Short-Term Outcome and In-Hospital Complications After Acute Cerebral Infarcts in Multiple Arterial Territories

Background and Purpose—

Patients with acute cerebral infarcts in multiple arterial territories (MACI) represent a substantial portion of the stroke population. There are no data on short-term outcome and in-hospital complications in patients with MACI. We compared patients with MACI with patients having acute cerebral infarct(s) in a single arterial territory.

Methods—

We analyzed 3343 patients with diffusion-weighted imaging-confirmed acute cerebral infarcts. MACI was defined as at least 2 acute cerebral ischemic lesions in at least 2 arterial cerebral territories. Patients with MACI were compared with patients with acute cerebral infarct(s) in a single arterial territory for relevant in-hospital complications and short-term outcome, namely National Institutes of Health Stroke Scale and modified Rankin Scale at day 7 after admission or at discharge when earlier.

Results—

A total of 311 patients (9.3%) met the definition of MACI. Both median National Institutes of Health Stroke Scale (2 [1–7] versus 1 [0–4]) and modified Rankin Scale (3 [1–4] versus 2 [1–3]) were higher in patients with MACI. MACI was independently associated with higher National Institutes of Health Stroke Scale and modified Rankin Scale. Deep venous thrombosis, myocardial infarction, and any complications were more frequent in patients with MACI.

Conclusions—

In-hospital complications were more frequent in patients with MACI, which may adversely affect short-term clinical and functional outcome. Closer follow-up of patients with MACI during hospitalization may prevent such events and negative progression.

Quantitative assessment of plant-arthropod interactions in forest canopies: A plot-based approach

Research on canopy arthropods has progressed from species inventories to the study of their interactions and networks, enhancing our understanding of how hyper-diverse communities are maintained. Previous studies often focused on sampling individual tree species, individual trees or their parts. We argue that such selective sampling is not ideal when analyzing interaction network structure, and may lead to erroneous conclusions. We developed practical and reproducible sampling guidelines for the plot-based analysis of arthropod interaction networks in forest canopies. Our sampling protocol focused on insect herbivores (leaf-chewing insect larvae, miners and gallers) and non-flying invertebrate predators (spiders and ants). We quantitatively sampled the focal arthropods from felled trees, or from trees accessed by canopy cranes or cherry pickers in 53 0.1 ha forest plots in five biogeographic regions, comprising 6,280 trees in total. All three methods required a similar sampling effort and provided good foliage accessibility. Furthermore, we compared interaction networks derived from plot-based data to interaction networks derived from simulated non-plot-based data focusing either on common tree species or a representative selection of tree families. All types of non-plot-based data showed highly biased network structure towards higher connectance, higher web asymmetry, and higher nestedness temperature when compared with plot-based data. Furthermore, some types of non-plot-based data showed biased diversity of the associated herbivore species and specificity of their interactions. Plot-based sampling thus appears to be the most rigorous approach for reconstructing realistic, quantitative plant-arthropod interaction networks that are comparable across sites and regions. Studies of plant interactions have greatly benefited from a plot-based approach and we argue that studies of arthropod interactions would benefit in the same way. We conclude that plot-based studies on canopy arthropods would yield important insights into the processes of interaction network assembly and dynamics, which could be maximised via a coordinated network of plot-based study sites.

Tenecteplase Versus Alteplase Between 3 and 4.5 Hours in Low National Institutes of Health Stroke Scale

Background and Purpose- Thrombolysis with alteplase has beneficial effect on outcome and is safe within 4.5 hours. The present study compares the efficacy and safety of tenecteplase and alteplase in patients treated 3 to 4.5 hours after ischemic stroke. Methods- The data are from a prespecified substudy of patients included in The NOR-TEST (Norwegian Tenecteplase Stroke Trial), a randomized control trial comparing tenecteplase with alteplase. Results- The median admission National Institutes of Health Stroke Scale for this study population was 3 (interquartile range, 2-6). In the intention-to-treat analysis, 57% of patients that received tenecteplase and 53% of patients that received alteplase reached good functional outcome (modified Rankin Scale score of 0-1) at 3 months (odds ratio, 1.19; 95% CI, 0.68-2.10). The rates of intracranial hemorrhage in the first 48 hours were 5.7% in the tenecteplase group and 6.7% in the alteplase group (odds ratio, 0.84; 95% CI, 0.26-2.70). At 3 months, mortality was 5.7% and 4.5%, respectively. After excluding stroke mimics and patients with modified Rankin Scale score of >1 before stroke, the proportion of patients with good functional outcome was 61% in the tenecteplase group and 57% in the alteplase group (odds ratio, 1.24; 95% CI, 0.65-2.37). Conclusions- Tenecteplase is at least as effective as alteplase to achieve a good clinical outcome in patients with mild stroke treated between 3 and 4.5 hours after ischemic stroke. Clinical Trial Registration- URL: https://www.clinicaltrials.gov . Unique identifier: NCT01949948.

