Aspirin non-responder in Thai ischemic stroke patients.

BACKGROUND: An important cause of recurrent ischemic stroke is failure to prevent secondary stroke due to poor control of important stroke risk factors. One of the proposed important risk factor is aspirin resistance. The prevalence of aspirin resistance varied widely. It depended on heterogeneity in studied populations and methods of platelet functional assessment. OBJECTIVE: To describe the prevalence of aspirin resistance based on optical platelet aggregometry in stroke patients who attended the Neurological Institute and investigate the clinical risk factors associated with aspirin resistance. MATERIAL AND METHOD: Three hundred stable ischemic stroke patients, whose aspirin dosage varied between 60 to 325 mg/day for at least 14 days before enrollment were recruited in the present study. Demographic data, modifiable risk factors, and treatment were collected by interview and from medical records. Aspirin resistance was determined by optical platelet aggregation technique, using arachidonicacid (AA) and adenosine diphosphate (ADP) as agonists. RESULTS: The patients were classified into two groups based on their platelet aggregatometry tests (PAT). The cases group (n = 40, 13.3%) included both patients with aspirin resistance (n = 2, 0.6%) and aspirin semi-responsiveness (n = 38, 12.7%). The control group was aspirin non-resistance (n = 260, 86.7%). The cases were older (64.8 year vs. 61.26 year, p = 0.049), higher proportion of females (60% vs. 41.5%, p = 0.029), and shorter in height (159.9 CM vs. 164.1 CM, p = 0.007) than the control group. Dosage and duration of the aspirin therapy were the same in both groups. The multivariate analysis showed old age was associated with aspirin resistance. CONCLUSION: The prevalence of aspirin resistance in the present study is 0.6% (95% CI, 0.18%-1.38%). The risk factor for aspirin resistance in post stroke patients is aging. No association between duration and aspirin dosage with aspirin resistance was found. The proportion of aspirin resistance was similar to a previous study done in post myocardial infarction patients.

Impact of risk factors for recurrent ischemic stroke in Prasat Neurological Institute.

BACKGROUND: Recurrent strokes are more likely to be more disabling or fatal than first-even strokes. The high frequency of recurrences underscores the importance ofsecondary prevention. OBJECTIVE: Investigate risk factors of recurrent ischemic stroke and to compare the outcomes after treatment following the Thai stroke guideline between patients with recurrent ischemic stroke and patients without recurrent ischemic stroke. MATERIAL AND METHOD: Sixty-seven patients with recurrent ischemic stroke and 167 patients without recurrent ischemic stroke were included in the present study. All patients were evaluated for demographic data, modifiable risk factors, and treatment. RESULTS: Patients without recurrent ischemic stroke had better controlled level of systolic blood pressure, diastolic blood pressure, and higher high-density lipoprotein level than patients with recurrent ischemic stroke. Carotid stenosis was higher in patients with recurrent ischemic stroke (43.3% vs. 28.7%, p = 0.032). Patients with recurrent ischemic stroke received statin therapy (67.2% vs. 86.8%, p = 0.001) and folic acid (61.2% vs. 78.4%, p = 0.007) less than patients without recurrent ischemic stroke. The multivariate analysis showed that well controlled diastolic blood pressure (p = 0.014), higher level of high-density lipoprotein (p = 0. 010), and receiving of statin (p = 0.002) were associated with decreased incidence of recurrent ischemic stroke. CONCLUSION: Well-controlled risk factors including blood pressure, fasting blood sugar, high-density lipoprotein, and low-density lipoprotein were crucial for the protection of recurrent ischemic stroke. Furthermore, the benefits of statin and folic acid therapies for the protection of recurrent ischemic stroke were emphasized