Microembolic signal monitoring in patients with HeartMate 3 and HeartWare left ventricular assist devices: Association with antithrombotic treatment and cerebrovascular events.

BACKGROUND: In patients with left ventricular assist devices (LVADs), ischemic and hemorrhagic stroke are dreaded complications. Predictive markers for these events are lacking. This study aimed to investigate the prevalence and predictive value of microembolic signals (MES) for stroke, detected by Transcranial Doppler sonography (TCD) in patients with HeartMate 3 (HM 3) or HeartWare (HW). METHODS: A thirty-minute bilateral TCD monitoring of the middle cerebral artery (MCA) was performed in 62 outpatients with LVAD (HM 3 N = 31, HW N = 31) and 31 healthy controls. Prevalence and quantity of MES were investigated regarding clinical and laboratory parameters. Cerebrovascular events (CVE) were recorded on follow-up at 90 and 180 days. RESULTS: MES were detected in six patients with HM 3, three patients with HW, and three controls. Within the LVAD groups, patients on monotherapy with vitamin-K-antagonist (VKA) without antiplatelet therapy were at risk for a higher count of MES (negative binomial regression: VKA: 1; VKA + ASA: Exp(B) = 0.005, 95%CI 0.001-0.044; VKA + clopidogrel: Exp(B) = 0.012, 95%CI 0.002-0.056). There was no association between the presence of MES and CVE or death on follow-up (p > 0.05). CONCLUSION: For the first time, the prevalence of MES was prospectively investigated in a notable outpatient cohort of patients with HM 3 and HW. Despite optimized properties of the latest LVAD, MES remain detectable depending on antithrombotic therapy. No association between MES and CVE could be detected.

Circulating Inflammatory Biomarkers in Early Prediction of Stroke-Associated Infections.

(1) Background: Patients with acute ischaemic stroke (AIS) are at high risk for stroke-associated infections (SAIs). We hypothesised that increased concentrations of systemic inflammation markers predict SAIs and unfavourable outcomes; (2) Methods: In 223 patients with AIS, blood samples were taken at ≤24 h, 3 d and 7d after a stroke, to determine IL-6, IL-10, CRP and LBP. The outcome was assessed using the modified Rankin Scale at 90 d. Patients were thoroughly examined regarding the development of SAIs; (3) Results: 47 patients developed SAIs, including 15 lower respiratory tract infections (LRTIs). IL-6 and LBP at 24 h differed, between patients with and without SAIs (IL-6: p < 0.001; LBP: p = 0.042). However, these associations could not be confirmed after adjustment for age, white blood cell count, reduced consciousness and NIHSS. When considering the subgroup of LRTIs, in patients who presented early (≤12 h after stroke, n = 139), IL-6 was independently associated with LRTIs (OR: 1.073, 95% CI: 1.002−1.148). The ROC-analysis for prediction of LRTIs showed an AUC of 0.918 for the combination of IL-6 and clinical factors; (4) Conclusions: Blood biomarkers were not predictive for total SAIs. At early stages, IL-6 was independently associated with outcome-relevant LRTIs. Further studies need to clarify the use of biochemical markers to identify patients prone to SAIs.

Advancement of door-to-needle times in acute stroke treatment after repetitive process analysis: never give up!

Background: In acute ischemic stroke, timely treatment is of utmost relevance. Identification of delaying factors and knowledge about challenges concerning hospital structures are crucial for continuous improvement of process times in stroke care. Objective: In this study, we report on our experience in optimizing the door-to-needle time (DNT) at our tertiary care center by continuous quality improvement. Methods: Five hundred forty patients with acute ischemic stroke receiving intravenous thrombolysis (IVT) at Hannover Medical School were consecutively analyzed in two phases. In study phase I, including 292 patients, process times and delaying factors were collected prospectively from May 2015 until September 2017. In study phase II, process times of 248 patients were obtained from January 2019 until February 2021. In each study phase, a new clinical standard operation procedure (SOP) was implemented, considering previously identified delaying factors. Pre- and post-SOP treatment times and delaying factors were analyzed to evaluate the new protocols. Results: In study phase I, SOP I reduced the median DNT by 15 min. The probability to receive treatment within 30 min after admission increased by factor 5.35 [95% confidence interval (CI): 2.46-11.66]. Further development of the SOP with implementation of a mobile thrombolysis kit led to a further decrease of DNT by 5 min in median in study phase II. The median DNT was 29 (25th-75th percentiles: 18-44) min, and the probability to undergo IVT within 15 min after admission increased by factor 4.2 (95% CI: 1.63-10.83) compared with study phase I. Conclusion: Continuous process analysis and subsequent development of targeted workflow adjustments led to a substantial improvement of DNT. These results illustrate that with appropriate vigilance, there is constantly an opportunity for improvement in stroke care.

