Related Experiment Videos
In vivo effects of contrast media on coronary thrombolysis
Insights
Radiographic contrast media (CM) can significantly delay reperfusion when used before alteplase-induced thrombolysis in a canine coronary artery thrombosis model. Iohexol and amidotrizoate notably impaired reperfusion, highlighting potential interactions with fibrinolytic therapy.
Area of Science:
- Cardiovascular Research
- Pharmacology
- Interventional Cardiology
Background:
- Contrast media (CM) are known to inhibit fibrinolysis in vitro.
- In vivo effects of CM on thrombolysis remain largely unknown.
- CM interact with endothelial cells, platelets, and the coagulation system.
Purpose of the Study:
- To evaluate the impact of radiographic contrast media on alteplase-induced coronary thrombolysis.
- To investigate the in vivo effects of different types of CM on thrombolysis efficacy.
Main Methods:
- Occlusive coronary artery thrombosis induced in a canine model using the copper coil technique.
- Randomization into four groups receiving intracoronary saline, ioxaglate, iohexol, or amidotrizoate.
- Thrombolysis initiated with alteplase, aspirin, and heparin, with coronary flow monitored.
Main Results:
- Iohexol and amidotrizoate significantly delayed reperfusion compared to placebo (67±48 min and 65±49 min vs. 21±11 min).
- These CM also reduced the duration of coronary perfusion (21±26 min and 21±28 min vs. 58±40 min).
- No significant differences in coagulation parameters (aPTT, TAT, fibrinogen) were observed between groups.
Conclusions:
- Administration of iohexol and amidotrizoate prior to thrombolysis significantly delayed reperfusion in this animal model.
- Potential interactions between CM and fibrinolytic agents warrant consideration in clinical trial design.
- Clinical implications for patients receiving local fibrinolytic therapy should be evaluated.
Objectives:
The aim of the present study was to evaluate the influence of radiographic contrast media (CM) on alteplase-induced coronary thrombolysis.
Background:
Contrast media inhibit fibrinolysis in vitro and interact with endothelial cells, platelets and the coagulation system. The in vivo effects of CM on thrombolysis are not known.
Methods:
Occlusive coronary artery thrombosis was induced in 4 groups of 10 dogs by the copper coil technique. After 70 min of occlusion the dogs were randomized to intracoronary injection of 2 ml kg(-1) of either saline, a low-osmolar ionic CM (ioxaglate), a low-osmolar nonionic CM (iohexol) or a high-osmolar ionic CM (amidotrizoate). Thrombolysis with alteplase and co-therapy with aspirin and heparin was initiated after 90 min of occlusion. The coronary artery flow was monitored with an electromagnetic flowmeter throughout the experiment.
Results:
Iohexol and amidotrizoate, but not ioxaglate, were associated with longer reperfusion delays (time to optimal reperfusion: 67+/-48 min and 65+/-49 min, respectively, vs. 21+/-11 min after placebo; p < 0.05) and shorter periods of coronary perfusion (optimal perfusion time: 21+/-26 min and 21+/-28 min, respectively, vs. 58+/-40 min after placebo; p < 0.05). No significant differences were observed between groups with regard to activated partial thromboplastin times, circulating thrombin-antithrombin III complex concentrations and fibrinogen.
Conclusions:
In this animal model administration of iohexol and amidotrizoate before thrombolysis significantly delayed reperfusion. This interaction should be considered in the design of clinical trials of thrombolytic therapy that evaluate coronary artery patency and in patients receiving local infusions of fibrinolytic agents.