Incidence and Etiologies of Stroke Mimics After Incident Stroke or Transient Ischemic Attack

Background and Purpose—

Stroke mimics (SM) pose a common clinical challenge, but the burden of SM in patients with previous ischemic stroke (IS) or transient ischemic attack is unknown. The objective of this study was to calculate the incidence of SM in IS survivors, compare it with the incidence of recurrent stroke in the same population, and explore the time-dependent patterns of SM etiologies.

Methods—

This prospective cohort study registered SM events and etiologies among 1872 IS and transient ischemic attack survivors diagnosed with index stroke at Haukeland University Hospital stroke unit from 2007 to 2013 by review of medical records. Cumulative incidences of SM were estimated with a competing risks Cox model and compared with incidence of recurrent stroke in the same population.

Results—

During 8172 person-years of follow-up, 339 patients had 480 SM events. The cumulative incidence rate of SM during follow-up was 58.7 per 1.000 person-years (95% CI, 53.7–64.2) compared with 34.0 per 1.000 person-years (95% CI, 30.2–38.2) for recurrent stroke in the same time period. The risks of SM and recurrent stroke were highest the first year after index IS or transient ischemic attack. The most frequent SM diagnoses were sequelae of cerebral infarction (19.8%), medical observation, and evaluation for suspected cerebrovascular disease (15.6%) and infections (14.0%). The 2 most frequent and unspecific diagnoses (sequelae of cerebral infarction and medical observation) were clustered in the first months after index stroke.

Conclusions—

SM after IS or transient ischemic attack are more frequent than recurrent stroke and the risk is especially high in the early period. SMs are multietiological and unspecific diagnoses are most frequent early after index stroke.

The ESC ACCA EAPCI EORP acute coronary syndrome ST-elevation myocardial infarction registry

Aims 

The Acute Cardiac Care Association (ACCA)–European Association of Percutaneous Coronary Intervention (EAPCI) Registry on ST-elevation myocardial infarction (STEMI) of the EurObservational programme (EORP) of the European Society of Cardiology (ESC) registry aimed to determine the current state of the use of reperfusion therapy in ESC member and ESC affiliated countries and the adherence to ESC STEMI guidelines in patients with STEMI.

Methods and results 

Between 1 January 2015 and 31 March 2018, a total of 11 462 patients admitted with an initial diagnosis of STEMI according to the 2012 ESC STEMI guidelines were enrolled. Individual patient data were collected across 196 centres and 29 countries. Among the centres, there were 136 percutaneous coronary intervention centres and 91 with cardiac surgery on-site. The majority of centres (129/196) were part of a STEMI network. The main objective of this study was to describe the demographic, clinical, and angiographic characteristics of patients with STEMI. Other objectives include to assess management patterns and in particular the current use of reperfusion therapies and to evaluate how recommendations of most recent STEMI European guidelines regarding reperfusion therapies and adjunctive pharmacological and non-pharmacological treatments are adopted in clinical practice and how their application can impact on patients’ outcomes. Patients will be followed for 1 year after admission.

Conclusion 

The ESC ACCA-EAPCI EORP ACS STEMI registry is an international registry of care and outcomes of patients hospitalized with STEMI. It will provide insights into the contemporary patient profile, management patterns, and 1-year outcome of patients with STEMI.

