Transcriptomic Analysis of Extracellular Vesicles in the Search for Novel Plasma and Thrombus Biomarkers of Ischemic Stroke Etiologies.

Accurate etiologic diagnosis provides an appropriate secondary prevention and better prognosis in ischemic stroke (IS) patients; still, 45% of IS are cryptogenic, urging us to enhance diagnostic precision. We have studied the transcriptomic content of plasma extracellular vesicles (EVs) (n = 21) to identify potential biomarkers of IS etiologies. The proteins encoded by the selected genes were measured in the sera of IS patients (n = 114) and in hypertensive patients with (n = 78) and without atrial fibrillation (AF) (n = 20). IGFBP-2, the most promising candidate, was studied using immunohistochemistry in the IS thrombi (n = 23) and atrium of AF patients (n = 13). In vitro, the IGFBP-2 blockade was analyzed using thromboelastometry and endothelial cell cultures. We identified 745 differentially expressed genes among EVs of cardioembolic, atherothrombotic, and ESUS groups. From these, IGFBP-2 (cutoff > 247.6 ng/mL) emerged as a potential circulating biomarker of embolic IS [OR = 8.70 (1.84-41.13) p = 0.003], which was increased in patients with AF vs. controls (p < 0.001) and was augmented in cardioembolic vs. atherothrombotic thrombi (p < 0.01). Ex vivo, the blockage of IGFBP-2 reduced clot firmness (p < 0.01) and lysis time (p < 0.001) and in vitro, diminished endothelial permeability (p < 0.05) and transmigration (p = 0.06). IGFBP-2 could be a biomarker of embolic IS and a new therapeutic target involved in clot formation and endothelial dysfunction.

Delayed Neurological Improvement After Full Endovascular Reperfusion in Acute Anterior Circulation Ischemic Stroke.

Background and Purpose: We aimed to determine the prevalence and predictors of delayed neurological improvement (DNI) after complete endovascular reperfusion in anterior circulation acute ischemic stroke (AIS). Methods: Retrospective analysis of an online multicenter prospective reperfusion registry of patients with consecutive anterior circulation AIS treated with endovascular thrombectomy (EVT) from January 2018 to June 2019 in tertiary stroke centers of the NORDICTUS (NORD-Spain Network for Research and Innovation in ICTUS) network. We included patients with AIS with a proximal occlusion in whom a modified Thrombolysis in Cerebral Infarction 3 reperfusion pattern was obtained. DNI was defined if, despite absence of early neurological improvement during the first 24 hours, patients achieved functional independence on day 90. Clinical and radiological variables obtained before EVT were analyzed as potential predictors of DNI. Results: Of 1565 patients with consecutive AIS treated with EVT, 1381 had proximal anterior circulation occlusions, 803 (58%) of whom achieved a modified Thrombolysis in Cerebral Infarction 3. Of these, 628 patients fulfilled all selection criteria and were included in the study. Mean age was 73.8 years, 323 (51.4%) were female, and median baseline National Institutes of Health Stroke Scale was 16. Absence of early neurological improvement was observed in 142 (22.6%) patients; 32 of these (22.5%) achieved good long-term outcome and constitute the DNI group. Predictors of DNI in multivariable-adjusted logistic regression were male sex (odds ratio, 6.4 [95% CI, 2.1­22.3] P=0.002), lower pre-EVT National Institutes of Health Stroke Scale score (odds ratio, 1.4 [95% CI, 1.2­1.5], P<0.001), and intravenous thrombolysis (odds ratio, 9.1 [95% CI, 2.7­30.90], P<0.001). Conclusions: One-quarter of patients with anterior circulation AIS who do not clinically improve within the first 24 hours after complete cerebral endovascular recanalization will achieve long-term functional independence, regardless of the poor early clinical course. Male sex, lower initial clinical severity, and use of intravenous thrombolysis before EVT predicted this clinical pattern.

Repeated Mechanical Thrombectomy in the Same Intracranial Artery Segment.

