Christian H. Nolte

Factors influencing in-hospital mortality and morbidity in patients treated on a stroke unit

Objective: To determine the extent that demographics, clinical characteristics, comorbidities, and complications contribute to the risk of in-hospital mortality and morbidity in acute stroke. Methods: Data of consecutive patients admitted to 14 stroke units cooperating within the Berlin Stroke Register were analyzed. The association of demographics, clinical characteristics, comorbidities, and complications with the risk of in-hospital death and poor outcome at discharge was assessed, and independent attributable risks were calculated, applying average sequential attributable fractions. Results: In a 3-year period, 16,518 consecutive patients with ischemic or hemorrhagic stroke were documented. In-hospital mortality was 5.4%, and 45.7% had a poor outcome (modifed Rankin Scale score ≥3). In patients with length of stay (LOS) ≤7 days, 37.5% of in-hospital deaths were attributed to stroke severity, 23.1% to sociodemographics (age and prestroke disability), and 28.9% to increased intracranial pressure (iICP) and other complications. In those with LOS >7 days, age and stroke severity accounted for 44.1%, whereas pneumonia (12.2%), other complications (12.6%), and iICP (8.3%) contributed to one-third of in-hospital deaths. For poor outcome, attributable risks were similar for prestroke disability, stroke severity, pneumonia, and other complications regardless of the patients LOS. Conclusions: Approximately two-thirds of early death and poor outcome in acute stroke is attributed to nonmodifiable predictors, whereas main modifiable factors are early complications such as iICP, pneumonia, or other complications, on which stroke unit treatment should focus to further improve the prognosis of acute stroke.

Cellular immunodepression preceding infectious complications after acute ischemic stroke in humans

Background: We have recently shown that ischemic stroke causes a stress-mediator-induced long-lasting immunodepressive state in mice. Methods: Using head magnetic resonance imaging and standardized immunoassays, we prospectively investigated whether poststroke immunodepression is also seen in humans. Results: Compared to healthy volunteers (n = 30), a rapid depression of lymphocyte counts and a functional deactivation of monocytes and T helper type 1 cells was observed in acute stroke patients (SP; n = 40). Immunodepression was more pronounced in patients with severe clinical deficit or large infarction. On admission the combination of monocytic tumor necrosis factor α release ex vivo and the National Institute of Health Stroke Scale score were the best predictors for nosocomial infection, preferentially affecting older SP. Conclusion: Our data provide evidence for an immediate suppression of cell-mediated immune responses after ischemic stroke in humans.

Mechanical recanalization in basilar artery occlusion: The ENDOSTROKE study

A study was undertaken to evaluate clinical and procedural factors associated with outcome and recanalization in endovascular stroke treatment (EVT) of basilar artery (BA) occlusion.

Knowledge of risk factors, and warning signs of stroke: a systematic review from a gender perspective

Stroke is one of the leading causes of death globally. Awareness of stroke risk factors and warning signs are important for stroke prevention and seeking care. The purpose of this systematic review was to review existing literature that assessed the knowledge of stroke risk factors and warning signs and allowed separate gender analysis. We conducted a systematic review of all published studies (to August 2008) examining knowledge of stroke risk factors and warning signs that included women and provided results separated by gender. Two reviewers selected studies for inclusion, assessed quality, and extracted data. The database search identified 2158 references for screening and 158 were selected for possible inclusion. Twenty-two studies were reviewed including 20 cross-sectional and two pretest–posttest design surveys. Overall, better stroke knowledge was observed in women compared with men in the majority of the studies although there is a general lack of knowledge in both genders. Four out of 18 studies reported better risk factor knowledge and eight out of 15 studies reported better knowledge in stroke warning signs in women compared with men. Women tended to know more evidence-based stroke risk factors than men. Stroke knowledge also appeared to be related to country of study origin, age, education, and medical history. Stroke knowledge among different populations and both in men and women is suboptimal. More research is necessary to further investigate gender differences in stroke knowledge with specific focus on how to use these differences to improve public health campaigns.

