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Information regarding the profile of reticulated platelets (RP) in ischemic cerebrovascular disease (CVD) patients is limited. Data from two prospective, observational, case-control studies were combined to compare the %RP using whole blood flow cytometry in patients ≤ 4 weeks of TIA/stroke onset (baseline, N = 210), and 14 ±7 days (14d, N = 182) and ≥ 90 days (90d, N = 145) after starting or changing antiplatelet therapy with healthy controls (N = 34). There were no differences in median %RP between the overall CVD patient population at baseline or 14d vs. controls (P ≥ 0.2). However, the median %RP was significantly higher in CVD patients overall at 90d (P = .036), and in the subgroup of patients with "lacunar" TIA/ischemic stroke at baseline (P = .04) and at 90d (P = .01), but not at 14d (P = .06) vs. controls. There were no significant differences in the median %RP between other TIA/stroke subgroups and controls (P ≥ 0.05). Elevated circulating reticulated platelets, as a marker of increased platelet production/turnover, may occur following an ischemic event in a well-phenotyped TIA/ischemic stroke population overall, but may precede symptom onset at least in the subgroup with small vessel occlusion. These data improve our understanding of the profile of reticulated platelets in CVD patients.

Background The relationship between von Willebrand factor antigen (VWF:Ag), VWF propeptide (VWFpp), VWFpp/VWF:Ag ratio, ADAMTS13 activity, and microembolic signal (MES) status in carotid stenosis is unknown. Methods This prospective, multicenter study simultaneously assessed plasma VWF:Ag levels, VWFpp levels and ADAMTS13 activity, and their relationship with MES in asymptomatic versus symptomatic moderate-to-severe (≥50–99%) carotid stenosis patients. One-hour transcranial Doppler ultrasound of the middle cerebral arteries classified patients as MES+ve or MES−ve. Results Data from 34 asymptomatic patients were compared with 43 symptomatic patients in the “early phase” (≤4 weeks) and 37 patients in the “late phase” (≥3 months) after transient ischemic attack (TIA)/ischemic stroke. VWF:Ag levels were higher (p = 0.049) and VWFpp/VWF:Ag ratios lower (p = 0.006) in early symptomatic than in asymptomatic patients overall, and in early symptomatic versus asymptomatic MES−ve subgroups (p ≤0.02). There were no intergroup differences in VWFpp expression or ADAMTS13 activity (p ≥0.05). VWF:Ag levels and ADAMTS13 activity decreased (p ≤ 0.048) and VWFpp/VWF:Ag ratios increased (p = 0.03) in symptomatic patients followed up from the early to late phases after TIA/stroke. Although there were no differences in the proportions of symptomatic and asymptomatic patients with blood group O, a combined analysis of early symptomatic and asymptomatic patients revealed lower median VWF:Ag levels in patients with blood group O versus those without blood group O (9.59 vs. 12.32 µg/mL, p = 0.035). Discussion VWF:Ag expression, a marker of endothelial ± platelet activation, is enhanced in recently symptomatic versus asymptomatic carotid stenosis patients, including in MES−ve patients, and decreases with ADAMTS13 activity over time following atherosclerotic TIA/ischemic stroke.

Stroke is a clinically defined syndrome of acute, focal neurological deficit attributed to vascular injury (infarction, haemorrhage) of the central nervous system. Stroke is the second leading cause of death and disability worldwide. Stroke is not a single disease but can be caused by a wide range of risk factors, disease processes and mechanisms. Hypertension is the most important modifiable risk factor for stroke, although its contribution differs for different subtypes. Most (85%) strokes are ischaemic, predominantly caused by small vessel arteriolosclerosis, cardioembolism and large artery athero-thromboembolism. Ischaemic strokes in younger patients can result from a different spectrum of causes such as extracranial dissection. Approximately 15% of strokes worldwide are the result of intracerebral haemorrhage, which can be deep (basal ganglia, brainstem), cerebellar or lobar. Deep haemorrhages usually result from deep perforator (hypertensive) arteriopathy (arteriolosclerosis), while lobar haemorrhages are mainly caused by cerebral amyloid angiopathy or arteriolosclerosis. A minority (about 20%) of intracerebral haemorrhages are caused by macrovascular lesions (vascular malformations, aneurysms, cavernomas), venous sinus thrombosis or rarer causes; these are particularly important in young patients (

