2. Triage and Initial Diagnostic Evaluation of Transient Ischemic Attack and Non-Disabling Stroke
- Section 2 recommendations pertain to the initial management of patients with a suspected acute transient ischemic attack (TIA) or acute ischemic stroke who are not candidates for acute thrombolysis or endovascular intervention. For patients with suspected acute stroke that warrant hyperacute assessment to determine eligibility for intravenous thrombolysis and endovascular thrombectomy (EVT), refer to the current CSBPR Acute Stroke Management treatment recommendations, Section 4 and Section 5.
- Some people experiencing acute stroke signs or symptoms may present to an outpatient setting such as a primary care physician or family health team office, community clinic, or urgent care centre. Processes should be in place to transport to emergency departments when indicated.
- The timing of symptom onset in patients who present to any healthcare facility with a suspected acute stroke or TIA should be carefully assessed.
- Individuals experiencing signs or symptoms of acute stroke require rapid assessment, diagnosis, and determination of risk for a recurrent stroke. Patients diagnosed with TIA or minor ischemic stroke who are not candidates for acute stroke treatment with intravenous thrombolysis or endovascular intervention may be prioritized for secondary prevention of stroke assessment and management.
- Ischemic stroke is a heterogenous condition with many different subtypes and causes, and it is beyond the scope of this guideline to address all of them. Section 2 focuses on the diagnostic studies that are relevant to the identification of common conditions (e.g., atherosclerosis, atrial fibrillation) or uncommon conditions requiring immediate treatment (e.g., bacterial endocarditis).
- Patients who present with onset of symptoms within 4.5 hours, regardless of whether the symptoms have resolved or not, should be sent for emergent assessment. Refer to Section 3 and Section 4 for additional information.
- Patients with onset of symptoms within 4.5 to 48 hours, regardless of whether the symptoms have resolved or not, should be referred for urgent assessment. Refer to Section 2.0 and 2.1 for additional information.
Recommendations and/or Clinical Considerations
- Patients with acute stroke or TIA who present to an outpatient setting (such as primary care) or to a hospital should undergo clinical evaluation by a healthcare professional with stroke expertise to determine the patient’s risk for recurrent stroke and initiate appropriate and timely investigations and management strategies [Strong recommendation; Moderate quality of evidence].
- Shared decision-making should take into account patient values, preferences, health goals, medical complexity, social determinants of health, health literacy and health needs [Strong recommendation; Low quality of evidence].
2.1 HIGH Risk for Recurrent Stroke (Symptom Onset Within Last 48 Hours)
- Individuals presenting within 48 hours of symptoms consistent with a new acute stroke or TIA (especially transient focal motor or speech symptoms, or persistent stroke symptoms) are at the highest risk for recurrent stroke and should be immediately sent to an emergency department (refer to Clinical Consideration 2.1) with a capacity for stroke care, which includes on-site brain imaging and ideally access to acute stroke treatments [Strong recommendation; Moderate quality of evidence].
- Urgent brain imaging (computerized tomography [CT] or magnetic resonance imaging [MRI]) with concurrent neurovascular imaging (e.g., CT angiography [CTA] or MR angiography [MRA]) should be completed as soon as possible and before discharge from the emergency department [Strong recommendation; Moderate quality of evidence].
- Patients presenting after 48 hours from the onset of an acute stroke or TIA should receive a comprehensive clinical evaluation and investigations as soon as possible by a healthcare professional with stroke expertise [Strong recommendation; Low quality of evidence]. Refer to Section 2.2 for more information on investigations.
Section 2.1 Clinical Considerations
- Referral to a healthcare professional with stroke expertise should be considered for patients with a suspected uncommon cause of stroke, including for young patients with stroke (e.g., <45 years of age) (Kapoor et coll., CJNS 2020); family history of young-onset stroke; suspected cerebral vasculitis or other intracranial arteriopathy/vasculopathy; or suspected hereditary or acquired thrombophilia.
