NEW YORK (Reuters Health) – The selective sinoatrial I-f current inhibitor ivabradine lowers heart rate in patients with stable coronary artery disease and impaired left ventricular systolic function without causing an increase in rhythm disturbances, according to a study reported in the American Journal of Cardiology online January 20.
Ivabradine was approved as Procoralan by the European Medicines Agency in 2005, but has not yet been approved by the US Food and Drug Administration.
The current findings come from a substudy of the so-called BEAUTIFUL study, which involved 10,917 CAD patients in 33 countries. All of the participants had a heart rate of at least 60 bpm at rest, an LV ejection fraction <40%, and nearly all were on a beta-blocker concomitantly. For the substudy, 840 of these patients underwent 24-hour Holter monitoring at baseline, 1 month, and 6 months. Dr. Michal Tendera of the Medical University of Silesia, Katowice, Poland, and colleagues report that there was no change in 24-hour heart rate over the 6-month period in patients assigned to placebo, but it decreased by 6.3 bpm in those given ivabradine., The occurrence of heart rates <30 bpm was low in both arms. For example, at the last Holter recording, the rate during awake periods was 1.0% with ivabradine and 0.5% with placebo; corresponding rates during sleep were 0.3% and 1.0%. Although there were more patients with a heart rate <40 or <50 beats/min with ivabradine than with placebo, “there was no difference in severity of episodes between groups,” according to the report. The incidence of conduction disturbances was also low, the investigators found. For example, pause due to atrioventricular block longer than 2 seconds during awake periods during the last visit occurred in 1% of patients whether on ivabradine or on placebo. The results confirm that ivabradine significantly lowers heart rate without raising concern for cardiac safety, the authors conclude. “Our observations strongly support the safety of combining ivabradine with beta-blockers in patients with coronary artery disease.” Am J Cardiol 2011.