How to manage a patient with a suspected false positive high sensitivity troponin (hs-troponin) result?

Management of Suspected False Positive High-Sensitivity Troponin

When managing a patient with suspected false positive high-sensitivity troponin, clinicians should implement a systematic diagnostic approach including serial troponin measurements, alternative troponin assays, and specialized laboratory techniques to confirm interference while continuing to evaluate for non-ACS causes of troponin elevation. 1

Recognizing Potential False Positives

High-sensitivity troponin (hs-troponin) assays have improved detection of myocardial injury but have also increased detection of non-ACS related elevations and false positives. When evaluating a suspected false positive:

• Consider the clinical context - absence of typical chest pain, normal ECG, and lack of risk factors for coronary disease
• Look for patterns inconsistent with acute myocardial injury:
  • Persistent "plateau" elevation without rise/fall pattern 2
  • Discordant results between different troponin assays (I vs T) 3
  • Extremely high values without corresponding clinical severity

Diagnostic Algorithm for Suspected False Positive hs-Troponin

1. Serial Troponin Measurements

   • Obtain serial measurements at 0,3, and 6 hours 1
   • Evaluate for characteristic rise/fall pattern (≥20% change) typical of acute myocardial injury 1
   • Stable values without significant change suggest possible interference

2. ECG and Clinical Correlation

   • Compare troponin results with ECG findings and clinical presentation
   • Absence of ECG changes with very high troponin values raises suspicion for false positive 4

3. Laboratory Techniques to Identify Interference

   • Request serial dilutions - non-linear dilution patterns suggest interference 5
   • Use antibody-binding tubes to remove heterophile antibodies 5
   • Test with alternative troponin assay (switch between I and T) 3
   • Consider specialized pretreatment with heterophile blocking agents 3

4. Evaluate for Non-ACS Causes of True Elevation

   • Consider conditions in Table 4 from ESC guidelines 4:
     • Tachyarrhythmias/bradyarrhythmias
     • Heart failure
     • Structural heart disease
     • Myocarditis
     • Tako-Tsubo cardiomyopathy
     • Pulmonary embolism
     • Renal dysfunction
     • Critical illness
     • Neurological events
     • Thyroid disorders

Common Causes of False Positive Troponin

• Heterophile antibodies (most common interference) 2, 3
• Human anti-mouse antibodies (HAMA) 3
• Rheumatoid factor
• Biotin interference
• Endogenous antibodies against the troponin complex 1

Clinical Management Approach

• For patients with suspected false positive but uncertain diagnosis:

  • Continue cardiac monitoring until interference is confirmed 1
  • Consider non-invasive cardiac imaging (echocardiography) to assess for wall motion abnormalities
  • Avoid rushing to invasive procedures like coronary angiography based solely on elevated troponin 2

• Once false positive is confirmed:

  • Document in medical record to prevent future unnecessary testing
  • Consider alternative cardiac biomarkers for future evaluations
  • Inform the laboratory about the interference for quality improvement

Pitfalls to Avoid

• Assuming all elevated troponin values represent acute coronary syndrome
• Performing unnecessary invasive procedures based solely on laboratory values 2
• Failing to consider analytical interference when clinical presentation doesn't match laboratory findings 6
• Missing true cardiac pathology by prematurely attributing elevation to false positive
• Overlooking the possibility of coincidental coronary disease with false positive troponin 2

By following this systematic approach, clinicians can accurately identify false positive high-sensitivity troponin results while ensuring appropriate care for patients with true myocardial injury.