CardioDetect® - Performing the test

The test may be performed with capillary or venous whole blood, serum or plasma. Citrate or Heparin may be used as anticoagulation reagent. EDTA as additive may not be used!

Make sure that at least 20 minutes have passed since the onset of symptoms.

Place the card on an even surface and peel off the seals of the test fields.

Fill both test fields completely with the sample material (with 3-4 drops equivalent to 80–100µl).

• Pay close attention to use sufficient sample! Insufficient sample volume is the most frequent cause of invalid results.

Wait for 15 minutes. Then read the results in the test result windows above the test fields.  (Do not read the results later than 20 minutes.)

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Evaluation of the results from CardioDetect^®

Result of the h-FABP test:

2 stripes	= positive (h-FABP > 7ng/ml)
Only 1 stripe at "CONTROL"	= negative (h-FABP < 7ng/ml)
Only 1 stripe at "RESULT"	= Invalid result. Perform new test.
No stripe at all	= Invalid result. Perform new test.

Result of the cTnI test:

2 stripes	= positive (cTnI > 1.5ng/ml)
Only 1 stripe at "CONTROL"	= negative (cTnI < 1.5ng/ml)
Only 1 stripe at "RESULT"	= Invalid result. Perform new test.
No stripe at all	= Invalid result. Perform new test

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"Interpretation of CardioDetect®

The point-of-care test CardioDetect^® shows either one or two lines. The “Control” line must appear in all cases for the test to be valid. The “h-FABP” line shows whether this cardiac marker is significantly elevated or not (positive/negative). The strength of the line indicates the degree of elevation:

Dark line	Light but definite line
AMI	AMI if other influences can be excluded (e.g. renal insufficiency).	No AMI

In case of doubt that “No AMI” is present perform a second test after 1 hour. An AMI is indicated if the second line is darker.

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Interpretation of results

A positive result of one or both markers means that the concentration of the corresponding marker in the sample is above the threshold. An acute myocardial infarction is highly likely.

A negative result means that the concentration of the corresponding marker in the sample is below the threshold. An acute myocardial infarction is not likely.

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Additional information regarding the interpretation

When whole blood is used as sample, colour changes in the test result window during the formation of the strips are normal. They stop when the stripes are completed.

In case of an excessive sample volume the lower part of the test result window may turn light red. This is due to the passing of Erythrocytes and does not influence the test result.

A positive result may be interpreted before 15 minutes if the CONTROL and the RESULT line are clearly visible. In all other cases the waiting time must be observed.

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Limitations and interferences

A false negative result can never be completely ruled out, especially if the testing is performed at the border of the diagnostic window (see “Diagnostic window”). A negative test result does not exclude the possibility that a myocardial infarction has taken place! No drugs are known to interfere in therapeutic concentrations.

h-FABP: h-FABP can be elevated in patients with renal insufficiency or angina pectoris. In low amounts h-FABP is also present in skeletal muscle. Therefore, it can be elevated in individuals that performed rigorously prior to the testing and in athletes.

cTnI: cTnI can be elevated in patients that underwent coronary bypass surgery. Samples that contain an unusually high concentration of heterophil antibodies or rheumatic factors (RF) can influence the test result.

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Theory

h-FABP: h-FABP is a protein abundantly present in the myocardium. It is released following damage to the myocardial cells.

cTnI: In the myocardium the complex Troponin ITC is present. Following a myocardial infarction this complex is released into the blood stream where it splits into its components TnI, TnT, and TnC.

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Test principle

h-FABP: The test contains two different monoclonal antibodies specific for cardiac FABP. One of them is gold-labelled. The sample liquid removes the gold-labelled anti-FABP-antibody from its matrix. This antibody forms an intermediary complex with h-FABP present in the sample. This complex passes through the detection zone. At the position named "RESULT” the intermediary complex forms a sandwich complex with the second antibody. This sandwich complex shows up as a violet line. A sample without h-FABP does not form such a sandwich complex and, therefore, forms no violet line.

cTnI: When the sample is applied it interacts with Anti-cTnI antibodies and biotinylised Anti-cTnI antibodies. Thereafter, this complex reacts with the Streptavidin that is present at the “RESULT” line. If the sample contains TnI a red line appears, without TnI no line appears.