Abstract 18840: Left Ventricular Enlargement Detected by Cardiac Magnetic Resonance Imaging Predicts Atrial Fibrillation Recurrence Following Pulmonary Vein Isolation

Abstract

Introduction: Recurrence rates of atrial fibrillation (AF) following catheter ablation remain substantial. Studies on cardiac magnetic resonance imaging (cMRI) assessment of predictors of AF recurrence following pulmonary vein (PV) isolation have centered on left atrial volume and fibrosis. We sought to identify other anatomic predictors of recurrent AF following PV isolation by cMRI. Methods: Eighty-seven consecutive patients (72 [83%] male; age 61 ± 10 yrs) who underwent PV isolation for symptomatic AF (63% paroxysmal) and baseline cMRI were evaluated. Baseline left ventricular (LV) mass, LV end-diastolic and end-systolic volumes, LV size, LV ejection fraction, left atrial diameter and area, right atrial sizes, right ventricular size and function and presence of left common PV and right middle PV were assessed by cMRI. Recurrent AF (defined as AT/AF ≥ 30 seconds) during follow up was noted. Results: Over mean follow-up of 372 ± 109 days, a total of 30 (35%) patients had evidence of recurrent AF. Patients with LV enlargement (≥ mild) by cMRI had significantly reduced AF-free survival (53% vs. 73% at 1 year; p = 0.012) and patients with LV mass index ≥ 74.5 g/m 2 had significantly reduced AF-free survival (54% vs. 72% at 1 year; p = 0.031). There was no difference in AF-free survival among patients with and without left atrial, right atrial, and right ventricular enlargement. Patients with and without recurrent AF had similar right ventricular function and LV ejection fractions. In a multivariate analysis of cMRI parameters of cardiac anatomy, LV enlargement was the only significant independent predictor of recurrent AF (HR 2.78; 95% CI 1.26-6.11; p=0.011). Conclusion: Left ventricular enlargement assessed by cMRI is a significant independent predictor of recurrent AF following PV isolation. In addition to abnormal left atrial substrate, negative LV remodeling may also be an important marker of increased susceptibility to AF after ablation.