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Section 3.1

Outpatient Management of TIA and Non-Disabling Stroke

3.1.1 Timing of Initial Assessment

  1. Patients presenting to a family physician’s office or other community primary care setting within one week of a suspected transient ischemic attack or non-disabling ischemic stroke should have an immediate clinical evaluation and investigations to establish the diagnosis, rule out stroke mimics, and develop a management plan [Evidence Level B].
  2. Patients who cannot be evaluated as an outpatient within 24 hours from clinical presentation should be transported to an emergency department that has access to neurovascular imaging facilities and stroke expertise [Evidence Level B].
  3. Patients presenting to a family physician’s office or other community primary care setting more than one week following a suspected transient ischemic attack or non-disabling ischemic stroke should be seen by a stroke specialist on a less urgent basis, generally within one month of presentation [Evidence Level B].

 

3.1.2 Evaluation

  1. Patients presenting to a family physician’s office or walk-in clinic with a suspected transient ischemic attack or non-disabling ischemic stroke should be immediately referred to a designated stroke prevention clinic with an interprofessional stroke team, or to a stroke specialist [Evidence Level B].
  2. All patients with suspected transient ischemic attack or non-disabling ischemic stroke should undergo an assessment that includes an electrocardiogram, brain imaging, and non-invasive vascular imaging (for carotid territory transient ischemic attacks or non-disabling strokes) within seven days of symptom onset, and have a consultation with a stroke specialist [Evidence Level B].
    Refer to recommendations 3.2 and 3.3.2 for additional information.
  3. Patients presenting with transient ischemic attack or non-disabling ischemic stroke and motor or speech symptoms should optimally have the assessment on the day of symptom onset [Evidence Level B].
  4. The following laboratory investigations should be undertaken routinely for patients with suspected transient ischemic attack or non-disabling ischemic stroke: haematology, electrolytes, coagulation, renal function, creatine kinase (CK), fasting lipid profile, fasting glucose level and A1c, and thyroid-stimulating hormone (TSH) [Evidence Level C]. Additional blood work may be required if a hypercoagulable or vasculitic cause is suspected.
    Refer to recommendation 3.2 for additional information.
  5. Patients with non-disabling ischemic stroke who are not admitted to hospital should be considered for referred for a comprehensive outpatient assessment of functional impairment, which should include a cognitive evaluation, screening for depression, screening of fitness to drive, and functional assessments for potential rehabilitation treatment [Evidence Level B].
    Refer to recommendation 5.1 for additional information.

3.1.3 Management (See also Section 2: Prevention of Stroke)

  1. All patients with transient ischemic attack or non-disabling ischemic stroke who are not on an antiplatelet agent at time of presentation should be started on antiplatelet therapy immediately after brain imaging has excluded intracranial hemorrhage [Evidence Level A].195 A loading dose of ASA should be at least 160 mg. If clopidogrel is used, a loading dose of 300 mg should be given then maintenance therapy should be started according to parameters set out in recommendation 2.5 for long-term antiplatelet therapy [Evidence Level A].
  2. Patients with transient ischemic attack or non-disabling ischemic stroke with a 50 to 99 percent carotid stenosis on the side implicated by their neurological symptoms, who are otherwise candidates for carotid re-vascularization, should have carotid endarterectomy performed as soon as possible, ideally within two to fourteen days [Evidence Level A].
    Refer to recommendation 2.7 for additional information.
  3. Patients with transient ischemic attack or non-disabling ischemic stroke with atrial fibrillation should begin anticoagulation immediately after brain imaging has excluded intracranial hemorrhage or large infarct. For patients on Warfarin, the target therapeutic I International Normalized Ratio (INR) is 2.5 with a range of two to three [Evidence Level A].
    Refer to recommendation 2.6 for additional information.
  4. All risk factors for cerebrovascular disease must be aggressively managed through pharmacological and non-pharmacological means to achieve optimal control [Evidence Level A]. While evidence of the benefit of modifying individual risk factors in the acute phase is lacking, there is evidence of benefit when adopting a comprehensive approach, including antihypertensives and statin medication [Evidence Level C].196
    Refer to recommendations 2.2 and 2.3 for additional information.
  5. Patients with transient ischemic attack or non-disabling ischemic stroke who smoke should be strongly advised to quit immediately, and be provided with the pharmacological and non-pharmacological means to do so [Evidence Level B].
    Refer to recommendation 2.1 for additional information.
    Rationale

