[Effects of contrast media under systemic heparinization on blood coagulation and fibrinolytic system during angiocardiography--comparison of ionic and nonionic contrast media].

Nonionic contrast media are suggested to cause increased thromboembolism (in vivo), because of less inhibitory action on blood coagulation and platelet aggregation (in vitro) as compared with ionic contrast media. Therefore, to prevent thrombotic complication, we examined whether differences in blood coagulation and fibrinolytic system between the two groups received nonionic (iopamidol) and ionic (ioxaglate) contrast media are seen in vivo when 2,500 unit heparin is administered during angiocardiography. 20 patients undergoing routine angiocardiography were randomized to two groups of 10 patients each. Blood heparin concentration, activated partial thromboplastin time, prothrombin time, thrombin-antithrombin III complex (TAT), antithrombin III, fibrinogen, alpha 2-plasmin inhibitor plasmin complex, fibrinogen and fibrin degradation product were measured at four stages during the procedure: before and 5 min after 2,500 unit bolus heparin administration, 5 min after left ventriculography, and at the end of procedure. Systemic heparinization inhibited clot formation in the presence of nonionic contrast media. TAT generations were elevated before heparinization, after heparinization, however these generations were remarkably inhibited in both groups. No remarkable differences were noted at 40 +/- 14 min duration of procedure when these parameters were compared between the two groups. Since nonionic contrast media did not activate blood coagulation and fibrinolytic system with 2,500 unit heparin administration as compared with ionic contrast media, systemic heparinization was demonstrated to be effective in the prevention of thrombotic complication.