This ABCD2 score TIA stroke risk calculator determines the risk of stroke at 2, 7 and 90 days after the transient ischemic attack based on patient data and TIA features. There is more information on the prognosis method and the risk factors involved in the text below the form.
How does the ABCD2 score TIA stroke risk calculator work?
This health tool determines the short term risk of stroke in the case of patients diagnosed with transient ischemic attack (TIA). It belongs to the prediction tools, along with the TIA index and offers a stratification method for stroke risk in three groups: low, moderate and high.
The following introduces the risk factors taken into account in the ABCD2 score calculator:
■ Age – with a cut off placed at 60 years old.
■ Blood pressure – with a cut off for hypertension placed at 140 mmHg systolic blood pressure and 90 mmHg diastolic BP.
■ History of diabetes – patient suffering from diabetes mellitus as this condition is one of the main risk factors for stroke.
■ Clinical features of the TIA – with a choice between:
- Unilateral weakness with or without speech impairment;
- Speech impairment without weakness;
- Other symptoms – such as uni- or bilateral limb numbness.
■ Duration of symptoms – with a choice between three answers, less than 10 minutes, between 10 and 59 minutes and 1 hour or more.
One of the criticisms received by the method is the fact that it has been found to perform poorly in the setting of the emergency department during the largest prospective study.
The poor performance was registered as low sensitivity and low specificity in the identification of high risk patients. The discussion is that high scores manage to separate, not necessarily patients at higher risk of stroke but rather patients with clear diagnosis of TIA from patients with alternative diagnoses such as seizure, migraine or other nonvascular spells.
This shouldn’t however, deter clinicians from using the score as it was specifically designed in outpatient (non-emergency) setting.
ABCD2 score interpretation
After every question in the score is answered, the number of points dedicated to each answer is summed to reveal a final score. This is then put in a risk group and offered the three stroke risk prognostics: after 2, 7 respectively 90 days.
| ABCD2 score | Risk group | 2-day stroke risk | 7-day stroke risk | 90-day stroke risk |
| 0 - 3 | Low risk | 1.0% | 1.2% | 3.1% |
| 4 - 5 | Moderate risk | 4.1% | 5.9% | 9.8% |
| 6 - 7 | High risk | 8.1% | 11.7% | 17.8% |
The low risk group patients may not need hospitalization, especially if there are no concurrent conditions that might be deemed risk prone, such as atrial fibrillation.
The moderate risk group patients are likely to be admitted, with some exceptions.
The high risk group patients are most likely to be admitted and kept under observation.
TIA management includes the initial observation within 12 and up to 48 hours for the finalization of it. Laboratory testing involves the full blood count, serum electrolytes, creatinine, lipids and fasting blood glucose. Investigations that may be deemed necessary include electrocardiography and brain CT or MRI.
In most cases, some kind of medical management of the situation is required in order to address both the more or less imminent risk of stroke and the underlying condition that caused the ischemic attack.
Antithrombotic therapy may be started along with medication for hypertension, lipids, glucose monitoring. Lifestyle changes such as the cessation of smoking and an easy exercise program are also advised.
In the case of patients with TIA caused by high grade internal carotid artery stenosis, surgical endarterectomy is scheduled.
References
1) Johnston SC, Rothwell PM, Nguyen-Huynh MN, et al. (2007) Validation and refinement of scores to predict very early stroke risk after tranisent ischemic attack. Lancet; 369:283-292.
2) Johnston SC, Gress DR, Browner WS, Sidney S. (2000) Short-term prognosis after emergency department diagnosis of TIA. JAMA; 284(22):2901-6.
3) Josephson SA, Sidney S, Pham TN, Bernstein AL, Johnston SC. (2008) Higher ABCD2 score predicts patients most likely to have true transient ischemic attack. Stroke; 39(11):3096-8.
4) Kernana WK. (2007) Stroke after transient ischaemic attack: dealing in futures. Lancet; 369:251-252.
5) Tonarelli SB, Vazquez G, Peacock JM, Luepker RV, Tsai AW, Zacharatos H, Lakshminarayan K. (2008) Stroke Prevention: The Best Outcome after a Transient Ischemic Attack. Results from the Minnesota Stroke Registry and Opportunities to Improve Care. J Vasc Interv Neurol; 1(4): 118–121.
6) Lemmens R, Smet S, Thijs VN. (2013) Clinical Scores for Predicting Recurrence After Transient Ischemic Attack or Stroke: How Good are They? Stroke; 44:1198-1203.
29 Aug, 2016