Insights Into Immunothrombotic Mechanisms in Acute Stroke due to Vaccine-Induced Immune Thrombotic Thrombocytopenia.

During the COVID-19 pandemic, vaccination is the most important countermeasure. Pharmacovigilance concerns however emerged with very rare, but potentially disastrous thrombotic complications following vaccination with ChAdOx1. Platelet factor-4 antibody mediated vaccine-induced immune thrombotic thrombocytopenia (VITT) was described as an underlying mechanism of these thrombotic events. Recent work moreover suggests that mechanisms of immunothrombosis including neutrophil extracellular trap (NET) formation might be critical for thrombogenesis during VITT. In this study, we investigated blood and thrombus specimens of a female patient who suffered severe stroke due to VITT after vaccination with ChAdOx1 in comparison to 13 control stroke patients with similar clinical characteristics. We analyzed cerebral thrombi using histological examination, staining of complement factors, NET-markers, DNase and LL-37. In blood samples at the hyper-acute phase of stroke and 7 days later, we determined cell-free DNA, myeloperoxidase-histone complexes, DNase activity, myeloperoxidase activity, LL-37 and inflammatory cytokines. NET markers were identified in thrombi of all patients. Interestingly, the thrombus of the VITT-patient exclusively revealed complement factors and high amounts of DNase and LL-37. High DNase activity was also measured in blood, implying a disturbed NET-regulation. Furthermore, serum of the VITT-patient inhibited reactive oxygen species-dependent NET-release by phorbol-myristate-acetate to a lesser degree compared to controls, indicating either less efficient NET-inhibition or enhanced NET-induction in the blood of the VITT-patient. Additionally, the changes in specific cytokines over time were emphasized in the VITT-patient as well. In conclusion, insufficient resolution of NETs, e.g. by endogenous DNases or protection of NETs against degradation by embedded factors like the antimicrobial peptide LL-37 might thus be an important factor in the pathology of VITT besides increased NET-formation. On the basis of these findings, we discuss the potential implications of the mechanisms of disturbed NETs-degradation for diagnostic and therapeutic approaches in VITT-related thrombogenesis, other auto-immune disorders and beyond.

Endogenous Deoxyribonuclease Activity and Cell-Free Deoxyribonucleic Acid in Acute Ischemic Stroke: A Cohort Study.

BACKGROUND: Cell-free DNA (cfDNA) and endogenous deoxyribonuclease activity are opposing mediators and might influence the inflammatory response following acute ischemic stroke. In this cohort study, we investigated the relation between these markers, circulating inflammatory mediators and clinical course including occurrence of stroke-associated infections (SAI) in patients with acute stroke. METHODS: Ninety-two patients with stroke due to large vessel occlusion undergoing mechanical thrombectomy were prospectively recruited at Hannover Medical School from March 2018 to August 2019. Deoxyribonuclease activity, cfDNA, damage-associated molecular patterns, and circulating cytokines were measured in venous blood collected immediately before mechanical thrombectomy and 7 days later. Reperfusion status was categorized (sufficient/insufficient). Clinical outcome was evaluated using the modified Rankin Scale after 90 days, where a score of 3 to 6 was considered unfavorable. To validate findings regarding SAI, another stroke cohort (n=92) was considered with blood taken within 24 hours after stroke onset. RESULTS: Patients with unfavorable clinical outcome had higher cfDNA concentrations. After adjustment for confounders (Essen Stroke Risk Score, National Institutes of Health Stroke Scale, and sex), 7-day cfDNA was independently associated with clinical outcome and especially mortality (adjusted odds ratio: 3.485 [95% CI, 1.001-12.134] and adjusted odds ratio: 9.585 [95% CI, 2.006-45.790]). No association was found between reperfusion status and cfDNA or deoxyribonuclease activity. While cfDNA concentrations correlated positively, deoxyribonuclease activity inversely correlated with distinct biomarkers. Baseline deoxyribonuclease activity was lower in patients who developed SAI compared with patients without SAI. This association was confirmed after adjustment for confounding factors (adjusted odds ratio: 0.447 [95% CI, 0.237-0.844]). In cohort 2, differences of deoxyribonuclease activity between patients with and without SAI tended to be higher with higher stroke severity. CONCLUSIONS: The interplay of endogenous deoxyribonuclease activity and cfDNA in acute stroke entails interesting novel diagnostic and potential therapeutic approaches. We confirm an independent association of cfDNA with a detrimental clinical course after stroke due to large vessel occlusion. This study provides first evidence for lower endogenous deoxyribonuclease activity as risk factor for SAI after severe stroke.

