HEP Score

HEP Score vs 4T: Expert-derived probability for HIT. Includes negative modifiers (penalties) for alternative causes like sepsis or liver disease.

Diagnostic Criteria

HIT Probability Result

0

Clinical Risk Class

Low

HIT effectively ruled out (NPV ~100%).

Guidelines & Evidence

Verified

Last Review: 2026-07-17

When to Use

Evaluating patients with suspected Heparin-Induced Thrombocytopenia (HIT).

Selecting patients who require specialized HIT testing (PF4 ELISA or SRA).

More accurate than the 4T score for clinicians in specialty contexts.

Exclusions

Do not use as a standalone diagnosis. Always correlate with the Presence/Absence of anti-PF4 antibodies.

How it Works

Points Calibration

Category	Condition	Points
Platelet Fall	30-50% fall (or nadir 10-19)	1
	> 50% fall (or nadir < 10)	2
Timing	Days 5-14 of heparin	3
	Recent heparin (within 30d)	1
Thrombosis	New proven thrombosis	2
	Skin necrosis	2
Other Causes	Sepsis, DIC, Liver disease	-1 to -3

Pretest Thresholds

< 2 points: HIT ruled out (NPV ~100%).

2 - 4 points: Intermediate risk.

≥ 5 points: High risk (requires urgent PEX/Switch to non-heparin anticoagulation).

Last Comprehensive Review: 2026-07-17

Recent Journal Updates

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Clinical Context

We think this might be relevant to the clinical guidance for HEP Score (HIT Expert Probability).

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Clinical Context

We think this has broad domain relevance to HEP Score (HIT Expert Probability).

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Clinical Context

We think this has broad domain relevance to HEP Score (HIT Expert Probability).

HEP Score

0

When to Use

When to Use

Exclusions

How it Works

Points Calibration

Pretest Thresholds

Clinical Pearls

HEP vs 4T

The Evidence

Primary Strategy

Development and validation of a predictive score for heparin-induced thrombocytopenia (HIT).

Origins & History

History

Recent Journal Updates

HEP Score

0

When to Use

When to Use

Exclusions

How it Works

Points Calibration

Pretest Thresholds

Clinical Pearls

HEP vs 4T

The Evidence

Primary Strategy

Development and validation of a predictive score for heparin-induced thrombocytopenia (HIT).

Origins & History

History

Recent Journal Updates