Introduction Cerebral micro-embolic signals (MES) predict risk of stroke in carotid stenosis patients. However, MES-negative ‘recently symptomatic patients’ also have a higher stroke risk than ‘asymptomatic patients’. Differences in platelet activation status may contribute to this disparity in risk. Methods This prospective, observational study assessed platelet biomarkers and their relationship with MES in asymptomatic versus symptomatic moderate (≥50–69%) or severe (≥70–99%) carotid stenosis patients. Full blood count parameters were measured and whole-blood flow cytometry was used to quantify platelet surface CD62P and CD63 expression and leucocyte–platelet complex formation. Bilateral simultaneous transcranial Doppler ultrasound of the middle cerebral arteries classified patients as ‘MES positive’ or ‘MES negative’. Results Data from 34 asymptomatic patients were compared with those from 43 symptomatic patients in the ‘early phase’ (≤ 4 weeks) and 37 of these symptomatic patients in the ‘late phase’ (≥ 3 months) after transient ischaemic attack/ischaemic stroke. There were no differences in %CD62P or %CD63 expression between early or late symptomatic and asymptomatic patients overall (p > 0.05). The percentage of lymphocyte–platelet complexes was higher in early symptomatic than in asymptomatic patients (2.8 vs. 2.16%; p Conclusion These data add to the evidence that leucocyte–platelet complex formation/platelet activation is increased in recently symptomatic versus asymptomatic patients, and may contribute to the pathogenesis of first and subsequent strokes in carotid stenosis patients, including those who are MES negative.

Objectives Carotid stenosis patients are at risk of vascular events despite antiplatelet therapy. Data on prescribed antiplatelet regimens have not been comprehensively collated from trials to guide optimal therapy in this population. Methods This review was conducted in line with the current Preferred Reporting Items for Systematic Reviews and Meta-Analyses (PRISMA) statement. Medline, Ovid, Embase, Web of Science, and Google Scholar from 1988 to 2018 were searched using the search terms “carotid stenosis”, “asymptomatic”, “symptomatic”, “antiplatelet”, and “anti-platelet” to identify randomised trials in patients with asymptomatic or symptomatic extracranial moderate–severe carotid stenosis on any form of antiplatelet therapy in which vascular events and pre specified composite outcome events were reported. Results Twenty-five studies were judged eligible for inclusion. Data from one randomised controlled trial showed no significant difference in benefit with aspirin versus placebo in asymptomatic carotid stenosis, but it is still reasonable to recommend aspirin (81–325 mg daily) for prevention of vascular events in these patients. Low to medium dose aspirin (81–325 mg daily) is superior to higher doses (>650 mg daily) at preventing recurrent vascular events in patients undergoing endarterectomy. Data from endovascular treatment (EVT) trials support peri-procedural treatment of asymptomatic and symptomatic patients with 81–325 mg of aspirin daily. The use of peri-procedural aspirin–clopidogrel in patients undergoing EVT is based on one pilot trial, but appears safe. Short-term aspirin–dipyridamole or aspirin–clopidogrel treatments are equally effective at reducing micro-embolic signals on transcranial Doppler ultrasound in patients with ≥50% symptomatic carotid stenosis. There is insufficient evidence to recommend routine aspirin–clopidogrel combination therapy to reduce the risk of recurrent clinical ischaemic events in patients with symptomatic moderate–severe carotid stenosis. Conclusions This comprehensive review outlines an evidence based approach to antiplatelet therapy in carotid stenosis patients. Future trials should randomise such patients to receive different antiplatelet regimens to assess their efficacy and safety and to optimise peri-procedural and long-term preventive treatment in this patient cohort.

