Troponin I measurement after myocardial infarction and its correlation with left ventricular ejection fraction: A prospective study

Abstract

Objective: To determine the relationship of serum troponin I after first acute myocardlal Infarction with left ventricular ejection fraction as assessed by echocardiography. Methods: A total of 50 patients of acute myocardial infarction were included in the study. Troponin I concentration was measured by ELISA method and echocardiographic ejection fraction was calculated by modified Simpson's rule. Echocardiographic ejection fraction was compared with serum troponin I concentration. Patients with previous myocardial infarction were excluded. Result: There was strong negative correlation between troponin I concentration and left ventricular ejection fraction, i.e., with an increasing troponin level, there was a fall in ejection fraction. The Pearson's correlation coefficient was-0.69, which was statistically significant (p < 0.0001). It was also found that cardiac troponin I (cTnI) concentration > 6.6 ng/ml predicted LVEF < 50% with a sensitivity of 100% and specificity of 92.4%. Conclusion: Serum troponin I concentration has a strong negative correlation with left ventricular ejection fraction after first acute myocardial infarction, and hence can be used to assess the LVEF in patients with first myocardial infarction. A level of 6.6 ng/ml provided a good indication for LVEF below 50% and thus can identify patients with higher risk.