Both ionic and nonionic contrast agents used in angiography are relatively well tolerated but have a number of undesirable effects, particularly on the cardiovascular system and the kidney.1-7 Whereas low osmolar agents may reduce acute events, contrast nephropathy remains a common cause of in-hospital renal injury, and the potential advantage of one contrast agent over another is less well defined.2,3 The best method of evaluating the relative toxicity of iopamidol and diatrizoate is by a randomized controlled clinical trial. In principle, there are 2 major designs for a randomized trial: (1) a cohort trial that compares results between different patients, and (2) a crossover trial that compares results within the same patient. The crossover design provides the greatest assurance that between-patient differences will not affect the results, and this design is generally well suited for investigations of pharmaceuticals. As part of a randomized trial using a cohort design,1,2 we prospectively designed a crossover protocol so that any patient randomized in the trial would receive the alternative contrast agent if a second coronary angiogram proved to be clinically indicated within the study period. In all, 67 of the 443 randomized patients had a second procedure, 41 of whom received the alternative agent. This report summarizes the results of 41 randomized patients in this prospective controlled crossover investigation.
ASJC Scopus subject areas
- Cardiology and Cardiovascular Medicine