Recurrent ischemic stroke: Incidence, predictors, and impact on mortality

Background and purpose

Recurrent ischemic stroke (IS) or TIA is frequent with a considerable variation in incidence and mortality across populations. Current data on stroke recurrence and mortality are useful to examine trends, risk factors, and treatment effects. In this study, we calculated the incidence of recurrent IS or TIA in a hospital‐based stroke population in Western Norway, investigated recurrence factors, and estimated the effect of recurrence on all‐cause mortality.

Methods

This prospective cohort study registered recurrence and mortality among 1872 IS and TIA survivors admitted to the stroke unit at Haukeland University Hospital between July 2007 and December 2013. Recurrence and death until September 1, 2016, were identified by medical chart review. Cumulative incidences of recurrence were estimated with a competing risks Cox model. Multivariate Cox models were used to examine recurrence factors and mortality.

Results

During follow‐up, 220 patients had 277 recurrent IS or TIAs. The cumulative recurrence rate was 5.4% at 1 year, 11.3% at 5 years, and 14.2% at the end of follow‐up. Hypertension (HR = 1.65, 95% CI 1.21‐2.25), prior symptomatic stroke (HR = 1.63, 95% CI 1.18‐2.24), chronic infarcts on MRI (HR = 1.48, 95% CI 1.10‐1.99), and age (HR 1.02/year, 95% CI 1.00‐1.03) were independently associated with recurrence. A total of 668 (35.7%) patients died during follow‐up. Recurrence significantly increased the all‐cause mortality (HR = 2.55, 95% CI 2.04‐3.18).

Conclusions

The risk of recurrent IS stroke or TIA was modest in our population and was associated with previously established risk factors. Recurrence more than doubled the all‐cause mortality.

Atrial fibrillation in cryptogenic stroke and transient ischaemic attack - The Nordic Atrial Fibrillation and Stroke (NOR-FIB) Study: Rationale and design

Purpose

Paroxysmal atrial fibrillation is often suspected as a probable cause of cryptogenic stroke. Continuous long-term ECG monitoring using insertable cardiac monitors is a clinically effective technique to screen for atrial fibrillation and superior to conventional follow-up in cryptogenic stroke. However, more studies are needed to identify factors which can help selecting patients with the highest possibility of detecting atrial fibrillation with prolonged rhythm monitoring. The clinical relevance of short-term atrial fibrillation, the need for medical intervention and the evaluation as to whether intervention results in improved clinical outcomes should be assessed.

Method

The Nordic Atrial Fibrillation and Stroke Study is an international, multicentre, prospective, observational trial evaluating the occurrence of occult atrial fibrillation in cryptogenic stroke and transient ischaemic attack. Patients with cryptogenic stroke or transient ischaemic attack from the Nordic countries are included and will have the Reveal LINQ® Insertable cardiac monitor system implanted for 12 months for atrial fibrillation detection. Biomarkers which can be used as predictors for atrial fibrillation and may identify patients, who could derive the most clinical benefit from the detection of atrial fibrillation by prolonged monitoring, are being studied.

Conclusion

The primary endpoint is atrial fibrillation burden within 12 months of continuous rhythm monitoring. Secondary endpoints are atrial fibrillation burden within six months, levels of biomarkers predicting atrial fibrillation, CHA₂DS₂-VASc score, incidence of recurrent stroke or transient ischaemic attack, use of anticoagulation and antiarrhythmic drugs, and quality of life measurements. The clinical follow-up period is 12 months. The study started in 2017 and the completion is expected at the end of 2020.

Thirty-day recurrence after ischemic stroke or TIA

BACKGROUND

Incidence of recurrent stroke is highest within 30 days after the initial ischemic stroke (IS) or TIA, but knowledge about early recurrence is lacking. We aimed to identify etiological groups with highest risk of early recurrence and assess how the TOAST classification identified index stroke etiology.

METHODS

Medical records of 1874 IS and TIA patients in the Bergen NORSTROKE registry were retrospectively reviewed for identification of recurrent IS or TIA within 30 days after index IS or TIA. Stroke etiology was determined by review of electronical medical journals. Logistic regression was used to calculate odds ratios (OR) for 30-day recurrence.