Number of Cerebral Microbleeds and Risk of Intracerebral Hemorrhage After Intravenous Thrombolysis

Background and Purpose— Cerebral microbleeds (CMBs) are found in a substantial proportion of patients with ischemic stroke eligible for treatment with intravenous thrombolysis. Until now, there is limited data on the impact of multiple CMBs on occurrence of intracerebral hemorrhage (ICH) after intravenous thrombolysis. Methods— Between 2008 and 2013, all patients receiving MRI-based intravenous thrombolysis were identified within our prospective thrombolysis register. Number of CMBs was rated on pretreatment T2*-weighted MRI by a rater blinded to clinical data and follow-up. Outcomes of interest were occurrence of symptomatic ICH (sICH) and parenchymal hemorrhage (PH). Results— Among 326 included patients, 52 patients had a single CMB (16.0%), 19 had 2 to 4 CMBs (5.8%), and 10 had ≥5 CMBs (3.1%). Frequency of sICH/PH was 1.2%/5.7% in patients without CMBs, 3.8%/3.8% in patients with a single CMB, 10.5%/21.1% in patients with 2 to 4 CMBs, and 30.0%/30.0% in patients with ≥5 CMBs, respectively (each P for trend <0.01). The unadjusted odds ratio per additional CMB for sICH was 1.19 (95% confidence interval, 1.07–1.33; P<0.01) and for PH was 1.13 (95% confidence interval, 1.03–1.24; P=0.01). Compared with patients without CMBs, both patients with 2 to 4 CMBs (P=0.02/P=0.02) and patients with ≥5 CMBs (P<0.01/P<0.01) had significantly increased odds ratios for sICH and PH, whereas in patients with a single CMB, odds ratios were not significantly increased (P=0.21/P=0.59). The association of CMB burden with sICH/PH remained significant after adjustment for possible confounders (age, age-related white matter changes score, atrial fibrillation, onset-to-treatment time, prior statin use, and systolic blood pressure on admission). Conclusions— Our findings indicate a higher risk of sICH and PH after intravenous thrombolysis when multiple CMBs are present, with a graded relationship to increasing baseline CMB number.

Medical resource use and costs of health care after acute stroke in Germany

The purpose of this study was to determine the 12 months medical resource use following admission to hospital with acute stroke and to calculate costs from a societal perspective. Data of consecutive patients with confirmed stroke were analysed. Acute hospital data were taken from medical records, socio‐demographic variables from patients’ interviews. A follow‐up questionnaire about resource utilization was completed by patients or proxies 12 months after acute hospital admission. Costs were calculated by multiplying medical resource units used with cost factors per unit. Mean age of a total of 383 patients was 65 years and 41% were female. The median length of the initial stay in the acute hospital was 12 days at an average cost of €4650 per patient (49% of direct costs). Rehabilitation (16%), readmission (11%), medication (9%), and nursing costs (6%) were other contributors to the direct costs which amounted to a total of €9452 ± 7599 per patient during 12 months. Indirect cost amounted to a total of €2014 ± 5312. Patients’ age, severity and type of stroke influenced the total stroke‐associated costs. The large economic burden of stroke indicates the need for assessing and improving efficient health care for affected patients.

Risk of Symptomatic Intracerebral Hemorrhage After Intravenous Thrombolysis in Patients With Acute Ischemic Stroke and High Cerebral Microbleed Burden: A Meta-analysis.

