A randomized prospective trial of ioxaglate 320 (Hexabrix) vs. iodixanol 320 (Visipaque) in patients undergoing percutaneous coronary intervention

The assessment of thrombotic markers utilizing ionic versus non-ionic contrast during coronary angiography and intervention trial

OBJECTIVE

To determine how two different types of iodinated contrast media (CM), low-osmolar ionic dimer ioxaglate (Hexabrix) and iso-osmolar non-ionic dimer iodixanol (Visipaque), affect multiple indices of hemostasis.

BACKGROUND

In vitro models demonstrate differential effects of ionic and non-ionic CM on markers of hemostasis.

METHODS

This blinded endpoint trial randomized 100 patients to ioxaglate or iodixanol. The primary endpoint was change in endogenous thrombin potential (ETP) following diagnostic angiography. Secondary endpoints included change in markers of fibrinolysis [tissue plasminogen activator (tPA) and plasminogen activator inhibitor 1 (PAI-1)] and platelet aggregation following diagnostic angiography and percutaneous coronary intervention (PCI) with bivalirudin. Data are presented as median [interquartile range].

RESULTS

ETP significantly decreased after diagnostic angiography in both ioxaglate (baseline 1810 nM*minute [1540-2089] to post-angiography 649 nM*minute [314-1347], p < 0.001) and iodixanol groups (baseline 1682 nM*minute [1534-2147] to post-angiography 681 nM*minute [229-1237], p < 0.001), but the decrease was not different between CM (p = 0.70). There was a significant increase in ETP during PCI (n = 45), despite the use of bivalirudin, suggesting a prothrombotic effect of PCI (post-angiography 764 nM*minute [286-1283] to post-PCI 1081 nM*minute [668-1552], p = 0.02). There were no significant differential effects on tPA, PAI-1, and markers of platelet activity.

CONCLUSION

There were no significant differential effects between ioxaglate and iodixanol. Both CM led to significant reductions in thrombin generation and no significant effects on fibrinolytic activity or platelet activity, thereby contributing to a favorable antithrombotic milieu. © 2016 Wiley Periodicals, Inc.

Outcome Differences between Intra-Arterial Iso- and Low-Osmolality Iodinated Radiographic Contrast Media in the Interventional Management of Stroke III Trial

BACKGROUND AND PURPOSE

Intracarotid arterial infusion of nonionic, low-osmolal iohexol contrast medium has been associated with increased intracranial hemorrhage in a rat middle cerebral artery occlusion model compared with saline infusion. Iso-osmolal iodixanol (290 mOsm/kg H2O) infusion demonstrated smaller infarcts and less intracranial hemorrhage compared with low-osmolal iopamidol and saline. No studies comparing iodinated radiographic contrast media in human stroke have been performed, to our knowledge. We hypothesized that low-osmolal contrast media may be associated with worse outcomes compared with iodixanol in the Interventional Management of Stroke III Trial (IMS III).

MATERIALS AND METHODS

We reviewed prospective iodinated radiographic contrast media data for 133 M1 occlusions treated with endovascular therapy. We compared 5 prespecified efficacy and safety end points (mRS 0-2 outcome, modified TICI 2b-3 reperfusion, asymptomatic and symptomatic intracranial hemorrhage, and mortality) between those receiving iodixanol (n = 31) or low-osmolal contrast media (n = 102). Variables imbalanced between iodinated radiographic contrast media types or associated with outcome were considered potential covariates for the adjusted models. In addition to the iodinated radiographic contrast media type, final covariates were those selected by using the stepwise method in a logistic regression model. Adjusted relative risks were then estimated by using a log-link regression model.

RESULTS

Of baseline or endovascular therapy variables potentially linked to outcome, prior antiplatelet agent use was more common and microcatheter iodinated radiographic contrast media injections were fewer with iodixanol. Relative risk point estimates are in favor of iodixanol for the 5 prespecified end points with M1 occlusion. The percentage of risk differences are numerically greater for microcatheter injections with iodixanol.

