Ivabradine reduced ventricular rate in patients with non-paroxysmal atrial fibrillation

Background: It has been shown that I-f channels can be found in AV node, apart from the sinus node. Previous animal studies showed that I-f inhibitor resulted in the rate-dependent reduction in AV node conduction during atrial fibrillation (AF). Therefore, we aimed to examine the effect of ivabradine on ventricular rate in patients with non-paroxysmal AF. Method: This study was a prospective randomized, double blind, placebo-controlled study. Ivabradine, 5 mg twice a day (n = 21), or placebo (n = 11) was administered for 1 month to adult patients with non-paroxysmal AF, in addition to standard therapy. The primary end point was the change in mean ventricular rate between baseline and 1 month, as assessed by 24-hour Holter. Results: The baseline characteristics did not differ between ivabradine and placebo groups (mean age was 59.7 +/- 13.3 years, male 62.5%). Mean 24-hour ventricular rate at baseline was comparable between 2 groups. We found that ivabradine significantly decreased mean ventricular rate from 86.0 +/- 10.9 beats/min to 79.2 +/- 9.6 beats/min (p < 0.001). In contrast, no significant change in ventricular rate was observed in placebo group (84.3 +/- 11.2 vs. 82.9 +/- 9.9 beats/min, p = 0.469). The effect of ivabradine on rate reduction was significantly greater than placebo (6.9 +/- 6.3 vs. 1.4 +/- 6.0 beats/min, p = 0.024). No drug-related adverse effects were observed in both groups. Conclusion: We demonstrated that ivabradine significantly decreased ventricular rate during AF compared to placebo. Therefore, ivabradine can be a potential treatment to improve ventricular control in patients with non-paroxysmal AF. Due to the small sample size, larger studies are needed to confirm this effect of ivabradine. (C) 2016 Elsevier Ireland Ltd. All rights reserved.