Effects Of Ionic Contrast Media On Platelet Activation And Aggregation

Objective:Contrast media is widely used in imaging examination and interventional therapy. In recent years, with the development of technology and increased of complicated cases the dosage of contrast media increased. Contrast media related complications of the cardiac toxicity, contrast-induced nephropathy and effects on platelet activation and aggregation have received more and more attentions. At present, there were many experimental and clinical studies respond to the cardiac toxicity and the contrast-induced nephropathy that had shown to be of clinical importance. But,the influence of contrast media on platelet activation and aggregation, for many years there were no significant development. We study whether platelet aggregation function is associated with contrast media by measuring platelet aggregation in various inducers and the key ways of influence approachs.Method: The study was performed in 22 patients (mean age 38.00±15.01 years, 9 males and 13 females) undergoing radio frequency catheter ablation for paroxysmal supraventricular tachycardia in The Second Hospital of Hebei Medical University. The criteria for exclusion include as the followings: hematological diseases, hemorrhagic disease and bleeding tendency; severe hepatorenal function insufficiency; receive the therapy of ticlopidine, clopidogrel, dipyridamole, warfarin, antifibrinolytic agents, standard heparin and low molecular weight heparin in four weeks; acute and subacute infection. After venipuncture successfully, ionic contrast media of compound meglumine diatrizoate were injected. Blood samples were obtained at pre-injection, post-injection 10 minutes and post-injection 20 minutes. Aggregation was assessed with a mobile four-channel impedance aggregometer (Chronolog-Log Corporation), which allowed measurement of aggregation beginning 1 hour after blood sampling. Platelet aggregation in the whole blood induced by ADP (10μmol/L), arachidonic acid (10μmol/L) and epinephrine (10μmol/L). Continuous variables were expressed as the mean value plus or minus standard deviation (SD). The repeated measures engineered variance analysis was performed to compare differences for individual time points. Multiple comparison was used LSD-t test. A P value of <0.05 was considered statistically significant.Results: In the arachidonic acid-induced platelet aggregation in the whole blood was lowest at pre-injection (10.68±4.79 Ohms), highest at post-injection 10 minutes (13.09±4.55Ohms). Platelet aggregation at post-injection 20 minutes (12.73±5.20 Ohms) was lower than post-injection 10 minutes but still higher than pre-injection. Multiple comparisons showed statistical difference between pre-injection and post-injection 10 minutes, but there were no statistical difference showed between either pre-injection and post-injection 20 minutes or post-injection 10 minutes and post-injection 20 minutes. In the epinephrine- induced platelet aggregation in the whole blood was also lowest at post-injection 10 minutes(8.83±3.23 Ohms), highest at post-injection 20 minutes(10.75±5.22 Ohms). Platelet aggregation at post-injection 20 minutes (9.92±5.76 Ohms) was lower than post-injection 10 minutes but still higher than pre-injection. But there were no statistical difference showed among three times. In the ADP-induced platelet aggregation at pre-injection(10.77±5.58 Ohms) was higher than post-injection 10 minutes. But platelet aggregation at post-injection 20 minutes was the highest among three times. But there were also no statistical difference showed among three times.Conclusions: We used the impedance method for measuring aggregation in whole blood,showed that in the arachidonic acid- induced platelet aggregation was significantly highest at post-injection 10 minutes, lowest at pre-injection and the differences achieve statistical significance. It demonstrated an enhancement effect of contrast media on platelet aggregation. Platelet aggregation in response to other inducers didn't show the association with contrast media.It showed that the arachidonic acid approach was the key way of contrast media influence platelet aggregation function.