High-Sensitivity Troponin — Acute Myocardial Infarction
Test Characteristics
| Metric | Value |
|---|---|
| False-negative rate | 6% (sensitivity 94%) |
| False-positive rate | 27% (specificity 73%) |
| Bayes factor (positive test) | 3× |
| Bayes factor (negative test) | 1/10× |
| Base rate | 10% of ED patients presenting with chest pain |
Interpreting Results
| Scenario | Prior | + Result | − Result |
|---|---|---|---|
| ED chest pain (undifferentiated) | 10% | 3 × 10% = 30%10%× 330% | 1/10 × 10% = 1%10%÷ 101% |
| Classic: substernal pressure, left arm, diaphoresis | 20% | 3 × 20% = 60%20%× 360% | 1/10 × 20% = 2%20%÷ 102% |
| Low-risk: young, atypical, no cardiac history | 2% | 3 × 2% = 6%2%× 36% | 1/10 × 2% = 0.2%2%÷ 100.2% |
A rule-out test. The positive Bayes factor (3×) is modest — troponin rises in many non-MI conditions (HF, PE, sepsis, renal failure). But the negative Bayes factor (1/10×) is powerful — a negative hs-troponin drops MI probability 10-fold.
- + result: risk only moves to 30%
- − result: risk drops from left-handed (10%) to shellfish allergy (1%) — the key clinical use
Sources:
- Systematic review and meta-analysis, PMC, 2014. PMC 4183183.
- ACC Expert Consensus, 2022. JACC.