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Journal of Medical Biochemistry

The Journal of Society of Medical Biochemists of Serbia

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Sensitive Cardiac Troponin Assays: Myth and Magic or a Practical Way Forward?

David Gaze1

Department of Chemical Pathology, Clinical Blood Sciences, St. George's Hospital and Medical School, Tooting, London, United Kingdom1

This content is open access.

Citation Information: Journal of Medical Biochemistry. Volume 29, Issue 4, Pages 270–273, ISSN (Online) 1452-8266, ISSN (Print) 1452-8258, DOI: 10.2478/v10011-010-0034-7, October 2010

Publication History

Published Online:
2010-10-09

Sensitive Cardiac Troponin Assays: Myth and Magic or a Practical Way Forward?

Cardiac troponins (cTn) are considered to be the ‘gold standard’ biomarkers for the diagnosis of acute coronary syndrome (ACS) a pathological spectrum which includes cardiac ischemia, angina, myocardial infarction and ultimately cardiac failure. The growing evidence base for the diagnostic and prognostic use of cTn in ACS has resulted in a universal redefinition of acute myocardial infarction (AMI). A diagnosis of AMI includes the detection of an elevated cTn (or CK-MB) with at least one measurement within 24 hours of the cardiac episode being >upper 99th percentile of a reference population, in conjunction with evidence of myocardial ischemia. A number of high sensitivity immunoassays with claims of superior imprecision and a definable 99th percentile have been produced. Clinically, these have two important impacts. First, there is a drive to change the values into whole numbers by the application of a unit change which carries the scope for confusion. Secondly, the near-normal Gaussian distribution of sensitive cTn in healthy subjects will increase the frequency of cTn positivity in the non-ACS population. The problem is to decipher if such minor elevations in cTn are of clinical concern. What is certain is that AMI remains a clinical not a biochemical diagnosis and the interpretation of cTn concentrations should be made according to the clinical context.

Osetljivi Testovi Za Srčani Troponin: Mit I Magija Ili Praktičan Napredak?

Srčani troponini (cTn) smatraju se »zlatnim standardom« među biomarkerima za dijagnostikovanje akutnog koronarnog sindroma (ACS), patološkog spektra koji obuhvata srčanu ishemiju, anginu, infarkt miokarda i konačno prestanak rada srca. Sve veći broj dokaza koji idu u prilog dijagnostičkoj i prognostičkoj upotrebi cTn u ACS doveo je do opšteg ponovnog definisanja akutnog infarkta miokarda (AMI). Dijagnoza AMI uključuje detekciju povišenog cTn (ili CK-MB) - najmanje jednom u 24 časa od srčane epizode izmeren je nivo > gornjeg 99. procenta referentne populacije - uz dokaze o ishemiji miokarda. Izrađeno je nekoliko veoma osetljivih imunoeseja s navodno superiornom nepreciznošću i 99. procentilnom vrednošću koji se može definisati. U kliničkom smislum, oni imaju dvojaku važnost. Prvo, postoji težnja da se vrednosti promene u cele brojeve, menjanjem jedinice koja unosi zabunu. Drugo, gotovo normalna Gaussova raspodela osetljivog cTn kod zdravih subjekata povećaće učestalost pozitivnog cTn u populaciji bez ACS. Problem je kako utvrditi da li su ti blago povišeni nivoi cTn od kliničkog značaja. Ono što je sigurno jeste da AMI ostaje klinička a ne biohemijska dijagnoza i da se tumačenje koncentracije cTn mora izvoditi u skladu s kliničkim kontekstom.

Keywords: cardiac troponins; biomarkers; acute myocardial infarction

Keywords: srčani troponini; biomarkeri; akutni infarkt miokarda

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