The aim was to enhance understanding of the role of platelet biomarkers in the pathogenesis of vascular events and risk stratifying patients with asymptomatic or symptomatic atherosclerotic carotid stenosis.Systematic review conducted in accordance with the Preferred Reporting Items for Systematic Reviews and Meta-Analyses (PRISMA) statement.A systematic review collated data from 1975 to 2020 on ex vivo platelet activation and platelet function/reactivity in patients with atherosclerotic carotid stenosis.Forty-three studies met the inclusion criteria; the majority included patients on antiplatelet therapy. Five studies showed increased platelet biomarkers in patients with ≥ 30% asymptomatic carotid stenosis (ACS) vs. controls, with one neutral study. Preliminary data from one study suggested that quantification of "coated platelets" in combination with stenosis severity may aid risk stratification in patients with ≥ 50% - 99% ACS. Platelets were excessively activated in patients with ≥ 30% symptomatic carotid stenosis (SCS) vs. controls (≥ 11 positive studies and one neutral study). Antiplatelet-High on Treatment Platelet Reactivity (HTPR), previously called "antiplatelet resistance", was observed in 23% - 57% of patients on aspirin, with clopidogrel-HTPR in 25% - 100% of patients with ≥ 50% - 99% ACS. Aspirin-HTPR was noted in 9.5% - 64% and clopidogrel-HTPR in 0 - 83% of patients with ≥ 50% SCS. However, the data do not currently support the use of ex vivo platelet function/reactivity testing to tailor antiplatelet therapy outside of a research setting. Platelets are excessively activated (n = 5), with increased platelet counts (n = 3) in recently symptomatic vs. asymptomatic patients, including those without micro-emboli on transcranial Doppler (TCD) monitoring (n = 2). Most available studies (n = 7) showed that platelets become more reactive or activated following carotid endarterectomy or stenting, either as an acute phase response to intervention or peri-procedural treatment.Platelets are excessively activated in patients with carotid stenosis vs. controls, in recently symptomatic vs. asymptomatic patients, and may become activated/hyper-reactive following carotid interventions despite commonly prescribed antiplatelet regimens. Further prospective multicentre studies are required to determine whether models combining clinical, neurovascular imaging, and platelet biomarker data can facilitate optimised antiplatelet therapy in individual patients with carotid stenosis.

[Background] The prevalence of ex vivo ‘high on-treatment platelet reactivity (HTPR)’ and its relationship with recurrent vascular events/outcomes in patients with ischaemic cerebrovascular disease (CVD) is unclear., [Methods] A systematic review and meta-analysis was performed in accordance with the PRISMA statement. MEDLINE, EMBASE and Cochrane Library were searched for completed manuscripts until May 2019 on TIA/ischaemic stroke patients, ≥ 18 years, treated with commonly-prescribed antiplatelet therapy, who had platelet function/reactivity testing and prospective follow-up data on recurrent stroke/TIA, myocardial infarction, vascular death or other cerebrovascular outcomes. Data were pooled using random-effects meta-analysis. Primary outcome was the composite risk of recurrent stroke/TIA, myocardial infarction or vascular death. Secondary outcomes were recurrent stroke/TIA, severe stroke (NIHSS > 16) or disability/impairment (modified Rankin scale ≥ 3) during follow-up., [Results] Antiplatelet–HTPR prevalence was 3–65% with aspirin, 8–56% with clopidogrel and 1.8–35% with aspirin–clopidogrel therapy. Twenty studies (4989 patients) were included in our meta-analysis. There was a higher risk of the composite primary outcome (OR 2.93, 95% CI 1.90–4.51) and recurrent ischaemic stroke/TIA (OR 2.43, 95% CI 1.51–3.91) in patients with vs. those without ‘antiplatelet–HTPR’ on any antiplatelet regimen. These risks were also more than twofold higher in patients with vs. those without ‘aspirin–HTPR’ and ‘dual antiplatelet–HTPR’, respectively. Clopidogrel–HTPR status did not significantly predict outcomes, but the number of eligible studies was small. The risk of severe stroke was higher in those with vs. without antiplatelet–HTPR (OR 2.65, 95% CI 1.00–7.01)., [Discussion] Antiplatelet–HTPR may predict risks of recurrent vascular events/outcomes in CVD patients. Given the heterogeneity between studies, further prospective, multi-centre studies are warranted., Dr. Lim’s research was funded by The Meath Foundation, The Irish Institute of Clinical Neuroscience/Novartis Ireland Fellowship Grant, The Vascular Neurology Research Foundation Ireland, the Irish Heart Foundation Stroke Prevention Bursary programme, and by an unrestricted educational grant from Biogen Idec, Ireland. Dr. Murphy’s research was funded by the Trinity College Dublin Innovation Bursary, The Meath Foundation, Joint Irish Institute of Clinical Neuroscience/Merck Serono Fellowship in Neuroscience Grant, The Vascular Neurology Research Foundation Ireland, and by an unrestricted educational grant from Bayer HealthCare, Ireland and Verum Diagnostica, GmbH. Dr Offiah’s Research is funded by The Meath Foundation and The Vascular Neurology Research Foundation Ireland and by an unrestricted educational grant from SINNOWA Medical Science & Technology Co., China. Prof Thijs’ research is supported by The Florey Institute of Neuroscience and Mental Health, which acknowledges support from the Victorian Government and funding from an Operational Infrastructure Support Grant. Prof Prodan’s research is supported by a United States Department of Veterans Affairs Merit Award (1I01CX000340). Prof Kelly is supported by grants from the Health Research Board Ireland. Prof Barber is supported by grants from the Canadian Institute of Health Research and the Heart and Stroke Foundation of Canada. Prof Werring receives research support from the Stroke Association and the British Heart Foundation. Prof Thijs has received personal fees for lectures and consulting fees from Bayer, Boehringer Ingelheim, BMS/Pfizer and Amgen. Prof. Bath is a Stroke Association Professor of Stroke Medicine and NIHR Senior Investigator, a non-executive Director of ‘Platelet Solutions Ltd.®, and owns 3 shares; he has received personal fees for consulting from DiaMedica, Moleac, Nestle, Sanofi and Phagenesis. Prof Werring has received honoraria for consulting and lectures from Bayer and Portola, and for consulting from Alnylam.

