LABORATORY
AVERA SACRED HEARTHOSPITAL
501 Summit• Yankton • SD 57078
668-8169
Technical Service Bulletin
The Interpretive comment attached to all Troponin T (TNT) results from Avera Sacred Heart Hospital has been modified. This comment was adapted from the TNT report recently implemented at Avera St Luke in Aberdeen and formatted after the Mayo Medical Laboratory Test interpretation. All of which use Roche instrumentation and reagent to perform the Troponin T assay.
Troponin T Interpretive comment reads:
“The upper limit for normal individuals is <0.01 ng/mL (undetectable by this method).
For patients who present with acute coronary syndromes, Troponin-T values >or=0.01 ng/mL that are rising make the diagnosis of cardiac injury. Decreasing values are indicative of recent cardiac injury. Troponin-T values >or=0.01 ng/mL are a prognostic sign of patients with ischemic heart disease and most other situations.
Clinical judgment is necessary to distinguish patients who have ischemic heart disease from those who do not. However, all patients with >or=0.01 ng/mL Troponin-T are at increased risk for cardiac events relative to patients with undetectable Troponin-T.
Patients with low level (<0.01 ng/mL) elevations of Troponin-T and diagnostic uncertainty for acute coronary syndrome should be evaluated by repeat measurement at 3 and 6 hours to determine whether this is an acute or more chronic elevation. The standard deviation of this assay at the cut-off value is 0.003 ng/mL. Below 0.1 ng/mL, changes greater than or equal to 3 standard deviations are considered significant changes. At 0.1 ng/mL or greater, a change of 20% is considered significant. However, all patients with >or=0.01 mg/mL Troponin-T are at increased risk for cardiac events relative to patients with undetectable Troponin-T.
As with all markers of cardiac injury, elevations of Troponin-T do not in and of themselves indicate the presence of an ischemic mechanism. Many other disease states are associated with elevations of Troponin-T via mechanisms different from those that cause injury in patients with acute coronary syndromes. These include, but are not limited to, trauma (contusion, ablation or pacing), congestive heart failure, hypertension, hypotension (often with arrhythmias), pulmonary embolism, renal failure and myocarditis.”
We have enhanced Meditech with a delta flag on Troponin T results
Result RangeDelta DifferenceLook back Time Span
0.000-0.099 ng/mL0.009ng/mL6 hours
>0.10020%6 hours
The Troponin Delta flag has been added to our Critical alert values. Notification will be made in accordance with our Physician alert protocol.
Very respectfully,
Doris L Heilman MT (ASCP)
Automation Coordinatorcc: Richard Strom, M.D.
Anatomic and Clinical Pathologist
Physicians Laboratory, Ltd.
ASHH Laboratory Medical Director