CONCLUSIONS

While data favoring the use of iso-osmolal iodixanol for reperfusion of M1 occlusion following IV rtPA are inconclusive, potential pathophysiologic mechanisms suggesting clinical benefit warrant further investigation.

Contrast media: are there differences in nephrotoxicity among contrast media?

Iodinated contrast agents are usually classified based upon their osmolality--high, low, and isosmolar. Iodinated contrast agents are also nephrotoxic in some but not all patients resulting in loss of glomerular filtration rate. Over the past 30 years, nephrotoxicity has been linked to osmolality although the precise mechanism underlying such a link has been elusive. Improvements in our understanding of the pathogenesis of nephrotoxicity and prospective randomized clinical trials have attempted to further explore the relationship between osmolality and nephrotoxicity. In this review, the basis for our current understanding that there are little if any differences in nephrotoxic potential between low and isosmolar contrast media will be detailed using data from clinical studies.

Sodium bicarbonate, N-acetylcysteine, and saline for prevention of radiocontrast-induced nephropathy. A comparison of 3 regimens for protecting contrast-induced nephropathy in patients undergoing coronary procedures. A single-center prospective controlled trial

BACKGROUND

Several protective therapies have been developed to prevent contrast-induced nephropathy (CIN). We aimed to investigate the efficacy of sodium bicarbonate by comparing 2 other regimens, including combination of N-acetylcysteine (NAC) plus sodium chloride and sodium chloride alone, to prevent CIN in patients undergoing cardiovascular procedures.

METHODS

We prospectively enrolled 264 patients who were scheduled for cardiovascular procedures and had a baseline creatinine level >1.2 mg/dL. The patients were assigned 1 of 3 prophylactic regimens: infusion of sodium bicarbonate, sodium chloride, sodium chloride plus oral NAC (600 mg bid). Contrast-induced nephropathy was defined as an increase in serum creatinine level >25% or 0.5 mg/dL after 48 hours.

RESULTS

There were no significant differences among groups regarding baseline demographic properties and nephropathy risk factors. The change in creatinine clearance was significantly better in the sodium bicarbonate group than other 2 groups (P = .007). The incidence of CIN was significantly lower in the sodium bicarbonate group (4.5%) compared with sodium chloride alone (13.6%, P = .036) and tended to be lower than in the combination group (12.5%, P = .059). After adjusting the Mehran nephropathy risk score, the risk of CIN significantly reduced with sodium bicarbonate compared with sodium chloride alone (adjusted risk ratio 0.29, P = .043).

CONCLUSIONS

Hydration with sodium bicarbonate provides better protection against CIN than the sodium chloride infusion does alone. Combination therapy of NAC plus sodium chloride did not offer additional benefit over hydration with sodium chloride alone.

Effects of iodinated contrast media on blood and endothelium

The aim of the study was to assess the effects of iodinated contrast media on blood components and endothelium based on experimental and clinical studies and to produce clinically relevant guidelines for reducing thrombotic and hematologic complications following the intravascular use of contrast media. A report was drafted after review of the literature and discussions among the members of the Contrast Media Safety Committee of the European Society of Urogenital Radiology. The final report was produced following discussion at the 12th European Symposium on Urogenital Radiology in Ljubljana, Slovenia (2005). Experimental data indicate that all iodinated contrast media produce an anticoagulant effect and that this effect is greater with ionic contrast media. Several of the in vitro and experimental in vivo studies on haematological effects of contrast media have not been confirmed by clinical studies. Low- or iso-osmolar contrast media should be used for diagnostic and interventional angiographic procedures, including phlebography. Meticulous angiographic technique is the most important factor for reducing the thrombotic complications associated with angiographic procedures. Drugs and interventional devices that decrease the risk of thromboembolic complications during interventional procedures minimize the importance of the effects of contrast media.

