The utility of 4D intracardiac echocardiography in transcatheter pulmonary valve replacement in adult congenital heart disease patients.

Background: Intracardiac echocardiography (ICE) has become a critical imaging modality in adult congenital heart disease (ACHD) interventions, offering high-resolution intracardiac imaging without the need for intubation. In transcatheter pulmonary valve replacement (TCPVR), ICE may overcome limitations of traditional imaging, particularly in visualizing the right ventricular outflow tract (RVOT) and pulmonary valve. Objectives: This study aimed to evaluate the feasibility, safety, and clinical utility of four-dimensional (4D) ICE in ACHD patients undergoing TCPVR. Methods: Beginning in February 2023, we prospectively enrolled all patients undergoing TCPVR at a tertiary ACHD center. Patients underwent preprocedural imaging and clinical evaluation. 4D ICE was used pre- and post-valve implantation to assess cardiac anatomy and valve function. Patients without valve implantation or 4D ICE imaging were excluded. Results: Of 55 referred patients, 45 underwent successful TCPVR with 4D ICE. The mean age was 42.6 ± 13.6 years, and 51 % were male. 4D ICE confirmed procedural indications, provided comprehensive anatomic and functional assessment, and detected post-implantation regurgitation in 35.6 % of cases, significantly more than angiography (11.1 %) or transthoracic echocardiography (4.4 %). Incidental but clinically relevant findings were identified in 33.3 % of patients, influencing management in 15.6 %. No ICE-related complications occurred. Conclusions: 4D ICE is a feasible, safe, and clinically valuable imaging tool during TCPVR in ACHD patients. It enhances procedural guidance, detects early valve-related complications, and identifies unexpected findings that affect management. Its integration into structural heart interventions may significantly improve outcomes, especially as technology continues to evolve.