Contrast media effects on hemostatic and thrombotic parameters. Possible consequences for practical techniques and prophylactic measures.

Abstract

This paper reviews the basic mechanisms of the thrombohemorrhagic balance and ways in which contrast media (CM) influence these processes. Coagulation and platelet functions are strongly inhibited by ionic CM, but weakly so by nonionic CM, whereas the former are more detrimental to endothelium, and thus thrombogenic in this sense. Some observations indicate a lower rate of thromboembolic events with the ionic CM in percutaneous transluminal coronary angioplasty (PTCA) and coronary artery bypass grafting (CABG), but this purported difference does not effect mortality or frequency of re-PTCA and emergency CABG. Thus, to challenge these events, strong acting antithrombotics, which also, unlike heparin, inactivate fibrin-bound thrombin, are necessary. Aggressive anti-atherogenic prophylaxis may hamper both thrombosis and reocclusion. The ideal antithrombotic in this setting is yet to be found.