The assessment of the left atrial myocardial fibrosis of atrial fibrillation with late Gadolinium enhancement MRI

Abstract

Objective To investigate the clinical value of 2 dimension late Gadolinium enhancement MRI (LGE-MRI) technique for the evaluation of atrial myocardial fibrosis in patients with atrial fibrillation. Methods Forty-nine cases of atrial fibrillation in our hospital from March 2015 to December 2016 were retrospectively collected. The LGE-MR was acquired by the Siemens 3.0 T MR machine before the catheter ablation. The findings of LGE-MR were evaluated by two experienced doctors. The left atrium (LA) were manually segmented into 8 regions in axial view. All patients were classified into 4 stages based on the extent of enhancement, stage 0: absence of enhancement, stage Ⅰ: enhancement appeared in minimal two consecutive slices in single region, stage Ⅱ: enhancement in two regions, stage Ⅲ: enhancement in three or more regions. All electroanatomic maps were obtained after electrical conversion during catheter ablation. The Kappa test was used to assess the consistency of LGE-MRI left atrial myocardial fibrosis and CARTO system of the left atrial endocardial voltage reconstruction. Results Forty-nine cases of atrial fibrillation with LGE-MRI and CARTO were included. There were 17 cases of atrial fibrosis stage 0, 10 cases of stage Ⅰ, 11 cases of stage Ⅱ, 11 cases of stage Ⅲ according to LGE-MRI findings;There were 17 cases of atrial fibrosis stage 0, 19 cases of stage Ⅰ, 12 cases of stage Ⅱ, 11 cases of stage Ⅲ with reference to CARTO findings. The diagnostic accuracy of the LGE-MRI atrial fibrosis was 81.6% (40/49), of which the correlation was good (Kappa= 0.751, P<0.001). Conclusions LGE-MRI can accurately assess the degree of left atrial myocardial fibrosis in patients with atrial fibrillation, help to select the proper candidate and strategy in catheter ablation. Key words: Atrial fibrillation; Magnetic resonance imaging; Comparative study