RESULTS

Thirty-three patients (1.8%) were readmitted with recurrent IS or TIA within 30 days after index stroke. By using TOAST, 12 patients were initially classified with stroke of unknown etiology (SUE). Etiologies behind recurrent IS or TIA were after the recurrent episode identified as extracranial large artery atherosclerosis (LAA) in 14 patients (42.4%), intracranial arterial pathology in seven patients (21.2%), active malignancy in six patients (18.2%), and cardio embolism in four patients (12.1%). Small vessel occlusion and SUE were the causes in one patient each. Logistic regression showed that patients with stroke of other determined etiology (SOE) and LAA had increased risk of 30-day recurrence (OR = 9.72, 95% CI 1.84-51.3, p < 0.01 and OR = 4.36, 95% CI 2.01-9.47, p < 0.01, respectively).

CONCLUSION

Patients with LAA and SOE had increased risk of recurrent IS or TIA within 30 days. TOAST was inadequate at identifying exact etiologies behind recurrent stroke at index event.

Spatial scale changes the relationship between beta diversity, species richness and latitude

The relationship between β-diversity and latitude still remains to be a core question in ecology because of the lack of consensus between studies. One hypothesis for the lack of consensus between studies is that spatial scale changes the relationship between latitude and β-diversity. Here, we test this hypothesis using tree data from 15 large-scale forest plots (greater than or equal to 15 ha, diameter at breast height ≥ 1 cm) across a latitudinal gradient (3-30^o) in the Asia-Pacific region. We found that the observed β-diversity decreased with increasing latitude when sampling local tree communities at small spatial scale (grain size ≤0.1 ha), but the observed β-diversity did not change with latitude when sampling at large spatial scales (greater than or equal to 0.25 ha). Differences in latitudinal β-diversity gradients across spatial scales were caused by pooled species richness (γ-diversity), which influenced observed β-diversity values at small spatial scales, but not at large spatial scales. Therefore, spatial scale changes the relationship between β-diversity, γ-diversity and latitude, and improving sample representativeness avoids the γ-dependence of β-diversity.

Safety and predictors of stroke mimics in The Norwegian Tenecteplase Stroke Trial (NOR-TEST)

Background

Stroke mimics are frequently treated with thrombolysis in clinical practice and thrombolytic trials. Although alteplase in stroke mimics has proven to be safe, safety of tenecteplase in stroke mimics has not been assessed in an ischemic stroke study setting. We aimed to assess clinical characteristics and safety of stroke mimics treated with thrombolysis in the Norwegian Tenecteplase Stroke Trial. We also aimed to identify possible predictors of stroke mimics as compared to patients with acute cerebral ischemia.

Methods

Norwegian Tenecteplase Stroke Trial was a phase-3 trial investigating safety and efficacy of tenecteplase vs. alteplase in patients with suspected acute cerebral ischemia. Two groups were defined based on diagnose at discharge: patients with a different diagnose than ischemic stroke or transient ischemic attack (stroke mimics group) and patients diagnosed with ischemic stroke or transient ischemic attack (acute cerebral ischemia group). Logistic regression analyses were performed with stroke mimics vs. acute cerebral ischemia as dependent variable to identify predictors of stroke mimics.

Results

Of 1091 randomized patients, 181 (16.6%) were stroke mimics. Migraine (22.2%) and peripheral vertigo (11.4%) were the two most frequent stroke mimic-diagnoses. There was no symptomatic intracerebral hemorrhage in the stroke mimics group. Stroke mimics were independently associated with age ≤60 years (OR 2.75, p < 0.001), female sex (OR 1.48, p = 0.026), no history of myocardial infarction (OR 2.03, p = 0.045), systolic BP ≤ 150 mmHg (OR 2.33, p < 0.001), NIHSS ≤ 6 points (OR 1.83, p = 0.011), sensory loss (OR 1.55, p = 0.015), and no facial paresis (OR 2.41, p < 0.001) on admission.

Conclusion

Thrombolysis with tenecteplase seems to be as safe as with alteplase in stroke mimics. Predictors were identified for stroke mimics which may contribute to differentiate stroke mimics from acute cerebral ischemia in future stroke trials.