- Patients with symptoms of vertebrobasilar ischemia may present with fluctuating brainstem/cerebellar type symptoms (e.g., diplopia, dysarthria, dysphagia, non-positional vertigo, ataxia; rarely as isolated symptoms) over a longer time course (i.e., >48 hours) and can be mistaken for stroke mimics; however, these patients also require urgent assessment, neurovascular imaging, and management as these types of strokes can have a high morbidity. Consultation with a healthcare professional with stroke expertise is strongly encouraged.
- Setting: In some regions, urgent/rapid TIA clinics are available that have rapid access to diagnostic services and specialist assessment and management. These clinics may be considered an appropriate referral option for patients with TIA and minor stroke.
2.2 Brain and Vascular Imaging
- Brain imaging (CT or MRI) and non-invasive vascular imaging (CTA or MRA) from aortic arch to vertex should be completed as soon as possible following acute disabling or non-disabling stroke, or TIA [Strong recommendation; Moderate quality of evidence].
- CTA of the head and neck from aortic arch to vertex, performed at the time of initial brain CT is recommended as an ideal way to assess both extracranial and intracranial circulation [Strong recommendation; Moderate quality of evidence]. Note: Some facilities may not have CTA readily available and so the timing and type of vascular imaging will need to be based on available resources and local practice protocols.
- Neurovascular imaging is recommended to identify patients with significant symptomatic extracranial carotid artery stenosis (i.e., 50-99% stenosis), which should trigger an urgent referral for potential carotid revascularization [Strong recommendation; High quality of evidence].
- CTA is the first-line vascular imaging test for stroke or TIA patients. If CTA is not possible, MRA and carotid ultrasound for extracranial vascular imaging are reasonable alternatives as first-line tests for assessment of carotid vessels, and selection should be based on availability and patient characteristics [Conditional recommendation; Low quality of evidence].
Section 2.2 Clinical Considerations
- MRI brain scanning is superior to head CT in terms of diagnostic sensitivity for identifying small ischemic lesions in patients presenting clinically with a TIA or minor stroke and can provide additional information to guide decisions about diagnosis, prognosis, and treatment. Decisions about MRI scanning should be based on MRI access, availability, and timing of appointments. For maximal diagnostic yield, MRI should be completed as soon as possible after the symptomatic event, ideally within 7 days of symptom onset so that diffusion-weighted imaging can identify any potential restricted diffusion changes representing infarct. MRI is particularly useful in lower-risk patients with transient symptoms where the presence of ischemia would change their management.
- Common scenarios where urgent brain MRI can be valuable include:
- Normal CT head despite symptoms persisting >24 hours. If diffusion-weighted imaging MRI is negative, cerebral ischemia is unlikely.
- Normal CT head where there is suspected brainstem or cerebellar ischemia (CT head is relatively insensitive for detecting strokes in the posterior fossa due to bone artifact).
- Focal transient symptoms that are clinically atypical for ischemia.
2.3 Blood Work
- The following laboratory investigations should be routinely considered for patients with a TIA or minor ischemic stroke as part of the initial evaluation:
- Initial blood work: Hematology (complete blood count), electrolytes, coagulation (aPTT, INR), renal function (creatinine, estimated glomerular filtration rate), random glucose, ALT [Strong recommendation; Low quality of evidence]. Refer to Table 2A for full list of recommended laboratory tests.
- Additional laboratory tests may be completed during the patient encounter or as an outpatient, including a lipid profile (fasting or non-fasting); and screening for diabetes with either a glycated hemoglobin (HbA1c), fasting glucose or 75g oral glucose tolerance test [Strong recommendation; Low quality of evidence]. Refer to Diabetes Canada Guidelines for additional information related to glucose testing.
- (NEW FOR 2022) Giant Cell Arteritis: If giant cell arteritis is suspected (e.g., retinal ischemia or headache), ESR or CRP should be measured [Strong recommendation; Low quality of evidence].
- (NEW FOR 2022) Extensive thrombophilia testing for hereditary hypercoagulable disorders is not recommended for routine investigation of a patient with arterial ischemic stroke and should be limited to selected situations [Strong recommendation; Low quality of evidence].
- If a hypercoagulable state is suspected, consultation with a healthcare professional with hematology or thrombosis expertise should be considered [Strong recommendation; Low quality of evidence].