Circulating Cytokines and Growth Factors in Acute Cerebral Large Vessel Occlusion-Association with Success of Endovascular Treatment.

Mechanical thrombectomy (MT) is a highly efficient treatment in patients with acute ischemic stroke due to large vessel occlusion (LVO). However, in a relevant proportion of LVO, no sufficient recanalization can be achieved. The composition of cerebral thrombi is highly heterogeneous and may constitute a relevant factor for insufficient reperfusion. We hypothesized that circulating cytokines and growth factors involved in thromboinflammation and platelet activation may be associated with reperfusion status and thrombus composition in patients undergoing MT. An according biomarker panel was measured in plasma specimens taken prior to MT and at a 7-day follow-up. The reperfusion status was categorized into sufficient or insufficient. The composition of retrieved thrombi was histologically analyzed. Differences of baseline biomarker concentrations between insufficient and sufficient reperfusions were highest for interferon (IFN)-γ, epidermal growth factor, platelet-derived growth factor (PDGF)-AB/BB, and IFN-γ-induced protein 10 (IP-10/CXCL10). After applying correction for multiple comparisons and logistic regression analysis adjusting for stroke etiology, intravenous thrombolysis, and vascular risk factors, PDGF-AB/BB was identified as an independent predictor of reperfusion status (odds ratio: 0.403; 95% confidence interval: 0.199-0.819). Histological analysis revealed that the majority of thrombi had a mixed composition. In conclusion, this study provides the first evidence that cytokines and growth factors are potential effectors in patients undergoing MT for the treatment of acute ischemic stroke.

ADAMTS-13 activity in stroke of known and unknown cause: Relation to vascular risk factor burden.

Background: The identification of the underlying mechanism in ischemic stroke has important implications for secondary prevention. A disintegrin and metalloprotease with a thrombospondin type 1 motif, member 13 (ADAMTS-13) has antithrombotic properties and was repeatedly implicated in the pathophysiology of stroke. In this study, we, therefore, aimed to investigate whether ADAMTS-13 is associated with stroke etiology and the burden of vascular risk factors. Methods: We determined ADAMTS-13 activity in two prospectively recruited stroke cohorts in the long-term course after the event. Cohort 1 (n = 88) consisted of patients who suffered a stroke due to embolic stroke of undetermined source (ESUS), cardioembolic stroke due to atrial fibrillation (AF), large-artery atherosclerosis, or small vessel disease. In cohort 2, patients with cryptogenic stroke and patent foramen ovale (PFO) scheduled for PFO closure (n = 38) were enrolled. As measures of vascular risk factor burden, the CHA2DS2VASC score, the Essen Stroke Risk Score (ESRS), and the Risk of Paradoxical Embolism (RoPE) score were calculated, as appropriate. Results: ADAMTS-13 activity was lower in patients with AF-related stroke compared to patients with ESUS (p = 0.0227), which was, however, due to confounding by vascular risk factors. ADAMTS-13 activity inversely correlated with the ESRS (r = -0.452, p < 0.001) and CHA2DS2VASC (r = -0.375, p < 0.001) in cohort 1. In accordance with these findings, we found a positive correlation between ADAMTS-13 activity and the RoPE score in cohort 2 (r = 0.413, p = 0.010). Conclusion: ADAMTS-13 activity is inversely correlated with the number of vascular risk factors across different stroke etiologies. Further study is warranted to establish ADAMTS-13 as a mediator of cerebrovascular risk.

Circulating microRNAs in Symptomatic and Asymptomatic Carotid Stenosis.