Cardiac events after low osmolar ionic or isosmolar nonionic contrast media utilization in the current era of coronary angioplasty

OBJECTIVES

Our study aimed to compare the isosmolar nonionic dimer iodixanol and the low osmolar ionic agent ioxaglate in the current era of percutaneous coronary intervention (PCI), using clopidogrel, enoxaparine, direct stenting, and drug eluting stent.

BACKGROUND

Previous studies have suggested an association between thrombus-related events and type of contrast media.

METHODS

Our prospective single-center study included 498 consecutive patients who were assigned to receive either iodixanol (n = 231) or ioxaglate (n = 267). The primary endpoint was the cumulative rate of in-hospital major adverse clinical events (MACE). A secondary endpoint was the rate of angiographic or procedural complications.

RESULTS

Clinical and angiographic baseline characteristics and procedural data were similar in the 2 groups. A peak anti-Xa > 0.5 IU/ml was obtained in 97% in both groups. Glycoprotein IIb/IIIa inhibitors were used in 42% of patients. Coronary stenting was performed in 91% of patients, with direct stenting in 70%, and drug-eluting stent in 28% of patients. In-hospital MACE was more frequent in patients receiving iodixanol compared with those receiving ioxaglate (4.8% vs. 0.3%, P < 0.005). This difference was mainly related to the appearance of a large thrombus during PCI (6% with iodixanol vs. 0.3% with ioxaglate, P < 0.0001). In multivariate analysis, independent predictors of in-hospital MACE were use of iodixanol (P < 0.01), the higher number of stent used (P < 0.008), bifurcation/ostial lesion (P < 0.01), and balloon dilation before stenting (p < 0.001).

CONCLUSIONS

In our study reflecting the current era of PCI, thrombus-related events are more frequent with the isosmolar nonionic dimer iodixanol than with the low osmolar ionic agent ioxaglate.

Differential effects of the iodinated contrast agents Ioxaglate, Iohexol and Iodixanol on thrombus formation and fibrinolysis

INTRODUCTION

Contrast media (CM) possess both pro-thrombotic and anticoagulant properties. Here we investigate the effect of three classes of CM; Iohexol, Iodixanol and Ioxaglate, on thrombus formation and fibrinolysis in vitro and evaluated the contribution of platelets to this process.

MATERIALS AND METHODS

Non-anticoagulated blood was mixed with CM or saline (50% or 20% (v/v)) for 1 min then citrated. Thrombi were produced in vitro under flow in a Chandler loop. Thrombus structure was visualized by immunohistochemistry using FITC-fibrin/ogen antibodies, and propidium iodide to identify nucleated blood cells. To measure fibrino/thrombolysis release of FITC-labeled fibrinogen, added prior to thrombus formation, was measured over 24 h. Platelet degranulation was analyzed by whole blood flow-cytometry.

RESULTS

No thrombi formed from blood incubated with Ioxaglate. Thrombi formed with Iohexol or Iodixanol weighed > OR = 10x more than saline controls (116+/-52 and 230+/-128 mg vs. 11+/-3 mg, respectively; p<0.0005), and were more resistant to thrombolysis as evidenced by the release of FITC over 24 h (19.1+/-8.9 and 31.9+/-17.2 U vs. 65.1+/-19.1 U, respectively; p<0.02). Thrombi formed with Iodixanol and Iohexol had larger, more diffuse platelet-rich head areas and tail regions composed of a more open fibrinogen/fibrin meshwork enclosing denser RBC rich areas compared to controls. Iodixanol and Ioxaglate did not increase platelet degranulation, but Iohexol caused a significant increase compared to the saline control (percentage of platelets expressing P-selectin 68.9+/-23.43% vs. 4.93+/-1.44%, respectively; p=0.001).

CONCLUSION

Thus thrombi formed with Iodixanol or Iohexol will be larger and more resistant to thrombolysis, whereas Ioxaglate may reduce the risk of thrombus formation.