A new troponin test has been developed by researchers from the University of Turku that can identify heart attack patients whose cardiac troponin values are elevated due to renal insufficiency.
Blood samples for cardiac troponins are essential in the diagnostics of heart attack patients. Results from these tests may be elevated due to other, unrelated transient or chronic conditions such as renal insufficiency, atrial fibrillation, or strenuous physical exercise.
The newly developed troponin tests may help to separate these patients and help to identify myocardial infarction (MI) faster and more specifically. The researchers believe their tests will improve treatment for MI patients.
The results of the study have been published in the scientific journal Circulation.
Current troponin tests are limited
Cardiac troponins are proteins normally found in the heart muscle cells only. According to previous studies, large fragments release troponins into the blood circulation of MI patients. In other conditions, troponins are found in the blood in small fragments.
Troponin is released into the bloodstream during a heart attack. Detecting levels of troponin in the blood can help doctors diagnose a heart attack. However, current commercial troponin tests, commonly used in hospitals, can only recognise the combined amount of both large and small troponin molecules in a combined figure.
The Heart Centre of Turku University Hospital and the Biotechnology unit of the Department of Life Technologies of the University of Turku joined together to address the issue of unreliable heart attack diagnostics in a collaborative study. Together, they developed a simple immunoassay test that could detect only the large troponin molecules.
The new test will allow for precise analysis
Researchers were able to calculate the troponin ratio in blood samples by dividing the level of large troponin molecules, determined by the new test, by the number of all troponin molecules, determined by the test currently in use in hospitals.
The research team found that the troponin ratio was significantly higher in MI patients than in patients with renal insufficiency. The current commercial tests were not able to identify this difference and reported similar troponin levels in both these groups.
“More than half of the small troponin elevations detected in emergency department patients are due to causes other than a heart attack. The developed test seems to separate very well the small troponin elevations caused by threatening MI from more benign transient troponin elevations,” explained Professor Emeritus Juhani Airaksinen from the Heart Centre of Turku University Hospital.
“A special feature of the test we have developed is that it would be possible to implement it in automated analysis systems in the hospital laboratories, similarly to the commercial troponin tests currently in use in the hospital laboratories,” concluded Assistant Professor Saara Wittfooth from the Department of Life Technologies, University of Turku.