Transient Ischemic Attack Treatment & Management

Updated: Sep 11, 2017
  • Author: Ashish Nanda, MD; Chief Editor: Andrew K Chang, MD, MS  more...
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Treatment

Approach Considerations

Rapid transport to hospital is essential to evaluate the patient who may have fleeting or stuttering symptoms. Fingerstick glucose testing can quickly rule out hypoglycemia. Intravenous (IV) access can be established, though transport should not be delayed for this. Collect all the patient’s prescription bottles.

The family or witnesses should be instructed to go to the emergency department (ED), or contact information for these individuals should be obtained. In some communities, emergency medical services (EMS) may preferentially transfer patients with high-risk stroke symptoms to centers with specific stroke expertise. [35]

Vital signs must be obtained promptly and addressed as indicated. Cardiac monitoring can capture a relevant dysrhythmia. Pulse oximetry can evaluate for hypoxia. IV access (if not already established by EMS) should be obtained. Obtain a fingerstick glucose level, and treat the patient accordingly.

Patients with possible transient ischemic attack (TIA) require urgent evaluation and risk stratification. Local resources and practice patterns will determine whether this is done on an inpatient or an outpatient basis.

Initiation of stroke prevention therapy must be provided urgently. Medical management is aimed at reducing both short-term and long-term risk of stroke and varies according to the underlying cause of the episode.

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Patient Disposition

Although controversy exists regarding the need for hospital admission, there is no controversy regarding the need for urgent evaluation, risk stratification, and initiation of stroke prevention therapy. [1, 36, 37, 26] When one community implemented a strategy to ensure patients were seen within an average of 1 day, compared with an average of 3 days, the 90-day stroke risk fell from 10% to 2%. [38]

Similarly, programs to admit patients to a "rapid evaluation unit" or "observation unit" have reduced the 90-day stroke risk from approximately 10% to 4-5%. [39, 40] Other authors have suggested similar benefits from rapid follow-up. [41]

The availability of local resources determines whether this urgent evaluation should occur on an inpatient basis, in an ED observation unit, or in rapid follow-up. To determine appropriate disposition, the emergency physician should decide on the necessary workup, then discuss with the neurologist or primary care physician how best to ensure that this occurs promptly. [42]

One randomized controlled trial of an ED diagnostic protocol found that it was possible to reduce cost, shorten length of stay, and provide appropriate risk stratification by performing this workup in an ED observation unit (with neurology consultation) rather than in an inpatient unit. [43] On the other hand, admission offers the potential benefit of decreased time to thrombolysis in hospitalized patients diagnosed with TIA who develop a new ischemic stroke in the first 24-48 hours after diagnosis.

The American Heart Association (AHA) suggests hospital admission as a reasonable choice for patients with TIA if they present within 72 hours of the event and meet any of the following criteria [1] :

  • ABCD 2 score of 3 (class IIa recommendation; evidence level C)
  • ABCD 2 score of 0-2 and uncertainty that diagnostic workup can be completed within 2 days as an outpatient (class IIa recommendation; evidence level C)
  • ABCD 2 score of 0-2 and other evidence that indicates the patient's event was caused by focal ischemia (class IIa recommendation; evidence level C)

The National Stroke Association consensus guidelines for the management of TIAs recommend considering patient hospitalization if it is the first TIA within the previous 24-48 hours. This would facilitate possible early treatment with tissue plasminogen activator (tPA) and other medical management for recurrent symptoms, and it would expedite risk stratification and implementation of secondary prevention.

For patients with a recent (≤1 week) TIA, the guidelines recommend a timely hospital referral with hospitalization for the following [26] :

  • Crescendo TIAs
  • Symptoms lasting longer than 1 hour
  • Symptomatic internal carotid stenosis greater than 50%
  • Known cardiac source of embolus (eg, atrial fibrillation)
  • Known hypercoagulable state
  • Appropriate combination of the California score or ABCD score
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Management of Hypertension

Patients may be significantly hypertensive. Unless there is specific concern for end-organ damage from a hypertensive emergency, blood pressure should be managed conservatively while ischemic stroke is being ruled out.

