Acute Myocardial infarction is most classically diagnosed by troponin T or I elevation. However, there are other etiologies than ACS where troponin T is also positive. It becomes imperative to understand the importance of Troponin test in correctly diagnosing a heart attack
Recently a researcher studied the incidences of a positive Troponin test in both ACS and Non-ACS patients, as well as tried to compare the specificities (levels) of the positive tropinin tests in both cases
Troponin elevation can be caused by etiologies other than acute coronary syndromes (ACS). The hypothesis was that elevated troponins occur more frequently in non-ACS cases but that ACS cases (type 1 ST-elevation myocardial infarction [STEMI] and type 1 non-STEMI [NSTEMI]) have significantly higher troponin elevations.
The study included patients medical record reviews looking for whether cardiologists or hospitalists attributed the elevated troponin to an ACS (NSTEMI or STEMI) or non-ACS cause. Non-ACS causes were categorized as infection, cancer, renal diseases, cardiovascular disease, pulmonary disease, trauma, cardiac arrest, neurologic disease, hypertension, or other. Data were extracted by 2 investigators on the cause of the elevated troponin.
The researcher evaluated 458 randomly selected patients from 1317 unique cases of all patients with initial elevated troponins at least 0.06 mg/mL during the study period and found…
Seventy-nine percent had a non-ACS cause of elevated troponin, and the average initial positive troponin I level was significantly lower in the non-ACS cases than those with documented STEMI or NSTEMIs .
In the non-ACS group, the median initial troponin was 0.14 ng/mL (0.08-0.37 ng/mL). Peak troponin levels were highest in STEMI, next NSTEMI, and lowest in non ACS causes.
The most frequent subgroups in the non-ACS group were non-ACS cardiovascular, infectious, renal, or hypertensive causes.
The researcher concluded that The etiology for most initial elevated troponin I levels in a randomly selected population is the result of non-ACS causes
The high level more than 0.6 more likely associated with ACS causes than with non-ACS causes. Average initial + and peak troponin values were highest in STEMIs, next highest in NSTEMIs, and lowest overall in non-ACS causes.