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)-β(1) is related to the degree of atrial fibrosis and the recurrence of AF after surgical maze procedures. Whether TGF-β(1) is associated with the outcome after catheter ablation for AF remains unclear.

Objective: The purpose of this study was to investigate whether plasma TGF-β(1) 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-β(1) 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-β(1) 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-β(1) levels. In patients with nonparoxysmal AF, TGF-β(1) levels and left atrial diameter (LAD) were independent predictors of AF recurrence after catheter ablation. Moreover, TGF-β(1) levels had an incremental value over LAD in predicting AF recurrence after catheter ablation (global χ(2) of LAD alone: 6.3; LAD and TGF-β(1) levels: 11.9; increment in global χ(2) = 5.6; P = .013). Patients with small LAD and low TGF-β(1) levels had the lowest AF recurrence rate at 11%.

Conclusion: TGF-β(1) 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.