What is the ABCD2 (Acute Brain Injury and Cardiovascular Disease 2) score?

From the Guidelines

The ABCD2 score is a clinical prediction tool used to assess the short-term risk of stroke in patients who have experienced a transient ischemic attack (TIA), consisting of five components: Age, Blood pressure, Clinical features, Duration of symptoms, and Diabetes, with higher scores indicating a greater risk of stroke within the next 2-7 days. The ABCD2 score is calculated as follows:

• Age: 1 point if ≥60 years
• Blood pressure: 1 point if systolic BP ≥140 mmHg or diastolic BP ≥90 mmHg
• Clinical features: 2 points for unilateral weakness, 1 point for speech disturbance without weakness
• Duration of symptoms: 2 points if ≥60 minutes, 1 point if 10-59 minutes
• Diabetes: 1 point if present The total score ranges from 0 to 7, with the following risk categories:
• 0-3 points: Low risk (1% risk of stroke)
• 4-5 points: Moderate risk (4-5% risk of stroke)
• 6-7 points: High risk (8-11% risk of stroke) Patients with higher scores should receive more urgent evaluation and management, including rapid imaging, cardiac monitoring, and initiation of antiplatelet therapy, as recommended by the 2021 guideline for the prevention of stroke in patients with stroke and transient ischemic attack 1. This tool helps clinicians prioritize resources and identify patients who may benefit from immediate hospitalization or expedited outpatient workup, and is based on easily obtainable clinical information, reflecting the pathophysiology of TIA and stroke risk factors, making it a practical and evidence-based tool for initial risk stratification in TIA patients 1. The use of the ABCD2 score is supported by multiple studies, including the 2021 guideline for the prevention of stroke in patients with stroke and transient ischemic attack 1, and the Canadian Stroke Best Practice Recommendations for acute stroke management 1. Overall, the ABCD2 score is a valuable tool for clinicians to assess the risk of stroke in patients with TIA and to guide management decisions, with the goal of reducing the risk of subsequent stroke and improving patient outcomes.

From the Research

Definition and Purpose of the ABCD2 Score

• The ABCD2 score is a clinical prediction rule used to determine the risk of stroke in the days following a transient ischemic attack (TIA) 2, 3, 4, 5, 6.
• It is calculated based on several factors, including age, blood pressure, clinical features, duration of symptoms, and diabetes.

Components of the ABCD2 Score

• Age: points are assigned based on the patient's age, with older patients receiving more points 2, 4.
• Blood pressure: elevated blood pressure is assigned points 2, 4.
• Clinical features: the type and severity of symptoms, such as unilateral weakness or speech disturbance, are assigned points 2, 4.
• Duration of symptoms: the longer the symptoms last, the more points are assigned 2, 4.
• Diabetes: the presence of diabetes is assigned points 2, 4.

Interpretation of the ABCD2 Score

• The total score ranges from 0 to 7, with higher scores indicating a higher risk of stroke 2, 3, 4.
• A score of 0-3 is generally considered low-risk, while a score of 4-5 is considered moderate-risk, and a score of 6-7 is considered high-risk 2, 3, 4.
• The American Heart Association recommends admission of patients with ABCD2 scores ≥3 for observation, rapid performance of diagnostic tests, and potential acute intervention 2.

Validation and Reliability of the ABCD2 Score

• The ABCD2 score has been validated in several studies, but its accuracy and reliability have been questioned 3, 5, 6.
• One study found that the inter-rater reliability of the ABCD2 score was only fair, with disagreement between raters in nearly one third of patients 5.
• Another study found that the ABCD2 score was inaccurate as a predictor of imminent stroke, with poor sensitivity and specificity 6.