We report a patient with an important scenario that may arise in the management of an acute ischemic stroke: the need for a repeated mechanical thrombectomy in the same intracranial artery segment. The patient had a history of atrial fibrillation and a mechanical mitral valve replacement. In her first stroke, she had an occlusion of the proximal segment of the right middle cerebral artery; 58 days later, she presented with an occlusion in the same segment of that cerebral artery. In both instances, the thrombus was extracted by a stent retriever with good clinical and radiographic results. To the best of our knowledge, this is the first report of a repeated mechanical thrombectomy in the same intracranial artery segment using stent retriever devices.

Comorbidity of dementia: a cross-sectional study of primary care older patients.

BACKGROUND: The epidemiologic study of comorbidities of an index health problem represents a methodological challenge. This study cross-sectionally describes and analyzes the comorbidities associated with dementia in older patients and reviews the existing similarities and differences between identified comorbid diseases using the statistical methods most frequently applied in current research. METHODS: Cross-sectional study of 72,815 patients over 64 seen in 19 Spanish primary care centers during 2008. Chronic diseases were extracted from electronic health records and grouped into Expanded Diagnostic Clusters®. Three different statistical methods were applied (i.e., analysis of prevalence data, multiple regression and factor analysis), stratifying by sex. RESULTS: The two most frequent comorbidities both for men and women with dementia were hypertension and diabetes. Yet, logistic regression and factor analysis demonstrated that the comorbidities significantly associated with dementia were Parkinson's disease, congestive heart failure, cerebrovascular disease, anemia, cardiac arrhythmia, chronic skin ulcers, osteoporosis, thyroid disease, retinal disorders, prostatic hypertrophy, insomnia and anxiety and neurosis. CONCLUSIONS: The analysis of the comorbidities associated with an index disease (e.g., dementia) must not be exclusively based on prevalence rates, but rather on methodologies that allow the discovery of non-random associations between diseases. A deep and reliable knowledge about how different diseases are grouped and associated around an index disease such as dementia may orient future longitudinal studies aimed at unraveling causal associations.

Role of factor XIII in ischemic stroke: a key molecule promoting thrombus stabilization and resistance to lysis.

BACKGROUND: Active coagulation factor XIII (FXIII) catalyzing crosslinking of fibrin and other hemostatic factors plays a key role in clot stability and lysis. OBJECTIVES: To evaluate the effect of FXIII inhibition in a mouse model of ischemic stroke (IS) and the role of activated FXIII (FXIIIa) in clot formation and lysis in patients with IS. METHODS: A ferric chloride IS murine model was performed before and after administration of a FXIIIa inhibitor (FXIIIinh). Thromboelastometry in human and mice blood was used to evaluate thrombus stiffness and lysis with FXIIIinh. FXIIIa-dependent fibrin crosslinking and lysis with fibrinolytic drugs (tissue plasminogen activator and tenecteplase) were studied on fibrin plates and on thrombi and clotted plasma of patients with IS. Finally, circulating and thrombus FXIIIa were measured in 85 patients with IS. RESULTS: FXIIIinh administration before stroke induction reduced infarct size, α2-antiplasmin (α2AP) crosslinking, and local microthrombosis, improving motor coordination and fibrinolysis without intracranial bleeds (24 hours). Interestingly, FXIII blockade after stroke also reduced brain damage and neurologic deficit. Thromboelastometry in human/mice blood with FXIIIinh showed delayed clot formation, reduced clot firmness, and shortened tissue plasminogen activator lysis time. FXIIIa fibrin crosslinking increased fibrin density and lysis resistance, which increased further after α2AP addition. FXIIIinh enhanced ex vivo lysis in stroke thrombi and fibrin plates. In patients with IS, thrombus FXIII and α2AP were associated with inflammatory and hemostatic components, and plasma FXIIIa correlated with thrombus α2AP and fibrin. CONCLUSION: Our results suggest a key role of FXIIIa in thrombus stabilization, α2AP crosslinking, and lysis resistance, with a protective effect of FXIIIinh in an IS experimental model.

Baseline Chronic Comorbidity and Mortality in Laboratory-Confirmed COVID-19 Cases: Results from the PRECOVID Study in Spain.