The relationship between plaque morphology, cerebral micro-embolic signals (MES) and platelet biomarkers in carotid stenosis patients warrants investigation. We combined data from two prospective, observational studies to assess carotid plaque morphology and relationship with cerebral MES and platelet biomarkers in patients with recently symptomatic (≤4 weeks of transient ischaemic attack (TIA)/ischaemic stroke) versus asymptomatic carotid stenosis. Plaque morphology on ultrasound was graded with Grey-Scale Median (GSM) and Gray–Weale (GW) scoring. Bilateral transcranial Doppler ultrasound classified patients as ‘MES+ve’ or ‘MES-ve’. Full blood counts were analysed and flow cytometry quantified CD62P and CD63 expression, leucocyte-platelet complexes and reticulated platelets. Data from 42 recently symptomatic carotid stenosis patients were compared with those from 36 asymptomatic patients. There were no differences in median GSM scores between symptomatic and asymptomatic patients (25 vs. 30; P = 0.31) or between MES+ve vs. MES-ve symptomatic patients (36 vs. 25; P = 0.09). Symptomatic patients with GSM-echodense plaques (GSM ≥25) had higher platelet counts (228 vs. 191 × 109/L), neutrophil–platelet (3.3 vs. 2.7%), monocyte–platelet (6.3 vs. 4.55%) and lymphocyte–platelet complexes (2.91 vs. 2.53%) than ‘ asymptomatic patients with GSM-echodense plaques’ ( P ≤ 0.03). Recently, symptomatic carotid stenosis patients with ‘GSM-echodense plaques’ have enhanced platelet production/secretion/activation compared with their asymptomatic counterparts. Simultaneous assessment with neurovascular imaging and platelet biomarkers may aid risk-stratification in carotid stenosis.

