Re-evaluating the Use of High Sensitivity Troponin to Diagnose Blunt Cardiac Injury

Area of Science:

• Emergency Medicine
• Cardiology
• Trauma Surgery

Background:

• Blunt cardiac injury (BCI) diagnosis is challenging and can lead to severe complications if missed.
• Previous studies used troponin I and electrocardiogram (EKG) for BCI screening, with a prior threshold of 76 ng/L for high-sensitivity troponin I (hsTnI).
• The current study aimed to evaluate the efficacy of an updated BCI screening protocol.

Purpose of the Study:

• To determine the effectiveness of the current institutional protocol for screening blunt cardiac injury (BCI) in patients with sternal fractures.
• To identify an optimized high-sensitivity troponin I (hsTnI) threshold for diagnosing clinically significant BCI.

Main Methods:

• Retrospective review of patients with sternal fractures at an urban level-1 trauma center (March 2022 - April 2023).
• Analysis included EKG findings, hsTnI trends, echocardiogram results, and clinical outcomes.
• Statistical comparison using Wilcoxon's rank sum test and Fisher's exact test; Youden indices calculated for hsTnI thresholds.

Main Results:

• 183 of 206 patients with sternal fractures underwent BCI screening; 28 had clinically significant BCIs.
• The previously identified hsTnI threshold of 76 ng/L had a Youden index of 0.31.
• An hsTnI threshold of 40 ng/L yielded the highest Youden index (0.50) with 79% sensitivity and 71% specificity for clinically significant BCI.

Conclusions:

• Screening for blunt cardiac injury (BCI) in sternal fracture patients using high-sensitivity troponin (hsTnI) and EKG remains a valuable protocol.
• Lowering the hsTnI threshold to 40 ng/L enhances the accuracy of diagnosing clinically significant BCI.
• Further multicenter analysis could refine institutional BCI screening protocols.