# Immediate and Intermediate-Term Outcomes of Right Ventricular Outflow Tract Interventions in Neonates and Infants: A Prospective Single-Center Study

## TL;DR

This study examines the safety and effectiveness of different heart procedures in infants with right ventricular outflow tract issues, showing high success rates and improved outcomes.

## Contribution

The study provides new insights into the immediate and intermediate-term outcomes of various transcatheter interventions for neonatal and infant right ventricular outflow tract anomalies.

## Key findings

- Transcatheter interventions showed high six-month survival rates with minimal complications.
- RVOT stenting was 100% successful and improved oxygen saturation, making some infants eligible for complete heart repair.
- Procedures like balloon pulmonary valvotomy significantly reduced right ventricular pressure and gradients.

## Abstract

Background: Right ventricular outflow tract (RVOT) anomalies in neonates and infants necessitate early intervention to restore adequate pulmonary blood flow and promote pulmonary artery (PA) growth. This study aimed to evaluate the immediate and intermediate-term outcomes of various transcatheter RVOT interventions in this vulnerable population.

Methods: This prospective, single-center descriptive study enrolled 52 infants (aged <1 year) undergoing balloon pulmonary valvotomy (BPV, n=29), RVOT perforation with BPV and patent ductus arteriosus (PDA) stenting (n=11), or RVOT stenting (n=12) between February 2021 and November 2022. Key immediate outcomes included hemodynamic changes, procedural success, and in-hospital complications. Intermediate outcomes at three and six months assessed oxygen saturation (SpO2), weight gain, PA growth, and re-intervention rates.

Results: Overall six-month survival was high at 96.2% (50/52), with minimal procedural complications, which included two transient arrhythmias. In-hospital mortalities occurred in one BPV patient and one RVOT perforation patient, both attributed to non-procedural causes such as septic shock.

BPV procedures achieved significant reductions in RV pressure (from 106±26.18 mmHg to 40.74±9.91 mmHg, p=0.04) and RVOT gradient (from 85.41±26.04 mmHg to 15.67±4.2 mmHg, p<0.0001), with a 14.3% re-intervention rate for restenosis by three months. For RVOT perforation with BPV and PDA stenting, there was marked hemodynamic improvement, with RV pressure decreasing from 105.36±18.98 mmHg to 40±12.06 mmHg (p<0.0001) and robust PA growth (RPA measuring 5.72±1.13 mm and LPA 5.10±0.93 mm at six months). Lastly, RVOT stenting was 100% successful, significantly improving SpO2 (from 73.83±5.46% to 86.83±4.61% at discharge) and enabling five infants to become candidates for complete intracardiac repair by six months.

Conclusion: Transcatheter RVOT interventions are safe and effective strategies for managing RVOT anomalies in neonates and infants. These intervention strategies offer targeted benefits and improve clinical outcomes.