A new study published in the British Medical Journal (BMJ), has concluded that the Canadian transient ischaemic attack (TIA) score identifies the risk of patients with transient ischaemic attack (or mini-stroke) for a subsequent stroke or carotid artery revascularisation within seven days.
The study was carried out over five years across 13 Canadian emergency departments and included 7,607 adult patients attending the emergency departments with TIA. Of this cohort, 108 (1.4%) has a subsequent stroke within seven days, 83 (1.1%) had carotid endarterectomy/carotid artery stenting within seven days, and nine had both.
The score includes 13 variables from history, physical examination, and testing performed at time of presentation to the emergency department. The assigned score ranges from -3 to 23, and can be used to assign a graded probability of stroke in the subsequent week. This risk can be assigned a range from 0.1% to 28%, or three risk levels — low, medium, and high risk.
According to study authors, one in six patients were found to be low risk (16.4%), one in eight were high risk (11.5%), and the remainder of patients were medium risk (72.5%). Investigators commented, “These risk strata were similar for the secondary outcome of subsequent stroke and for risk stratification at both two and 90 days.”
“For high-risk patients we do absolutely everything we can while they are in the ED, including diagnostic imaging, starting treatment and bringing in a neurologist,” said Jeffrey Perry, professor at the University of Ottawa and lead author of this paper, Ottawa, Canada. “For medium-risk patients, we do similar things but refer them to a stroke prevention clinic, where they can see a neurologist in a day or two. Low-risk patients can safely start their treatment as a neurology outpatient or with their family doctor.”
Investigators claim that the Canadian TIA score proved more accurate than the ABCD2 Score. Authors commented in their discussion, “we believe that having three levels of risk provides clinicians with more options for management.”
Authors further commented, “Although our score is more complex and is not intended to be memorised, it requires only routinely available information from the history, bedside assessment, and test results to stratify patients. It can be readily used and applied by physicians in the emergency department, as it does not require advanced neuroimaging, which is often unavailable.” Additionally, Perry notes that Canadian TIA score is available on the ‘Ottawa Rules’ app, which is free to download on Apple and Android devices.
According to the study’s conclusion, the Canadian TIA score can identify the risk of patients with TIA for subsequent carotid artery revascularisation within seven days and inclusion of this score into management plans could improve decisions on the benefits of hospital admission at the index visit, urgency of testing and intervention, and prioritisation of specialist follow-up of patients discharged from the emergency department. Perry comments, “The Canadian TIA Score can now be safety used in emergency departments, where it can help physicians make the best care decisions for patients with mini-strokes.”