Anticoagulant profile of iopamidol and meglumine amidotrizoate and their lack of thrombin generation: an in vitro study.

The aim of this in vitro study was to sketch the subtle anticoagulant profile of iopamidol 300 mg l/ml (low osmolality non ionic contrast medium) and meglumine amidotrizoate 370 mg l/ml (high osmolality ionic contrast medium) in situations where variable amounts of clotting factors are observed and to check whether thrombin-generation significantly occurred in non anticoagulated blood-contrast materials mixtures. In the first experiment, mixtures of deficient plasmas with a routine plasma pool provided different ranges with variable amounts of clotting factors II, V, VIII, X, XI and XII. For each clotting factor level studied within these ranges, an activated partial thromboplastin time was determined with either contrast material loaded thromboplastin (5% v/v) or glucose loaded thromboplastin (5% v/v) used as a control. In the second experiment fibrino-peptide A (FpA) or modified antithrombin III (ATM) assays were performed in either (9:1) non anti-coagulated blood contrast materials mixtures or blood-glucose mixtures (control). Differing aPTT prolongation profiles were observed when clotting factors V, VIII, XI and XII were lowered in the plasma. However, neither iopamidol nor amidotrizoate induced an aPTT prolongation with decreasing clotting factor II. In the second experiment no significant thrombin generation was observed as both blood-contrast materials mixtures showed significantly lower FpA and ATM levels (p < 0.001) than glucose control after 5 minutes and 10 minutes incubation at room temperature. These findings provide evidence that the use of iopamidol in angiographic procedures does not increase risk of clotting or hemorrhage.