title: Comparison of the effect of low- and iso-osmolar contrast agents on heart rate during chest CT angiography: results of a prospective randomized multicenter study.
abstract: OBJECTIVE
  To prospectively compare the effect of intravenous injection of low-osmolar iopamidol with that of intravenous injection of iso-osmolar iodixanol on heart rate (HR) during nongated chest computed tomographic (CT) angiography.
  
  
  METHODS
  This multicenter study was approved by local institutional review boards, and patients provided written informed consent. Patient enrollment and examination at centers in the United States complied with HIPAA regulations. One hundred and thirty patients (54 male; mean age, 52 years) clinically suspected of having pulmonary embolism were referred for pulmonary CT angiography and were randomly assigned to receive 80 mL of either iopamidol (370 mg of iodine per milliliter, n = 63) or iodixanol (320 mg of iodine per milliliter, n = 67) at a rate of 4 mL/sec. HR (measured in beats per minute) was monitored from 5 minutes before the start of injection to the end of imaging, and precontrast HR and maximum postcontrast HR were recorded. Student t and χ(2) tests were used for continuous and categorical variables, respectively.
  
  
  RESULTS
  Precontrast HR in patients who received iopamidol (mean, 81 beats per minute ± 18 [standard deviation]) was similar to that in patients who received iodixanol (mean, 77 beats per minute ± 17) (P = .16). Mean postcontrast HR was 87 beats per minute ± 17 and 82 beats per minute ± 18 (P = .16) in the iopamidol and iodixanol groups, respectively. Mean increase from precontrast HR to postcontrast HR was 5 beats per minute ± 9 and 5 beats per minute ± 7 (P = .72) in the iopamidol and iodixanol groups, respectively. Thirty-five (56%) of the 63 patients who received iopamidol and 33 (49%) of the 67 patients who received iodixanol had an HR increase of fewer than 5 beats per minute, 15 (24%) and 18 (27%) patients, respectively, had an increase of 5-9 beats per minute, and four (6%) and three (4%) patients, respectively, had an increase of more than 20 beats per minute. These proportions were not significantly different between the groups (P = .51, χ(2) test).
  
  
  CONCLUSIONS
  High-rate intravenous administration of 80 mL of iopamidol and iodixanol during pulmonary CT angiography slightly increased HR; there was no difference in HR between the contrast agent groups.
authors.affiliation: Radiology Department and Research Center, University of Montreal Medical Center, Hôtel-Dieu Hospital, 3840 Saint-Urbain St, Montréal, QC, Canada H2W 1T8. chartrandlef@videotron.ca
authors.forename: Carl
authors.initials: C
authors.lastname: Chartrand-Lefebvre
authors.forename: Charles S
authors.initials: CS
authors.lastname: White
authors.forename: Sanjeev
authors.initials: S
authors.lastname: Bhalla
authors.forename: William W
authors.initials: WW
authors.lastname: Mayo-Smith
authors.forename: Julie
authors.initials: J
authors.lastname: Prenovault
authors.forename: Kay H
authors.initials: KH
authors.lastname: Vydareny
authors.forename: Jorge A
authors.initials: JA
authors.lastname: Soto
authors.forename: Orhan S
authors.initials: OS
authors.lastname: Ozkan
authors.forename: Aamer R
authors.initials: AR
authors.lastname: Chughtai
authors.forename: Gilles
authors.initials: G
authors.lastname: Soulez
mesh_terms: D016009:Chi-Square Distribution; D003287:Contrast Media / Q000008:administration & dosage / Q000494:pharmacology*; D017023:Coronary Angiography / Q000379:methods*; D004311:Double-Blind Method; D004562:Electrocardiography; D005260:Female; D006339:Heart Rate / Q000187:drug effects*; D006801:Humans; D007275:Injections, Intravenous; D007479:Iopamidol / Q000008:administration & dosage / Q000494:pharmacology*; D008297:Male; D008875:Middle Aged; D009994:Osmolar Concentration; D011446:Prospective Studies; D011655:Pulmonary Embolism / Q000000981:diagnostic imaging*; D014057:Tomography, X-Ray Computed; D014283:Triiodobenzoic Acids / Q000008:administration & dosage / Q000494:pharmacology*; D014481:United States
chemical_list: D003287:Contrast Media; D014283:Triiodobenzoic Acids; C044834:iodixanol; D007479:Iopamidol