Abstract 4136698: Comparative Analysis of Transthoracic and Transesophageal Echocardiography for Diagnosis of High-Risk Patent Foramen Ovale

Background: Transthoracic contrast echocardiography using hand-agitated saline and provocative maneuver (cTTE) has been considered a gold standard of diagnosis of patent foramen ovale (PFO), and transesophageal echocardiography (TEE) is generally recommended for selected patients who are going to undergo percutaneous closure of PFO. Recent studies have highlighted the clinical significance and prognostic implication of various anatomical features of PFO and the adjacent atrial septum, and risk stratification using the concept of ‘a high-risk PFO (HRPFO)’ has been widely accepted. We sought to evaluate the diagnostic role of TEE with contrast study (cTEE). Methods: Clinical data from patients who underwent both cTTE and cTEE without sedation for evaluation of cryptogenic stroke was retrospectively analyzed. The bubble gradings of right-to-left shunt were classified into four groups: grade 0 (none), grade 1 (< 20), grade 2 (20-99 bubbles), and grade 3 (≧100 bubbles). HRPFO was defined as PFO with an atrial septal aneurysm or hypermobile atrial septum, or PFO with large amount of shunt (≧20 bubbles), or PFO size (distance between septum secundum and primum) of ≧2 mm. Results: From January 2017 to December 2022, a total of 572 patients underwent both cTTE and cTEE. The prevalence of PFO was 65.9 % (377 patients), and 331 patients (57.9% of the total, 87.8% of those with PFOs) were diagnosed with HRPFO using cTTE or cTEE. The prevalence of grade 2 and 3 was significantly higher in cTEE than in cTTE among proven PFO cases (68.7 % vs 75.6 %, P = 0.04). Among patients initially assessed as having a low-risk PFO or no PFO by cTTE, 22% were subsequently reclassified as having a HRPFO following cTEE. As a result, the positivity of HRPFO significantly increased from 46% to 56.8% after cTEE (P < 0.001). The sensitivity of cTTE for diagnosing a HRPFO was significantly lower than that of cTEE (79.5 % vs 98.2 %, P < 0.001). Conclusions: Diagnostic performance of cTTE can be significantly improved with the addition of cTEE without sedation. Given the beneficial effects of percutaneous closure of HRPFO, cTEE without sedation should be considered a useful screening test for patients with cryptogenic stroke.