Variability in High-Sensitivity Cardiac Troponin T Testing in Stable Patients With and Without Coronary Artery...

Area of Science:

• Cardiology
• Biomarkers
• Clinical Chemistry

Background:

• High-sensitivity cardiac troponin T (hs-cTnT) is crucial for diagnosing acute myocardial infarction.
• Interpretation often relies on the 99th percentile threshold (14 ng/L) of normal populations.
• The variability of hs-cTnT in stable patients with or without coronary artery disease (CAD) remains largely unknown.

Purpose of the Study:

• To investigate the short- and long-term variability of hs-cTnT.
• To assess hs-cTnT levels in stable patients with CAD and controls without CAD.
• To identify predictors of elevated hs-cTnT values.

Main Methods:

• A prospective cohort study involving 75 stable patients with CAD and 25 controls without CAD.
• Each participant provided 15 hs-cTnT measurements over a one-year period.
• Patients with CAD were categorized into stable angina, remote myocardial infarction, or repetitive acute coronary syndrome groups.

Main Results:

• Individual hs-cTnT measurements showed no significant variation across different time windows (within-day to yearly).
• The repetitive acute coronary syndrome group exhibited the highest median hs-cTnT (6.3 ng/L) and variability (IQR 6.9 ng/L).
• Diabetes, impaired renal function, and elevated C-reactive protein independently predicted higher hs-cTnT values, with the 99th percentile reaching 39 ng/L in CAD patients.

Conclusions:

• Individual hs-cTnT readings are stable over extended periods in both CAD and non-CAD patients.
• Diabetes, renal dysfunction, and elevated C-reactive protein are key predictors of higher hs-cTnT, potentially exceeding conventional diagnostic thresholds.
• Clinical context is essential for accurate hs-cTnT interpretation due to influencing factors.