Review


Table 1: Key Factors for Assessing Candidacy for Thrombolytic Therapy


• Diagnosis of ischemic stroke causing measurable neurologic deficit • Neurologic signs should not be clearing spontaneously • Neurologic signs should not be minor and isolated • Caution should be exercised in treating a patient with major deficits • Symptoms of stroke should not be suggestive of subarachnoid hemorrhage


• Onset of symptoms <3 hours before beginning treatment • No head trauma or prior stroke in previous 3 months • No myocardial infarction in previous 3 months • No gastrointestinal or urinary tract hemorrhage in previous 21 days • No major surgery in previous 14 days • No arterial puncture at a non-compressible site in previous 7 days • No history of previous intracranial hemorrhage • Blood pressure not elevated (systolic <185mmHg and diastolic <110mmHg)


• No evidence of active bleeding or acute trauma (fracture) on examination


• Not taking an oral anticoagulant or, if anticoagulant being taken, INR ≤1.7


• If receiving heparin in previous 48 hours, aPTT must be in normal range


• Platelet count ≥100,000/mm3 • Blood glucose concentration ≥50mg/dl (2.7mmol/l) • No seizure with postictal residual neurologic impairments • CT does not show a multilobar infarction (hypodensity more than one-third of cerebral hemisphere)


• Patient or family members understand potential risks and benefits of treatment


aPTT = activated partial thromboplastin time; CT = computed tomography; INR = international normalized ratio. Source: Adams et al., 20077


In another study, rapid assessment and treatment in TIA triage units achieved a 90-day stroke rate of 1.24% (95% confidence interval [CI] 0.72–2.12) compared with a predicted stroke rate of 5.96%.6


diagnosis decreased from three days to one day and the median time to first prescription decreased from 20 days to one day.5


These studies demonstrate


that rapid initiation of treatment in patients having TIA may reduce the risk for stroke.5,6


To improve the speed of clinical assessment, diagnosis, and early management decisions for patients with TIA or stroke, a dedicated stroke team and protocol can be useful.7


Initial


The ABCD2 score, which considers age, blood pressure, clinical features, duration of symptoms, and diabetes history, predicts short-term stroke recurrence and can be key for helping ED physicians rapidly assess patients with suspected TIA or stroke.8,9


In addition, the


National Institutes of Health Stroke Scale (NIHSS) provides information regarding the severity of the stroke.7


In general, the diagnostic studies performed when a patient presents to the ED with TIA or stroke include magnetic resonance imaging (MRI) with diffusion-weighted imaging


92 Management of Acute Stroke and Transient Ischemic Attack


clinical assessment should be performed by physicians in the ED.7


The American Heart Hospital Journal


or MR angiography of the head and neck to identify areas of ischemia that confirm stroke.4


Carotid artery sonography


If a cardioembolic source is suspected, a transthoracic echocardiogram or a transesophageal echocardiogram may be performed. A hypercoagulable work-up may be warranted in a younger patient with no vascular risk factors and absence of other causes.4


or transcranial Doppler may be used to determine whether a carotid lesion or extracranial source is responsible for symptoms.4


Emergency Treatment of Acute Ischemic Stroke. Once a patient receives a diagnosis of acute ischemic stroke, a determination as to whether the patient qualifies for thrombolytic therapy needs to be made.10


Although use of


intravenous (IV) tPA within 90 minutes of stroke onset is best, many patients benefit when treatment is initiated within 91–180 minutes.11


In the US, IV tPA is approved for treatment of acute ischemic stroke within three hours of onset in a broad spectrum of patients (see Table 1). When administered within three hours, IV tPA is effective at three months for the following outcome measures: Barthel Index, modified Rankin Scale, Glasgow Outcome Scale, and the NIHSS.11


Cooperative Acute Stroke Study (ECASS) III, a randomized trial, indicated that improved outcomes were achieved even in stroke patients who received IV tPA up to 4.5 hours after stroke onset.12


addition, patients treated with tPA are at least 30% more likely to have minimal or no disability at three months.11


Safety concerns with IV tPA were summarized in a meta- analysis of 15 open-label studies.13


The most common


adverse effect of tPA is intracerebral hemorrhage (ICH), which occurs in 5.2–6.4% of patients.11,13


Other adverse


effects are rare and include systemic bleeding, myocardial rupture, anaphylaxis, and angioedema.7


A recent


report compared the rate of symptomatic ICH after IV tPA in patients receiving antiplatelet therapy at the time of their stroke.14


This prospective audit of the Safe Implementation of Treatments in Stroke-Monitoring Study (SITS) data showed that, compared with patients not receiving antiplatelet therapy prior to stroke onset, those receiving antiplatelet therapy had an absolute excess of symptomatic ICH of 1.4%, which was not associated with poor functional outcomes or higher mortality rates at three months. Of all antiplatelet therapy groups (aspirin, clopidogrel, aspirin + clopidogrel, dipyridamole, aspirin + dipyridamole, and ‘others’), the combination of aspirin + clopidogrel was a significant predictor of symptomatic ICH compared with antiplatelet-naïve patients as per National Institute of Neurological Disorders and Stroke (NINDS) definition (odds ratio [OR] 1.74, 95% CI 1.11–2.73; p=0.0167) and


Winter 2010 Recent results of the European


In


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