Atrial and Biventricular Dysfunction Persists after Catheter Ablation and is a Factor of Risk for Post-procedure Atrial Fibrillation Recurrence in Patients with Preserved Left Ventricular Ejection Fraction

BackgroundCatheter ablation (CA) is the leading rhythm control strategy for atrial fibrillation (AF). Despite its effectiveness, AF recurrences, driven by underlying structural and electrical remodeling in both the atria and the ventricle, remain prevalent. Cardiac magnetic resonance (CMR) imaging has emerged as a key modality for assessing myocardial remodeling and potentially identifying predictors of AF recurrence. This study aimed to investigate atrial and biventricular remodeling following CA of AF and its impact on AF recurrence. Methods and ResultsFifty patients with AF (52% male, age 68{+/-}10 years) and twenty healthy controls (45% male, age 68{+/-}10 years) underwent CMR at least three months following CA. Recurrence of AF was evaluated over 1-year follow-up and defined as at least two unsuccessful attempts to restore SR. Atrial function was measured using phasic volumetric and strain parameters. Ventricular function was evaluated through volumetry, global left ventricular (LV) and right ventricular (RV) strain and LV structure through parametric mapping (native T1/T2 mapping and extracellular volume (ECV)). Patients with AF recurrence at 1 year showed significantly impaired LA active emptying function (14{+/-}12% vs 26{+/-}14%, P=0.009) and strain (-4.5{+/-}4.3% vs -10.6{+/-}6.8%, P=0.004), prolongation of both LV T1 (1040{+/-}55ms vs 985{+/-}43ms, P=0.007) and T2 (53.6{+/-}1.6ms vs 50.6{+/-}2.5ms, P=0.002) times and elevated LV ECV (28.0{+/-}3.0% vs 26.2{+/-}1.7%, P=0.027) compared with those without recurrence. A combined model incorporating LA active strain, LV T1 native, ECV and T2 further improved prediction of AF recurrence at 1-year follow-up (HR: 17.70, 95% CI=3.89 - 80.61, log-rank P value <0.001 for cut-off values of LA Active Strain > -8%, T1 > 1017.3ms, ECV > 27% and T2 > 52.4ms). RV free wall longitudinal strain was more negative in AF non-recurrence group compared with controls but not in the AF recurrence group, suggesting the compensatory importance of RV function in post-procedural hemodynamic recovery. ConclusionAF recurrence after CA appears linked to persistent atrial dysfunction and ventricular remodelling, potentially fostering a pro-arrhythmic milieu. Incorporating CMR-derived measures into AF care might help improve personalized risk stratification for CA outcomes.