The majority of patients with ischaemic cerebrovascular disease (CVD) are not protected from further vascular events with antiplatelet therapy. Measurement of inhibition of platelet function ex vivo on antiplatelet therapy, using laboratory tests that correlate with the clinical effectiveness of these agents, would potentially enable physicians to tailor antiplatelet therapy to suit individuals. A systematic review of the literature was performed to collate all available data on ex vivo platelet function/reactivity in CVD patients, especially those treated with aspirin, dipyridamole or clopidogrel. Particular emphasis was paid to information from commonly available whole blood platelet function analysers (PFA-100®, VerifyNow® and Multiplate®). Data on pharmacogenetic mechanisms potentially influencing high on-treatment platelet reactivity (HTPR) on antiplatelet therapy in CVD were reviewed. Two-hundred forty-nine potentially relevant articles were identified; 93 manuscripts met criteria for inclusion. The prevalence of ex vivo HTPR in CVD varies between 3-62% with aspirin monotherapy, 8-61% with clopidogrel monotherapy and 56-59% when dipyridamole is added to aspirin in the early, subacute or late phases after TIA/stroke onset. The prevalence of HTPR on aspirin was higher on the PFA-100 than on the VerifyNow in one study (p < 0.001). Furthermore, the prevalence of HTPR on aspirin was lower when one used 'novel longitudinal' rather than 'cross-sectional, case-control' definitions of HTPR on the PFA early after TIA or stroke (p = 0.003; 1 study). Studies assessing the influence of genetic polymorphisms on HTPR in CVD patients are limited, and need validation in large multicentre studies. Available data illustrate that an important proportion of CVD patients have ex vivo HTPR on their prescribed antiplatelet regimen, and that the prevalence varies depending on the definition and assay used. Large, adequately-sized, prospective multicentre collaborative studies are urgently needed to determine whether comprehensive assessment of HTPR at high and low shear stress with a range of user-friendly whole blood platelet function testing platforms, in conjunction with pharmacogenetic data, improves our ability to predict the risk of recurrent vascular events in CVD patients, and thus enhance secondary prevention following TIA or ischaemic stroke.

The pathophysiological mechanisms responsible for the disparity in stroke risk between asymptomatic and symptomatic carotid stenosis patients are not fully understood. The functionally important reticulated platelet fraction and reticulocytes could play a role. We performed a prospective, multi-centre, observational analytical study comparing full blood count parameters and platelet production/turnover/activation markers in patients with asymptomatic versus recently symptomatic moderate (≥ 50–69%) or severe (≥ 70–99%) carotid stenosis. Data from 34 asymptomatic patients were compared with 43 symptomatic patients in the ‘early phase’ (≤ 4 weeks) and 37 of these patients in the ‘late phase’ (≥ 3 months) after TIA/ischaemic stroke. Reticulated platelets were quantified by whole blood flow cytometry and reticulated platelets and red cell reticulocytes by ‘automated assays’ (Sysmex XE-2100™). Bilateral simultaneous transcranial Doppler ultrasound monitoring classified patients as micro-embolic signal (MES)+ve or MES−ve. Mean platelet count was higher in early (216 × 109/L; P = 0.04) and late symptomatic (219 × 109/L; P = 0.044) than asymptomatic patients (194 × 109/L). Mean platelet volume was higher in early symptomatic than asymptomatic patients (10.8 vs. 10.45 fl; P = 0.045). Automated assays revealed higher % reticulated platelet fractions in early (5.78%; P

Data are limited on the optimal management of cryptogenic TIA/stroke patients with a patent foramen ovale (PFO)±inter-atrial septal aneurysm (IASA), especially with an inherited thrombophilia.Prospectively-collected data on TIA/ischaemic stroke patients with PFO, IASA or both who received 'goal-directed secondary-prevention medical treatment' were analysed. All patients had trans-oesophageal echocardiography, anti-nuclear, anti-cardiolipin, anti-beta 2 glycoprotein I antibodies, rheumatoid factor, lupus anticoagulant, protein CS, anti-thrombin, factor VIII activity, activated protein C resistance, Factor V Leiden, prothrombin gene and MTHFR-c.677CT mutation screening. ENA and homocysteine were assessed in the latter study period.Eighty-three patients were recruited. Mean follow-up: 48.1months. Forty-seven patients (56.6%) had an isolated PFO, 32 (38.6%) a PFO and an IASA, and 4 (4.8%) an IASA alone. Eighteen (21.7%) had ≥1 abnormality on thrombophilia screening. The most important abnormalities which lead to treatment changes in 11 patients (13.3%) were primary anti-phospholipid syndrome (N=3; 3.6%), protein S deficiency (N=2; 2.4%) hyper-homocysteinaemia (N=6/72 screened, 8.3%). Four patients (4.8%) opted for PFO closure: two with protein S deficiency, and two with no identified thrombophilia. Seven (8.4%) had recurrent TIA/ischaemic stroke during follow-up (overall annualised incidence: 2.1%), of whom five had a PFO alone and two a PFO and IASA.Comprehensive arterial and venous thrombophilia screening is warranted in TIA/ischaemic stroke patients with a PFO±IASA, is conclusively abnormal in over a fifth, and informed important decision-making regarding individualised therapy in 13.3% of patients. The incidence of recurrent vascular events in this population is low on optimal, personalised secondary-prevention treatment, even with an underlying thrombophilia.