Background: Specific microRNAs (miRs) have been implicated in the pathophysiology of atherosclerosis and may represent interesting diagnostic and therapeutic targets in carotid stenosis. We hypothesized that the levels of specific circulating miRs are altered in patients with symptomatic carotid stenosis (sCS) in comparison to those in patients with asymptomatic carotid stenosis (aCS) planned to undergo carotid endarterectomy (CEA). We also studied whether miR levels are associated with plaque vulnerability and stability over time after CEA. Methods: Circulating levels of vascular-enriched miR-92a, miR-126, miR-143, miR-145, miR-155, miR-210, miR-221, miR-222, and miR-342-3p were determined in 21 patients with sCS and 23 patients with aCS before CEA and at a 90-day follow-up. Transcranial Doppler ultrasound for detection of microembolic signals (MES) in the ipsilateral middle cerebral artery was performed prior to CEA. Carotid plaques were histologically analyzed. Results: Mean levels of miRs were not considerably different between groups and were only marginally higher in sCS than aCS concerning miR-92a, miR-210, miR-145, and miR-143 with the best evidence concerning miR-92a. After adjustment for vascular risk factors and statin pre-treatment, the effect sizes remained essentially unchanged. At follow-up, however, these modest differences remained uncorroborated. There were no relevant associations between miR-levels and MES or histological plaque vulnerability features. Conclusions: This study does not provide evidence for strong associations between specific circulating miRs and symptomatic state in a collective of comprehensively characterized patients with carotid stenosis. Further work is needed to elucidate the role of circulating miRs as targets in advanced carotid atherosclerosis.

Endovascular Treatment of Acute Ischemic Stroke in Clinical Practice: Analysis of Workflow and Outcome in a Tertiary Care Center.

Background and Purpose: Pre- and intra-hospital workflow in mechanical recanalization of large cervicocephalic arteries in patients with acute ischemic stroke still needs optimization. In this study, we analyze workflow and outcome in our routine care of stroke patients undergoing mechanical thrombectomy as a precondition for such optimization. Methods: Processes of pre- and intra-hospital management, causes of treatment delay, imaging results (Alberta Stroke Program Early Computed Tomography Score, localization of vessel occlusion), recanalization (modified thrombolysis in cerebral infarction score), and patient outcome (modified Rankin scale at discharge and at the end of inpatient rehabilitation) were analyzed for all patients who underwent mechanical thrombectomy between April 1, 2016, and September 30, 2018, at our site. Results: Finally, data of 282 patients were considered, of whom 150 (53%) had been referred from external hospitals. Recanalization success and patient outcome were similar to randomized controlled thrombectomy studies and registries. Delay in treatment occurred when medical treatment of a hypertensive crisis, epileptic fits, vomiting, or agitation was mandatory but also due to missing prenotification of the hospital emergency staff by the rescue service, multiple mode or repeated brain imaging, and transfer from another hospital. Even transfer from external hospitals located within a 10-km radius of our endovascular treatment center led to a median increase of the onset-to-groin time of ~60 min. Conclusion: The analysis revealed several starting points for an improvement in the workflow of thrombectomy in our center. Analyses of workflow and treatment results should be carried out regularly to identify the potential for optimization of operational procedures and selection criteria for patients who could benefit from endovascular treatment.

Autoantibodies against the NMDAR subunit NR1 are associated with neuropsychiatric outcome after ischemic stroke.

