Evaluation of platelet activation, coagulation, and fibrinolytic activation in patients with symptomatic lacunar stroke

Effect of mean platelet volume and platelet count on the prognosis of branch atheromatous disease

OBJECTIVE

The purpose of this study was to investigate the predictive value of mean platelet volume (MPV) and platelet count (PC) in branch atheromatous disease (BAD).

METHODS

This retrospective study included 216 patients with BAD-stroke within 48 h of symptom onset. These patients were divided into good and poor prognosis groups according to their 3-month modified Rankin scale scores after discharge. Multiple logistic regression analysis was used to evaluate independent predictors of poor prognosis in BAD-stroke patients. Receiver-operating characteristic (ROC) analysis was used to estimate the predictive value of MPV and PC on BAD-stroke.

RESULTS

Our research showed that a higher MPV (aOR, 2.926; 95% CI, 2.040-4.196; p < .001) and PC (aOR, 1.013; 95% CI, 1.005-1.020; p = .001) were independently associated with poor prognosis after adjustment for confounders. The ROC analysis of MPV for predicting poor prognosis showed that the sensitivity and specificity were 74% and 84.9%, respectively, and that the AUC was .843 (95% CI, .776-.909, p < .001). The optimal cut-off value was 12.35. The incidence of early neurological deterioration (END) was 24.5% (53 of 163), and 66% of patients in the poor prognosis group had END (33 of 50). Multiple logistic regression analyses showed that elevated MPV and PC were associated with the occurrence of END (p < .05).

CONCLUSION

Our results suggested that an elevated MPV and PC may be important in predicting a worse outcome in BAD-stroke patients. Our study also demonstrated an independent association of MPV and PC with END, which is presumably the main reason for the poor prognosis.

Inflammation-associated D-dimer predicts neurological outcome of recent small subcortical infarct: A prospective clinical and laboratory study

OBJECTIVE

Elevated level of D-Dimer often indicates a worse prognosis in cerebral infarction. However, there is limited research on this impact within recent small subcortical infarction (RSSI). We aim to explore the role of inflammation and the total magnetic resonance imaging (MRI) burden of cerebral small vessel disease (cSVD) in this process.

METHODS

384 RSSI patients and 189 matched healthy controls were strictly registered in the current research. We evaluated short-term and long-term outcomes by measuring the percentage of the National Institutes of Health Stroke Scale (NIHSS) improvement and the modified Rankin Scale (mRS) at 3 months, respectively. We also assessed the chronic, sustained brain damage associated with cSVD using the total MRI burden and confirmed the relationship between prognosis and the total MRI burden of cSVD. Furthermore, we explored the associations between D-dimer and C-reactive protein (CRP) levels with NIHSS improvement and mRS at 3 months, as well as their relationships with both the total MRI burden of cSVD and its 4 imaging features.

RESULTS

Both NIHSS improvement and the mRS at 3 months were found to be correlated with the total MRI burden of cSVD. Higher D-dimer and CRP levels showed a linear correlation, indicating worse prognosis and a higher total MRI burden of cSVD. The four imaging features of the total MRI burden of cSVD did not exhibit entirely consistent patterns when exploring their correlations with prognosis and laboratory indicators.

CONCLUSION

Inflammation-associated D-dimer predicts neurological outcomes in patients with recent small subcortical infarct, and reflects a more severe total MRI burden of cSVD.

The Potential Impact of Neuroimaging and Translational Research on the Clinical Management of Lacunar Stroke

Lacunar infarcts represent one of the most frequent subtypes of ischemic strokes and may represent the first recognizable manifestation of a progressive disease of the small perforating arteries, capillaries, and venules of the brain, defined as cerebral small vessel disease. The pathophysiological mechanisms leading to a perforating artery occlusion are multiple and still not completely defined, due to spatial resolution issues in neuroimaging, sparsity of pathological studies, and lack of valid experimental models. Recent advances in the endovascular treatment of large vessel occlusion may have diverted attention from the management of patients with small vessel occlusions, often excluded from clinical trials of acute therapy and secondary prevention. However, patients with a lacunar stroke benefit from early diagnosis, reperfusion therapy, and secondary prevention measures. In addition, there are new developments in the knowledge of this entity that suggest potential benefits of thrombolysis in an extended time window in selected patients, as well as novel therapeutic approaches targeting different pathophysiological mechanisms involved in small vessel disease. This review offers a comprehensive update in lacunar stroke pathophysiology and clinical perspective for managing lacunar strokes, in light of the latest insights from imaging and translational studies.

