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Initial Risk Stratification and Management of Nondisabling Stroke and TIA

5th Edition
December 2014

The Canadian Stroke Best Practice Recommendations for the Secondary Prevention of Stroke, 5th Edition 2014 module is published in the International Journal of Stroke (IJS) (Online Open‑Access available December 2014; Printed Journal scheduled for April 2015).

To access the specific recommendations for Initial Risk Stratification and Management of Non‑Disabling Stroke and Transient Ischemic Attack and all other sections of the Secondary Prevention of Stroke module, please click on this URL which will take you to the recommendations online in the IJS:  http://onlinelibrary.wiley.com/doi/10.1111/ijs.12439/full. For the French version of these recommendations, open the appendix at this link : http://onlinelibrary.wiley.com/store/10.1111/ijs.12439/asset/supinfo/ijs12439-sup-0001-si.pdf?v=1&s=b0ed4fff1d7fc435cf4e2a83ccbcbffbdad767de.

All other supporting information, including performance measures, implementation resources, evidence summaries and references, remain available through www.strokebestpractices.ca, and not through the IJS.  Please click on the appropriate sections below for this additional content.


The goal of outpatient management of transient ischemic attack and non-disabling ischemic stroke is rapid assessment and management to reduce the risk of a recurrent, possibly more serious, event.

There is clear evidence that transient ischemic attacks or minor strokes are unstable conditions that warn of high future risk of stroke, other vascular events, or death. The risk of recurrent stroke after a transient ischemic attack is 10 to 20 percent within 90 days, and the risk is “front-loaded”, with half of the strokes occurring in the first two days following initial symptom onset. The seven-day risk of stroke following a transient ischemic attack can be as high as 36 percent in patients with multiple risk factors. Timely initiation of secondary prevention medical therapy and carotid endarterectomy has been shown to significantly reduce the risk of major stroke after an initial transient ischemic attack or non-disabling stroke.

System Implications
  • Education for the public and healthcare providers about the urgency of assessment and management of transient ischemic attack or non-disabling ischemic stroke is critical to reduce the risk of recurrent, potentially more serious events. Patients and families will also require ongoing education and support related to prevention and management of stroke.
  • Education and training for physicians who work in primary, secondary, and tertiary care settings, to provide the knowledge to manage patients with transient ischemic attack or non-disabling ischemic stroke in a timely manner.
  • Processes and protocols to enable rapid access to diagnostic tests and expertise for patients with transient ischemic attack or minor stroke in community healthcare settings and acute healthcare facilities.
  • Established and accessible stroke prevention clinics, or broader vascular prevention programs in all communities, and healthcare practitioners who are aware of these programs. These resources should be listed, easily accessible to primary care physicians and healthcare providers, and updated annually.
  • Any suspicion of ischemic stroke in a child warrants an emergent consult or assessment in a pediatric emergency department. All hospitals should have a referral process established with the closest specialized pediatric facility.
Performance Measures
  1. Proportion of acute stroke and TIA patients who are discharged alive from an emergency department or after an inpatient stay and then readmitted to hospital with a new stroke or TIA diagnosis within 90 days of index acute care discharge (core).
  2. Time from first encounter with medical care (primary care or emergency department) to assessment by a stroke expert (in clinic or other setting).
  3. Proportion of patients with motor and speech TIAs who have CT head and CTA completed (or other vascular imaging) within 24 hours of presentation.
  4. Time from first encounter with medical care to brain imaging (CT/MRI) and vascular imaging (Doppler of cervical arteries, CT or MR angiography) and electrocardiogram.

