Biochemical aspirin resistance in acute stroke patients and its association with clinical factors: a prospective pilot study.

INTRODUCTION: Aspirin is still widely used in treatment and prevention of cardiovascular diseases. To predict which patients cannot benefit from aspirin due to aspirin resistance remains a great clinical challenge. MATERIAL AND METHODS: Fifty one acute stroke/transient ischemic attack (TIA) patients (ASG) with a history of regular aspirin intake for the previous 7 days or more were included to the study within 24 hours of symptoms onset. Twenty nine patients admitted to our department for other reasons were the controls (CG). Each patient underwent routine blood tests (white blood cells, platelets, total cholesterol, C-reactive protein) and additional blood test: glycated haemoglobin (HbA1c), insulin, and N-terminal prohormone of brain natriuretic peptide (NT-proBNP). Biochemical aspirin resistance was measured using the VerifyNow Aspirin platelet function analyzer. RESULTS: There were 9 aspirin resistance patients in ASG (17.5%) and 3 in CG (10.3%) (p = 0.38). There were no differences in either age or gender between those groups. Twelve aspirin-resistant patients differed from aspirin nonresistant patients in age, NT-proBNP and total cholesterol levels (univariate model, p = 0.004, 0.04, 0.02, respectively). In a multivariate model patients aged 76 years and more would likely to be aspirin resistant with odds ratio = 9 (95% confidence interval: 1-78). CONCLUSIONS: Patients aged 76 and more can be more likely aspirin resistant than younger patients. We believe that especially in the elderly with congestive heart failure there is a strong need for further investigations in this field, including searching for alternative antiplatelet therapies.

Differentiating Stroke and Seizure in Acute Setting-Perfusion Computed Tomography?

BACKGROUND: Perfusion computed tomography (PCT) is part of acute stroke protocol in many hospitals; however, its clinical utility is still being disputed. Beyond its use in core and penumbra estimation, there is also a question about PCT role in stroke mimics diagnosis. Case series or small, retrospective studies showed equivocal results. This is the first published prospective, comparative study on PCT in differentiating stroke and seizure in acute setting. METHODS: Patients with acute focal neurologic deficits and without acute ischemic lesions on routine CT underwent PCT and electroencephalography (EEG) within 12 hours after symptom onset. Perfusion parameters were set up as asymmetry indices for corresponding regions of brain hemispheres. EEG findings were assigned to 1 of 5 classes. Neurologic examination was performed using the National Institutes of Health Stroke Scale (NIHSS). Follow-up noncontrast computed tomography was performed on the third day after symptom onset. If no CT changes appeared, magnetic resonance diffusion-weighted imaging was conducted. RESULTS: Final diagnosis was hemispheric ischemic stroke in 17 patients and focal neurologic deficits in the course of seizures (post- and intraictally) in 12 patients. Those groups were significantly different only in one single PCT parameter-time to peak (TTP)-in the lateral part of the middle cerebral artery territory. Analyzed groups were not significantly different in the NIHSS scores and the EEG evaluation. CONCLUSIONS: TTP may stay relatively when seizure is a cause of focal neurologic deficits, but not stroke. Further, large, prospective studies are necessary to verify the results.