title: A comparison of nonionic, low-osmolality radiocontrast agents with ionic, high-osmolality agents during cardiac catheterization.
abstract: BACKGROUND
  Nonionic, low-osmolality radiocontrast agents are used frequently because they are believed to be safer than ionic, high-osmolality agents, but they are also more expensive. We conducted a randomized trial to compare the incidence of adverse events after the administration of ionic, high-osmolality and of non-ionic, low-osmolality radiocontrast agents during cardiac angiography.
  
  
  METHODS
  We compared the need to treat patients for adverse reactions and the frequency and severity of specific hemodynamic, systemic, and symptomatic side effects in two groups of patients randomly assigned to receive either ionic, high-osmolality or nonionic, low-osmolality radiocontrast material, and also in 366 patients who could not be randomized.
  
  
  RESULTS
  Treatment for adverse events was required in 213 of 737 patients who received high-osmolality contrast agents (29 percent) but in only 69 of 753 patients who received nonionic agents (9 percent) (95 percent confidence interval for the percent difference, 15.9 to 23.6 percent). Hemodynamic deterioration and symptoms also occurred more often in the high-osmolality group, as did severe or prolonged reactions (2.9 percent, as compared with 0.8 percent in the nonionic group; P = 0.035). The severe reactions were largely confined to patients with severe cardiac disease. Multivariate analysis showed that the presence of severe coronary disease and unstable angina were predictors of clinically important adverse reactions. If all the patients in our randomized trial had been given nonionic contrast material, the incremental cost per procedure would have been $89.
  
  
  CONCLUSIONS
  Nonionic, low-osmolality contrast material is better tolerated during cardiac angiography than ionic, high-osmolality contrast material. Since cost constraints may prevent the universal use of nonionic contrast material, its selective use in patients with severe cardiac disease could be considered.
authors.affiliation: Department of Medicine, General Hospital, Memorial University, St. John's, Newfoundland, Canada.
authors.forename: B J
authors.initials: BJ
authors.lastname: Barrett
authors.forename: P S
authors.initials: PS
authors.lastname: Parfrey
authors.forename: H M
authors.initials: HM
authors.lastname: Vavasour
authors.forename: F
authors.initials: F
authors.lastname: O'Dea
authors.forename: G
authors.initials: G
authors.lastname: Kent
authors.forename: E
authors.initials: E
authors.lastname: Stone
mesh_terms: D003287:Contrast Media / Q000009:adverse effects / Q000191:economics*; D017023:Coronary Angiography; D003362:Cost-Benefit Analysis; D004311:Double-Blind Method; D005260:Female; D006801:Humans; D008297:Male; D008875:Middle Aged; D015999:Multivariate Analysis; D009994:Osmolar Concentration; D017064:Process Assessment, Health Care; D012044:Regression Analysis
chemical_list: D003287:Contrast Media