Troponin T measurement after myocardial infarction can identify left ventricular ejection of less than 40%

Abstract

Aim: To determine whether measurement of serum troponin T concentration after first acute myocardial infarction can be used to identify patients with a left ventricular ejection fraction of < 40%, who have an adverse prognosis.

Methods: Troponin T concentration was measured, and coronary and left ventriculography performed in 50 consecutive patients with acute myocardial infarction. Angiographic left ventricular ejection fraction was compared with serum troponin T concentration. Patients with previous myocardial infarction were excluded.

Results: There was a strong negative correlation between left ventricular ejection fraction and troponin T concentration. Spearman's rank correlation coefficient (corrected for ties) was -0.72 (95% confidence intervals (CI) -0.55 to -0.83; p < 0.0001). Analysis by receiver operator characteristic curve produced an area under the curve of 0.9773 (95% CI 0.9409 to 1.0136). A troponin T concentration of > 2.8 micrograms/l predicted a left ventricular ejection fraction of < 40% with a sensitivity of 100% (CI 84.6 to 100.0) and specificity of 92.9% (CI 76.5 to 99.1). Exclusion of patients who did not receive thrombolytic treatment did not significantly affect the results.

Conclusion: Serum troponin T concentration measured 12-48 hours after admission for first myocardial infarction is a reliable, simple, quick, inexpensive, non-invasive method for identifying patients with a left ventricular ejection fraction of < 40% for whom there is a poor prognosis.

Figure 1

Relation between troponin T concentration and left ventricular fraction.

Figure 2

Receiver operator characteristic curve showing sensitivity and specificity of troponin T.