    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 additional 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.
    • Physicians who work in primary, secondary, and tertiary care settings who have education, training, and knowledge to manage patients with transient ischemic attack or non-disabling ischemic stroke.
    • Processes and protocols in community healthcare settings and acute healthcare facilities to enable rapid access to diagnostic tests and expertise for patients with transient ischemic attack or minor stroke.
    • 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.
    Performance Measures
    1. Proportion of acute stroke and TIA patients that are discharged alive that are 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 neurological assessment by a stroke expert (in clinic or other setting).
    3. Time from first encounter with medical care to brain imaging (CT/MRI) and other vascular imaging (Doppler of cervical arteries, 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 diagnoses as these may be less accurate.
    • Measures from other prevention recommendations in this document also apply applicable to this recommendation but are not repeated here.
    Implementation Resources and Knowledge Transfer Tools
    Summary of the Evidence

    The purpose of this recommendation is to reduce the risk of recurrent stroke following an initial transient ischemic attack or minor stroke, and to address specific issues of secondary prevention for patients with transient ischemic attack and non-disabling stroke who are not admitted to hospital.

    Recurrent stroke contributes a disproportionate share of the overall national burden of stroke compared to first-time stroke. Also, recurrent strokes have higher fatality rates and, for those who survive, a greater proportion of patients are unable to return to independent living and require long term nursing care. Recurrent stroke risk is up to ten percent in the week immediately following a transient ischemic attack or minor stroke.196 Increasing evidence emphasizes the need for diagnostic evaluation and stroke prevention strategies to be delivered promptly after a cerebral ischemic event.

    The American Stroke Association published a position statement in 2009 redefining a transient ischemic attack.197 Their current definition of Transient ischemic attack (TIA) is “a transient episode of neurological dysfunction caused by focal brain, spinal cord, or retinal ischemia, without acute infarction”. This definition has removed the time factor that has traditionally been in the definition of TIA from the World Health Organization:  i.e., symptoms lasting less than 24 hours. This definition has not yet been widely endorsed but other groups are examining its validity and sensitivity.198

    As part of the Oxford Vascular Study, Chandratheva and colleagues studied delay in seeking medical attention following a transient ischemic attack or minor stroke. 199 of 1000 patients interviewed (459 TIAs, 541 minor strokes), 300 (67%) with TIA and 400 (74%) with minor stroke sought medical attention within 24 hours and 208 (47%) and 234 (46%), respectively, sought attention within three hours. Most patients (77%) first sought attention through their primary care physician. In patients with TIA, incorrect recognition of symptoms, absence of motor or speech symptoms, shorter duration of event, lower ABCD2 score, no history of stroke or atrial fibrillation, and weekend presentation were associated with significantly longer delays in seeking treatment. Of 129 patients with TIA or minor stroke who had a recurrent stroke within 90 days, 41 (31%) did not seek medical attention after their initial event. These patients were more likely to have had a TIA (P=0.003), shorter duration of event (P=0.02), and a history of TIA (P=0.09) and less likely to have motor (P=0.004) or speech symptoms (P=0.04) compared with those patients who sought medical attention for their initial event. The results of this study emphasize the need for primary care practitioners to be educated in stroke recognition and management and ensure patients who do seek medical attention in their offices are managed with aggressive and appropriate secondary prevention strategies.

    Giles and Rothwell conducted a systematic review and meta-analysis to develop overall estimates of the risk of stroke within two and seven days after transient ischemic attack.200 Eighteen independent studies were identified with data on 10 126 transient ischemic attack patients. Stroke risk at seven days ranged from zero percent to 12.8 percent with substantial heterogeneity between studies (p200 Lowest risk was demonstrated in studies of emergency treatment in specialist stroke services.