BACKGROUND AND PURPOSE: Preexisting autoantibodies against N-methyl-D-aspartate-receptor subunit NR1 (NMDAR1-AB) in acute ischemic stroke patients with previously intact blood-brain-barrier were associated with smaller evolution of lesion size. Effects of chronic exposure to NMDAR1-AB long after stroke, however, have remained unclear. We investigated in a prospective follow-up study whether long-term neuropsychiatric outcome after stroke differs depending on NMDAR1-AB status. METHODS: Blood samples for NMDAR1-AB analysis were collected within 24 h after ischemic stroke from n = 114 patients. Outcome was assessed 1-3 years later using NIHSS, modified Rankin-scale, Barthel-Index, RBANS (Repeatable Battery for the Assessment of Neuropsychological Status) subcategories (immediate/delayed memory, attention, visuoconstruction), anamnesis evaluating neuropsychiatric symptoms (e.g. hallucinations, psychomotor slowing, reduced alertness, depressiveness, fatigue) and questionnaires (Beck's Depression Inventory-BDI, Fatigue Impact Scale-FIS). Scores were generated to cover RBANS plus neuropsychiatric symptoms (Score A; n = 96) or only neuropsychiatric symptoms (Score B; n = 114, including patients unable to conduct RBANS). Depression/fatigue were measured in patients, capable to perform questionnaires (n = 86). RESULTS: NMDAR1-AB (IgM, IgA, IgG) were detected in n = 27 patients (23.7%). NMDAR1-AB seropositive patients showed inferior results in Score A (p = 0.006), Score B (p = 0.004), BDI (p = 0.013) and FIS (p = 0.018), compared to seronegative patients. Multiple regression analysis including covariates age, NIHSS at day 7 post-stroke, and days from stroke to follow-up, showed NMDAR1-AB seropositivity associated with worse outcome in Scores A (b: 1.517, 95%CI: 0.505-2.529, p = 0.004) and B (b: 0.803, 95%CI: 0.233-1.373; p = 0.006). Also FIS was unfavorably associated with NMDAR1-AB seropositivity (binary logistic regression: OR: 3.904, 95%CI: 1.200-12.695; p = 0.024). CONCLUSIONS: Even though the numbers of included patients are low, our data apparently indicate that NMDAR1-AB seropositivity at the time point of acute ischemic stroke is associated with neuropsychiatric symptoms including cognitive dysfunction and fatigue years after stroke. Preclinical proof of a causal relation provided, targeted immunosuppression may be a future prophylactic option to be clinically evaluated.

Impact of the coronavirus disease 2019 pandemic on stroke teleconsultations in Germany in the first half of 2020.

BACKGROUND AND PURPOSE: The effects of the coronavirus disease 2019 (COVID-19) pandemic on telemedical care have not been described on a national level. Thus, we investigated the medical stroke treatment situation before, during, and after the first lockdown in Germany. METHODS: In this nationwide, multicenter study, data from 14 telemedical networks including 31 network centers and 155 spoke hospitals covering large parts of Germany were analyzed regarding patients' characteristics, stroke type/severity, and acute stroke treatment. A survey focusing on potential shortcomings of in-hospital and (telemedical) stroke care during the pandemic was conducted. RESULTS: Between January 2018 and June 2020, 67,033 telemedical consultations and 38,895 telemedical stroke consultations were conducted. A significant decline of telemedical (p < 0.001) and telemedical stroke consultations (p < 0.001) during the lockdown in March/April 2020 and a reciprocal increase after relaxation of COVID-19 measures in May/June 2020 were observed. Compared to 2018-2019, neither stroke patients' age (p = 0.38), gender (p = 0.44), nor severity of ischemic stroke (p = 0.32) differed in March/April 2020. Whereas the proportion of ischemic stroke patients for whom endovascular treatment (14.3% vs. 14.6%; p = 0.85) was recommended remained stable, there was a nonsignificant trend toward a lower proportion of recommendation of intravenous thrombolysis during the lockdown (19.0% vs. 22.1%; p = 0.052). Despite the majority of participating network centers treating patients with COVID-19, there were no relevant shortcomings reported regarding in-hospital stroke treatment or telemedical stroke care. CONCLUSIONS: Telemedical stroke care in Germany was able to provide full service despite the COVID-19 pandemic, but telemedical consultations declined abruptly during the lockdown period and normalized after relaxation of COVID-19 measures in Germany.

Distinct systemic cytokine networks in symptomatic and asymptomatic carotid stenosis.