Measurement Notes

  • Data access and quality with respect to timing of first encounter and referral dates and times.
  • Primary care data from physician billing. This should rely on International Classification of Diseases (ICD) codes and not on physician descriptions of diagnoses, as these may be less accurate.
  • Measures from other prevention recommendations in this document also apply to this recommendation but are not repeated here.
Implementation Resources and Knowledge Transfer Tools

Health Care Provider Information

Patient Information

Summary of the Evidence, Evidence Tables and References

Initial Triage and Evaluation Evidence Tables and Reference List

Patients who present with TIA or minor stroke are at increased risk or recurrent stroke, particularly within the first week following the initial event. In a systematic review conducted by Giles & Rothwell (2007), the results from 18 studies (10,126 patients with TIA) were pooled. The risk of stroke was 3.1% at day 2 and 5.2% at day 7. More recently, Perry et al. (2014) examined stroke risk in 3,906 patients admitted to 8 emergency departments with TIA over a 5-year period. In this cohort, 86 patients (2.2%) developed subsequent stroke within 7 days and 132 (3.4%) at 90 days. Purroy et al. (2012) reported recurrent stroke in 2.6% of patients within 7 days and 3.9% within 90 days among 1137 patients admitted to 30 centers in Spain with TIA. Following the first 30 days, the risk of recurrent stroke appears to decline. Thacker et al. (2010) reported the odds (ratio) of recurrent stroke were 30.4 (95% CI 10.4 to 89.4) within the first month. Although still markedly elevated the odds had declined to 18.9 (95% CI 8.58 to 41.6) from one to three months, with continual decrease thereafter. These findings highlight the value of assessing patients who present with suspected stroke or TIA according to time since onset of symptoms.

It remains unclear whether there are differences in progression to stroke associated with different models of care. Neither Paul et al. (2013), nor Martinez-Martinez et al. (2013) reported significant differences in recurrent stroke following TIA in patients who were managed in outpatient clinics or hospital settings, although both authors noted that the costs were significantly increased (up to 5-fold) when patients were managed in hospital. Giles & Rothwell (2007) reported that the risk of recurrent stroke varied considerably depending on the clinical setting, with the lowest risk associated with specialized stroke services, where stroke recurrence was only 0.6% at day 2 and 0.9% at day 7.

It is particularly important for healthcare personnel at non-emergent health centers, such as a family physician’s offices to refer a suspected stroke or TIA to appropriate assessment and diagnostic services. A study by Chandratheva et al. (2010) found that 72.1% of patients with minor stroke and 77.3% of patients with TIA accessed a general practitioner as their first contact with the healthcare system following a suspected stroke or TIA. Recognizing symptoms are further complicated when a patient waits to access care. Delays in seeking care are particularly evident for patients who fail to recognize their symptoms, experience no motor or speech deficits and have a TIA of short duration.

Several tools are available to assess the likelihood of recurrent stroke in patients presenting with TIA. Purroy et al. (2012) assessed the ability of 8 different tools and reported that ABCD3 and ABCD3V were the best predictors of stroke at 7 and 90 days. The corresponding areas under the ROC curve (AUC) were 0.66 (p=0.004) and 0.69 (p<0.001) at day 7 and 0.61 (p=0.015) and 0.63 (p=0.003), at day 90. All other tools, including the California Risk Score, ABCD, ABCD2, ABCDI, ABCD2I, SPI-II and ESRS were unable to predict stroke risk beyond chance alone (p>0.05) at either days 7 or 90. Perry et al. (2014) identified 13 independent predictor of stroke recurrence within 7 days and used them to develop the Canadian TIA Score. The AUC for this tool was 0.77 (95% CI 0.73-0.82). The strongest predictors of stroke were established antiplatelet therapy, initial diastolic blood pressure ≥110 mm Hg, and initial blood glucose ≥15 mmol/L. Coutts et al. (2012) reported that for patients with TIA or minor stroke, a CT/CTA performed within 24 hours was predictive of recurrent stroke at 90 days. In fact, a positive CT/CTA was the only clinical or imaging parameter that remained a significant predictor identified in multivariable analysis. Patients who have immediate access to services that offer diagnostic testing such as imaging achieve better outcomes. Rothwell et al. (2007) found that immediate access to a stroke unit and timely initiation of prophylactic medication resulted in fewer recurrent strokes and fewer adverse events for patients compared to patients who had a lengthier delay in receiving this care.

