Heart-type Fatty Acid-Binding Protein

1. Early Marker of Acute Myocardial Infarction (AMI)

H-FABP is released very early after myocardial injury.

Rises: 1–3 hours after onset of chest pain

Peaks: 6–8 hours

Returns to normal: within 24 hours

👉 This makes it one of the earliest cardiac biomarkers, often preceding troponins.

2. Diagnosis of Acute Coronary Syndrome (ACS)

Useful in early presenters (within the first 3–6 hours).

Improves early rule-in and rule-out of MI when combined with:

Cardiac troponins

ECG findings

Clinical assessment

3. Risk Stratification in ACS

Elevated H-FABP levels are associated with:

Larger infarct size

Higher short-term mortality

Increased risk of heart failure

Thus, it has prognostic value, not just diagnostic.

4. Detection of Minor Myocardial Injury

Because of its high sensitivity, H-FABP may be elevated in:

Unstable angina

Microinfarctions

Peri-procedural myocardial injury (PCI, cardiac surgery)

5. Limitations (Low Specificity)

H-FABP is also present in skeletal muscle and kidneys.

Levels may be elevated in:

Renal failure

Skeletal muscle injury

Sepsis or severe trauma

⚠️ Therefore, it should not be used alone.

Comparison with Cardiac Troponins
Feature H-FABP Troponins
Time to rise 1–3 hours 3–6 hours
Sensitivity (early MI) Very high Moderate
Specificity Lower Very high
Duration of elevation < 24 hours 7–14 days
Clinical Use Today

Primarily used as an adjunct early biomarker.

In many centers, high-sensitivity troponins have reduced routine use of H-FABP.

Still valuable where very early MI detection is critical.