ACTIVATION OF PLATELETS BY LOW-OSMOLAR CONTRAST-MEDIA - DIFFERENTIAL-EFFECTS OF IONIC AND NONIONIC AGENTS

PURPOSE: To determine the effects of an ionic low-osmolar contrast med ium (ioxaglate) and two nonionic low-osmolar contrast media (iohexol a nd iopamidol) on human platelet activation in vitro. MATERIALS AND MET HODS: Flow cytometry analysis subsequent to reaction with fluorescence -labeled monoclonal antibodies was used to detect antigens that appear on the platelet surface on activation. RESULTS: Ioxaglate did not act ivate platelets, but evidence of platelet activation by iohexol and io pamidol was found in blood from two and three healthy volunteers, resp ectively, of the six volunteers studied. In addition, ioxaglate inhibi ted the thrombin-induced in vitro activation of platelets, whereas ioh exol and iopamidol did not. CONCLUSION: These findings support a tende ncy toward a higher frequency of thromboembolic complications with non ionic low-osmolar contrast media, although clinical trials will be nee ded to confirm this possible trend.