Transforming growth factor-β₁ level and outcome after catheter ablation for nonparoxysmal atrial fibrillation

Background: Atrial fibrosis plays a role in the development of a vulnerable substrate for atrial fibrillation (AF). Transforming growth factor (TGF)-β₁ is related to the degree of atrial fibrosis and the recurrence of AF after surgical maze procedures. Whether TGF-β₁ is associated with the outcome after catheter ablation for AF remains unclear. Objective: The purpose of this study was to investigate whether plasma TGF-β₁ was an independent predictor of AF recurrence after catheter ablation. Methods: Two hundred consecutive AF patients (154 with paroxysmal AF and 46 with nonparoxysmal AF) underwent catheter ablation. Their TGF-β₁ levels and clinical and echocardiographic data were collected before ablation. Results: Thirty patients (65%) with nonparoxysmal AF and 57 (37%) with paroxysmal AF had AF recurrence after catheter ablation. Among patients with nonparoxysmal AF, those experiencing recurrence had higher TGF-β₁ levels than did those who did not experience recurrence (34.63±11.98 ng/mL vs 27.33±9.81 ng/mL; P =.026). In patients with paroxysmal AF, recurrence was not associated with different TGF-β₁ levels. In patients with nonparoxysmal AF, TGF-β₁ levels and left atrial diameter (LAD) were independent predictors of AF recurrence after catheter ablation. Moreover, TGF-β₁ levels had an incremental value over LAD in predicting AF recurrence after catheter ablation (global χ² of LAD alone: 6.3; LAD and TGF-β₁ levels: 11.9; increment in global χ² = 5.6; P =.013). Patients with small LAD and low TGF-β₁ levels had the lowest AF recurrence rate at 11%. Conclusion: TGF-β₁ level is an independent predictor of AF recurrence in patients with nonparoxysmal AF and might be useful for identifying those patients likely to have better outcomes after catheter ablation.