Left ventricular fibrosis by extracellular volume fraction and the risk of atrial fibrillation recurrence after catheter ablation

Background: Left ventricular (LV) extracellular volume fraction (ECV) provides prognostic information in patients with variety of cardiomyopathies. However, data on the clinical significance of LV ECV in patients with atrial fibrillation (AF), especially in patients without replacement fibrosis are sparse. This study sought to investigate whether the presence of LV fibrosis identified by cardiac magnetic resonance (CMR) ECV quantification would independently predict the recurrence of AF after first catheter ablation (CA) in patients with AF. Methods: A total of 130 consecutive patients who were referred for CA of AF underwent CMR examination prior to ablation. LV function, T1 mapping derived LV ECV, LV late gadolinium enhancement (LGE) were assessed. Patients were followed for arrhythmia recurrence after the CA procedure. Results: Of 130 AF patients, 65 patients had paroxysmal AF, and 65 patients had persistent AF. There were 50 AF recurrences over a median follow-up period of 13 months. LV ECV were significantly higher in patients with recurrent AF compared to those with no recurrence (30.4%±3.3% vs. 27.4%±2.9%, P<0.001). In multivariable model, gender (HR: 0.348, 95% CI: 0.174-0.697, P=0.003), body mass index (BMI) (HR: 1.159, 95% CI: 1.050-1.279, P=0.003), AF duration (HR: 1.006, 95% CI: 1.001-1.011, P=0.017), and LV ECV (HR: 1.158, 95% CI: 1.071-1.251, P=0.000) were significantly associated with AF recurrence. In subgroup of patients without LGE, gender, BMI, AF duration and LV ECV were still the independent predictors of AF recurrence. Conclusions: LV ECV expansion is associated with AF recurrence after CA and is a strong independent predictor of AF recurrence.