Big endothelin-1 as a predictor of atrial fibrillation recurrence after primary ablation only in patients with paroxysmal atrial fibrillation

Atrial fibrillation (AF) recurrence after ablation is difficult to predict. The development of AF is associated with inflammation, and inflammatory markers such as big endothelin-1 (big ET-1) reflect inflammatory status. It is unknown, however, whether big ET-1 can be used as a predictor for AF recurrence. The aim of this study was to investigate the relationship between plasma levels of big ET-1 and AF recurrence.

A total of 158 patients who had undergone primary ablation for symptomatic and/or drug-refractory AF, including 103 with paroxysmal and 55 with persistent AF, were included in this study. Left atrial diameter was measured with echocardiography and plasma big ET-1 levels with ELISA. All patients were followed up for at least 12 months and AF recurrence defined as an episode of AF lasting ≥ 30 s, with or without atrial flutter or atrial tachycardia.

The AF recurrence rate was 44.9% (71/158) during the median follow-up period of 22 (13, 40) months. Plasma levels of big ET-1 in the recurrence group were higher than those in the non-recurrence group in all patients [0.80 (0.54, 1.30) vs. 0.57 (0.48, 0.72) fmol·L^{− 1}, p  = 0.001], in patients with paroxysmal AF [0.81 (0.46, 1.30) vs. 0.57 (0.48, 0.70) fmol·L^{− 1}, p  = 0.009] as well as in patients with persistent AF [0.77 (0.57, 1.28) vs. 0.57 (0.49, 0.89) fmol·L^{− 1}, p = 0.034]. Multiple logistic regression analyses showed that plasma levels of big ET-1 were associated with AF recurrence in patients with paroxysmal AF (p  = 0.037). Kaplan-Meier analysis demonstrated that the sinus rhythm maintenance rate was lower in patients with higher big ET-1 levels than those with lower levels (p  < 0.05).

Baseline plasma big ET-1 levels are associated with AF recurrence after primary ablation procedure in patients with paroxysmal AF, and may be used in the prediction of AF recurrence in these patients.