Influence of radiographic contrast media on myocardial oxygen tension: A randomized, NaCl-controlled comparative study of iodixanol versus iomeprol in pigs

Purpose: To examine how a one-time bolus injection of radiographic contrast media (RCM; iodixanol 320 and iomeprol 350) into the left coronary artery of six pigs affects tissue oxygen tension in the artery's supply area (pO(2) LAD) compared to a 0.9% sodium-chloride (NaCl) bolus. Material and Methods: Each animal received a total of three boluses: one iodixanol, one iomeprol, and one NaCl (10 ml each). The radiographic contrast media and NaCl boluses were randomly assigned, and pO(2) profiles were recorded. Results: 26.7 +/- 16.4 s after iodixanol injection, pO(2) LAD had declined by 3.5% from 42.2 +/- 5.6 mmHg to 40.7 +/- 5.9 mmHg (P = 0.0357). After 53 +/- 16.7 s, the initial value was restored. The pO(2) LAD was 41.9 +/- 7.4 mmHg before iomeprol injection, and, 303.3 +/- 58.9 s after injection, pO(2) LAD had declined by 13.1% to 36.4 +/- 7.5 mmHg (P = 0.0001). After 577 +/- 22 s, the initial value was restored. The bolus application of an isotonic NaCl solution resulted in no effect on pO(2) LAD. Immediately after injection, it increased by 3%. In the supply area of the right coronary artery and the peripheral skeletal muscle, no effect of the RCM or NaCl on tissue oxygen tension was observed. Furthermore, no effect on tissue temperature, heart rate, systolic and diastolic blood pressure, or cardiac output per minute occurred. Conclusion: The injection of RCM in a coronary artery can result in a significant local contrast-medium-induced microcirculation disorder. The high viscosity of iodixanol led to a very short-term insignificant effect on the microcirculation, while iomeprol induced a slight time-delayed pO(2) decrease, which might be caused by the rigidification of erythrocytes. In comparison to a previous study with iopromide, the influence of iodixanol and iomeprol on myocardial oxygen tension was markedly less pronounced.