Evaluation of the Relationship between Serum Troponin Levels and the Incidence of Cardiac Complications in Patients with Unstable Angina and Myocardial Infarction

Abstract

Background and Aim:  Many people die annually due to nosocomial complications caused by heart diseases around the world. Several diagnostic methods have been proposed to determine the severity and prognosis of these patients, which can estimate the rate of myocardial involvement and the severity of nosocomial complications in these patients. Among cardiac markers, troponin is more sensitive and specific than other markers and can even shows mild necrosis and mild myocardial muscle injuries. The present study aimed to evaluate the statistical indicators related to the qualitative serum troponin levels, obtained from the follow-up of cardiac complications in patients with a diagnosis of unstable angina and acute myocardial infarction.

Materials and Methods: In this prospective study, 400 patients with unstable angina and acute myocardial infarction evaluated for serum troponin levels, mortality and cardiac and non-cardiac complications during recent hospitalization. Required data were extracted from clinical findings, electrocardiogram, echocardiography and tests, especially quantitative serum troponin levels, which was measured serially. Also, complications of the disease during hospitalization and patients' outcome were recorded. Then, their complications in groups with higher troponin than normal troponin range were compared and statistically analyzed.

Results: Out of 400 patients, 41% were diagnosed with unstable angina and 59% with acute myocardial infarction. The mortality rate during hospitalization was 13 cases (3.25%). No statistically significant relationship was found between patients' age and quantitative troponin levels (p = 0.365). There was a significant inverse relationship between serum troponin and percentage of Ejection Fraction (r= -0.407, p <0.0001). Comparison of the results related to troponin levels in the two groups of dead and alive groups showed that the levels of troponin are higher in the dead group than in the alive group. Also, there was a direct and significant relationship between increased troponin levels and mortality and cardiac complications (p <0.0001).

Conclusion: According to the results of the present study, 236 hospitalized patients had troponin level higher than normal troponin range. Mortality rate during hospitalization was 13 cases (3.25%). All dead patients had higher troponin levels than normal level and even 69.23% of dead cases showed troponin levels above 50 (Ng/ml) Nano gram per milliliter. Hence, based on the results of this study, serum troponin as a biomarker can detect myocardial damages and it was found as a suitable indicator for predicting mortality in these patients.