The ABCD2 score is a risk assessment tool designed to improve the prediction of short-term stroke risk after a TIA. The score is optimised to predict the risk of stroke within 2 days after a TIA, but also predicts stroke risk within 90 days. The ABCD2 score is calculated by summing up points for five independent factors.
Higher ABCD2 scores are associated with greater risk of stroke during the 2, 7, 30, and 90 days after a TIA. The authors (Ref 1) of the ABCD2 score made the following recommendations for hospital observation:
ABCD2 score |
2 day stroke risk |
Comment |
|---|---|---|
| 0 -4 | 1-4% | Hospital observation may be unnecessary without another indication (e.g. new AF) |
| 5 | 4% | Hospital admission justified in most situations |
| 6 - 7 | 8.1% | Hospital admission recommended |
ABCD2 score
| Variable | Score |
|---|---|
| Age : >60 | 1 |
| BP : SBP >140 or DBP>90 | 1 |
| Clinical Features (choose one) | |
| Any unilateral weakness (face/arm/leg) with or without speech disturbance | 2 |
| Speech disturbance (without motor weakness) | 1 |
| Duration symptoms | |
| 10 - 59 min | 1 |
| >60min | 2 |
| Diabetes | 1 |
| Total ABCD2 score | |
Evaluation
- Initial Evaluation: Prompt initial evaluation (within 12h); evaluation completed within 48 hours
- Hospitalization: Should be considered to facilitate early therapy and secondary prevention
- Lab testing: FBC, U&E, fasting blood glucose & lipids
- ECG in all
- Brain imaging : MRI within 48 hours
- Vascular imaging: Carotid imaging, CT or MR angiography, or transcranial Doppler within 48 hrs
CUH ambulatory TIA Clinic
Patients with suspected TIA who:
- Had focal neurological symptoms lasting <24hrs
- Have already made a complete recovery with no residual signs
- Have no red flags for immediate AMAU/ED referral
- Have an ABCD2 score of 4 or below
are suitable for referral by their GP or EM staff. Fax a RASP TIA Referral proforma and list of medicines to 021 4920355. Please start these patients on aspirin on leaving the ED.
RASP suitable patients will be contacted and given an 8am appointment usually within 24-48 hours of referral.
Patients with high risk clinical features or ABCD2 of above 4 should be referred for medical admission. These patients are a ≈10% risk of completed/disabling recurrent stroke within 14 days, in contrast to those with low ABCD2 and no red flags.
Patients will have standardized investigations across the morning including blood tests, ECG, carotid imaging and brain imaging. They will be evaluated by the RASP (rapid-access stroke prevention) service and an urgent decision will be made regarding diagnosis, antithrombotic therapy and risk for recurrence.
There are two slots per day.
As this service is to be provided with no additional resources and with carotid and brain imaging it is essential that only patients with suspected TIA are referred to the Rapid Access service.
Dr Simon Cronin, Consultant Neurologist
Not suitable TIA clinic:
Those not suitable for discharge to the TIA clinic (as per proforma) include: High risk patients (should be admitted) with any one of:
- ABCD2 above 4 - these high score patients have a 1 in 9 chance of major disabling stroke within 6 days and most likely to occur within 24 hours
- Known carotid stenosis
- Known AF
- More than one attack within the last month
- Residual symptoms or signs, not fully resolved
- Isolated dizziness
- Collapse with loss of consciousness or collapse query cause
Medical management
- Antithrombotic Therapy
- Please start Aspirin for those referred to the TIA clinic and are awaiting a confirmed appointment
- Atherothrombotic TIA confirmed: Daily long-term antiplatelet therapy: combination extended-release dipyridamole plus aspirin (reasonable as first choice), clopidogrel, or aspirin alone. Anticoagulation is not recommended
- Cardioembolic TIA confirmed: Long-term anticoagulation for atrial fibrillation (continuous or paroxysmal). If patient intolerant to anticoagulation, aspirin 325 mg daily; clopidogrel 75 mg daily if intolerant to aspirin
- Hypertension: Lower blood pressure to <140/90 mmHg or <130/80 mmHg for diabetics, with an ACE inhibitor alone or in combination with a diuretic, or with an angiotensin-receptor blocker
- Lipids: Initiate a daily statin. Goal LDL-cholesterol level <2.59 mmol/l (<100mg/dl)
- Smoking: Initiate a cessation program
- Diabetes: Fasting blood glucose goal <126mg/dl
- Physical activity: Recommend ≥10 min of exercise such as walking, bicycling, running, or swimming ≥3 times/week
- Please ensure vehicle driving status has been considered / recommendations made. More on Driving.
Surgical management
- Carotid endarterectomy: Preferably within 2 weeks of cerebral or retinal TIA in those with TIA attributed to a high-grade internal carotid artery stenosis:
- 70-99% internal carotid artery stenosis: Recommended
- 50-69% stenosis: Recommended for patients but only at centres with perioperative complication rate <6%
- <50% stenosis: Not recommended
- Bypass surgery: Not recommended
References
[1] Johnston SC, Rothwell PM, Huynh-Huynh MN, Giles MF, Elkins JS, Sidney S, "Validation and refinement of scores to predict very early stroke risk after transient ischaemic attack," Lancet, 369:283-292, 2007.