2.4 Cardiac Studies
2.4A Detection of Atrial Fibrillation
- Patients with suspected ischemic stroke or TIA should have a 12-lead electrocardiogram (ECG) to assess for atrial fibrillation, concurrent myocardial infarction, or structural heart disease (e.g., left ventricular hypertrophy) as potential causes or risk factors of stroke [Strong recommendation; Moderate quality of evidence].
- For patients being investigated for an acute embolic ischemic stroke or TIA, ECG monitoring for 24 hours or more is recommended as part of the initial stroke work-up to detect paroxysmal atrial fibrillation in patients who would be potential candidates for anticoagulant therapy [Strong recommendation; High quality of evidence].
- For patients being investigated for an embolic ischemic stroke or TIA of undetermined source whose initial short-term ECG monitoring does not reveal atrial fibrillation but a cardioembolic mechanism is suspected, continuous ECG monitoring for at least 2 weeks is recommended to improve detection of paroxysmal atrial fibrillation in selected patients aged ≥55 years who are not already receiving anticoagulant therapy but who would be potential candidates for anticoagulant therapy [Strong recommendation; High quality of evidence]. Refer to CSBPR Secondary Prevention of Stroke module Section 7 for additional guidance in management of patients with stroke and atrial fibrillation. Refer to the current Canadian Cardiovascular Society recommendations on atrial fibrillation.
- Routine echocardiography is not required for all patients with stroke [Strong recommendation; Low quality of evidence].
- Echocardiography should be considered for patients with an embolic ischemic stroke or TIA of undetermined source or when a cardioembolic etiology or paradoxical embolism is suspected [Strong recommendation; Moderate quality of evidence].
- For patients ≤60 years who are being investigated for an embolic ischemic stroke or TIA of undetermined source, echocardiography with saline bubble study is recommended for detection of a patent foramen ovale (PFO) if it may change patient management (i.e., in patients who would be potential candidates for PFO closure or anticoagulant therapy if a PFO were detected) [Strong recommendation; Moderate quality of evidence].
- Contrast-enhanced (agitated saline) transesophageal echocardiography or transcranial Doppler has greater sensitivity than transthoracic echocardiography for detection of right-to-left cardiac and extra-cardiac shunts and should be conducted when available, [Strong recommendation; Moderate quality of evidence].
2.5 Functional Assessment
- Patients with stroke should be assessed for neurological impairments and functional limitations (e.g., cognitive evaluation, screening for depression, screening for dysphagia, screening for aphasia, screening for fitness to drive, need for rehabilitation therapy, assistance with activities of daily living, functional mobility) [Strong recommendation; Moderate quality of evidence]. Refer to Rehabilitation and Recovery Following Stroke module for additional information.
- Patients with stroke found to have neurological impairments that could impact daily functioning should be referred to the appropriate rehabilitation specialist for in-depth assessment and management [Strong recommendation; Moderate quality of evidence].
2.6 (NEW FOR 2022) Virtual Care for Secondary Stroke Prevention
- Secondary stroke prevention services should establish information technology infrastructure and protocols to increase and ensure access to virtual care delivery for patients who do not require in-person visits. Emphasis should be placed on considerations for those individuals who do not require in person visits such as, for patients living in rural and remote settings who do not have local access to healthcare professionals with stroke expertise [Strong recommendation; Low quality of evidence]. Refer to CSBPR Virtual Stroke Care Implementation Toolkit for additional information.
- Clinicians should follow established/validated criteria to determine the best form of visit for each patient at each encounter (i.e., virtual or in person) based on the purpose, goals, digital literacy, and availability for each visit [Strong recommendation; Low quality of evidence]. Refer to Heart & Stroke Virtual Care Decision Framework for additional information and criteria.
Section 2.6 Clinical Considerations
- Consulting sites and individual clinicians should have triage protocols and local intake criteria to ensure patients referred to their services are seen in a timely manner, especially high-risk patients described in Section 2.1.
- The use of virtual care for stroke prevention should include decision tools to identify patients who require in-person visits and those who can reasonably be managed through virtual care, and a scheduling mechanism for virtual visits that support a collaborative team approach to care where appropriate and feasible. Refer to Heart & Stroke Virtual Care Decision Framework for additional guidance and criteria.
