Validation and correlation of high-sensitive troponin I and troponin T in the emergency department

Area of Science:

• Cardiology
• Clinical Chemistry
• Emergency Medicine

Background:

• Troponin elevation is common in the Emergency Department (ED).
• Limited studies compare simultaneously measured high-sensitivity cardiac troponin T (hs-cTnT) and troponin I (hs-cTnI) in diverse clinical populations.
• Understanding differences in troponin assays is crucial for accurate diagnosis.

Purpose of the Study:

• To compare the performance of simultaneously measured hs-cTnT and hs-cTnI.
• To evaluate the diagnostic accuracy and prognostic implications of these assays in a broad patient cohort.
• To investigate the frequency of troponin elevations above the upper reference limit (URL).

Main Methods:

• Retrospective analysis of 1987 simultaneous hs-cTnT and hs-cTnI samples from 1134 patients.
• Inclusion of all patients undergoing troponin testing regardless of chief complaint.
• Statistical analysis of correlation, diagnostic accuracy (AUC, sensitivity, specificity, PPV, NPV), and 1-year mortality.

Main Results:

• A significant correlation was found between hs-cTnT and hs-cTnI (r=0.86, p<0.01).
• Elevated hs-cTnT (65%) was twice as frequent as elevated hs-cTnI (30%), with 39% showing elevated hs-cTnT and normal hs-cTnI.
• hs-cTnI demonstrated higher AUC (0.87) for AMI compared to hs-cTnT (0.80), with better specificity (80% vs 39%) and PPV (21.3% vs 9.3%).
• Both assays showed high negative predictive value (NPV) for AMI (98.5% for hs-cTnT, 98.3% for hs-cTnI).
• Elevated hs-cTnT and hs-cTnI were associated with increased 1-year mortality (HR 1.52 and 1.26, respectively).

Conclusions:

• Elevated troponin levels are common in a diverse ED population, especially hs-cTnT.
• hs-cTnT exhibits lower specificity and PPV for acute myocardial infarction (AMI) compared to hs-cTnI.
• The findings highlight potential differences in clinical utility between hs-cTnT and hs-cTnI assays for diagnosing AMI.