The Impact of Transforming Growth Factor‐β1 Level on Outcome After Catheter Ablation in Patients With Atrial Fibrillation
It is known that atrial remodeling due to AF causes an increase in fibrosis, which is associated with a reduction in conduction velocity, and a consequent increase in vulnerability to AF.4 A previous study has showed that transforming growth factor‐β1 (TGF‐β1) is an important factor that induces atrial fibrosis and AF.5 One study reported that elevated TGF‐β1 level is associated with poor outcome after CA for non‐PAF; however, the results were limited because this study included some patients with structural heart disease (SHD) or prior congestive heart failure (CHF).6 This study also suggested that SHD/prior CHF leads to progression of atrial remodeling such as fibrosis. Sanders et al. studied atrial remodeling in non‐AF patients with symptomatic CHF compared to control patients.7 Their study indicated that patients with CHF had increased atrial effective refractory periods, prolonged conduction times, and decreased bipolar voltage signal amplitudes than patients without CHF. Therefore, we believe that it is essential to reevaluate the effect of TGF‐β1 level on CA outcome for AF patients without SHD/prior history of CHF. We also believe that more selective targets may be needed to better characterize an individual patient's‐specific arrhythmic substrate. We hypothesized that repeated occurrence of AF results in elevated TGF‐β1 level, and TGF‐β1 level impacts CA outcome for AF patients without SHD/prior CHF. We evaluated the association between TGF‐β1 level and clinical factors before CA, and investigated the impact of TGF‐β1 level on the outcome after CA for AF.