ABCD² Score for TIA

Age ≥60

BP ≥140/90 mmHg

Clinical Features

Duration of Symptoms

Diabetes

ABCD² Score: 0

–

Estimates the risk of stroke after a suspected transient ischemic attack (TIA).

Why Use

There are approximately 250,000 transient ischemic attacks (TIAs) diagnosed in the United States annually. The ABCD² Score may help physicians identify those patients with TIA who are at very low risk of stroke and may be appropriate for an outpatient work-up vs. those who are at increased risk and may benefit from hospital admission.

When to Use

The ABCD ² Score can help physicians risk stratify stroke in patients presenting with a TIA.

Formula

Addition of the selected points. Criteria Value Points Age ≥60 years Y/N +1 BP ≥140/90 mmHg Y/N +1 Clinical features of the TIA Unilateral Weakness +2 Speech disturbance without weakness +1 Other symptoms 0 Duration of symptoms <10 minutes 0 10-59 minutes +1 ≥60 minutes +2 History of diabetes Y/N +1

Pearls / Pitfalls

The ABCD ² Score was developed to help physicians risk stratify patients presenting with a TIA for how likely they are to suffer a subsequent stroke. The largest prospective study of using the ABCD ² Score in the emergency department found that the score performed poorly (low sensitivity for identifying low risk patients, low specificity for identifying high risk patients). Multiple studies have shown that as the ABCD² Score increases the risk of a subsequent stroke also increases. Patients with a low baseline risk of stroke (≤2%) with a low ABCD² score (0-2) are at low risk for having a stroke within the next 7 days (0.4-0.8%). Points to keep in mind: The ABCD² Score was developed in the outpatient (non-emergency department) setting. It has been shown to have lower accuracy when used by non-specialists (primary care or emergency physicians). The ABCD² Score has less impact on risk stratification when applied in settings where the patients were at low baseline risk of stroke.

Management

Consider further imaging modalities including MRI and carotid ultrasound. Consider consulting Neurology to help determine whether the patient would benefit from further inpatient evaluation or to expedite outpatient follow-up when appropriate. In patients who are determined at high risk for developing a stroke: Consult Neurology. Consider obtaining an MRI and other appropriate vascular and embolic imaging. Have a lower threshold to admit the patient for further evaluation. In patients who are determined to be at low risk of developing a stroke in the short term: Arrange expedited evaluation as an outpatient with the goal of obtaining the relevant studies and consultations within 24 hours.

Critical Actions

The ABCD² Score should not be used as a substitute for clinical judgement or decision making. In populations with a low baseline stroke risk, a low ABCD² Score (0-2) correlates with a less than 1% risk of stroke within the next week. These patients may be appropriate for expedited outpatient evaluation. In centers where computed tomography and carotid ultrasound studies are performed in collaboration with a stroke service, adding the ABCD² Score to the evaluation appears unnecessary.