What is the clinical evidence from this study?

Study design: Cohort. Population: Transient ischemic attack (n=284). Intervention: ABCD and ABCD2 scores vs. Low or intermediate risk scores (≤4) vs high risk scores (>4). Primary outcome: Stroke and death.

June 12, 2009Open Access

Validation and Refinement of the ABCD2 Score

Key Result

Reliance on the ABCD2 score missed 25% (9 of 36) of strokes within 7 days of a transient ischemic attack, which occurred in patients with low or intermediate risk scores (≤4).

Study Design

Type

Cohort (n=284)

Multicenter

Structured PICO

Does the ABCD2 score accurately predict stroke risk within 7 days in patients presenting with transient ischemic attack?

Population

284 residents with incident transient ischemic attack between 1985 and 1994 evaluated for stroke risk using ABCD and ABCD2 scores.

Exposure

Risk stratification using ABCD and ABCD2 scores, and modified scores adding hyperglycemia and history of hypertension

Outcome

Stroke and death (specifically stroke within 7 days)hard clinical

Reliance on the ABCD2 score alone misses a substantial proportion of patients who will have a stroke within 7 days of a TIA, suggesting that adding hyperglycemia and a history of hypertension may improve predictive sensitivity.

Limitations

The value of adding hyperglycemia and a history of hypertension to the predictive model needs to be evaluated further.

Abstract

BACKGROUND AND PURPOSE: Transient ischemic attacks are a frequent diagnosis in the emergency department setting, yet expert opinion as to the proper follow-up and need for hospitalization differs widely. Recently, an effort has been made to risk-stratify patients presenting with transient ischemic attacks through scoring systems such as the ABCD and ABCD2 scales. The aim of our study was to independently validate these scores using a population-based cohort. METHODS: Using the data from the Rochester Stroke and Transient Ischemic Attack Registry and resources of the Rochester Epidemiology Project, medical records of all residents of Rochester, Minn, with a diagnosis of incident transient ischemic attack from 1985 through 1994 were examined (N=284). Patients were scored on the ABCD and ABCD2 scales and new scores were created by adding hyperglycemia and a history of hypertension. The end points of stroke and death were collected previously and were verified through the Rochester Epidemiology Project data. RESULTS: Although our study did find that scores >4 had a statistically significant predictive value for future stroke, a substantial proportion of strokes within 7 days (9 of 36 cases 25%) occurred in patients with low or intermediate risk scores (< or =4) on the ABCD2 scale. Including history of hypertension and hyperglycemia on presentation increased the sensitivity of the score to identify patients who had a stroke within 7 days. CONCLUSIONS: Reliance on the ABCD and ABCD2 scores misses some patients who will have a stroke within 7 days of a transient ischemic attack. Adding hyperglycemia and a history of hypertension to the predictive model could be useful, but the value of these additions need to be evaluated further.