Evaluation of platelets activity and reactivity as risk factors for acute ischemic non-embolic stroke in young adults

Background

Ischemic stroke (IS) constitutes a relevant health concern recently in younger population causing permanent cognitive and function-limiting disability and ranks as the 3rd cause of death in Egypt after cardiac and hepatic diseases. Platelet activation has a crucial mechanism in arterial thrombogenesis, thus in pathophysiology of IS. Surface expression of P-selectin (CD62P) reflects platelet activation and measured by flowcytometry. The purpose of the study is to evaluate whether platelet activity and reactivity are considered risk factors for IS so more restrict antiplatelet protocols could be implemented for management and recurrence prevention.

Results

Study population was 60 IS patients and 60 apparently healthy age and gender-matched controls. Patients were subdivided into 37 patients without classical risk factors, aged 46.1 ± 8.2, and 23 patients with > 1 vascular risk factors, aged 52 ± 9.9. The percentage of platelets expressing CD62P reflecting ex vivo baseline activity was significantly higher in stroke patients to controls (p = 0.001), also platelet reactivity (CD62P expression after ADP provocation) was statistically significantly elevated in patients than in controls (p < 0.0001) and was significantly higher in IS patients with vascular risk factors compared to patients without risk factors (p = 0.02).

Conclusion

Both baseline platelet activity and reactivity were significantly higher in IS patients, and were also higher in IS patients with other vascular risk factors than in cryptogenic stroke and considered risk factors for IS.

Platelet count and mean volume in acute stroke: a systematic review and meta-analysis

Changes of mean platelet volume (MPV) and platelet count (PC) could be a marker or a predictor of acute stroke (AS). We conducted a systematic review and meta-analysis of the published literature on the reporting of MPV and PC in AS. Studies were included in accordance with Patient Population or Problem, Intervention, Comparison, Outcomes, and Setting framework. The PRISMA strategy was used to report findings. Risk of bias was assessed with the Newcastle-Ottawa Scale. We included 34 eligible articles retrieved from the literature. PC was significantly lower in AS patients [standardized mean difference (SMD) = - 0.30, (95% CI: - 0.49 to - 0.11), N = 2492, P = .002] compared with controls (N = 3615). The MPV was significantly higher [SMD = 0.52 (95% CI: 0.28-0.76), N = 2739, P < .001] compared with controls (N = 3810). Subgroup analyses showed significantly lower PC in both ischemic stroke (Difference SMD = -0.18, 95% CI: -0.35-0.01) and hemorrhagic stroke (-0.94, -1.62 to -0.25), but only samples by citrate anticoagulant showed significantly lower result for patients compared to controls (-0.36, -0.68 to -0.04). Ischemic stroke patients had higher MPV (0.57, 0.31-0.83), and samples by Ethylenediaminetetraacetic acid (EDTA) anticoagulant showed significantly higher result for patients compared to controls (0.86, 0.55-1.17). PC and MPV appeared to be significantly different between patients with AS and control populations. MPV was significantly higher in ischemic stroke and PC was significantly lower in both ischemic and hemorrhagic strokes. These characteristics might be related to AS and associated with it. It is advisable to pay attention to elapsed time between phlebotomy and hematology analysis, anticoagulant and hemocytometer types in AS.

SYSTEMATIC REVIEW REGISTRATION

This meta-analysis is registered on the International Prospective Register of Systematic Reviews (PROSPERO) under registration number CRD42017067864 (https://www.crd.york.ac.uk/prospero/display_record.php?RecordID=67864).

Point-of-Care-Testing in Acute Stroke Management: An Unmet Need Ripe for Technological Harvest

Stroke, the second highest leading cause of death, is caused by an abrupt interruption of blood to the brain. Supply of blood needs to be promptly restored to salvage brain tissues from irreversible neuronal death. Existing assessment of stroke patients is based largely on detailed clinical evaluation that is complemented by neuroimaging methods. However, emerging data point to the potential use of blood-derived biomarkers in aiding clinical decision-making especially in the diagnosis of ischemic stroke, triaging patients for acute reperfusion therapies, and in informing stroke mechanisms and prognosis. The demand for newer techniques to deliver individualized information on-site for incorporation into a time-sensitive work-flow has become greater. In this review, we examine the roles of a portable and easy to use point-of-care-test (POCT) in shortening the time-to-treatment, classifying stroke subtypes and improving patient's outcome. We first examine the conventional stroke management workflow, then highlight situations where a bedside biomarker assessment might aid clinical decision-making. A novel stroke POCT approach is presented, which combines the use of quantitative and multiplex POCT platforms for the detection of specific stroke biomarkers, as well as data-mining tools to drive analytical processes. Further work is needed in the development of POCTs to fulfill an unmet need in acute stroke management.