Inflammatory processes are crucial in atherosclerosis and atherothrombosis. This study aimed to identify a cytokine-pattern that is associated with plaque-vulnerability or symptomatic state in comprehensively investigated patients with symptomatic (sCS) and asymptomatic carotid stenosis (aCS). Twenty-two patients with sCS and twenty-four patients with aCS undergoing carotid endarterectomy (CEA) were considered. A cytokine-panel was measured in plasma-specimens prior to surgery and at a 90 day follow-up. Doppler-ultrasound detecting microembolic signals (MES) in the ipsilateral middle cerebral artery was performed. Carotid plaques were analysed regarding histopathological criteria of plaque-vulnerability and presence of chemokine receptor CXCR4. Correction for multiple comparisons and logistic regression analysis adjusting for vascular risk factors, grade of stenosis, antithrombotic and statin pretreatment were applied. In sCS-patients higher plasma-levels of Fractalkine (CX3CL1), IFN-α2, IL-1ß, IL-2, IL-3, IL-7 were found compared to aCS-patients. CXCR4-expression on inflammatory cells was more evident in sCS- compared to aCS-plaques and was associated with vulnerability-criteria. In contrast, plasma-cytokine-levels were not related to CXCR4-expression or other vulnerability-criteria or MES. However, in both groups distinct inter-cytokine correlation patterns, which persisted at follow-up and were more pronounced in the sCS-group could be detected. In conclusion, we identified a distinct cytokine/chemokine-network in sCS-patients with elevated and closely correlated mediators of diverse functions.

Nonstenotic Carotid Plaque in Embolic Stroke of Undetermined Source: Interplay of Arterial and Atrial Disease.

BACKGROUND AND PURPOSE: Approximately one-sixth of all ischemic strokes are attributable to embolic stroke of undetermined source (ESUS). Recent analyses suggest that atrial cardiopathy and nonstenotic carotid plaque (nsCP) may represent 2 distinct underlying causes in patients with ESUS, although both diseases share common risk factors and are pathophysiologically intertwined. In this study, we, therefore, aimed to search for associations between nsCP and markers of atrial remodeling and function in patients with embolic stroke. METHODS: Sixty-eight patients with ESUS or atrial fibrillation (AF)-related stroke proven by imaging who underwent comprehensive echocardiographic studies, including measurements of left atrial function and remodeling, were considered. Patients with ESUS underwent a follow-up of at least 1 year after index stroke. For 20 patients with ESUS, NT-proBNP (N-terminal pro-B-type natriuretic peptide) values were available. Presence of nsCP was evaluated considering Duplex sonography and computed tomography angiography and was further categorized in possibly or probably symptomatic nsCP. RESULTS: ESUS patients with nsCP tended to have higher values of septal and lateral total atrial conduction times (P=0.071 and P=0.072, respectively), left atrial volume index (P=0.077), and revealed significantly higher strain rates during early diastole (P=0.013) as well as higher NT-proBNP values (P=0.010) than ESUS patients without nsCP. Moreover, septal total atrial conduction time was significantly longer in ESUS patients with possibly symptomatic nsCP compared with those without (P=0.015). Comparison of ESUS with AF patients revealed significantly higher proportions of nsCP (P=0.010), possibly symptomatic nsCP (P=0.037), and probably symptomatic nsCP (P=0.036) in patients with atrial fibrillation-related stroke. In the regression analysis adjusted for vascular risk factors probably symptomatic nsCP remained significantly associated with AF (P=0.048, odds ratio: 4.46 [95% CI, 1.02-19.56]). CONCLUSIONS: Presence of nsCP is associated with AF and markers of left atrial disease in patients with embolic stroke. Therefore, a thorough evaluation regarding atrial cardiopathy and AF in patients with ESUS should not be restricted if nsCP are found, even if high-risk plaque characteristics are evident.

Early Post-Stroke Infections Are Associated with an Impaired Function of Neutrophil Granulocytes.

To investigate whether neutrophil granulocytes' function relates to post-stroke infections and clinical outcome after stroke, we prospectively recruited 95 patients after ischemic stroke and tested them for their microbiocidal neutrophil functions in this exploratory study. Additionally, 24 age-adjusted controls were examined regarding neutrophil function. Phagocytic capacity and the ability of the neutrophil granulocytes to produce reactive oxygen species (ROS) as well as CD11b and CD16 receptor expression profile were measured by flow cytometry at days 1, 3, 7, and 90 after symptom onset. Primary outcome was the development of an infection within the first week after stroke. Results of neutrophil functional measurements were compared between patients with and without infection as well as between all stroke patients and controls. Further risk factors for the development of infections were summarized in an infection-risk score for the purpose of multivariate statistical analysis. The ROS production in neutrophils after stimulation with formyl-methionyl-leucyl-phenylalanine (fMLP) was reduced at baseline in patients with post-stroke infections compared to those without (p = 0.013). This difference proved to be independent from the infection-risk score in the binary logistic regression (p = 0.011). Phagocytosis and oxidative bursts were not significantly reduced in the whole stroke patient group compared to controls. Dysfunction of neutrophil granulocytes seems to play a significant role in the development of post-stroke infections. Further studies are warranted to investigate neutrophil granulocytes´ function as a potential biomarker of post-stroke infections.

