Late Gadolinium Enhancement and Recovery of Left Ventricular Function After Catheter Ablation for Atrial Fibrillation

Lay Summary Atrial fibrillation (AF) is an abnormal heart rhythm that can weaken the heart’s pumping function, resulting in heart failure. Catheter ablation is a procedure used to treat AF, in which thin tubes are passed through the blood vessels to the heart to target the areas responsible for the abnormal rhythm. In some patients with AF and heart failure, ablation can allow heart function to recover. However, it remains difficult to predict which patients will benefit most. Magnetic resonance imaging (MRI) of the heart can identify areas of damaged heart muscle, often referred to as scar or fibrosis. The pattern of scar is often used to help identify the cause of heart failure, and previous studies have shown that patients with scar are less likely to have improvement in heart function. In this study, we assessed 134 patients with AF and heart failure who underwent MRI before catheter ablation. We examined whether scar was present, its location and pattern, and how much of the heart muscle was affected. Overall, 101 patients had meaningful improvement in heart function after ablation. Patients who did not improve had approximately twice as much scar as those who did. Scar pattern or location did not predict recovery, but the amount of scar did. This suggests that clinicians should consider the amount of scar, rather than its presence or pattern alone, when estimating recovery after ablation. Even when MRI suggests another cause of heart failure, AF may still be contributing and patients may still benefit from ablation.