Specimen recentrifugation and elevated troponin I levels

Area of Science:

• Clinical Chemistry
• Biomarker Analysis
• Laboratory Medicine

Background:

• Cardiac troponin I (cTnI) is a critical biomarker for diagnosing myocardial infarction.
• Accurate cTnI measurements are essential for timely and correct patient management.
• Specimen handling procedures can impact biomarker concentrations.

Purpose of the Study:

• To investigate the effect of recentrifugation on plasma troponin I levels.
• To determine if recentrifugation alters cTnI concentrations in clinically relevant samples.

Main Methods:

• 189 plasma specimens with elevated troponin I (>60 ng/L) were recentrifuged and re-assayed.
• Statistical analysis (Wilcoxon test, Passing-Bablok regression) compared pre- and post-recentrifugation values.

Main Results:

• A statistically significant decrease in troponin I was observed after recentrifugation (P <.01).
• Specimens near the cutoff showed a median reduction of 10 ng/L.
• Confidence intervals indicated a consistent decrease in cTnI concentrations.

Conclusions:

• Recentrifugation of plasma reduces elevated troponin I levels.
• This reduction poses a risk of misclassifying patients with cardiac events.
• The practice also leads to extended laboratory turnaround times.