For acute ischemic stroke, the AHA recommends initiating antihypertensive therapy only if blood pressure is higher than 220/120 mm Hg or if mean arterial pressure exceeds 130 mm Hg. Unless there is a comorbid cardiac or other condition that necessitates reduction of blood pressure, allowing the patient’s blood pressure to autoregulate at a higher level (during the acute phase) may help maximize cerebral perfusion pressure. [44]

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Pharmacologic Therapy

In view of the high short-term risk of stroke after TIA, antithrombotic therapy should be initiated as soon as intracranial hemorrhage has been ruled out. The guidelines developed by the AHA and the American Stroke Association (ASA) for the prevention of stroke in patients with stroke or TIA, issued in 2006 [45] and updated in 2014, [46] are summarized below.

Noncardioembolic transient ischemic attack

Antiplatelet agents, rather than oral anticoagulants, are recommended as initial therapy. Aspirin 50-325 mg/day, a combination of aspirin and extended-release dipyridamole, and clopidogrel are all reasonable first-line options (class I recommendation). [46]

The AHA/ASA guidelines state that the combination of aspirin and clopidogrel might be considered for initiation within 24 hours of a minor ischemic stroke or TIA and for continuation for 21 days. However, the combination of aspirin and clopidogrel, when initiated days to years after a minor stroke or TIA and continued 2 to 3 years, increases the risk of hemorrhage relative to either agent alone and is not recommended for routine long-term secondary prevention after ischemic stroke or TIA. [46]

Cardioembolic transient ischemic attack

In patients who have atrial fibrillation in association with a TIA, long-term anticoagulation with warfarin to a target international normalized ratio (INR) of 2-3 is typically recommended. Aspirin 325 mg/day is recommended for patients unable to take oral anticoagulants. However, the addition of clopidogrel to aspirin therapy, compared with aspirin therapy alone, might be reasonable. For most patients with a stroke or TIA in the setting of AF, it is reasonable to initiate oral anticoagulation within 14 days after the onset of neurological symptoms. Anticoagulation can be delayed beyond 14 days in the presence of high risk for hemorrhagic conversion. [46]

The 2014 AHA/ASA guidelines also state that bridging therapy with subcutaneous low-molecular-weight heparin (LMWH) is reasonable for patients with atrial fibrillation who require temporary interruption of oral anticoagulation but are at high risk for stroke. [46]

In acute myocardial infarction (MI) with left ventricular thrombus, oral anticoagulation with warfarin (target INR, 2-3) is reasonable. [46]

In dilated cardiomyopathy, either oral anticoagulation with warfarin (target INR, 2-3) or antiplatelet therapy may be considered. In rheumatic mitral valve disease, oral anticoagulation with warfarin (target INR, 2-3) is reasonable. Antiplatelet agents would not normally be added to warfarin unless patients experience recurrent embolism despite a therapeutic INR. The benefit of warfarin after stroke or TIA in patients with sinus rhythm and cardiomyopathy characterized by systolic dysfunction has not been established. [46]

In mitral valve prolapse, long-term antiplatelet therapy is reasonable. In mitral annular calcification, antiplatelet therapy can be considered. Patients with mitral regurgitation can be considered for warfarin or antiplatelet therapy.

In aortic valve disease, antiplatelet therapy may be considered. For patients with mechanical prosthetic valves, oral anticoagulation with warfarin (target INR, 2.5-3.5) is recommended. For those who experience TIAs despite therapeutic INR, aspirin 75-100 mg/day can be added to the regimen. Patients with bioprosthetic valves and no other source of thromboembolism who experience TIAs can be considered for oral anticoagulation with warfarin (target INR, 2-3).

