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Troponin T does not rule out myocardial damage until 12 hours after the onset of chest pain

Three Part Question

In [patients with cardiac chest pain and a normal ECG] is [a troponin T measurement at 12 hours] sensitive enough to [rule out myocardial damage in the first 12 hours]?

Clinical Scenario

A 50 year old man attends the emergency department with a 12 hour history of chest pain that may be cardiac in origin. His ECG is normal. You want to rule out possible myocardial damage and wonder whether a single troponin T measurement taken at this time is sensitive enough to do this.

Search Strategy

Medline 1966-01/00 using the OVID interface.
({exp diagnosis OR diagnosis.mp} AND troponin$.mp) LIMIT to human AND english.

Search Outcome

590 papers found of which 581 were irrelevant or of insufficient quality. The remaining 9 papers are shown in the table.

Relevant Paper(s)

Author, date and country Patient group Study type (level of evidence) Outcomes Key results Study Weaknesses
Mair J et al,
1995,
Austria
114 emergency department patients with chest painDiagnostic test studyAMISensitivity 46% on admissionOnly admitted patients. Troponin cut-off set at 0.032 ng/l
De Winter RJ et al,
1995,
Netherlands
309 emergency department patients with chest painDiagnostic test studyAMISensitivity 67% in patients with less than 75% chance of AMIUnclear if gold standard blinded. Risk assessment was by clinical judgement. Patients with abnormal ECGs included
Tucker JF et al,
1997,
USA
177 emergency department patients within 24h of onset of chest painDiagnostic test studyAMISensitivity 33.3% at 1h

Sensitivity 33.3% at 2h

Sensitivity 59.3% at 6h

Sensitivity 96.3% at 12-24h

Specificity 86.7% at 12-24h
Only admitted patients.
REACTT investigators,
1997,
USA
926 emergency department patients with chest pain Rapid bedside test vs laboratory testDiagnostic test studyAMISensitivity 19.6% vs 25% on admission

Sensitivity 59% vs 69.6% at 3h

Sensitivity 69.7% vs 79.8% at 6h
206 patients excluded due to lack of data. Discharged patients not followed up with same gold standard
Hamm CW et al,
1997,
Germany
773 emergency department patients within 12h of onset of chest pain, with no ST elevationObservationalDeath or non-fatal AMI within 30 days44% predicted on arrival

79% predicted after 4h
No indipendent gold standard applied to all patients. Inadequate follow up of discharged patients. Sensitivity could not be calculated
Moher ER et al,
1998,
USA
100 patients with chest discomfortDiagnostic test studyAMISensitivity 90% at 4hCumulative sensitivities at 4h.
Sayre MR et al,
1998,
USA
667 patients with chest painDiagnostic test studyAMISensitivity 88% at 12h post admission

Sensitivity 97% at 24h post admission
Only admitted patients studied.
Zimmerman J et al,
1999,
USA
955 emergency department patients with chest painDiagnostic test studyAMISensitivity 87% at 10h post onset
Johnson PA et al,
1999,
USA
1477 emergency department patients with chest painDiagnostic test studyAMI in the 24h following presentationSensitivity 99% at 24h

Specificity 86% at 24h
174 cases excluded

Comment(s)

No study has evaluated the point at which troponin T becomes sensitive enough to effectively rule-out acute myocardial infarction in emergency department patients. However no study has shown a high enough sensitivity (> 95%) to allow use as a SnNout at less than 12-24 hours.

Clinical Bottom Line

Troponin T is not sensitive enough to rule out myocardial damage in the first 12 hours after onset of chest pain.

References

  1. Mair J, Smidt J, Lechleitner P at al. Rapid accurate diagnosis of acute myocardial infarction in patients with non-traumatic chest pain withn one hour of admission. Coronary Artery Dis 1995;6:539-45.
  2. De Winter RJ, Koster RW, Sturk A at al. Value of myoglobin, troponin T and CK-MB mass in ruling out acute myocardial infarction in the emergency room. Circulation 1995;92:3401-7
  3. Tucker JF, Collins RA, Anderson AJ at al. Early diagnostic efficiency of cardiac troponin I and troponin T for acute myocardial infarction. Acad Emerg Med 1997;4:13-21.
  4. REACTT investigators study group. Evaluation of a bedside whole blood rapid troponin T assay in the Emergency Department. Rapid evaluation by assay of cardiac troponin T (REACTT). Acad Emerg Med 1997;4:1018-24.
  5. Hamm CW, Goldman BU, Heeschen C at al. Emergency room triage of patients with acute chest pain by means of rapid testing for cardiac troponin T or I. New Engl J Med 1997;337:1648-53.
  6. Moher ER 3rd, Ryan T, Segar DS at al. Clinical utility of troponin T levels and echocardiography in the Emergency Department. Am Heart J 1998;135:253-60.
  7. Sayre MR, Kaufmann KH, Chen IW at al. Measurement of cardiac troponin T is an effective method for predicting complications among emergency department patients with chest pain. Ann Emerg Med 1998;31:539-49.
  8. Zimmerman J, Fromm R, Meyer D at al. Diagnostic marker cooperative study for the diagnosis of myocardial infarction. Circulation 1999;99:1671-7.
  9. Johnson PA, Goldmman L, Sacks DB at al. Cardiac troponin T as a marker for myocardial ischaemia in patients seen at the Emergency Department for acute chest pain. Am Heart J 1999;137:1137-44.