- A contingency plan should be established to quickly see patients in person should the need arise following a virtual care encounter. Refer to CSBPR Virtual Stroke Care Implementation Toolkit for additional information.
- Virtual care-enabled evaluations of patients for secondary stroke prevention should be modeled on the topics defined in the post-stroke checklist and core elements of stroke prevention care. Refer to CSBPR Post Stroke Checklist for additional information
- Validated approaches to virtual neurological exams should be followed.
- Processes should be in place to book follow-up tests, referrals, and other consultations after a virtual care visit.
- Processes to ensure appropriate documentation and communication to other team members who may be involved in remote care should be in place.
- Patients and their families should be encouraged to acquire home blood pressure monitors where appropriate and education or reliable resources on proper use should be provided. Mechanisms should be in place for follow-up and management of blood pressure for patients using home blood pressure devices, by either primary care providers or a stroke prevention service.
- For timely investigations, the use of prolonged cardiac monitors, if available, that can be sent to patient’s homes, self-applied, and returned by mail, should be considered.
The goal of outpatient management in the early period following discharge from the hospital or other healthcare setting is rapid assessment and management to reduce the risk of a recurrent, possibly more serious, stroke.
TIAs or minor strokes are unstable conditions that warn of a high risk of recurrent stroke, other vascular events, or death. The risk of recurrent stroke after a TIA has been reported to be 4.7% within 90 days (Shahjouei et al., 2021; JAMA Neurol. 2021;78(1):77-87), with the risk being “front-loaded”: 3.8% of recurrent strokes occur in the two days following initial symptom onset. These percentages are an improvement from the 20% estimate reported previously and reinforce the importance and benefits of timely, aggressive management. The seven-day risk of stroke following a TIA can be as high as 36% in patients with multiple risk factors. Timely initiation of secondary prevention medical therapy and carotid revascularization has been shown to significantly reduce the risk of major stroke after an initial TIA or non-disabling stroke. A study by the TIARegistry.org group reported that the estimates of stroke at days 2, 7, 30, 90, and 365 from 2009 to 2011 were 1.5%, 2.1%, 2.8%, 3.7%, and 5.1%, respectively. These estimates were almost half of those compared with historical cohorts and were attributed to the widespread establishment of TIA clinics, providing faster access to secondary stroke prevention treatments (Amarenco et al., N Engl J Med 2016;374:1533-42). In Canada, a decreased trend in stroke recurrence over 12 years, from 2003 to 2015, has been reported (Wang R et al., Can J Neurol Sci. 2021;48(3):335-343), a trend which is also attributed to improvements in early care.
There is growing implementation of virtual care modalities across healthcare, and they are particularly impactful for stroke care. Cost and time of travel can be a barrier to rural and remote residents trying to access distant specialty services, and often they decline referrals or fail to attend appointments due to travel time, cost, and adverse weather conditions, especially in winter.
People with lived experience and their families expressed the importance of early access to assessment and diagnosis to prevent a recurrent event. They emphasized the need to receive timely education about signs and symptoms of stroke, and clear explanations about the risk for recurrent stroke and the relevance of the time frames for those who are at different risk levels for recurrence events. The wait time from an initial TIA to further investigations can be stressful and patients would like this to be considered in management planning. People with lived experience also expressed concerns about potential biases for women seeking treatment and experiencing missed or delayed diagnosis, especially when they present with a TIA or with fluctuating symptoms, emphasizing the need for individualized assessment and management.
To ensure people experiencing a stroke receive timely stroke assessments, interventions and management, interdisciplinary teams need to have the infrastructure and resources required. These may include the following components established at a systems level.
- Well-established and accessible stroke prevention clinics or broader vascular prevention programs appropriately funded and available in all communities through traditional or technological/virtual means, and referral pathways and promotion of programs for healthcare practitioners to increase timely access.
- Education for the public and healthcare providers (primary care, emergency services, acute care, specialty care) about the urgent need for assessment and management of TIA or non-disabling ischemic stroke, to reduce the risk of recurrent, potentially more serious events.