Detecting atrial fibrillation (AF) after a stroke or TIA is important since it is a major risk factor for subsequent stroke and, once identified, can be effectively treated. However, AF is under-diagnosed because it is frequently paroxysmal and asymptomatic, and patients do not routinely undergo prolonged screening. A prospective cohort study that compared the effectiveness of serial ECGs and Holter monitoring for the identification of AF in patients post stroke found that both methods were equally effective in identifying cases that were not present on a baseline assessment (Douen et al. 2008). Together, serial ECG’s and Holter monitoring identified 18 new cases of AF after baseline ECG assessment in the 144 patients included in the study. The majority of these cases were identified within 72 hours (83%).

The results from two recent RCTs demonstrate the benefits of enhanced monitoring using insertable or portable devices to detect AF. In the EMBRACE trail (Gladstone et al. 2014), a 30-day ambulatory cardiac event monitor was found to be superior to 24-hour Holter monitoring in identifying AF in 572 patients aged 52 to 96 years (mean=72.5 years) without known AF, who had sustained a cryptogenic ischemic stroke or TIA within the previous 6 months and already underwent 24-hour Holter monitoring. Atrial fibrillation lasting ≥30 seconds was detected in 16.1% of patients, using the cardiac event monitor compared with 3.2% of patients in the Holter group (absolute difference, 12.9%; 95% CI 8.0 to 17.6; p<0.001; number needed to screen= 8). The cardiac event monitor was also superior for identifying AF lasting longer than ≥2.5 minutes (9.9% vs. 2.5%, absolute difference, 7.4%, 95% CI, 3.4 to 11.3; p<0.001). By 90 days, oral anticoagulant therapy had been prescribed for more patients in the intervention group (18.6% vs. 11.1%, p=0.01). Three-quarters of AF cases identified in the intervention group were detected within the first 2 weeks of monitoring in this trial. A UK randomized trial (n=100) showed that a strategy of 7-day ECG monitoring in the acute phase post-stroke was superior to standard care for AF detection (18% vs. 2%; p<0.05) and resulted in a significant increase in OAC use (Higgins et al, 2013).

Similar findings were reported in the CRYSTAL-AF trial (Sanna et al. 2014) when patients (mean age of 61.5 years) received long-term monitoring with an insertable cardiac monitor (ICM). At 6 months, the rate of detection of AF was significantly higher among patients assigned to the ICM group (8.9% vs. 1.4%, HR=6.4, 95% CI 1.9- 21.7, p<0.001), compared with those who received standard monitoring using ECG monitoring on a schedule at the discretion of their treating physician. Similar results were reported at 12 months (12.4% vs. 2.0%, HR=7.3, 95% CI 2.6- 20.8, p<0.001). Flint et al. (2012) followed 239 patients with cryptogenic ischemic stroke who underwent outpatient cardiac monitoring using an electrocardiographic loop recorder for 30 days. Paroxysmal atrial fibrillation (PAF) was detected in 26 patients (11.0%; 95% CI: 7.6% to 15.7%) who were previously undiagnosed. Most patients (45%) had their PAF detected within the first 10 days, 31% from day 11 to 20 and 24% from day 21 to 30.

Laboratory investigations and assessment of physiological variables as part of a patient’s initial evaluation provides important information for patient management. A small case control study found that maintenance of normal physiological variables within the first three days of stroke has a beneficial effect on outcomes post stroke (Langhorne et al. 2000). Furthermore, blood biomarkers have been found to correlate with cerebral lesion size and stroke severity (Kisialiou et al. 2012). Ferrari et al. (2010) found that hypertension, diabetes, possible etiology, acute infection and cardiac abnormalities were predictors of deterioration for patients presenting with TIA or minor stroke. The researchers recommend immediate diagnostic testing to identify these risk factors in patients post TIA or minor stroke. Together, these findings suggest a complete evaluation of patients presenting with suspected stroke or TIA is beneficial for predicting risk of recurrent stroke and guiding patient management.