, left ventricular systolic eccentricity index, direction of intracardiac shunts. The first assessment for identifying cPHT changes will begin from the second week of life and continue these assessments fortnightly until home discharge or transfer to another health facility. We will exclude infants with a confirmed genetic or a metabolic abnormality or those with major structural congenital abnormalities of the heart. We will also collect information on prenatal and post-natal risk factors associated with cPHT in infants with bronchopulmonary dysplasia (BPD). Example: Prenatal factors– maternal hypertension, diabetes, receipt of antenatal steroids etc Postnatal factors – pulmonary haemorrhage, sepsis, patent ductus arteriosus etc. All infants born <29weeks gestation and/or weighing <1,000 grams at birth are routinely enrolled in the Growth and Development Clinic for long term neurodevelopment assessment throughout hospitals in Australia. Standardised tools are used for neurodevelopment assessments which are conducted by certified examiners at corrected ages of 4 months, 12 months, 24 months and at 5 years of age. We will compare the neurodevelopment outcomes in infants with and those without cPHT. The co-investigator, Dr Moni Singh, holds a neonatal Certificate in Clinician Performed Ultrasound and has received advanced training under the supervision of a paediatric cardiologist. Over the past six months, multiple cardiac ultrasound scans performed for cPHT assessment have been reviewed by the cardiologist, confirming that all imaging parameters are accurately captured and measurements are reliable. The cardiologist has verified the adequacy of image quality and measurement accuracy, and no further training is required prior to study commencement. All ultrasound assessments will be performed by Dr Singh using the GE Vivid E95 ultrasound system (standard neonatal unit machine). The device itself has not been modified; however, additional measurement calculations have been incorporated into the software for ease of data collection. Each ultrasound assessment is expected to require approximately 20–25 minutes. Strategies to ensure adherence include fortnightly review meetings with study supervisors, departmental ultrasound review meetings, and monthly review sessions with the paediatric cardiologist. Neurodevelopmental assessments will be conducted by certified examiners using validated and standardised tools, including the Bayley Scales of Infant and Toddler Development, Fourth Edition (Bayley-IV) and the Wechsler Preschool and Primary Scale of Intelligence, Fourth Edition (WPPSI-IV). The overall duration of the study will be either five or eight years, depending on whether follow-up is completed at two years or extended to five years of age.