[Comparison of iodixanol (Visipaque) and ioxaglate (Hexabrix) in coronary angiography and ventriculography: a double-blind randomized study]. / Comparaison de l'iodixanol (Visipaque) et de l'ioxaglate (Hexabrix) en coronaro-ventriculographie: une étude randomisée en double aveugle.

OBJECTIVE: To evaluate and compare in a double-blinded and prospective study the incidence of adverse reactions between two contrast agents used for coronary angiography and ventriculography. The first agent was the non-ionic, dimeric, isotonic contrast medium iodixanol (Visipaque), the other was the ionic dimeric contrast medium ioxaglate (Hexabrix). METHODS: A total of 110 consecutive patients were randomized and received either iodixanol 320 mgl/ml or ioxaglate 320 mgl/ml. The efficacy, safety, tolerability and specific cardiovascular effects were evaluated. Adverse reactions were recorded during the procedure and during the first 24 hours after the examination. Hemodynamic and electrophysiological parameters were recorded before and after the ventricular injection and the first injections into the left and right coronary artery, respectively. RESULTS: The incidence of clinical adverse reactions was significantly different between iodixanol and ioxaglate (3% vs 28%, p = 0.0004). 24 patients (16 iodixanol; 8 ioxaglate) experienced no discomfort (sensation of warmth, coldness or pain), and the intensity of discomfort experienced by the remainder was similar for the two groups. No patient reported pain. During the 3 minutes after injection of contrast medium, the LV end-diastolic pressure increased but, apart from one reading, the increases with iodixanol were always significantly different (p < 0.05), and less than those for ioxaglate. During the same time period, heart rate was increased to a greater extent by ioxaglate (p < 0.05). QT interval was significantly (p < 0.05) prolonged with both ioxaglate and iodixanol, but the changes were less marked after iodixanol. The angiographic studies were of diagnostic quality for all patients and optimal diagnostic information was achieved in 92% of both groups. CONCLUSION: This randomized study shows that iodixanol and ioxaglate are of comparable diagnostic efficacy in coronary angiography and ventriculography, but that iodixanol is better tolerated by patients and results in less marked hemodynamic and eletrophysiological changes than does ioxaglate.

Comparison of iodixanol 270 with iohexol 300 in infrapopliteal arteriography. Digital densitometric analysis of angiographic opacification.

PURPOSE: To compare iodixanol 270 mg I/ml with iohexol 300 mg I/ml in infrapopliteal arteriography by measuring digital densitometric vessel opacification and by visually assessing angiographic enhancement. MATERIAL AND METHODS: In a double-blind, dual-balanced, 4-sequence cross-over design, 50 claudicant patients received two contrast media injections (10 min interval) in the superficial femoral artery. Digital angiography was performed at 8 frames/s and time-density curves with a circular region of interest over a distal calf artery were generated. A mixed, linear model was used to identify effects influencing the density measurements. Subjective evaluation of the image quality was made independently by two observers. RESULTS: No statistically significant difference between the contrast media was revealed in the analysis of the densitometric measurements (p=0.14) nor in the subjective visual evaluation (p=0.74). However, the mean density at the time of maximum opacification was higher after the first injection than that after the second injection (p=0.02). There was a tendency towards lower intensity of warmth during injection of iodixanol 270 than during injection of iohexol 300. CONCLUSION: In patients with severe occlusive atherosclerotic disease, iodixanol yielded the same image quality as iohexol in infrapopliteal arteriography, in spite of the 30 mg I/ml lower iodine concentration.

Main results of the first comparative clinical studies on Visipaque.

The results are reviewed from 18 European clinical vascular studies in 1950 patients where iodixanol (Visipaque) - a new isotonic, dimeric, nonionic contrast medium (CM) - is compared to other CM. Visipaque gave better patient comfort, i.e., less pain and heat sensation after vascular injections than the comparative CM. Adverse events reported after Visipaque were otherwise similar to nonionic CM but lower than after ioxaglate (Hexabrix) and other ionic CM. Human renal safety of Visipaque has been extensively studied. Only small changes in glomerular filtration rate and serum creatinine were measured with the monomeric nonionic CM as well as with Visipaque. The excretion of marker enzymes for renal tubular cell function was generally lowest for Visipaque. Thus Visipaque was highly tolerable in the kidneys. To study cardiac safety, electrophysiological and hemodynamic changes were recorded. Visipaque had generally no electrophysiological or hemodynamic effects, or less pronounced effects compared to the other CM. Radiograms revealed that Visipaque 320 mg I/ml yielded the same attenuation as 350 to 370 mg I/ml of the other CM and, similarly, 270 mg I/ml of Visipaque gave as good visualization as 300 mg I/ml of comparative CM.