- Availability of services and systems to refer patients and families to access services that support ongoing education about prevention and management of risk factors, along with additional resources and supports such as lists of self-management programs and education materials that are easily accessible and updated regularly.
- Education and training for healthcare professionals who work in primary, secondary, and tertiary care settings, to enable the management of patients with transient ischemic attack or non-disabling ischemic stroke in a timely manner. Education should also include content about the heart-brain connection and need to approach care holistically, considering all vascular risk factors.
- Processes, protocols, and infrastructure in place to enable rapid access to diagnostic tests and expertise for patients with TIA or minor stroke in community healthcare settings and acute healthcare facilities.
- Universal access to necessary stroke prevention medicines like anti-hypertensives for management and secondary prevention. Provincial and national systems should develop an equitable pharmaceutical strategy to improve access to cost effective medicine for all people in Canada, regardless of geography or ability to pay.
- Mechanisms to monitor, assess, and improve uptake, adherence to, and quality of stroke prevention programs to ensure patients can access effective services. Consideration should be given to community and individual barriers as well as motivators and enablers.
- Mitigation of challenges to virtual care delivery, including how health professions are regulated to deliver virtual care and cross-border barriers (interprovincial and cross-provincial/territorial).
- Virtual care service models within stroke systems of care that improve the accessibility of secondary prevention services for patients in rural and remote locations, and for patients who have difficulty attending in-person appointments. Governments and organizations should consider ways to ensure that barriers to access and use are addressed and mitigated.
- Mitigation of barriers to access, equity, and use of virtual care.
- Data collection and quality improvement mechanisms to monitor efficiency, effectiveness, and quality of virtual care encounters.
- Proportion of acute stroke and TIA patients who are discharged alive from an emergency department or an inpatient stay and then readmitted to hospital for any cause within 7 days and/or 14 days of index acute stroke discharge (core).
- Proportion of patients with TIA or non-disabling stroke who are investigated and discharged from the emergency department who are referred to organized secondary stroke prevention services at discharge (KQI).
- Time from first encounter with medical care (primary care or emergency department) to assessment by a stroke expert (in clinic or other setting).
- Time from first encounter with medical care to brain imaging (CT/MRI); and vascular imaging (Doppler of cervical arteries, CT or MRA).
- Proportion of patients with motor and speech TIAs or minor stroke who have CT head and CTA (or other vascular imaging) completed within 24 hours of presentation.
Patient-oriented Outcome and Experience Indicators:
- Proportion of people discharged with a minor stroke or TIA who are readmitted within 30 days (or 90 days) with a recurrent stroke or TIA.
- 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.
Resources and tools listed below that are external to Heart & Stroke and the Canadian Stroke Best Practice Recommendations may be useful resources for stroke care. However, their inclusion is not an actual or implied endorsement by the Canadian Stroke Best Practices team or Heart & Stroke. The reader is encouraged to review these resources and tools critically and implement them into practice at their discretion.
Healthcare Provider Information
- Canadian Stroke Best Practice Recommendations Prehospital and Emergency Department Module: Table 2A: Recommended Laboratory Investigations for Patients with Acute Stroke or Transient Ischemic Attack
- Canadian Stroke Best Practice Recommendations Acute Stroke Management Module: Appendix 3 Table 3A of Standardized Acute Prehospital Stroke Screening Tools; Table 3B Additional Tools and Table 3C Prehospital Stroke Screening Scales to Identify Large Vessel Occlusion (LVO)
- Heart & Stroke: FAST Signs of Stroke
- Heart & Stroke: Post -Stroke Checklist
- Heart & Stroke 2020 CPR & EEC Guidelines
- Heart & Stroke: Canadian Neurological Scale Training (video)
- Heart & Stroke: Virtual Stroke Care Implementation Toolkit
- Stroke Engine: Canadian Neurological Scale
- Canadian Cardiovascular Society: Atrial Fibrillation Guidelines
- Thrombosis Canada: Clinical Guidelines
- Diabetes Canada: Clinical Practice Guidelines
- American College of Chest Physicians (ACCP) Pulmonary Vascular Guidelines
- American College of Chest Physicians (ACCP) Anticoagulation Guidelines
- Virtual neurological exam examples:
- Hussona MA, Maher M, Chan D, et al. The virtual neurologic exam: Instructional videos and guidance for the COVID-19 era. Can J Neurol Sci. 2020;47;598–603. DOI:10.1017/cjn.2020.96
- American Academy of Neurology
- CorHealth: Secondary Stroke Prevention Resources
- CorHealth: ED Assessment and Triage
- Canadian Association of Radiologists Guidelines
- Depression, Obstructive Sleep Apnea and Cognitive Impairment – DOC Screening Tool
- Recommendations of the 5th Canadian Consensus Conference on the diagnosis and treatment of dementia
- The Ontario Acute Stroke Best Practice Coordinators and the Ontario Regional Education Group in collaboration with Heart & Stroke: Key Changes to the 2022 Acute Stroke Management Canadian Stroke Best Practice Recommendations
Information for people with lived experience of stroke, including family, friends and caregivers
- Heart & Stroke: FAST Signs of Stroke
- Heart & Stroke: Signs of stroke
- Heart & Stroke: What is stroke?