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Large-Artery Atherosclerotic Disease

Intracranial atherosclerosis

The 2014 AHA/ASA guidelines state the following for patients with stroke or TIA due to 50-99% stenosis of a major intracranial artery: [46]

  • Aspirin 50-325 mg/day, rather than warfarin, is recommended
  • Maintenance of blood pressure below 140/90 mm Hg and total cholesterol below 200 mg/dL is recommended
  • Extracranial or intracranial bypass surgery is not recommended
  • Angioplasty and stent placement are investigational and of unknown utility

A randomized trial has shown that aggressive medical management (antiplatelet therapy combined with intensive management of vascular risk factors) is safer than percutaneous transluminal angioplasty and stenting (PTAS) in patient with 70-99% stenosis of a major intracranial artery. Enrollment in this trial was stopped after 451 patients underwent randomization because the 30-day rate of stroke or death was 14.7% in the PTAS group and 5.8% in the medical-management group. [47]

Ipsilateral carotid artery stenosis

Patients with TIA and ipsilateral carotid artery stenosis may be candidates for urgent (performed within 2 weeks) carotid endarterectomy. In certain patients, carotid artery angioplasty and stenting is a reasonable alternative. This can be discussed acutely, or rapid follow-up can be arranged.

Extracranial vertebral stenosis

Patients with symptoms attributable to extracranial vertebral stenosis may be candidates for endovascular treatment. Again, this should be arranged expeditiously if available.

According to the AHA/ASA 2014 guidelines, optimal medical treatment for these patients includes antiplatelet and statin therapies, as well as risk factor modification. This is also optimal medical treatment for patients with symptomatic extracranial carotid disease. [46]

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Consultations

Ideally, decisions regarding ED evaluation and inpatient versus rapid outpatient follow-up are made in concert with a neurologist. There is clear consensus on the importance of rapid evaluation. [4] For example, in the EXPRESS (Early use of eXisting PREventive Strategies for Stroke) study, the 90-day risk of recurrent stroke in patients with TIA or minor stroke was 10.3% in those patients who underwent assessment after a median of 3 days, compared with 2.1% in those assessed in a median of 1 day, who then received prompt treatment. [48]

In some settings, the only way to access expedited evaluation and workup may be through interfacility transfer to a hospital with the appropriate resources. The National Stroke Association consensus guidelines recommend that “[h]ospitals and general practitioners should agree on a local admissions policy and a local protocol for referral to specialist assessment clinics for patients with TIA who do not require hospital admission.” [26]

For ED physicians, consultation with the patient’s primary care physician is the most important consultation because the primary care physician will monitor the patient over the long term and ensure risk-factor and lifestyle modification. In addition, a rapid neurology consultation is not available in many communities, and the primary care doctor may be primarily responsible for managing urgent risk stratification. However, when a neurologist is rapidly available, this consultation should be obtained on an urgent basis as well.

Consultation with a cardiologist can be considered for patients with clear cardiac findings that influence stroke risk, such as atrial fibrillation, patent foramen ovale, intracardiac thrombus, or valvular abnormalities.

Consultation with a neurosurgeon or vascular surgeon should be considered for patients with significant vessel stenosis or occlusion, with a goal of specialist assessment within 1 week and treatment within 2 weeks of symptom onset. [4, 49, 50] In many centers, some endovascular interventions can be performed by other specialists, including interventional neurologists, radiologists, and neuroradiologists.

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Long-Term Monitoring

Patients selected for outpatient care should have a clear follow-up plan and stroke prevention initiated as described, including antiplatelet medication and risk-factor modification. Antiplatelet agents typically should be initiated as soon as intracranial bleeding is ruled out. As noted (see above), the agent to be used varies with the patient and the specific indication.

The following measures should be included in any long-term monitoring of TIA patients:

  • Antihypertensive control should be optimized for patients with hypertension
  • Lipid control should be initiated, potentially including a statin agent
  • Blood glucose control should be optimized for patients with diabetes
  • A smoking-cessation strategy, which may include medication, should be initiated
  • Heavy drinkers should eliminate or reduce alcohol consumption
  • Overweight patients should be encouraged to lose weight
  • All patients should be encouraged to exercise
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