Rate of accumulation of blood lactate during graded exercise as a predictor of 'anaerobic threshold'.

The subject group comprised 35 endurance-trained males: 11 young adults, 11 seniors and a control group of 13 young adults. A graded submaximal exercise test on a treadmill was performed by 22 of the subjects. The exponential function [La-] = a.ebx + c (where x = running velocity) showed a high degree of correlation with the experimental results (mean r = 0.997) and had randomly distributed residuals. Twenty-two subjects performed a series of running sessions at constant speed to establish the highest working intensities that could be endured without an increase in blood lactate (BLa) - the maximal steady-state workload (MSSW). The observed velocities of MSSW were related to the BLa vs velocity curves from the graded test. The graded submaximal exercise tests yielded mean derivatives from the BLa vs velocity relationship curves equal to 0.089 and 0.083 mM per m.min-1 for the young and senior groups, respectively. The derivatives had moderate inter-individual variations. In reversing the procedure, MSSW was estimated for all of the subjects using a common slope of 0.086. Only small individual variations were found between observed and estimated MSSW. The mean BLa value f (x), calculated using exponential functions where x = individual observed MSSW, was 3.0 mM. Thus, for endurance-trained athletes, a BLa accumulation rate of 0.086 mM per m.min-1 or, alternatively, a fixed BLa concentration of 3 mM, is recommended as a predictor of MSSW when analysing the BLa-velocity profiles from a graded submaximal test.

Safety and tolerability of iodixanol in healthy volunteers with reference to two monomeric X-ray contrast media.

The low osmolar, non-ionic X-ray contrast media have shown a lower frequency of adverse events than the older ionic ones. In this study changes in routine clinical-chemical parameters in blood and urine, vital signs and adverse events were recorded in six groups of 10 healthy male volunteers receiving either iodixanol, a new non-ionic, dimeric X-ray contrast medium for general vascular use, or one of the two non-ionic, monomeric contrast media iopentol and iopamidol. Minor decreases were observed in the values for haemoglobin, haematocrit and erythrocytes 5 min and 3 days after injection of iodixanol. A minor increase was seen in platelets and total protein after 3 days. A transient increase in serum osmolality was seen 5 min after the injections of iopentol and iopamidol. This was not seen in any iodixanol group. The level of thyrotropin showed an increase in all groups at 3 days. It was back to normal within 21 days. No changes of clinical importance were seen regarding blood pressure, heart rate or ECG in any volunteer. No severe adverse events were reported. All events were of short duration, and of mild or moderate intensity. The results, however, may indicate a lower frequency of adverse events/discomfort after the administration of the dimeric iodixanol than the 2 monomeric contrast media iopentol and iopamidol.

Evaluation of renal function with delayed CT after injection of nonionic monomeric and dimeric contrast media in healthy volunteers.

A new nonionic dimeric contrast medium (CM), iodixanol, was intravenously administered to 40 healthy male volunteers in doses of 0.3-1.2 g of iodine per kilogram of body weight, nonionic monomeric iopamidol and iopentol were administered to 20 others, and the renal effects were studied up to 120 hours after administration. Computed tomography of the kidneys was performed up to 80 hours after injection. Creatinine clearance as an index of the glomerular filtration rate was unchanged with all CM. Urine volume and osmolar clearance increased most with the monomeric CM. The proximal tubular brush border enzyme alkaline phosphatase increased with all CM. The lysosomal enzyme N-acetyl-beta-glucosaminidase increased more with the monomeric CM than with iodixanol. A persistent increased attenuation in the region of the cortex was observed with all CM. Attenuation returned to baseline within 80 hours, with the slowest decline with iodixanol. This delayed cortical enhancement did not correlate with the effects of the CM on the tubular enzyme excretion.