IMPORTANCE Cerebral microbleeds (CMBs) have been established as an independent predictor of cerebral bleeding. There are contradictory data regarding the potential association of CMB burden with the risk of symptomatic intracerebral hemorrhage (sICH) in patients with acute ischemic stroke (AIS) treated with intravenous thrombolysis (IVT). OBJECTIVE To investigate the association of high CMB burden (>10 CMBs on a pre-IVT magnetic image resonance [MRI] scan) with the risk of sICH following IVT for AIS. DATA SOURCES Eligible studies were identified by searching Medline and Scopus databases. No language or other restrictions were imposed. The literature search was conducted on October 7, 2015. This meta-analysis has adopted the Preferred Reporting Items for Systematic Reviews and Meta-Analyses (PRISMA) guidelines and was written according to the Meta-analysis of Observational Studies in Epidemiology (MOOSE) proposal. STUDY SELECTION Eligible prospective study protocols that reported sICH rates in patients with AIS who underwent MRI for CMB screening prior to IVT. DATA EXTRACTION AND SYNTHESIS The reported rates of sICH complicating IVT in patients with AIS with pretreatment MRI were extracted independently for groups of patients with 0 CMBs (CMB absence), 1 or more CMBs (CMB presence), 1 to 10 CMBs (low to moderate CMB burden), and more than 10 CMBs (high CMB burden). An individual-patient data meta-analysis was also performed in the included studies that provided complete patient data sets. MAIN OUTCOMES AND MEASURES Symptomatic intracerebral hemorrhage based on the European Cooperative Acute Stroke Study-II definition (any intracranial bleed with ≥4 points worsening on the National Institutes of Health Stroke Scale score). RESULTS We included 9 studies comprising 2479 patients with AIS. The risk of sICH after IVT was found to be higher in patients with evidence of CMB presence, compared with patients without CMBs (risk ratio [RR], 2.36; 95% CI, 1.21-4.61; P = .01). A higher risk for sICH after IVT was detected in patients with high CMB burden (>10 CMBs) when compared with patients with 0 to 10 CMBs (RR, 12.10; 95% CI, 4.36-33.57; P < .001) or 1 to 10 CMBs (RR, 7.01; 95% CI, 3.20-15.38; P < .001) on pretreatment MRI. In the individual-patient data meta-analysis, high CMB burden was associated with increased likelihood of sICH before (unadjusted odds ratio, 31.06; 95% CI, 7.12-135.44; P < .001) and after (adjusted odds ratio, 18.17; 95% CI, 2.39-138.22; P = .005) adjusting for potential confounders. CONCLUSIONS AND RELEVANCE Presence of CMB and high CMB burdens on pretreatment MRI were independently associated with sICH in patients with AIS treated with IVT. High CMB burden may be included in individual risk stratification scores predicting sICH risk following IVT for AIS.

Functional outcomes of pre-hospital thrombolysis in a mobile stroke treatment unit compared with conventional care: an observational registry study

BACKGROUND Specialised CT-equipped mobile stroke treatment units shorten time to intravenous thrombolysis in acute ischaemic stroke by starting treatment before hospital admission; however, direct effects of pre-hospital thrombolysis on clinical outcomes have not been shown. We aimed to compare 3-month functional outcomes after intravenous thrombolysis in patients with acute ischaemic who had received emergency mobile care or and conventional care. METHODS In this observational registry study, patients with ischaemic stroke received intravenous thrombolysis (alteplase) either within a stroke emergency mobile (STEMO) vehicle (pre-hospital care covering 1·3 million inhabitants of Berlin) or within conventional care (normal ambulances and in-hospital care at the Charité Campus Benjamin Franklin in Berlin). Patient data on treatment, outcome, and demographics were documented in STEMO (pre-hospital) or conventional care (in-hospital) registries. The primary outcome was the proportion of patients who had lived at home without assistance before stroke and had a 3-month modified Rankin Scale (mRS) score of 1 or lower. Our multivariable logistic regression was adjusted for demographics, comorbidities, and stroke severity. This study is registered with ClinicalTrials.gov, number NCT02358772. FINDINGS Between Feb 5, 2011, and March 5, 2015, 427 patients were treated within the STEMO vehicle and their data were entered into a pre-hospital registry. 505 patients received conventional care and their data were entered into an in-hospital thrombolysis registry. Of these, 305 patients in the STEMO group and 353 in the conventional care group met inclusion criteria and were included in the analysis. 161 (53%) patients in the STEMO group versus 166 (47%) in the conventional care group had an mRS score of 1 or lower (p=0·14). Compared with conventional care, adjusted odds ratios (ORs) for STEMO care for the primary outcome (OR 1·40, 95% CI 1·00-1·97; p=0·052) were not significant. Intracranial haemorrhage (p=0·27) and 7-day mortality (p=0·23) did not differ significantly between treatment groups. INTERPRETATION We found no significant difference between the proportion of patients with a mRS score of 1 or lower receiving STEMO care compared with conventional care. However, our results suggest that pre-hospital start of intravenous thrombolysis might lead to improved functional outcome in patients. This evidence requires substantiation in future large-scale trials. FUNDING Zukunftsfonds Berlin, the Technology Foundation Berlin with EU co-financing by the European Regional Development Fund via Investitionsbank Berlin, and the German Federal Ministry for Education and Research via the Center for Stroke Research Berlin.

