Chromium chloride administration causes a substantial reduction of coronary lipid deposits, aortic lipid deposits, and serum cholesterol concentration in rabbits.

This experiment was carried out to test the null hypothesis that intramuscular trivalent chromium administration would not remove lipids from the heart and ascending aorta of the hyoercholesterolemic rabbits and would not lower their serum cholesterol levels. A novel computer-based method, previously described, was used to assess the sizes of the intracardiac and aortic lesions. Clinical chemistry and histopathology were performed through routine methods. The sizes of the lipid deposits in the coronary vasculature of the hypercholesterolemic rabbits were greatly reduced as a result of the intramuscular chromium chloride injections. Lipid deposits in the ascending aorta were similarly reduced, as well as the serum cholesterol concentrations. The terminal serum chromium concentrations in the chromium-treated group were in the range of 3,258-4,513 microg/L, whereas, in the untreated animals, the concentrations were 3.2 to 6.3 microg/L. The general condition of the chromium-treated animals was good and they were continuing to gain weight up to the time they were killed. However, it was found that their liver function tests had become abnormal even though there was no evidence of hepatic histopathological lesions specifically affecting the chromium-treated group. The kidney function tests and histopathology were normal. These findings suggest that a more aggressive approach than those tried hitherto might be useful in treating atherosclerotic human patients with chromium.

Reliability of the rapid bedside whole-blood quantitative cardiac troponin T assay in the diagnosis of myocardial injury in patients with acute coronary syndrome.

BACKGROUND: A rapid bedside whole-blood quantitative cTnT assay has recently been developed. We evaluated the reliability of this test for the diagnosis of myocardial injury in patients with acute coronary syndrome (ACS). MATERIAL/METHODS: Whole-blood cTnT levels were measured in 96 patients with ACS using the Roche Cardiac Reader(R) rapid bedside assay device, and the results were compared with serum cTnT levels in the same patients measured by the Roche Elecsys(R) Immunoanalyzer. There were 50 patients with clinical evidence of myocardial injury and 56 without. RESULTS: From the qualitative point of view (reporting negative or positive tests), the results of the rapid bedside tests were identical to those obtained by the serum immunoanalyzer. From quantitative the point of view, the rapid bedside tests could not measure exact values below 0.1 ng/ml (reported negative) or above 2.0 ng/ml (reported >2.0). The measurements made by the rapid bedside tests within the range of 0.1 to 2.0 ng/ml correlated well with those of the serum immunoanalyzer (Cardiac Reader(R) cTnT=0.61, Elecsys(R) cTnT+0.12; r=0.88), but their mean values were significantly lower (1.20I0.71 vs. 1.41I1.03, p=0.0007). CONCLUSIONS: The rapid bedside cTnT assay correlates well with immunoanalyzer measurements between the values of 0.1 and 2.0 ng/ml. However, they tend to give significantly lower values and fail to give exact values below 0.1 and above 2.0 ng/ml, which may affect their performance in monitoring and managing patients with ACS, and limit their use in predicting outcome.

Evaluation of 6 cardiac troponin assays in patients with acute coronary syndrome.

OBJECTIVE: An increasing body of evidence has demonstrated the value of strategies based on cardiac troponin (cTn) assays in the diagnosis, prognosis and monitoring of patients with acute coronary syndrome (ACS). We evaluated the performance and the practicability of 6 commercially available assays (5 cTnI and 1 cTnT) in patients with ACS. METHODS: This study was carried out between October 2001 and June 2002 at Armed Forces Hospital in collaboration with Prince Sultan Cardiac Center, Riyadh, Kingdom of Saudi Arabia. Blood samples from 96 patients, 40 with and 56 without clinical evidence of myocardial injury, were used for the evaluation. Cardiac TnI assays were performed using 5 different immunoanalyzers AxSYM (Abbott Laboratories), Stratus CS (Dade Behring), ACS:180 (Bayer), Centaur (Bayer) and Immulite (Diagnostic Products Corporation) while cTnT was measured on the Elecsys (Roche) immunoanalyzer. The sensitivity, specificity and positive and negative predictive values (PV) were calculated for all assays. General and special features related to installation, routine operation, quality control and other various special parameters of each immunoanalyzer were evaluated (using the score of 1-5 for each parameter) and compared with those of other analyzers. RESULTS: The highest reliability values were observed with Immulite, followed by AxSYM, then Stratus, then ACS:180, and Centaur, and lastly by Elecsys. The highest practicability values were observed with Elecsys, and Centaur, followed by AxSYM and the lowest values were observed with Stratus. CONCLUSION: Considering the combined performance and practicability score, the difference between the 10% coefficient variation cut off value and the 99th percentile value, and the difference in the relative reactivities to the various cTnI forms, the most favorable values were observed with AxSYM, followed by Immulite and Elecsys, then Centaur and Stratus, and lastly by ACS:180.