HAT (Hemorrhage After Thrombolysis) Score for Predicting Post-tPA Hemorrhage

Why Use

The HAT Score can objectify tPA risk which is often difficult with gestalt alone, and provide patients and family members information about possible risk and benefit.

When to Use

The HAT Score can help determine risk/benefit of tPA in borderline cases for emergency and neurology providers. It can also help determine which patients need the closest monitoring if given tPA.

Formula

Pearls / Pitfalls

While symptomatic ICH definitions vary greatly, it is clear from several studies that increasing HAT Score correlates with increasing risk of symptomatic ICH and fatal ICH, from <5% at low scores to >10% at highest scores.

Advice

Stop tPA immediately if it is still running. All patients with ICH should receive neurosurgical consultation. Consider hematology consult to reverse the tPA.

More Information

Score interpretation: HAT Score Risk of Any Hemorrhage Risk of Symptomatic ICH Risk of Fatal Hemorrhage 0 6% 2% 0% 1 16% 5% 3% 2 23% 10% 7% 3 36% 15% 6% >3 78% 44% 33%