Introduction Consistent adherence to treatment is essential for effective secondary prevention following TIA/ischaemic stroke. Representative data on long-term treatment continuation and adherence rates are limited. Methods This single centre study recruited patients attending our Rapid Access Stroke Prevention clinic in Ireland from 07/09/2006 → 30/11/2009. Demographic and clinical data, and prescribed medication regimens at initial assessment were recorded. All patients received copies of clinical correspondence containing clear ‘goal-directed treatment advice’ sent to their general practitioner or referring physician. Patients were subsequently interviewed with a standardised pro-forma to assess continuation and adherence rates; overall adherence rates with secondary prevention therapy were also assessed with a validated self-reporting tool (Morisky Scale). Recurrent vascular events during follow-up were recorded. Results One hundred and fourteen patients were recruited; mean age: 64.5 ± 13.8 years; median duration of follow-up: 630 days. Patients were prescribed aspirin (69.3%), alone (17.5%) or in combination with dipyridamole MR (51.8%), clopidogrel (18.2%), warfarin (16.7%), statins (76.3%) and anti-hypertensives (51.8%). During follow-up, the percentages of patients continuing treatment prescribed at the initial visit were: Aspirin (93.7%), dipyridamole MR (72.9%), clopidogrel (81%), warfarin (94.7%), statins (87.9%) and anti-hypertensives (89.8%). Overall, 99.1% reported taking their medication the preceding day. Morisky scale scores for all treatments revealed that 41.2% (N = 47) were high, 36.8% (N = 42) medium, and 12.3% (N = 14) low adherers; 9.7% (N = 11) had incomplete data. Two patients (1.8%) had recurrent cerebrovascular events, and two (1.8%) had myocardial infarctions. Discussion This novel study in European TIA/ischaemic stroke patients, who were provided with a goal-directed secondary prevention plan, showed high rates of medication-continuation and self-reported adherence with prescribed treatment, associated with a low incidence of recurrent vascular events during a median follow up of 1.7 years.

Assessment of the long-term safety of anti-tumour necrosis factor therapies is vital for the safe treatment of inflammatory bowel disease, a disease affecting a young cohort of patients.The aim of this retrospective study was to assess the safety and long-term outcome of infliximab use in clinical practice in our institution on an intention to treat basis over the 10-year period from December 1998 to 31 December 2008.All cases receiving infliximab for ulcerative colitis or Crohn's disease over a 10-year period were identified from hospital pharmacy records. The study was based on a single centre cohort, with an unselected patient group.A total of 271 patients were identified as receiving infliximab for either Crohn's disease or ulcerative colitis over the 10-year study period. In total, 2169 infusions were given to the patient cohort. Fifty adverse events led to discontinuation of infliximab therapy in 47 cases. Two patients stopped due to neurological complications. There were six malignancies diagnosed within the cohort during the study period. Four of these were diagnosed while the individual was receiving Infliximab and two occurred at an interval of 21-52 months post their final infliximab infusion. A total of five deaths (1.5%) were observed during the study period.Infliximab therapy seems to be safe and efficacious in the long term. Although the development of malignancy remains a concern, we have not seen an increased risk of serious infection within our cohort.