The effect of ethylene oxide sterilization on electrospun vascular grafts made from biodegradable polyesters

The study describes the detailed examination of the effect of ethylene oxide sterilization on electrospun scaffolds constructed from biodegradable polyesters. Different fibrous layers fabricated from polycaprolactone (PCL) and a copolymer consisting of polylactide and polycaprolactone (PLCL) were investigated for the determination of their mechanical properties, degradation rates and interaction with fibroblasts. It was discovered that the sterilization procedure influenced the mechanical properties of the electrospun PLCL copolymer scaffold to the greatest extent. No effect of ethylene oxide sterilization on degradation behavior was observed. However, a delayed fibroblast proliferation rate was noticed with concern to the ethylene oxide sterilized samples compared to the ethanol sterilization of the materials.

Response to Comment on "Plant diversity increases with the strength of negative density dependence at the global scale"

Hülsmann and Hartig suggest that ecological mechanisms other than specialized natural enemies or intraspecific competition contribute to our estimates of conspecific negative density dependence (CNDD). To address their concern, we show that our results are not the result of a methodological artifact and present a null-model analysis that demonstrates that our original findings-(i) stronger CNDD at tropical relative to temperate latitudes and (ii) a latitudinal shift in the relationship between CNDD and species abundance-persist even after controlling for other processes that might influence spatial relationships between adults and recruits.

Contrast-enhanced sonothrombolysis in acute ischemic stroke patients without intracranial large-vessel occlusion

BACKGROUND

Contrast-enhanced sonothrombolysis (CEST) leads to a more rapid recanalization in acute ischemic stroke caused by intracranial large-vessel occlusion (LVO). Animal studies have shown that CEST also may be safe and efficient in treating the ischemic microcirculation in the absence of LVO. The exact mechanism behind this treatment effect is not known. We aimed to assess safety and efficacy of CEST in acute ischemic stroke patients included in the Norwegian Sonothrombolysis in Acute Stroke Study (NOR-SASS) without LVO on admission CT angiography (CTA).

METHODS

NOR-SASS was a randomized controlled trial of CEST in ischemic stroke patients treated with intravenous thrombolysis within 4.5 hours after stroke onset. Patients were randomized to either CEST or sham CEST. In this study, patients were excluded if they had partial or total occlusion on admission CTA, ultrasound-resistant bone window, had received CEST with incorrect insonation as compared to stroke location on Magnetic resonance imaging (MRI), or were stroke mimics.

RESULTS

Of the 183 patients included in NOR-SASS, a total of 83 (45.4%) patients matched the inclusion criteria, of which 40 received CEST and 43 sham CEST. There were no patients with symptomatic intracranial hemorrhage (sICH) in the CEST group. Rates of asymptomatic ICH, microbleeds, and mortality were not increased in the CEST group. Neurological improvement at 24 hours and functional outcome at 90 days were similar in both groups.

CONCLUSION

CEST is safe in ischemic stroke patients without intracranial LVO. There were no differences in clinical outcomes between the treatment groups.

Higher predation risk for insect prey at low latitudes and elevations

Biotic interactions underlie ecosystem structure and function, but predicting interaction outcomes is difficult. We tested the hypothesis that biotic interaction strength increases toward the equator, using a global experiment with model caterpillars to measure predation risk. Across an 11,660-kilometer latitudinal gradient spanning six continents, we found increasing predation toward the equator, with a parallel pattern of increasing predation toward lower elevations. Patterns across both latitude and elevation were driven by arthropod predators, with no systematic trend in attack rates by birds or mammals. These matching gradients at global and regional scales suggest consistent drivers of biotic interaction strength, a finding that needs to be integrated into general theories of herbivory, community organization, and life-history evolution.

Plant diversity increases with the strength of negative density dependence at the global scale

Theory predicts that higher biodiversity in the tropics is maintained by specialized interactions among plants and their natural enemies that result in conspecific negative density dependence (CNDD). By using more than 3000 species and nearly 2.4 million trees across 24 forest plots worldwide, we show that global patterns in tree species diversity reflect not only stronger CNDD at tropical versus temperate latitudes but also a latitudinal shift in the relationship between CNDD and species abundance. CNDD was stronger for rare species at tropical versus temperate latitudes, potentially causing the persistence of greater numbers of rare species in the tropics. Our study reveals fundamental differences in the nature of local-scale biotic interactions that contribute to the maintenance of species diversity across temperate and tropical communities.