Abstract 14836: Left Ventricular Extracellular Volume on Computed Tomography is Useful for Predicting Reverse Remodeling After Catheter Ablation for Atrial Fibrillation

Introduction: In the CAMERA-MRI study, restoring sinus rhythm with catheter ablation (CA) for atrial fibrillation (AF) significantly improved left ventricular (LV) ejection fraction (EF), particularly in the absence of LV myocardial fibrosis, determined by magnetic resonance imaging (MRI). LV extracellular volume fraction (ECV) on MRI correlates with myocardial fibrosis. Recently analysis of LVECV on computed tomography (CT) has been feasible and LVECV on CT and MRI correlate well. Little is known about what predicts achieving LV reverse remodeling (LVRR) after CA. Hypothesis: LVECV on pre-ablation planning CT could predict LVRR after CA in patients with AF and reduced LVEF. Methods: One thousand three hundred twenty patients underwent CA for AF in our institutions from Apr 2014 to Aug 2022. Of these, 50 patients (4%) with LVEF under 50% on transthoracic echocardiography (TTE) were included. All patients underwent cardiac CT using 320-detector or 256-detector row CT before the CA. LVECV was measured by CT using non-contrast and late-phase cardiac images (Figure A). We defined LVRR as an LV end-systolic volume decrease of 15% or more, an increase in LVEF to 50% or more, or an absolute LVEF increase of 15% or more. We evaluated the utility of LVECV for the prediction of LVRR after CA. Results: LVRR was achieved in 31 patients (62%) after CA, and LVECV was significantly lower in them than in the others (31.3 ± 3.3% vs. 35.9 ± 6.6%, P < 0.01) (Figure B). On receiver operating characteristic curve analysis, the best cut-off of LVECV for the prediction of LVRR was 34.8%, and the sensitivity and specificity of LVECV for the prediction of RR were 90 and 68% (the area under the curve was 0.72, Figure C). On multivariate logistic regression analysis, LVECV less than or equal to 34.8% was the only significant predictor of LVRR. Conclusion: LVECV on CT is useful for predicting LVRR in patients with AF after CA.