ADAMTS13 activity is associated with early neurological improvement in acute ischemic stroke patients treated with intravenous thrombolysis.

Although intravenous thrombolysis (IVT) with recombinant tissue-plasminogen-activator represents a highly effective treatment in acute ischemic stroke patients, not every patient benefits. We hypothesized that pretreatment levels of mediators of hemostasis (VWF and ADAMTS13) and dimethylarginines (ADMA and SDMA) are associated with early neurological improvement and outcome after IVT in ischemic stroke. Moreover we aimed to investigate the link between ADAMTS13 and markers of inflammation (CRP, IL-6, MMP-9 and MCP-1). In 43 patients with acute ischemic stroke treated with IVT blood samples for determination of the different markers were strictly taken before treatment, as well as at 24 h, 3, 7 and 90 days after symptom onset. Early neurological improvement was assessed using the shift between National Institutes of Health Stroke Scale (NIHSS) at baseline and at 24 h. Outcome at 90 days was assessed using the modified Rankin Scale. The lowest quartile of ADAMTS13 activity was independently associated with less improvement in NIHSS (baseline-24 h) (OR 1.298, p = 0.050). No independent association of ADMA or SDMA levels at baseline with outcome could be shown. Furthermore, IL-6, MCP-1 and CRP levels at 90 days significantly differed between patients with low and high ADAMTS13 activity. Thus, ADAMTS13 might indicate or even influence efficacy of IVT.

Septal total atrial conduction time for prediction of atrial fibrillation in embolic stroke of unknown source: a pilot study.

BACKGROUND: Subclinical atrial fibrillation (AF) is the underlying cause in a relevant part of patients with embolic stroke of unknown source (ESUS). This pilot study aims to identify novel echocardiographic parameters predicting AF subsequently detected in patients originally hospitalized with ESUS. METHODS AND RESULTS: Patients with acute ischemic stroke [baseline diagnosis of ESUS (n = 69), stroke of macro- or microvascular cause (n = 16/25), stroke caused by AF (n = 5)] and controls with paroxysmal AF without acute ischemic stroke (n = 22) as well as healthy controls of young and old age (n = 21/17) in sinus rhythm were included (overall n = 175). Echocardiography was performed in all participants. Prolonged Holter-ECG-monitoring was performed in all stroke patients. In the overall cohort, septal total atrial conduction time (sPA-TDI), left atrial (LA) volume index to tissue Doppler velocity (LAVI/a`) and second negative peak strain rate during LA contraction (SRa), representing echocardiographic parameters of LA remodelling and function, were statistically significant different in patients with and without AF and predictive for subclinical AF (multivariate regression analysis: sPA-TDI: HR 1.06 [1.04-1.08], p < 0.001; LAVI/a`: HR 0.85, [0.74-0.97], p = 0.02; SRa: HR 2.35 [0.9-5.5], p = 0.05). Multivariate Cox regression analysis revealed sPA-TDI as an independent predictor of AF in ESUS patients (sPA-TDI: HR 1.10 [1.04-1.17], p = 0.001). A sPA-TDI of 126 ms strictly discriminated between presence and absence of subclinical AF within 48 h after initiation of Holter-ECG-monitoring in ESUS patients. CONCLUSIONS: sPA-TDI seems to be a strong independent predictor of subclinical AF in patients hospitalized for ESUS and might support risk-stratified clinical decision making in these patients. Septal Total Atrial Conduction Time (sPA-TDI) determined by echocardiography for prediction of Atrial Fibrillation in Embolic Stroke of Unknown Source (ESUS).

Markers of endothelial pathology to support detection of atrial fibrillation in embolic stroke of undetermined source.