- Heart & Stroke: Atrial Fibrillation
- Heart & Stroke: Your Stroke Journey
- Heart & Stroke: Post-Stroke Checklist
- Heart & Stroke: Are you at risk for heart disease and stroke?
- Heart & Stroke Canadian Resuscitation and First Aid Guidelines
- Heart & Stroke: Virtual Healthcare Checklist
- Heart & Stroke: Secondary Prevention Infographic
- Heart & Stroke: Rehabilitation and Recovery Infographic
- Heart & Stroke: Transitions and Community Participation Infographic
- Heart & Stroke: Online and Peer Support
- Stroke Engine
Sex and Gender Considerations Reference List
The risk of recurrent ischemic stroke is heightened, especially in the early days following stroke or TIA. In a systematic review and meta-analysis including the results from 68 studies, Shahjouei et al. (2021) reported the frequency of recurrent events was 2.4% within 2 days, 3.8% within 7 days, 4.1% within 30 days, and 4.7% within 90 days. Rapid clinical assessment by stroke specialists and subsequent investigations to differentiate between TIA and minor stroke from other potential causes are essential to ensure secondary prevention strategies can be implemented as soon as possible.
Urgent TIA clinics provide such a model of care. The TIARegistry.org project is a prospective registry designed to follow patients presenting with TIA or minor stroke over a five-year period. Patients were included if the event had occurred within the previous 7 days. The preliminary one-year results, which included 4,583 patients recruited from 61 sites in 21 countries from 2009 to 2011, indicated that 78.4% of patients were seen by a stroke specialist within 24 hours of the event (Amarenco et al., 2016). Most patients received key urgent investigations before discharge and appropriate treatments were initiated. For example, 5% of patients received a new diagnosis of atrial fibrillation, of which 66.8% received anticoagulant therapy before discharge. Carotid stenosis of ≥50% was found in 15.5% of patients, of which 26.9% underwent carotid revascularization before discharge. The one-year estimate of risk of the primary outcome, a composite of death from cardiovascular causes, nonfatal stroke and nonfatal acute coronary syndrome, was 6.2% (95% CI 5.5-7.0%). Estimates of the stroke rate at days 2, 7, 30, 90, and 365 were 1.5%, 2.1%, 2.8%, 3.7%, and 5.1%, respectively. These estimates were much lower than those compared with historical cohorts and were attributed to the widespread establishment of TIA clinics. Rothwell et al. (2007) reported that patients who had immediate access to a TIA clinic (EXPRESS) had a significantly reduced risk of recurrent stroke (2.1% vs.10.3%, p=0.0001), compared with an historical cohort who did not have immediate access to the same care. Patients with immediate access also received their prescriptions sooner (median of 1 vs. 20 days). Lavallée et al. (2007) reported the 90-day risk of stroke for all patients seen at their TIA-SOS clinic was lower than that predicted by their ABCD2 score (1.24% vs. 5.96%).