    Effect of urgent treatment of transient ischemic attack and minor stroke on early recurrent stroke (EXPRESS study):196 The aim was to determine the effect of rapid treatment following transient ischemic attack and minor stroke in patients who are not admitted directly to hospital. Rothwell et al. prospectively studied the effect on process of care and outcome of more urgent assessment and immediate treatment in clinic, rather than subsequent initiation in primary care, in all patients with transient ischemic attack or minor stroke not admitted direct to hospital. 196 The study was nested within a rigorous population-based incidence study of all transient ischemic attack and stroke (Oxford Vascular Study; OXVASC), 201 such that case ascertainment, investigation, and follow-up were complete and identical in both periods. It was concluded that early initiation of existing treatments after transient ischemic attack or minor stroke was associated with an 80 percent relative reduction in the risk of early recurrent stroke. Further follow-up is required to determine long-term outcome, but these results have immediate implications for service provision and public education about TIA and minor stroke.

     

    The Fast assessment of stroke and transient ischaemic attack to prevent early recurrence (FASTER)trial examined whether the immediate risk of stroke following transient ischemic attack or minor stroke might be

    reduced by using clopidogrel in addition to aspirin.202 Kennedy et al. (2007) investigated the aggressive treatment of these patients using antiplatelets.202 The hemorrhagic risks of the combination of aspirin and clopidogrel do not seem to offset this potential benefit. The authors were unable to determine the benefits of simvastatin in this setting. Within 24 hours of symptom onset, patients with transient ischemic attack or minor stroke (n=392) were randomly assigned to clopidogrel (300 mg loading dose than 75 mg daily) or placebo (n=194), and simvastatin (40 mg daily; 199 patients) or placebo (n=193). All patients were also given aspirin and were followed for 90 days. The median time to stroke outcome was 1 day (range 0–62 days). The trial was stopped early due to a failure to recruit patients at the pre-specified minimum enrolment rate because of increased use of statins. The FASTER trial underscores the high risk of stroke in the immediate aftermath of symptom onset in patients with acute ischemic cerebrovascular events, whose symptoms have completely recovered or are too mild, precluding them from treatment with alteplase. Early aggressive antiplatelet therapy may be associated with a reduction in these events, although at the cost of slightly increased hemorrhagic complications. Early simvastatin use does not seem to have a similar effect, and may attenuate the effect of the antiplatelet strategy. Although it was possible to enroll patients within 24 hours of symptom onset into a prevention trial, the trial failed to meet its recruitment rate target and was stopped prematurely.

    The SOS –TIA study conducted in France set up a hospital-based rapid assessment clinic for patients who appeared to have symptoms of ischemia with complete recovery.203 Referral by telephone was available 24 hours/day.   Over a two-year period they saw 1085 patients with suspected TIA,  and assessment and imaging was done within 4 hours of arrival. Of these patients, 574 (53%) were seen within 24 h of symptom onset; 701 (65%) patients had confirmed TIA or minor stroke, and 144 (13%) had possible TIA. 108 (17%) of the 643 patients with confirmed TIA had brain tissue damage. Median duration of symptoms was 15 min (IQR 5–75 min). Of the patients with confirmed or possible TIA, all started a stroke prevention program, 43 (5%) had urgent carotid revascularization, and 44 (5%) were treated for atrial fibrillation with anticoagulants. 808 (74%) of all patients seen were sent home on the same day. The 90-day stroke rate was 1·24% (95% CI 0·72–2·12). They concluded that the rapid access clinic reduced the incidence of recurrent stroke compared to expected rates.

    Well-validated triage tools for predicting risk of stroke recurrence are not available at this time. The ABCD2 rule is a prognostic index based on retrospective data.204 When this tool was validated against a second data set from Oxfordshire, it did not have strong results in predicting stroke outcomes. A validation of the California and ABCD scores was conducted in four independent groups of patients (n=2893) diagnosed with TIA in emergency departments and clinics in defined populations in the USA and UK.205 The two groups used to derive the original scores (n=1916) were used to derive a new unified score based on logistic regression. The two existing scores predicted the risk of stroke similarly in each of the four validation cohorts, for stroke risks at 2 days, 7 days, and 90 days (c statistics 0·60–0·81). In both derivation groups, c statistics were improved for a unified score based on five factors: age ≥60 years; blood pressure ≥140/90 mmHg; clinical features: unilateral weakness, speech impairment without weakness; duration; and diabetes. The c-statistics score for ABCD2, was 0.62–0.83. At this time, while the ABCD and ABCD2 tools are important because they have focused attention upon transient ischemic attack and minor stroke and clinical risk factors for early stroke recurrence, however, their sensitivity is low and their place in routine clinical practice remains unclear.124