Structural Heart Disease Intervention (SHDI) is one of the fastest-growing medical fields. This discipline is highly predicated upon preprocedural and intraprocedural imaging. The latter has mostly meant transesophageal (TEE) imaging. However, intracardiac echocardiography (ICE) technology has rapidly accelerated and is gaining steam. Potential advantages include less patient sedation, faster workflows, and less recovery time.

In the clinical arena, ICE is sometimes used in left atrial appendage occlusion (LAAO) procedures. The recent SCAI/HRS LAAO consensus document strongly recommends intraprocedural imaging with TEE or ICE.¹ Pure ICE guidance for LAAO should be reserved for experienced centers at this point in time. Less experienced centers planning to transition to ICE are recommended to do so in a stepwise approach starting with both TEE and ICE to build comfort levels.

While 3D ICE technology is expanding, 3D TEE is still the gold standard method for guidance, given its higher resolution, familiarity, and reproducibility. 2D modalities, whether TEE or ICE, are inadequate for SHDI guidance. Recent data from Alkhouli et al.² show that “all leaks matter” for the occurrence of stroke, and thus careful assessment of leaks intraprocedurally has become more critical than ever before. This requires viewing color Doppler along the entire circumference of the device and suggests that we need views beyond the four traditional TEE angles. Although 3D color Doppler has a lower frame rate, the wider view can help to localize leaks which can then be measured more precisely on higher resolution 2D color Doppler imaging.

In the research arena, ICE has been used frequently for transcatheter tricuspid valve interventions (TTVI) as an adjunctive therapy, where TEE imaging is far field from the esophagus (posterior) to the tricuspid valve (anterior). 3D and live multi-planar (MPR) imaging are critical to guidance of TTVI, particularly edge-to-edge repair. The evolution of 3D ICE has increased its utility in this setting (Figure 1).

While enthusiasm for and use of ICE is increasing, a number of questions remain. Availability training is expanding but still very limited. Current ICE catheters are costly and single-use only. Offsetting cost is difficult in the current environment, and with outcomes appearing similar thus far is not a clear goal. The interventional imager is needed for manipulation and interpretation of 3D reconstructions, but the role in handling the catheter is unclear and does not currently include reimbursement.

ICE will continue to be developed and will have an increasing role as a tool in the armamentarium of the SHDI and LAAO teams.

Figure 1: 3D TEE and 3D ICE images from the same patient s/p mitral and tricuspid edge-to-edge repair. Note the higher spatial resolution and anatomical coverage of 3D TEE images. Courtesy of Saint Francis Hospital and Heart Center, Roslyn, NY

¹Saw J, Holmes DR, Cavalcante JL, et al. SCAI/HRS Expert Consensus Statement on Transcatheter Left Atrial Appendage Closure. JACC Cardiovasc Interv 2023.

²Alkhouli M, Du C, Killu A et al. Clinical Impact of Residual Leaks Following Left Atrial Appendage Occlusion: Insights From the NCDR LAAO Registry. JACC Clin Electrophysiol 2022;8:766-778.