The effect of radiographic contrast agents on bleeding time and platelet aggregation

Abstract

Summary:The purpose of this study was to determine whether the use of relatively small amounts of radiographic contrast agents may impair hemostasis. Before and after injection of contrast agents, we measured the template bleeding time, platelet count in whole blood and platelet-rich plasma, platelet aggregation induced by epinephrine and adenosine diphosphate (ADP). and percent disaggregation of ADP-induced platelet aggregates in platelet-rich plasma of 18 patients. Ten patients received 50-100 ml of sodium iothalamate (66.8%) for intravenous urography and 8 patients received 125-200 ml of a combination of meglumine diatrizoate (66%) and sodium diatrizoate (10%) for coronary angiography and left ventriculography. Neither group demonstrated a statistically significant mean difference (p >0.05) for any parameter measured before and after administration of the contrast agents. However, 2 pa- tients who received diatrizoate had lengthening of their bleeding times to greater than twice the baseline value without any change in in vitro platelet aggregation. Physicians should be aware of this potential cause of bleeding which could be of particular danger to patients undergoing cardiopulmonary bypass with its inherent hemostatic defects.

Radiographic contrast agents and platelet function: A quenched‐flow study

“…However, a 1982 French study employing significantly lower RCM concentrations, showed ioxaglate to be the most consistent inhibitor of platelet aggregation, while diatrizoate appeared to promote platelet aggregation, though the increase was not staistically significant [5]. Shortly thereafter, two separate groups of investigators reported no effect of diatrizoate on platelet aggregation in vitro and ex vivo [7,12]. The amount of contrast agent used in these studies was comparable to that in previous reports.…”

“…[ l ] However, there are several reports of inhibition by contrast agents of platelet aggregation, [3-111 while Verdirame et al [12] and Shapiro et al [13] found no effects.…”

Platelet activation during coronary angioplasty in humans.

“…[17][18][19][20][21][22][23][32][33][34] We have demonstrated previously that the use of a low-osmolarity nonionic contrast agent was associated with increased thrombus formation during coronary angioplasty in humans. 24 This observation suggested the hypothesis that contrast agents might influence the effect of balloon dilation on platelet activation and that different agents might have different effects.…”

Spontaneous occlusion of the left anterior descending artery immediately following coronary angiography

“…Different contrast media have been found to have different effects on in vitro platelet function. [2] Previous studies have suggested that the use of different contrast media is associated with different rates of thrombus formation during angioplasty, suggesting that different effects of contrast agents on platelet function and thrombosis demonstrated in vitro may have important clinical implications. [3] During angiography, blood is transiently replaced by the contrast media, which also rapidly reaches the vascular smooth muscles and affects different elements of the blood and blood vessels.…”

“…[1] In vitro studies have demonstrated that contrast media have noticeable effects on platelet function and thrombosis and that these effects differ between various contrast agents. [2] …”