P. Hu1, R. Uhlich1, A. Witcher1, J. Kerby1, P. Bosarge1 1UAB,Acute Care Surgery/Surgery,Birmingham, AL, USA
Introduction:
Blunt cardiac injury (BCI) is often identified in the presence of sternal fractures in blunt trauma. Full evaluation and management of this injury remains controversial. Electrocardiogram (ECG) is the current standard in diagnosis and is recommended for any patient with possible BCI. The utility of troponins are less clear. It remains a matter of debate as to the type of troponin to be measured, the ideal timing, and required duration of monitoring. We sought to determine the role of troponin I measurement in the evaluation of BCI following sternal fracture.
Methods:
Trauma patients admitted to an American College of Surgeons verified level I trauma center from 2011-2013 with a diagnosis of sternal fracture were identified from the trauma registry. A retrospective review of the medical record was performed to determine patient age, gender, length of stay, results of ECG, echocardiography, troponin I values, patient cardiac morbidity and mortality. The first three Troponin I levels collected during hospitalization were recorded. BCI was diagnosed by newly identified ECG abnormalities.
Results:
203 trauma patients were admitted with sternal fracture following blunt trauma. BCI was diagnosed in 89 patients by ECG. 101 patients had at least one troponin I level measured. Troponin I levels were undetectable in 15 patients with BCI compared to 14 without BCI. Mean troponin I levels were 0.328 ng/mL in patients with BCI compared to 0.055 ng/mL without. Troponin I greater than 0.1 ng/mL on admission has a positive predictive value of 89%. Negative predictive value of undetectable troponin I levels for BCI is 48%. Twelve patients died within 30 days of hospital admission, however no deaths were due to acute heart failure, myocardial infarction, or cardiogenic shock.
Conclusion:
Troponin I levels offer little benefit following sternal fracture in excluding the possibility of blunt cardiac injury. While the presence of elevated troponins increases the likelihood of BCI, it does not appear to correlate with cardiac related morbidity or mortality.