Abstract 16390: Advanced Atrial Tissue Fibrosis Quantified Using Late-Gadolinium Enhanced Cardiac MRI Predicts Trans-Esophageal Echo Abnormalities in Patients with Atrial Fibrillation

Abstract

Introduction: Atrial fibrillation (AF) leads to spontaneous echo contrast (SEC) and thrombus formation commonly seen in the left atrial appendage (LAA) on trans-esophageal echocardiography (TEE). We hypothesized that advanced atrial fibrosis, quantified using LGE-MRI,increases the risk of TEE abnormalities.

Methods: This study included patients undergoing TEE prior to catheter ablation. Baseline characteristics including the CHADS2 score, anti-coagulation status and mitral regurgitation (MR) were collected. Late-gadolinium enhanced cardiac MRI (LGE-MRI) was obtained in all patients and quantification of atrial tissue fibrosis was obtained. Patients were staged as follows: Utah Stage I (atrial tissue fibrosis 35%).

Results: 178 patients were included and a therapeutic INR was present in 111 (62.4%). LAA thrombus was found in 11 patients (6.2%) while left atrial SEC was identified in 18 patients (10.1%). TEE abnormalities were significantly more prevalent in Utah stages III and IV compared to Utah stages I and II: 6 of 56 patients (32.0%) vs 5 of 118 patients (13.7%); p<0.05 for LAA thrombus and 9 of 55 patients (43.2%) vs 9 of 118 patients (8.3%); p<0.05 for LA-SEC. Logistic regression analysis showed that atrial fibrosis (Odds Ratio 2.7; p=0.03) and CHADS2 score (Odds Ratio 4.9; p=0.02) were significant multivariate predictors of LAA thrombus. For LA-SEC, atrial fibrosis (OR 2.2; p=0.01) was the only significant predictor.

Conclusions: Atrial tissue fibrosis is an independent predictor of both LAA thrombus and SEC on TEE. It provides incremental risk stratification to the commonly used CHADS2 score.