Phase II: Clinical Decision Rule for High Risk TIA Patients in the ED 

Logo ICT

Principal Investigator: Jeffrey J. Perry, MD, CCMF (MU), FRCP C), associate professor University of Ottawa, ED Physician Ottawa Hospital

Local Investigator: Marcel Émond, MD, MSc, Centre de Recherche du CHU de Québec- Université Laval

Co-investigators: Borgundvaag, B; Hohn, C; Lee, J; Sharma, M; Sivilotti, M; Stiell, I; Wells, G; Worster, A

Local nurse coordinator: Suzy Lavoie

Granting agency: Canadian Institutes of Health Research – CIHR

The Transient ischemic Attack are often called in currant language, mini CVA.  They can occur frequently and are lightly to be a premise to a true CVA and leave permanent damage in brain.  The World Health Organisation (WHO) defines a TIA to be a sudden neurologic deficit, localized, last less than 24 hours and is presumed to be issued from vascular origin.   The most frequent symptoms are: hemi paresthesia (weakness on one side of the body), dysarthria (difficulty to speak and articulate), diplopia (double vision), difficulty with equilibrium, dysphasia (difficulty in spoken or written language), finally, monocular vision (the loss of vision on one side of the body.  TIA’s are generally caused by ischemia, an ineffective flow of blood to the brain either by a vascular disease or vascular embolism. The TIA is a clinical diagnostic that is done often when taking patient history, and then during physical examination.  Initially TIA was considered benign, but is now recognized as a potential risk of stroke, and possible death shortly after diagnostic. Naturally, the identification and triage of TIA and having proper treatment is ideal for preventing CVA/stoke. This phase II project follows the phase I that recruited close to 4000 patients in 8 Canadian institutions; 85 patients having stroke within 7 days following primary visit to the ED.  During the last 4 years, a sensitive algorithm was created to evaluate the risk of stoke when consulting for TIA.  The CTS (Canadian TIA Score) algorithm, identity’s the risk from minimal (0.5%) to critical (>10%) that requires an immediate investigation.  The score has a good discrimination criteria with a space under curb ROC of 0.77.  The intention behind the phase II is to validate prospectively the CTS by recruiting patient with TIA on 17 Canadian sites during an approximate period of 3 years.

Objective: The main objective of this study is a prospective validation of the Canadian TIA Score performance by recruiting a new group of patients different than phase I, presenting symptoms of TIA and consulting an ED physician; also evaluating the latest algorithm of ABCD2i.

Conduct: A prospective cohort study will be performed on 17 Canadian sites for an approximate of 3 years.  Eligible participants will be contacted by the healthcare professionals when a TIA diagnosis will be made.  The patient will then be informed of a possible phone call by the healthcare team to do a follow-up.  A verbal consent will be obtained and noted in the recruiting sheet by the ED physician.  A second evaluation will be performed by a different observator after a verbal consent is obtained by the patient.

Hypothesis: The hypothesis is that the ABCD2i algorithm in the previous phase is valid.  The propose validation in this phase is necessary for the implementation phase of the Canadian TIA Score in the practice of ED and first-line physicians.

Expected results: After validation, this algorithm should enable the identification of patients at high risk of suffering from a stroke following a consultation at the ED within 7 days after primary consultation.  The score that was develop has the potential not only to identify the patients necessity of  an urgent referral and management after TIA, but also to identify the patients that don’t need unnecessary testing, consultation or intervention; in the objective of optimizing the use of limited resource.