title: The effect of heart rate reduction by ivabradine on collateral function in patients with chronic stable coronary artery disease.
abstract: OBJECTIVE
  To evaluate the effect of heart rate reduction by ivabradine on coronary collateral function in patients with chronic stable coronary artery disease (CAD).
  
  
  METHODS
  This was a prospective randomised placebo-controlled monocentre trial in a university hospital setting. 46 patients with chronic stable CAD received placebo (n=23) or ivabradine (n=23) for the duration of 6 months. The main outcome measure was collateral flow index (CFI) as obtained during a 1 min coronary artery balloon occlusion at study inclusion (baseline) and at the 6-month follow-up examination. CFI is the ratio between simultaneously recorded mean coronary occlusive pressure divided by mean aortic pressure both subtracted by mean central venous pressure.
  
  
  RESULTS
  During follow-up, heart rate changed by +0.2±7.8 beats/min in the placebo group, and by -8.1±11.6 beats/min in the ivabradine group (p=0.0089). In the placebo group, CFI decreased from 0.140±0.097 at baseline to 0.109±0.067 at follow-up (p=0.12); it increased from 0.107±0.077 at baseline to 0.152±0.090 at follow-up in the ivabradine group (p=0.0461). The difference in CFI between the 6-month follow-up and baseline examination amounted to -0.031±0.090 in the placebo group and to +0.040±0.094 in the ivabradine group (p=0.0113).
  
  
  CONCLUSIONS
  Heart rate reduction by ivabradine appears to have a positive effect on coronary collateral function in patients with chronic stable CAD.
  
  
  BACKGROUND
  NCT01039389.
authors.affiliation: Department of Cardiology, University Hospital, , Bern, Switzerland.
authors.forename: Steffen
authors.initials: S
authors.lastname: Gloekler
authors.forename: Tobias
authors.initials: T
authors.lastname: Traupe
authors.forename: Michael
authors.initials: M
authors.lastname: Stoller
authors.forename: Deborah
authors.initials: D
authors.lastname: Schild
authors.forename: Hélène
authors.initials: H
authors.lastname: Steck
authors.forename: Ahmed
authors.initials: A
authors.lastname: Khattab
authors.forename: Rolf
authors.initials: R
authors.lastname: Vogel
authors.forename: Christian
authors.initials: C
authors.lastname: Seiler
mesh_terms: D000368:Aged; D001552:Benzazepines / Q000494:pharmacology / Q000627:therapeutic use*; D001783:Blood Flow Velocity / Q000187:drug effects; D006328:Cardiac Catheterization; D003097:Collateral Circulation / Q000187:drug effects* / Q000502:physiology; D017023:Coronary Angiography; D003324:Coronary Artery Disease / Q000188:drug therapy* / Q000503:physiopathology; D003326:Coronary Circulation / Q000187:drug effects* / Q000502:physiology; D004562:Electrocardiography; D005260:Female; D006339:Heart Rate / Q000187:drug effects* / Q000502:physiology; D006801:Humans; D064428:Hyperpolarization-Activated Cyclic Nucleotide-Gated Channels / Q000037:antagonists & inhibitors*; D000077550:Ivabradine; D008297:Male; D008875:Middle Aged; D011446:Prospective Studies; D016037:Single-Blind Method; D016896:Treatment Outcome
chemical_list: D001552:Benzazepines; D064428:Hyperpolarization-Activated Cyclic Nucleotide-Gated Channels; D000077550:Ivabradine