Comparative evaluation of intracardiac, transesophageal, and transthoracic echocardiography in the assessment of patent foramen ovale: A retrospective single‐center study

INTRODUCTION: Certain patent foramen ovale (PFO) characteristics, such as a large right-to-left shunt (RLS) or atrial septal aneurysm, identify patients who may receive the highest clinical benefit from percutaneous PFO closure. This study aimed to compare intracardiac echocardiography (ICE) with standard echocardiographic imaging in the evaluation of high-risk PFO characteristics and RLS severity in patients with PFO-associated stroke. METHODS: We conducted a retrospective review of all patients aged ≥18 years who underwent percutaneous PFO closure for PFO-associated stroke and received all three ultrasound-based cardiac imaging modalities and had interpretable results (N = 51). We then compared RLS severity, high-risk PFO characteristics, and the proportion of patients with a higher likelihood of PFO-associated stroke by ICE versus transthoracic echocardiogram (TTE) and transesophageal echocardiogram (TEE). RESULTS: The final cohort had a mean (±SE) age of 48.4 (±1.8) years and was predominantly female (58.8%). ICE was more likely to identify a large RLS versus TTE/TEE combined (66.7% vs. 45.1%; p = 0.03). The use of ICE resulted in significantly more patients being reclassified as having a higher likelihood of PFO-associated stroke (TTE vs. TEE vs. ICE: 10.4% vs. 14.6% vs. 25%; p = 0.03). A high-quality bubble study was found to be the single most important factor associated with identifying a larger RLS across all modalities (ρ [p]; TTE: 0.49 [<0.001], TEE: 0.60 [<0.001], ICE: 0.32 [0.02]). The presence of a hypermobile septum was associated with significantly greater RLS on ICE (ρ [p]: 0.3 [0.03]), especially with poor quality bubble studies (ρ [p]: 0.49 [0.02]). CONCLUSION: In this observational study of patients with PFO-associated stroke, ICE detected a large RLS more frequently than TTE and TEE; and reclassified some patients as having a higher likelihood of PFO-associated stroke.