Comparison of cardiovascular and renal toxicity after cardiac catheterization using a nonionic versus ionic radiographic contrast agent

Incidence, predictors, and outcomes of post-percutaneous coronary intervention nephropathy in patients with diabetes mellitus and normal baseline serum creatinine levels

Diabetes mellitus is an independent predictor of nephropathy after percutaneous coronary intervention (PCI). The outcomes of patients with diabetes with normal baseline serum creatinine who undergo PCI remain underevaluated. The aim of the present study was to assess the incidence, outcomes, and correlates of post-PCI nephropathy in this subset. The study cohort consisted of 570 patients with diabetes with normal serum creatinine (< or =1.3 mg/dl) who underwent PCI from August 2004 to December 2006. Patients aged >75 years and those presenting with either acute myocardial infarctions or cardiogenic shock were excluded. Post-PCI nephropathy was defined as a > or =25% increase in baseline creatinine. The study end points were post-PCI nephropathy and major adverse cardiac events at 6 months. Logistic regression was performed to identify independent predictors. Post-PCI nephropathy occurred in 70 patients (incidence 12.3%). These patients were more likely to be women (55.7% vs 35.5%, p = 0.001) and to have histories of congestive heart failure (24.2% vs 14.7%, p = 0.048). Entry-site complications (hematoma, pseudoaneurysm) and the need for blood transfusion (16.7% vs 1.7%, p <0.001) were more common in this group. In-hospital mortality (8.6% vs 0.2%, p <0.001) and length of stay (4.51 +/- 5.2 vs 2.23 +/- 2.9 days, p <0.001) were significantly higher in the group with post-PCI nephropathy. No study patient required dialysis. At 6 months, major adverse cardiac events were markedly higher in patients with post-PCI nephropathy (21.4% vs 6.0%, p <0.001), driven by death and revascularization. Independent predictors of post-PCI nephropathy were lower body mass index and blood transfusion. Post-PCI nephropathy independently predicted major adverse cardiac events (hazard ratio 4.3, 95% confidence interval 2.1 to 8.6, p <0.001). In conclusion, post-PCI nephropathy occurred in 12.3% of patients with diabetes with normal baseline serum creatinine and carried a significant detrimental impact on prognosis. The requirement for blood transfusions was the strongest correlate identified.

Epidemiology and prognostic implications of contrast-induced nephropathy

Contrast-induced nephropathy (CIN), usually defined as an increase in serum creatinine of 0.5 mg/dL (44.2 mumol/L), or a 25% increase from the baseline value 48 hours after the procedure, is a common and potentially serious complication of the use of iodinated contrast media in patients at risk of acute renal injury. It is an important cause of hospital-acquired renal failure, responsible for approximately 11% of cases. CIN may be difficult to distinguish from cholesterol embolization, another cause of postprocedure renal impairment. The reported incidence of CIN varies depending on the patient population studied. The impact of postprocedural renal impairment on clinical outcomes has been evaluated most extensively in patients undergoing percutaneous coronary intervention. CIN is associated with increased mortality both in hospital and at 1 year. A higher incidence of in-hospital and late cardiovascular events, as well as longer hospital stays, has been reported in patients developing CIN. In a small proportion of patients, CIN is severe enough to require dialysis, and these patients have a particularly poor prognosis. Many of the risk markers for CIN are also predictive of a worse prognosis.

Effects of Different Contrast Media on Glutathione Peroxidase and Superoxide Dismutase Activities in the Heart and Kidneys of Normal and Streptozotocin-induced Diabetic Rats

BACKGROUND/PURPOSE

Hemodynamic changes and contrast nephropathy are well known complications of contrast media injection. However, the mechanisms of toxicity leading to these complications remain unclear. We hypothesized that contrast media toxicity would manifest as a change in antioxidant enzyme activity, thus leading to tissue damage.

