NEW YORK (Reuters Health) – The “ABCD” rule for predicting stroke following a first transient ischemic attack (TIA) can be used by emergency physicians to decide which patients may be candidates for discharge home if followed with urgent outpatient evaluation.
That’s the conclusion reached by lead author Dr. Kaushal H. Shah, from St. Luke’s-Roosevelt Hospital in New York, and colleagues after they conducted a literature review published in the May issue of the Annals of Emergency Medicine.
Recent data suggest that the short-term risk of stroke (as high as 5% in 2 days and 7% in 7 days) in patients with TIA is substantially higher than previously thought, the authors write. Even though high-risk patients benefit from immediate evaluation and initiation of appropriate interventions, they add, 50% of TIA patients are discharged home from United States emergency departments.
This prompted the team to search several databases in which they identified five articles that derived or validated clinical prediction rules for stratifying stroke risk up to 7 days after a first TIA. Inclusion criteria were adult patients evaluated in an acute care setting.
Risk factors included in the ABCD rule were age 60 years or older, elevated blood pressure, unilateral weakness, speech impairment without unilateral weakness, and symptom duration, for a total of 6 possible points. The ABCD rule has been validated in multiple studies, but lacked an impact analysis, the rule was categorized as level 2 evidence.
Among four validation studies, ABCD scores of less than 4 indicated the risk of stroke was reliably less than 2% at days 2 and 7, the authors report. At scores of 4 or higher, the risk of stroke increased to 5.4% at 2 days and ranged from 6.3% to 13.2% at 7 days.
Dr. Shah’s group calls for impact studies to ensure that routine use of such rules will actually improve patient outcomes, and to evaluate the role of brain imaging in predicting risk.
No matter what protocol is used, they warn, the discharge of a patient implies that “the patient and the system have the resources to conduct an expedited outpatient evaluation within days.”
Ann Emerg Med 2009;53:662-673.