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 3 days of stroke has a beneficial effect on outcomes post stroke (Langhorne et al., 2000). Blood biomarkers have been shown 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 all independent predictors of deterioration following TIA or minor stroke, and recommended immediate diagnostic testing for their identification. 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.
Atrial fibrillation (AF) is a common arrhythmia which is associated with an increased risk of ischemic stroke. Following minor stroke or TIA, detecting AF in patients with no previous history is important, particularly in those with a cryptogenic stroke or embolic stroke of unknown source. Once identified, AF can be effectively managed, typically with a switch from an antiplatelet to an anticoagulant. However, AF is under-diagnosed because it is frequently paroxysmal and asymptomatic, and patients do not routinely undergo prolonged screening. AF can be detected using a variety of methods including a12-lead ECG, Holter monitoring, event recorders, and implantable devices. Prolonged ECG monitoring using wearable or insertable devices has been shown to be effective for improving the detection of paroxysmal AF (numbers needed to screen range from 8 – 14) in persons with recent stroke with longer monitoring durations, ranging from 7 days to 1 year associated with an increased probability of AF detection (Bernstein et al., 2021; Haeusler et al., 2021; Wachter et al., 2017; Higgins et al., 2013). At 12 months, newly diagnosed AF was identified significantly more frequently in patients who received additional Holter-ECG recording for up to 7 days in hospital, compared with those who received usual care (5·8% vs. 4·0%; HR=1·4, 95% CI 1·0–2·0) (Haeusler et al., 2021). In the FIND-AF trial, Wachter et al. (2016) reported that at both 6 and 12 months, detection of AF was significantly higher in the prolonged Holter ECG monitoring group (10 days) compared with the standard care group, which received an average of 73 hours of inpatient telemetry plus an average of 24 hours of Holter monitoring (13.5% vs. 4.5% and 13.5% vs. 6.1%, respectively). The associated numbers needed to screen were 11 and 13. There were no significant differences between groups in stroke recurrence (2.5 vs. 4.5%, p=0.28) or death (3.0 vs. 4.5%, p=0.45).
It has been estimated that 5% of all people >65 years of age in Canada have evidence of vascular cognitive impairment. The reported prevalence tends to be higher in those individuals who have experienced a stroke, with up to 29% developing vascular cognitive impairment over the five years following stroke (Pendlebury et al., 2015). Therefore, patients should be screened at the time of presentation using validated instruments such as the Montreal Cognitive Assessment test (MoCA) or the Mini-Mental State Exam (MMSE).
When in-hospital or in-clinic visits are not possible, some prevention interventions can be provided through virtual means, such as telephone or computer-mediated communication. Virtual care interventions have been shown to be effective for cardiovascular risk factor reduction. Monthly phone calls with a health advisor resulted in significantly lower systolic and diastolic blood pressures, and was also associated with significant improvements in diet, physical activity, drug adherence, and satisfaction with access to care, compared with usual care (Salisbury et al., 2016). Mobile health interventions were associated with a significantly reduced HgbA1C compared with the control condition, and significantly increased the odds of smoking cessation at 6 months (Liu et al. 2017). Digital health interventions including telemedicine, web-based strategies, email, mobile applications, text messaging, and monitoring sensors significantly reduced the risk of cardiovascular events (RR=0.61, 95% CI, 0.46–0.80, p<0.001) (Widmer et al., 2015).
Sex and Gender Considerations
In terms of risk factors, the prevalence of hypertension and atrial fibrillation tend to be higher in women, while diabetes and smoking tend to be lower. Women specific factors such as the use of oral combined contraceptives, gestational hypertension, pre-term delivery and hormone replacement therapy, among others can also increase the risk of ischemic stroke (Cordonnier et al. 2017). Women are more likely to be diagnosed as stroke mimics, less likely to be diagnosed with stroke, and less likely to have a full work-up to establish stroke etiology, compared with men (Kapral & Bushnell 2021). As for investigations for cardiac abnormalities, in two trials, FIND-AF (Wachter et al. 2016) and CRYSTAL-AF (Sanna et al. 2014), examining the potential benefit of prolonged cardiac monitoring for the detection of previously unknown atrial fibrillation, no interactions were found with respect to sex and treatment group.