Evaluation of incidence, clinical significance, and prognostic value of circulating cardiac troponin I and T elevation in hemodynamically stable patients with suspected myocardial contusion after blunt chest trauma

Background: The frequency and prognostic influence of myocardial injury in patients with blunt chest trauma is controversial. We investigated the valu e of cardiac troponin I (cTn-I) and cardiac troponin T (cTn-T), highly spec ific markers of myocardial injury, to determine whether their measurement w ould improve the ability to detect myocardial contusion in stable patients with blunt chest trauma in comparison with conventional markers and whether they, were associated with significantly worse late clinical outcome. Methods and Results: Over an 18-month period, myocardial contusion was diag nosed in 26 of 94 patients (27.6%) with acute blunt chest trauma (motor veh icle trash; 81%), because of echocardiographic abnormalities (n = 12), elec trocardiographic abnormalities in = 29), or both, Patients with myocardial contusion had a significantly higher Injury Severity Score at the time of a dmission (p = 0.001) and a significantly longer hospital stay (p = 0.0008). All patients survived admission to hospital and n ere hemodynamically stab le. None of the patients died or had severe in-hospital cardiac complicatio ns, The percentage of patients with elevated CK, (CK-MB/total CK) ratio, or CK-MB mass concentration was not significantly different between patients with or without myocardial contusion, However, there were significant diffe rences between the two groups when we applied the commonly used threshold l evels of CK-MB LB activity and myoglobin, The percentage of patients with e levated circu- lating cTn-I and cTn-T (greater than or equal to 0.1 mu g/L) was significantly higher in patients with myocardial contusion (23% vs, 3% ;p = 0.01 and 12% vs. 0%;p = 0.03, respectively). Complete changes in cTn-I and cTn-T correlated well (r = 0.91, p = 0.0001), Sensitivity, specificity , and negative and positive predictive values of cTn-I and cTn-T in predict ing a myocardial contusion in blunt trauma patients were 23%, 97%, and 77%, 75%, and 12%, 100%, and 74%, 100%, respectively, Clinical follow-up was av ailable in 83 patients (88%) (mean, 16 +/- 7.5 months). There were no death s in either group directly attributed to cardiac complications. None of the patients had any long-term cardiac complications or myocardial failure rel ated to blunt chest trauma. Conclusion: Although improved specificity of cTn-I and cTn-T compared with conventional markers, it should be emphasized that the main problem,vith cT n-I and cTn-T is low sensitivity as well as low predictive values in diagno sing myocardial contusion, cTn-I and cTn-T measurement is currently not an improved method in diagnosing blunt cardiac injury in hemodynamically stabl e patients, Moreover, there was no association of postmyocardial contusion cell injury and late outcome in these patients when cTn-I and cTn-T and oth er conventional markers were considered.