title: Topical nitroglycerin and lidocaine to dilate the radial artery prior to transradial cardiac catheterization: a randomized, placebo-controlled, double-blind clinical trial: the PRE-DILATE Study.
abstract: OBJECTIVE
  Transradial access (TRA) is being increasingly used for both diagnostic and interventional cardiac procedures. Use of TRA offers many advantages: decreased bleeding, vascular complications, reduced length of hospital stay, and reduced cost. However, the small size of the radial artery limits the size of the equipment that can be used via this approach. We sought to determine whether pre-procedural administration of topical nitroglycerin and lidocaine increases the size of the radial artery.
  
  
  METHODS
  Patients undergoing transradial cardiac catheterization were randomized in a double-blind fashion to a topical combination of nitroglycerin+lidocaine or placebo ointment. The primary endpoint was change in radial artery size. Secondary endpoints included radial artery spasm and radial artery patency.
  
  
  RESULTS
  86 patients were enrolled (43 allocated to treatment group and 43 to placebo group). Patients underwent ultrasound of the radial artery at baseline and before the catheterization. Complications were rare: one hematoma (placebo group) and one radial artery occlusion (placebo group). Baseline demographic and clinical characteristics were similar. The baseline radial artery cross-sectional area (CSA) was similar in both groups (4.95 ± 0.24 mm(2) in placebo group and 5.14 ± 0.34 mm(2) in the treatment group). However, the final CSA decreased to 4.66 ± 0.25 mm(2) in the placebo group and increased to 5.78 ± 0.38 mm(2) in the treatment group (p=0.02), which corresponded to a decrease in CSA by -5.6 ± 2.1% and an increase in CSA by 16.5 ± 4.2% (p<0.0001), respectively.
  
  
  CONCLUSIONS
  Pre-procedural administration of topical mixture of nitroglycerin+lidocaine increases the size of the radial artery in patients undergoing transradial cardiac catheterization.
  
  
  BACKGROUND
  NCT01155167.
authors.affiliation: Division of Cardiology, University of California San Francisco, San Francisco CA.
authors.forename: Anna T
authors.initials: AT
authors.lastname: Beyer
authors.forename: Ramford
authors.initials: R
authors.lastname: Ng
authors.forename: Amardeep
authors.initials: A
authors.lastname: Singh
authors.forename: Jeffrey
authors.initials: J
authors.lastname: Zimmet
authors.forename: Kendrick
authors.initials: K
authors.lastname: Shunk
authors.forename: Yerem
authors.initials: Y
authors.lastname: Yeghiazarians
authors.forename: Thomas A
authors.initials: TA
authors.lastname: Ports
authors.forename: Andrew J
authors.initials: AJ
authors.lastname: Boyle
mesh_terms: D000287:Administration, Topical; D006328:Cardiac Catheterization / Q000379:methods*; D004311:Double-Blind Method; D005260:Female; D006801:Humans; D008012:Lidocaine / Q000008:administration & dosage* / Q000494:pharmacology; D008297:Male; D008875:Middle Aged; D005996:Nitroglycerin / Q000008:administration & dosage* / Q000494:pharmacology; D017534:Radial Artery / Q000187:drug effects*; D014664:Vasodilation / Q000187:drug effects*; D014665:Vasodilator Agents / Q000008:administration & dosage* / Q000494:pharmacology
chemical_list: D014665:Vasodilator Agents; D008012:Lidocaine; D005996:Nitroglycerin
keywords: Cardiac catheterization; Radial artery; Transradial; Vasodilation