Comparison of Siemens Vista and i-STAT Troponin I

I had this combination at a previous facility.  I had the ER staff run the troponin on the iSTAT immediately at draw and then pulled the lab ordered Vista result.  I found that the results correlated well with the understanding that the Vista Troponin rose faster than the iSTAT.
example: 
iSTAT    Vista
0.05       0.07
1.0           1.5
10            15
Of course you need to stress to the users that serial comparisons between the iSTAT and Lab results can not be done.

Also, there were outliers: istat reports negative to low and the Vista reports out elevated.  When investigating these you will find that the patients are chronically elevated, CHF, hypertensive, liver/kidney patients.