Prevalence of Aspirin Resistance in Ischemic Stroke Patients at Assiut University Hospital

Study Overview
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Brief Summary
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This study aims to assess the prevalence of aspirin resistance in patients with acute ischemic stroke and its importance in secondary stroke prevention. Effect of aspirin resistance on short and long term mortality and detection of its relationship with recurrence of stroke.

Detailed Description
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Stroke is the rapidly developing loss of brain functions due to disturbance in the blood supply to the brain. It is the leading cause of adult disability in the United States and Europe and currently the second leading cause of death, ranking after heart disease and before cancer, accounting for 10% of deaths worldwide . About 80-90% of strokes are caused by ischemia, and the remainder by hemorrhage . Arterioarterial micro thromboembolism is an important etiological factor in the pathogenesis of ischemic stroke. Platelet activation in cerebrovascular disease is associated with recurrent stroke and death, while inhibition of platelet function by antiplatelet drugs including aspirin lowers the risk of ischemic stroke. Aspirin is an effective antiplatelet agent, exhibiting its action by irreversibly inhibiting platelet cyclooxygenase-1 enzyme, thus preventing the production of thromboxane A2 (TXA2). It has been used in the primary and secondary prevention of thromboembolic vascular events. Yet, some patients experience recurrent ischemic events despite optimal antiplatelet therapy. This has raised the possibility that these patients may be resistant to aspirin and generated much interest in identification of such patients with laboratory tests of platelet function. Although many studies have demonstrated aspirin resistance in cardiovascular disorders including coronary artery disease, metabolic syndrome , and diabetes by certain tests of aspirin resistance, there are still concerns that these tests have not correlated closely with subsequent recurrent events, and have not reliably identified non-responders to antiplatelet therapy . In addition to the absence of any standardized approach to the diagnosis, there is currently no proven effective treatment for aspirin resistance. Although aspirin resistance has been demonstrated as a possible risk factor for recurrent cardiovascular ischemic events, there is a lack of data correlating aspirin resistance and risk of cerebrovascular ischemic events

Official Title
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Prevalence of Aspirin Resistance in Ischemic Stroke Patients at Assiut University Hospital

Conditions
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Ischemic Stroke

Intervention / Treatment
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* Drug: Acetyl Salicylate
* Diagnostic Test: Optical Platelet Aggregation test


Participation Criteria
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Eligibility Criteria
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Inclusion Criteria: At least 7 days of aspirin therapy (acetylsalicylic acid, 100 mg daily) prior to stroke onset Within 24 h of experiencing a new focal or global neurological deficit. Evidence of new or old ischemic infarct on CT brain or magnetic resonance imaging (MRI). With informed consents. Presence or not previous cerebrovascular event as previous history of transient ischemic attack (TIA) before the onset of stroke. Exclusion Criteria: Patients with other neurological deficits due to stroke mimics or hemorrhagic insult. Patients is subjected to anticoagulant treatment (atrial fibrillation, valve replacement, others).

Ages Eligible for Study
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Minimum Age: 18 Years
Maximum Age: 85 Years

Sexes Eligible for Study
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All

Accepts Healthy Volunteers
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No

Study Plan
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How is the study designed?
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Arms and Interventions

| Intervention/Treatment |
| --- |
|Drug: Acetyl Salicylate|Aspirin is an effective antiplatelet agent, exhibiting its action by irreversibly inhibiting platelet cyclooxygenase-1 enzyme, thus preventing the production of thromboxane A2 (TXA2). It has been used in the primary and secondary prevention of thromboembolic vascular events|
|Diagnostic Test: Optical Platelet Aggregation test|The evaluation of platelet aggregation was performed using an optical aggregometer (AggRAM, using fresh citrated blood. Platelet-rich plasma was obtained by centrifugation of the citrated blood at 190 g for 5 min. The platelet count was adjusted to 200,000 to 300,000 platelets/mm3. Platelet-rich plasma (250 μl) was deposited in each equipment channel, and the activators adenosine diphosphate, epinephrine, collagen, and arachidonic acid were used according to the manufacturer's instructions. aspirin resistance was defined as platelet aggregation ≥ 20% with arachidonic acid and ≥70% with adenosine diphosphate.|

What is the study measuring?
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Primary Outcome Measures

| Outcome Measure | Measure Description | Time Frame |
| --- | --- | --- |
| clinical assessment of patients with ischemic stroke | assessment of ischemic stroke patient using National Institute of Health Stroke Scale (NIHSS)which is a tool used by healthcare providers to objectively quantify the impairment caused by a stroke. The NIHSS is composed of 11 items, each of which scores a specific ability between a 0 and 4. For each item, a score of 0 typically indicates normal function in that specific ability, while a higher score is indicative of some level of impairment.The individual scores from each item are summed in order to calculate a patient's total NIHSS score. The maximum possible score is 42, with the minimum score being a 0. Score Stroke severity 0 No stroke symptoms 1-4 Minor stroke 5-15 Moderate stroke 16-20 Moderate to severe stroke 21-42 Severe stroke | 15-30 min | 
| detection of aspirin resistance prevalence between ischemic stroke patients as risk factors and prevention of its recurrence. | Prevalence of aspirin resistance between patients of acute new onset stroke are calculated .and among patients with recurrent stroke on aspirin antiplatelet therapy who has aspirin resistance as risk factor calculated. Patients with aspirin resistance shifted to other antiplatelet therapy and MRS (modified Rankin score) evaluated on discharge | 7-10 days | 
| clinical assessment of patients with ischemic stroke | assessment of ischemic stroke patient using modified Rankin score (MRS).The scale runs from 0-6, running from perfect health without symptoms to death. 0 - No symptoms. - No significant disability. Able to carry out all usual activities, despite some symptoms. - Slight disability. Able to look after own affairs without assistance, but unable to carry out all previous activities. - Moderate disability. Requires some help, but able to walk unassisted. - Moderately severe disability. Unable to attend to own bodily needs without assistance, and unable to walk unassisted. - Severe disability. Requires constant nursing care and attention, bedridden, incontinent. - Dead | 10-15 min |