We aimed to analyze baseline socio-demographic and clinical factors associated with an increased likelihood of mortality in men and women with coronavirus disease (COVID-19). We conducted a retrospective cohort study (PRECOVID Study) on all 4412 individuals with laboratory-confirmed COVID-19 in Aragon, Spain, and followed them for at least 30 days from cohort entry. We described the socio-demographic and clinical characteristics of all patients of the cohort. Age-adjusted logistic regressions models were performed to analyze the likelihood of mortality based on demographic and clinical variables. All analyses were stratified by sex. Old age, specific diseases such as diabetes, acute myocardial infarction, or congestive heart failure, and dispensation of drugs like vasodilators, antipsychotics, and potassium-sparing agents were associated with an increased likelihood of mortality. Our findings suggest that specific comorbidities, mainly of cardiovascular nature, and medications at the time of infection could explain around one quarter of the mortality in COVID-19 disease, and that women and men probably share similar but not identical risk factors. Nonetheless, the great part of mortality seems to be explained by other patient- and/or health-system-related factors. More research is needed in this field to provide the necessary evidence for the development of early identification strategies for patients at higher risk of adverse outcomes.

Oral Anticoagulation and Risk of Symptomatic Hemorrhagic Transformation in Stroke Patients Treated With Mechanical Thrombectomy: Data From the Nordictus Registry.

Introduction: We aimed to evaluate if prior oral anticoagulation (OAC) and its type determines a greater risk of symptomatic hemorrhagic transformation in patients with acute ischemic stroke (AIS) subjected to mechanical thrombectomy. Materials and Methods: Consecutive patients with AIS included in the prospective reperfusion registry NORDICTUS, a network of tertiary stroke centers in Northern Spain, from January 2017 to December 2019 were included. Prior use of oral anticoagulants, baseline variables, and international normalized ratio (INR) on admission were recorded. Symptomatic intracranial hemorrhage (sICH) was the primary outcome measure. Secondary outcome was the relation between INR and sICH, and we evaluated mortality and functional outcome at 3 months by modified Rankin scale. We compared patients with and without previous OAC and also considered the type of oral anticoagulants. Results: About 1.455 AIS patients were included, of whom 274 (19%) were on OAC, 193 (70%) on vitamin K antagonists (VKA), and 81 (30%) on direct oral anticoagulants (DOACs). Anticoagulated patients were older and had more comorbidities. Eighty-one (5.6%) developed sICH, which was more frequent in the VKA group, but not in DOAC group. OAC with VKA emerged as a predictor of sICH in a multivariate regression model (OR, 1.89 [95% CI, 1.01-3.51], p = 0.04) and was not related to INR level on admission. Prior VKA use was not associated with worse outcome in the multivariate regression model nor with mortality at 3 months. Conclusions: OAC with VKA, but not with DOACs, was an independent predictor of sICH after mechanical thrombectomy. This excess risk was associated neither with INR value by the time thrombectomy was performed, nor with a worse functional outcome or mortality at 3 months.

[Concordance in the registry of dementia among the main sources of clinical information]. / Concordancia del registro de demencia en las principales fuentes de información clínica.

BACKGROUND: The objective of this work was to analyse the concordance in the registry of dementia among the main sources of clinical information, with the aim of determining their usefulness for epidemiological and clinical research. METHODS: Descriptive study of patients assigned to the Aragon Health Service in 2010 (n=1,344,891). DATABASES USED: (i)the pharmacy billing database (n=9,392); (ii)Primary Care electronic health records (EHR) (n=9,471), and (iii)the hospital minimum basic data set (n=3,289). When studying the concordance of the databases, the group of patients with a specific treatment for dementia (i.e., acetylcholinesterase inhibitors and/or memantine) was taken as the reference. RESULTS: The diagnosis in Primary Care was missing for 47.3% of patients taking anti-dementia drugs. The same occurred with 38.3% of dementia patients admitted to hospital during the study year. Among patients with a diagnosis of dementia in the EHR, only half (52.3%) was under treatment for this condition. This percentage decreased to 34.4% in patients with the diagnosis registered in the hospital database. CONCLUSIONS: The weak concordance in the registry of the dementia diagnosis between the main health information systems makes their use and analysis more complex, and supports the need to include all available health data sources in order to gain a global picture of the epidemiological and clinical reality of this health condition.