Why Me? To Be an Ultra-Responder to Antiplatelet Therapy: A Case Report.

Background: Platelet function testing is a valid tool to investigate the clinical response to antiplatelet therapy in different clinical settings; in particular, it might supply helpful information in patients with cerebrovascular disease. Oral antiplatelet treatment, such as Aspirin (ASA) and Clopidogrel, is the gold standard in secondary stroke prevention of non-cardiogenic ischemic stroke; conversely, its application as a primary prevention therapy is not routinely recommended in patients with vascular risk factors. Multiple electrode platelet aggregometry (MEA) impedance aggregometer is a validated device to test platelet inhibition induced by ASA or Clopidogrel. Case Report: We report the case of a 78-year-old patient without relevant clinical history, taking ASA as primary prevention strategy, who was admitted for sudden onset of dysarthria and left facial hyposthenia during physical effort. Brain CT revealed two small subcortical bilateral spontaneous intracranial hemorrhages. Platelet aggregometry with MEA performed upon admission revealed a very strong platelet inhibition induced by ASA (result of the ASPI Test was 5 U, consistent with an ultra-responsiveness to ASA, and the cutoff value of correct responsiveness is <40 U). MRI at longitudinal follow-up revealed the presence of two small cavernous angioma underlying hemorrhagic spots. Conclusion: The evaluation of platelet reactivity in stroke patients undergoing antiplatelet therapies, not commonly performed in clinical practice, could be useful to optimize prevention strategies; the verification of the biological effectiveness of ASA or Clopidogrel could be a valid tool in the definition of each patient's risk profile, particularly in patients with cerebrovascular disease known to be at increased risk for both hemorrhagic and thrombotic complications.

Platelet Function Monitoring Performed after Carotid Stenting during Endovascular Stroke Treatment Predicts Outcome.

OBJECTIVES: Many studies showed that platelet reactivity testing can predict ischemic events after carotid stenting or ischemic stroke. The aim of our study was to assess the role of early platelet function monitoring in predicting 90-days functional outcome, stent thrombosis and hemorrhagic transformation in patients with ischemic stroke treated with endovascular procedures requiring emergent extracranial stenting. MATERIALS AND METHODS: We performed a retrospective study on consecutive patients with acute anterior circulation stroke admitted to our hospital between January 2015 and March 2020, in whom platelet reactivity testing was performed within 10 days from stenting. Patients were divided according to validated cutoffs in acetylsalicylic acid and Clopidogrel responders and not responders. Group comparison and regression analyses were performed to identify differences between groups and outcome predictors. RESULTS: We included in the final analysis 54 patients. Acetylsalicylic acid resistance was an independent predictor of poor 90 days outcome (OR for modified Rankin scale (mRS) ≤ 2: 0.10 95% CI: 0.02 - 0.69) whereas Clopidogrel resistance was an independent predictor of good outcome (OR for mRS ≤ 2: 7.09 95%CI: 1.33 - 37.72). Acetylsalicylic acid resistance was also associated with increased 90-days mortality (OR: 18.42; 95% CI: 1.67 - 203.14). CONCLUSION: We found a significant association between resistance to acetylsalicylic acid and poor 90-days functional outcome and between resistance to Clopidogrel and good 90-days functional outcome. If confirmed, our results might improve pharmacological management after acute carotid stenting.

Platelet Function Testing in Patients with Acute Ischemic Stroke: An Observational Study.

BACKGROUND: The measurement of platelet reactivity in patients with stroke undergoing antiplatelet therapies is not commonly performed in clinical practice. We assessed the prevalence of therapy responsiveness in patients with stroke and further investigated differences between patients on prevention therapy at stroke onset and patients naive to antiplatelet medications. We also sought differences in responsiveness between etiological subtypes and correlations between Clopidogrel responsiveness and genetic polymorphisms. METHODS: A total of 624 stroke patients on antiplatelet therapy were included. Two different groups were identified: "non-naive patients", and "naive patients". Platelet function was measured with multiple electrode aggregometry, and genotyping assays were used to determine CYP2C19 polymorphisms. RESULTS: Aspirin (ASA) responsiveness was significantly more frequent in naive patients compared with non-naive patients (94.9% versus 82.6%, P < .0010). A better responsiveness to ASA compared with Clopidogrel or combination therapy was found in the entire population (P < .0010), in non-naive patients (P < .0253), and in naive patients (P < .0010). Multivariate analysis revealed a strong effect of Clopidogrel as a possible "risk factor" for unresponsiveness (odds ratio 3.652, P < .0001). No difference between etiological subgroups and no correlations between responsiveness and CYP2C19 polymorphisms were found. CONCLUSION: In our opinion, platelet function testing could be potentially useful in monitoring the biological effect of antiplatelet agents. A substantial proportion of patients with stroke on ASA were "resistant", and the treatment with Clopidogrel was accompanied by even higher rates of unresponsiveness. Longitudinal studies are needed to assess whether aggregometry might supply individualized prognostic information and whether it can be considered a valid tool for future prevention strategies.

Role of cerebrospinal fluid biomarkers to predict conversion to dementia in patients with mild cognitive impairment: a clinical cohort study.

BACKGROUND: Cerebrospinal fluid (CSF) levels assessment of Aß1-42 and Tau proteins may be accurate diagnostic biomarkers for the differentiation of preclinical Alzheimer's disease (AD) from age-associated memory impairment, depression and other forms of dementia in patients with mild cognitive impairment (MCI). The aim of our study was to explore the utility of CSF biomarkers in combination with common cognitive markers as predictors for the risk of AD development, and other forms of dementia, and the time to conversion in community patients with MCI. METHODS: A group of 71 MCI patients underwent neurological assessment, extended neuropsychological evaluation, routine blood tests, ApoE determination, and lumbar puncture to dose t-tau, p-tau181, Aß1-42. We investigated baseline CSF and neuropsychological biomarker patterns according to groups stratified with later diagnoses of AD conversion (MCI-AD), other dementia (MCI-NAD) conversion, or clinical stability (sMCI). RESULTS: Baseline Aß1-42 CSF levels were significantly lower in MCI-AD patients compared to both sMCI and MCI-NAD. Additionally, p-tau181 was higher in the MCI-AD group compared to sMCI. The MCI-AD subgroup analysis confirmed the role of Aß1-42 in its predictive role of time to conversion: rapid converters had lower Aß1-42 levels compared to slow converters. Logistic regression and survival analysis further supported the key predictive role of baseline Aß1-42 for incipient AD and dementia-free survival. CONCLUSIONS: Our results confirm the key role of CSF biomarkers in predicting patient conversion from MCI to dementia. The study suggests that CSF biomarkers may also be reliable in a real world clinical setting.