Electrochemical impedimetric detection of stroke biomarker NT-proBNP using disposable screen-printed gold electrodes

Stroke is the second top leading cause of death globally. It is caused by an abrupt interruption of blood flow to the brain. In that course, brain natriuretic peptide (BNP) and its derivative N-terminal pro b-type natriuretic peptide (NT-proBNP), neurohormones produced mainly by the heart ventricles in response to excessive stretching of cardiomyocytes (heart muscle cells), are proven to be good biomarkers for heart failure diagnosis. Moreover, there is growing clinical interest of the use of NT-proBNP for stroke diagnosis and prognosis because it is significantly associated with cardioembolic stroke and secondary stroke reoccurrence, with sensitivity >90% and specificity >80%. However, in diagnostic settings, there is still a need to address the encountered analytical problems, particularly assay specificity and set up. In this study, a novel approach for NT-proBNP detection is demonstrated using an electrochemical immunoassay method. A label-free impedimetry immunosensor for stroke biomarker was developed using modified disposable screen-printed gold electrodes (SPGE) hosting specific anti-NT-proBNP capture antibody. The performance of our immunosensor was studied in the presence of NT-proBNP in both buffered and mock (porcine) plasma samples. A linear relation between the relative total resistance (ΔRtot) responses and the NT-proBNP concentrations in buffer was observed in a range from 0.1 to 5 ng mL-1 with a correlation coefficient (R2) of 0.94656. Overall, the biosensor has demonstrated the capability to quantitate NT-proBNP and differentiate such concentrations in a low concentration range, especially among 0, 0.1, 0.5, 1, and 3 ng mL-1 in plasma samples within 25 min. This range is valuable not only for classifying cardioembolic stroke (higher or equal to 0.5 ng mL-1), but also predicting the risk of secondary stroke reoccurrence (higher than 0.255 ng mL-1). Our biosensor has the potential to be used as an easy-to-use point-of-care test that is both accurate and affordable.

The acute effect of the antioxidant drug "U-74389G" on mean platelet volume levels during hypoxia reoxygenation injury in rats

Background

This experimental study examined the effect of the antioxidant drug "U-74389G", on a rat model and particularly in a hypoxia - reoxygenation protocol. The effects of that molecule were studied hematologically using blood mean platelets volume (MPV) levels.

Methods

40 rats of mean weight 231.875 g were used in the study. MPV levels were measured at 60 min of reoxygenation (groups A and C) and at 120 min of reoxygenation (groups B and D). The drug U-74389G was administered only in groups C and D.

Results

U-74389G administration kept significantly increased the predicted MPV levels by 12.77 ± 3.07% (p = 0.0001). Reoxygenation time non-significantly decreased the predicted MPV levels by 2.55 ± 3.71% (p = 0.4103). However, U-74389G administration and reoxygenation time together kept significantly increased the predicted MPV levels by 7.09 ± 1.91% (p = 0.0005).

Conclusions

U-74389G administration whether it interacted or not with reoxygenation time kept significantly increased the predicted MPV levels. This finding has great clinical interest in blood clotting and coagulation pathophysiology.

Elevated Release of Beta-thromboglobulin and Platelet Factor 4 in Cerebral Infarction Patients with Branch Atheromatous Disease: A Preliminary Report

This study evaluated the levels of the platelet activation markers beta-thromboglobulin (beta-TG) and platelet factor 4 (PF4) in patients with branch atheromatous disease (BAD). Patients with newly diagnosed cerebral infarctions were recruited into the study; those with cardiogenic cerebral infarctions were excluded. Beta-TG and PF4 levels were measured before therapeutic intervention and compared between patients with and without BAD; Welch’s t-test was used to determine significant differences between the groups. A total of 15 subjects were enrolled in the study, and 8 were diagnosed with BAD. Beta-TG (P = 0.031) and PF4 (P = 0.041) levels were significantly higher in the BAD patients than in the non-BAD patients. Platelet activity is normally elevated in patients with cerebral infarctions, but is elevated to an even greater extent in BAD patients. The evaluation of beta-TG and PF4 levels may be beneficial for the elucidation of BAD.