METHODS

This study investigated the effects of injection of ionic high-osmolar diatrizoate, ionic low-osmolar ioxaglate, and nonionic low-osmolar iopromide on the activities of two antioxidant enzymes, glutathione peroxidase (GPX) and superoxide dismutase (SOD), in the heart and kidney tissue of normal male Wistar rats (n = 51) and streptozotocin (STZ)-induced diabetic rats (n = 54). Activities of GPX and SOD were assayed spectrophotometrically.

RESULTS

Renal GPX activities were significantly decreased in both normal (458.3 +/- 64.6 to 385.5 +/- 63.4 mU/mg, p = 0.005) and diabetic rats (669.0 +/- 98.1 vs. 564.0 +/- 153.3 mU/mg, p = 0.035) at 1 hour after diatrizoate injection. Renal SOD activities were not affected after contrast injection. Ioxaglate and iopromide injection did not cause any change in renal antioxidant enzyme activity. In contrast to kidney tissue, there was no significant change in GPX and SOD activities in heart tissue at 1 hour after injection of different contrast media.

CONCLUSION

Intravenous injection of ionic high-osmolar diatrizoate reduced renal GPX activity during the first hour in both normal and STZ-induced diabetic rats. Heart tissue was not prone to antioxidant enzyme activity changes after intravenous contrast media injection. GPX activity reduction can be an important mechanism of nephrotoxicity after contrast media injection.

Comparison of a low osmolarity nonionic radiographic contrast agent with a standard medium on renal function in cyanotic and normal dogs

Renal dysfunction may follow administration of iodinated radiographic contrast agents. This complication may be less common when low osmolarity nonionic agents are used. Although potential benefits from the use of low osmolarity nonionic contrast may be minimal in individuals with normal physiology, a greater benefit has been postulated in the presence of chronic cyanosis. To test this hypothesis, six adult mongrel dogs underwent anastomosis of the inferior vena cava to the left atrium. This produced chronic cyanosis with a mean pO2 of 48 +/- 4 mm Hg and polycythemia with a mean hematocrit of 56 +/- 2 gm%. Three to 5 months after preparation, these cyanotic dogs and five control dogs each received diatrizoate (a high osmolarity ionic agent) or ioversol (a low osmolarity nonionic agent), 465 mg iodine/kg body weight, by intravenous bolus injection. One month later, each animal received the other agent. The order of administration was randomized. Renal function studies, including serum creatinine and creatinine clearance, were performed precontrast, after 60 min, and 24 hr postcontrast. Neither agent adversely affected renal function in either the cyanotic or the normal group. We conclude that at the doses that are commonly used in clinical practice, high osmolarity ionic contrast agents do not create a greater risk of renal injury than do low osmolarity nonionic agents in this model of cyanosis.

Multicenter trial of ionic versus nonionic contrast media for cardiac angiography. The Iohexol Cooperative Study

Contrast agents used for cardiac angiography are different in regard to ionicity, osmolality and physiologic effects. The nonionic contrast media have been shown to have less toxic effects and a better safety profile than do higher osmolar agents. To better assess this risk, clinically stable patients undergoing cardiac angiography were stratified according to the presence of diabetes mellitus, and level of serum creatinine, and then randomized to receive either iohexol (Omnipaque 350) or sodium meglumine diatrizoate (Renografin 76). All adverse events that occurred during and immediately after angiography were tabulated. A multivariate model was used to identify patients at increased risk for adverse outcome. The 1,390 patients were randomized to iohexol (n = 696) or diatrizoate (n = 694). Significant differences were found in the number of patients with contrast media-related adverse (iohexol vs diatrizoate: 10.2 vs 31.6%; p < 0.001) and cardiac adverse (7.2 vs 24.5%; p < 0.001) events. Severe reactions and the need for treatment were more frequent with diatrizoate than with iohexol, but there was no difference in the incidence of death. The presence of New York Heart Association classification 3 or 4 and serum creatinine > or = 1.5 mg/dl predicted a higher incidence of adverse events as a result of contrast media alone. Use of iohexol is associated with a lower incidence of all types of adverse events during cardiac angiography than is diatrizoate.