A relevant part of embolic strokes of undetermined source (ESUS) is assumed to be cardiogenic. As shown previously, certain biomarkers of endothelial pathology are related to atrial fibrillation (AF). In this long-term follow-up study, we aimed to investigate whether these biomarkers are associated with subsequently diagnosed AF and with atrial cardiopathy. In 98 patients who suffered ischemic stroke of known and unknown origin L-arginine, Asymmetric (ADMA) and Symmetric Dimethylarginine (SDMA) have been measured on follow-up at least one year after index stroke. Stroke-diagnostics were available for all patients, including carotid Intima-Media-Thickness (CIMT) and comprehensive echocardiography studies. CIMT was larger in AF- compared with ESUS-patients (P < 0.001), independently from CHA2DS2VASC in the regression analysis (P = 0.004). SDMA-values were stable over time (P < 0.001; r = 0.788), whereas for ADMA moderate correlation with the initial values could be found (P = 0.007; r = 0.356). According to Kaplan-Meier-analyses, AF-detection rates were associated with CIMT (P = 0.003) and SDMA (P < 0.001). SDMA correlated with left atrial volume-index within the whole collective (P = 0.003, r = 0.322) and within the ESUS-subgroup (P = 0.003; r = 0.446). These associations were independent from CHA2DS2VASC and renal function in the regression analysis (P = 0.02 and P = 0.005, respectively). In conclusion, these results highlight SDMA and CIMT as potential markers of atrial cardiopathy and AF in ESUS-patients.

Plasma Dimethylarginine Levels and Carotid Intima-Media Thickness are related to Atrial Fibrillation in Patients with Embolic Stroke.

A relevant part of embolic strokes of undetermined source (ESUS) is assumed to be due to non-detected atrial fibrillation (AF). In this study, we aimed to investigate if markers of endothelial dysfunction and damage may indicate AF risk in embolic stroke. Eighty-eight patients with ischemic stroke confirmed by imaging were assigned to one of three groups: ESUS, AF, or micro-/macroangiopathy. ESUS patients underwent prolonged Holter electrocardiography scheduled for three days. The National Institutes of Health Stroke Scale (NIHSS), the CHA2DS2VASC score, and the carotid intima⁻media thickness (CIMT) were obtained. Markers of endothelial (dys)function (L-arginine, asymmetric dimethylarginine (ADMA), symmetric dimethylarginine (SDMA)) were measured at day seven after stroke. ESUS patients were younger and had fewer cardiovascular risk factors than patients with determined stroke etiology. Compared with AF patients, ESUS patients showed significantly lower values of SDMA (p = 0.004) and higher values of L-arginine (p = 0.031), L-arginine/ADMA ratio (p = 0.006), L-arginine/SDMA ratio (p = 0.002), and ADMA/SDMA ratio (p = 0.013). Concordant differences could be observed comparing ESUS patients with those with newly diagnosed AF (p = 0.026; p = 0.03; p = 0.009; p = 0.004; and p = 0.046, respectively). CIMT was significantly larger in AF than in ESUS patients (p < 0.001), and was identified as an AF risk factor independent from CHA2DS2VASC in the regression analysis (p = 0.014). These findings may support future stratification for AF risk in patients who have suffered embolic stroke.

Cerebral patterns of neuropsychological disturbances in hepatitis C patients.

Neuropsychiatric symptoms and cognitive impairment have been consistently reported in patients with hepatitis C virus (HCV) infection. Since the mechanisms behind remain to be established, the present study attempted to assess whether neuropsychological impairments in HCV-infected patients are accompanied by structural alterations in the brain. Therefore, 19 anti-HCV-antibody-positive women with mild liver disease and 16 healthy controls underwent extensive neuropsychological testing and cranial magnetic resonance imaging (MRI) examination. Nine of the patients and five controls were followed up after 6-7 years. Voxel-based morphometry and magnetization transfer imaging were utilized to study HCV-associated structural gray and white matter changes. The HCV-infected patients had significantly worse fatigue and depression scores and significantly poorer performance on attention and memory tests than controls. The patients displayed gray matter (GM) atrophy in the bilateral insula and thalamus and a profound GM volume increases in the cerebellum. Microstructural GM changes in the insula were also evident by a reduced magnetization transfer ratio. Structural white matter changes were observed along several descending and crossing fiber tracts. Follow-up at 7 years revealed increased GM atrophy in the left amygdala and left parahippocampal regions over time. We conclude that our data provide evidence for structural alterations in the brains of patients with chronic HCV infection. Disturbances of cerebellothalamocortical regions and circuits, linking cerebellar projections to the prefrontal cortex through the thalamus, underpin the emotional and cognitive dysfunction characteristically observed in these patients.