Xueshuantong improves cerebral blood perfusion in elderly patients with lacunar infarction

A total of 64 patients with acute lacunar infarction were enrolled within 24 hours of onset. The patients received conventional therapy (antiplatelet drugs and hypolipidemic drugs) alone or conventional therapy plus 450 mg Xueshuantong once a day. The main ingredient of the Xueshuantong lyophilized powder used for injection was Panax notoginseng saponins. Assessments were made at admission and at discharge using the National Institutes of Health Stroke Scale, the Activity of Daily Living and the Mini-Mental State Examination. Additionally, the relative cerebral blood flow, relative cerebral blood volume and relative mean transit time in the region of interest were calculated within 24 hours after the onset of lacunar infarction, using dynamic susceptibility contrast magnetic resonance perfusion imaging technology. Patients underwent a follow-up MRI scan after 4 weeks of treatment. There was an improvement in the Activity of Daily Living scores and a greater reduction in the scores on the National Institutes of Health Stroke Scale in the treatment group than in the control group. However, the Mini-Mental State Examination scores showed no significant differences after 4 weeks of treatment. Compared with the control group, the relative cerebral blood flow at discharge had increased and showed a greater improvement in the treatment group. Furthermore, there was a reduction in the relative mean transit time at discharge and the value was lower in the treatment group than in the control group. The experimental findings indicate that Xueshuantong treatment improves neurological deficits in elderly patients with lacunar infarction, and the mechanism may be related to increased cerebral perfusion.

Potential serum biomarkers in the pathophysiological processes of stroke

Stroke is a leading cause of death and serious long-term disability. Ischemic stroke is the major subtype of stroke. Currently, its diagnosis is mainly dependent upon clinical symptoms and neuroimaging techniques. Despite these clinical and imaging modalities, often strokes are not recognized after initial onset. As early intervention of medical or surgical therapy is often associated with improved outcomes, there is an urgent need to improve the speed and accuracy of stroke diagnosis. Stroke is a complex pathophysiological process involving; energy failure, imbalance of ion homeostasis, acidosis, intracellular calcium overload, neuronal excitotoxicity, free radical-mediated lipid oxidation, inflammatory cell infiltration, and glial cell activation. These events ultimately lead to neuronal apoptotic cell death or necrosis. In this review, we have summarized the serum biomarkers according to the pathophysiological processes of stroke, which have been intensively studied in clinical trials of stroke over the past five years, and also used Medline's 'related article' option to identify further articles. We focused on the potential biomarkers pertaining to vascular injury, metabolic changes, oxidative injury, and inflammation, and newly studied biomarkers, and discussed how these biomarkers could be used for the diagnosis or determining the prognosis of stroke.

Platelets and acute cerebral infarction

Stroke is worldwide a leading cause of death and disability. Its etiology is regarded as heterogeneous. Platelets are implicated in its pathophysiology, but our understanding of their specific role is incomplete. Only sparse and conflicting information exists about platelet reactivity and activity in acute stroke. Some scientists take the view that platelets activate in conjunction with acute cerebral infarctions. Others put forward evidence corroborating the contrary notion. Increased soluble P-selectin as a sign of platelet and/or endothelial activity seems to be a feature of the disease. The latter point of view is opposed by other researchers. Due to these conflicting opinions, this study is devoted to platelet characteristics in acute cerebral infarctions. We studied subjects (n = 72; age 74 ± 10(SD) years; 31 females) having acute stroke. As controls served atrial fibrillation (AF) patients (n = 58; age 69 ± 7(SD) years; 12 females) subject to electrical cardioversion, a flow cytometer was put to use for measuring platelet reactivity and activity. After agonist provocation, both platelet bound P-selectin and fibrinogen were employed as estimates of platelet reactivity. Dilutions of a thrombin-receptor-activating peptide (TRAP-6) (74 and 57 µmol/l) (P-selectin and fibrinogen) and ADP (8.5 and 1.7 µmol/l) (fibrinogen only) were put to use as platelet agonists. Membrane-bound P-selectin without agonist stimulation served as a measure of in vivo platelet activation. Soluble P-selectin, as determined from a commercial ELISA, was used to assess platelet and/or endothelial activity. In acute stroke neither platelet-bound P-selectin nor fibrinogen after stimulation, i.e. reactivity, differed from AF controls. In contrast, lower platelet activity as judged from surface attached and circulating P-selectin without agonist stimulation proved to be a feature of cerebral infarctions. The p-values were p < 0.001 and p < 0.01, respectively. It is concluded that acute stroke is not associated with platelet reactivity platelets circulate less activated during the disease. It is evident that the mechanisms reflecting platelet reactivity and activity being investigated in this study play minor roles in stroke pathophysiology. New powerful platelet inhibitory drugs are currently introduced. To avoid major bleeding studies on platelet, behavior in acute stroke are necessary before including these medications in stroke treatment protocols.