Clinical Significance

   It is useful for : Aiding in the exclusion of the diagnosis of acute coronary syndrome in a single plasma specimen, Aiding in the diagnosis of acute coronary syndrome, Monitoring acute coronary syndromes and estimating prognosis, Possible utility in monitoring patients with nonischemic causes of cardiac injury.

Specimen

   Plasma

Stability

   Frozen (preferred) : 365 days

   Refrigerated : 24 hours

   Ambient : 24 hours

Reference Range

   < 14 pg/ml

Interpretation

   Increased troponin concentrations should not be used by themselves to diagnose or rule out a heart attack. A physical examination, clinical history and electrocardiogram (ECG) or imaging investigations are also essential. The internationally agreed definition of heart attack requires evidence of a significant increase in troponin concentration with time together with evidence of a sudden reduction of heart muscle blood supply (ischaemia) from characteristic symptoms of the acute coronary syndrome (ACS) and new ECG changes or new imaging changes.

   Without evidence of ischaemia, possible causes of rising troponin values include other causes of heart damage such as myocarditis (inflammation of the heart muscle), acute heart failure, an arrhythmia (abnormal heart rhythm), chest injury, stroke or pulmonary embolism (blood clot lodged in the lung). Elevated but unchanging values may be seen in chronic heart failure, high blood pressure (hypertension), severe infections, kidney disease and some chronic inflammatory conditions of muscle.

Limitation

   As with all markers of cardiac injury, elevations of cardiac troponin T (cTnT) do not in and of themselves indicate the presence of an ischemic mechanism. Many other disease states can be associated with elevations of cTnT via mechanisms different from those that cause injury in patients with acute coronary syndromes. These include trauma including contusion, ablation, and pacing; congestive heart failure; pulmonary embolism; kidney failure; and myocarditis.