Dose-Related Effects of Statins on Symptomatic Intracerebral Hemorrhage and Outcome After Thrombolysis for Ischemic Stroke

Background and Purpose— The aim of our study was to assess whether statins have dose-dependent effects on risk of symptomatic intracerebral hemorrhage (sICH) and outcome after intravenous thrombolysis for ischemic stroke. Methods— We pooled data from 2 European intravenous thrombolysis registries. Statin doses were stratified in 3 groups according to the attainable lowering of cholesterol levels (low dose: simvastatin 20 mg or equivalent; medium dose: simvastatin 40 mg or equivalent; and high dose: simvastatin 80 mg or equivalent). sICH was defined according to the European Cooperative Acute Stroke Study. Modified Rankin Scale score 0 to 2 at 3 months was considered a favorable outcome. Results— Among 1446 patients analyzed (median age, 75 years; median initial National Institutes of Health Stroke Scale score, 11; 54% men), 317 (22%) used statins before intravenous thrombolysis. Of them, 120 patients had low-dose, 134 medium-dose, and 63 high-dose statin therapy. sICH occurred in 4% of patients (n=53). Frequency of sICH was 2%, 6%, and 13% in patients with low-, medium-, and high-dose statin treatment, respectively (P<0.01). Adjusted odds ratio (OR) for sICH was 2.4 (95% confidence interval [CI], 1.1–5.3) and 5.3 (95% CI, 2.3–12.3) for patients with medium- and high-dose statins compared with non–statin users. Statin users more often achieved favorable outcome compared with non–statin users (58% versus 51%; P=0.03). An independent association of statin use with favorable outcome was detected (adjusted OR, 1.8; 95% CI, 1.3–2.5). The association was maintained when stratifying for statin dose, although it was not significant in the high-dose group anymore (OR, 1.7; 95% CI, 0.9–3.2). Conclusions— We observed an association between increasing dose of statin use and risk of sICH after intravenous thrombolysis. Nevertheless, there was an overall beneficial effect of previous statin use on favorable 3-month outcome.

Smoking-Thrombolysis Paradox Recanalization and Reperfusion Rates After Intravenous Tissue Plasminogen Activator in Smokers With Ischemic Stroke

Background and Purpose— The so-called smoking-thrombolysis paradox of an improved outcome after thrombolysis was first described in smokers with myocardial infarction. We investigated whether reperfusion rates and clinical outcome differ between smokers and nonsmokers with ischemic stroke after intravenous tissue plasminogen activator. Methods— Consecutive acute ischemic stroke patients, who had magnetic resonance imaging before and 1 day after thrombolysis, were included for analysis. All of the patients received intravenous tissue plasminogen activator within 4.5 hours. Reperfusion was defined as a 75% reduction in perfusion deficit (mean transit time >6 s) after thrombolysis compared with baseline. Magnetic resonance angiography was used to evaluate arterial stenosis and occlusion. Functional outcome was assessed 3 months after stroke using the modified Rankin Score. Results— Of 148 patients, 21.6% were smokers (n=32). Smokers were younger (median, 61 years [SD, 9.4 years] versus 75 years [SD, 11.6 years]; P<0.001), less often women (28% versus 51%; P=0.03), had lower baseline glucose levels (median, 6.2 mmol/L [interquartile range, 5.7–6.8 mmol/L] versus 6.7 mmol/L [interquartile range, 6.1–8.2 mmol/L]; P<0.01) and higher baseline perfusion deficits (median, 53 mL [interquartile range, 13–141 mL] versus 17 mL [interquartile range, 2–66 mL]; P=0.04). In a backward stepwise regression analysis including age, sex, hypertension, glucose, perfusion deficit, and smoking, smoking had an odds ratio of 4 (95% confidence interval, 1–16; P=0.03) for reperfusion and 6 (95% confidence interval, 1–30; P=0.05) for recanalization (regression analysis for recanalization also included localization of arterial occlusion). Smokers had a better outcome (modified Rankin Score=0–2) than nonsmokers (77% versus 55%; P=0.05). Conclusions— Smoking is independently associated with recanalization and reperfusion, indicating that thrombolytic therapy acts more effectively in smokers; because of small numbers, these results should be considered preliminary. Clinical Trial Registration— URL: http://clinicaltrials.gov. Unique Identifier: NCT00715533.