Thromboembolic complications in critically ill COVID-19 patients are associated with impaired fibrinolysis

BACKGROUND

There is emerging evidence for enhanced blood coagulation in coronavirus 2019 (COVID-19) patients, with thromboembolic complications contributing to morbidity and mortality. The mechanisms underlying this prothrombotic state remain enigmatic. Further data to guide anticoagulation strategies are urgently required.

METHODS

We used viscoelastic rotational thromboelastometry (ROTEM) in a single-center cohort of 40 critically ill COVID-19 patients.

RESULTS

Clear signs of a hypercoagulable state due to severe hypofibrinolysis were found. Maximum lysis, especially following stimulation of the extrinsic coagulation system, was inversely associated with an enhanced risk of thromboembolic complications. Combining values for maximum lysis with D-dimer concentrations revealed high sensitivity and specificity of thromboembolic risk prediction.

CONCLUSIONS

The study identifies a reduction in fibrinolysis as an important mechanism in COVID-19-associated coagulopathy. The combination of ROTEM and D-dimer concentrations may prove valuable in identifying patients requiring higher intensity anticoagulation.

Coagulation factor XII, XI, and VIII activity levels and secondary events after first ischemic stroke

BACKGROUND

Though risk for recurrent vascular events is high following ischemic stroke, little knowledge about risk factors for secondary events post-stroke exists.

OBJECTIVES

Coagulation factors XII, XI, and VIII (FXII, FXI, and FVIII) have been implicated in first thrombotic events, and our aim was to estimate their effects on vascular outcomes within 3 years after first stroke.

PATIENTS/METHODS

In the Prospective Cohort with Incident Stroke Berlin (PROSCIS-B) study, we followed participants aged 18 and older for 3 years after first mild to moderate ischemic stroke event or until occurrence of recurrent stroke, myocardial infarction, or all-cause mortality. We compared high coagulation factor activity levels to normal and low levels and also analyzed activities as continuous variables. We used Cox proportional hazards models adjusted for age, sex, and cardiovascular risk factors to estimate hazard ratios (HRs) for the combined endpoint.

RESULTS

In total, 94 events occurred in 576 included participants, resulting in an absolute rate of 6.6 events per 100 person-years. After confounding adjustment, high FVIII activity showed the strongest relationship with the combined endpoint (HR = 2.05, 95% confidence interval [CI] 1.28-3.29). High FXI activity was also associated with a higher hazard (HR = 1.80, 95% CI 1.09-2.98), though high FXII activity was not (HR = 0.86, 95% CI 0.49-1.51). Continuous analyses yielded similar results.

CONCLUSIONS

In our study of mild to moderate ischemic stroke patients, high activity levels of FXI and FVIII but not FXII were associated with worse vascular outcomes in the 3-year period after first ischemic stroke.

Influence of Sedation Level and Ventilation Status on the Diagnostic Validity of Delirium Screening Tools in the ICU-An International, Prospective, Bi-Center Observational Study (IDeAS)

Background and objectives: The use of delirium screening instruments (DSIs) is recommended in critical care practice for a timely detection of delirium. We hypothesize that the patient-related factors “level of sedation” and “mechanical ventilation” impact test validity of DSIs. Materials and Methods: This is a prospective, bi-center observational study (clinicaltrials.gov: NCT01720914). Critically ill patients were screened for delirium daily for up to seven days after enrollment using the Nursing Delirium Screening Scale (Nu-DESC), Intensive Care Delirium Screening Checklist (ICDSC), and Confusion Assessment Method for the Intensive Care Unit (CAM-ICU). Reference standard for delirium diagnosis was the neuropsychiatric examination using the criteria of the Diagnostic and Statistical Manual of Mental Disorders, Fourth Edition, Text Revision (DSM-IV-TR). Immediately before delirium assessment, ventilation status and sedation levels were documented. Results: 160 patients were enrolled and 151 patients went into final analysis. Delirium incidence was 23.2%. Nu-DESC showed a sensitivity and specificity of 88.5%, a positive predictive value (PPV) of 71.9%, and a negative predictive value (NPV) of 95.8%. ICDSC had a sensitivity of 62.5%, a specificity of 92.4%, a PPV of 71.4%, and a NPV of 89.0%. CAM-ICU showed a sensitivity of 75.0%, a specificity of 94.7%, a PPV of 85.7%, and a NPV of 90.0%. For Nu-DESC and ICDSC, test validity was significantly better for non-sedated patients (Richmond Agitation Sedation Scale (RASS) 0/−1), whereas test validity for CAM-ICU in a severity scale version showed no significant differences for different sedation levels. No DSI showed a significant difference in test validity between noninvasively and invasively ventilated patients. Conclusions: Test validities of DSIs were comparable to previous studies. The observational scores ICDSC and Nu-DESC showed a significantly better performance in awake and drowsy patients (RASS 0/−1) when compared with other sedation levels. Physicians should refrain from sedation whenever possible to avoid suboptimal performance of DSIs.

Critical care guidelines on pain, agitation and delirium management: Which one to use? A systematic literature search and quality appraisal with AGREE II

BACKGROUND

Clinical practice guidelines (CPGs) facilitate the provision of standardized, high-quality intensive care medicine. For the management of pain, agitation and delirium, several coexisting CPGs have been published. This study aims at the appraisal of CPGs on pain, agitation and delirium management in the intensive care unit to (a) identify high quality guidelines appropriate for clinical use and (b) identify potential areas for future improvement.

METHODS

We performed a systematic literature search of Medline, three guideline registers and two grey-literature databases. The scope covered guidelines from 2007 to 2020 available in English or German. Identified CPGs were appraised by three independent reviewers using the appraisal of Guidelines Research and Evaluation (AGREE II) instrument.

RESULTS

Eight CPGs were included in the final analysis. Three of the included guidelines exceeded the quality threshold of 60% in all six domains. The highest median [IQR] scores were achieved in the domain "Scope and Purpose" (84.3% [78.7-88.9]), whereas "Applicability" (45.8% [19.4-79.9]) received the lowest median score.

CONCLUSION

Three of the eight reviewed guidelines exceeded the quality threshold in all domains, while the overall guideline quality was also very high. Focusing on guideline applicability and identifying strategies to facilitate implementation can improve future CPGs.

Instruments to measure outcomes of post-intensive care syndrome in outpatient care settings - Results of an expert consensus and feasibility field test

Background

There is no consensus on the instruments for diagnosis of post-intensive care syndrome (PICS). We present a proposal for a set of outcome measurement instruments of PICS in outpatient care.

Methods

We conducted a three-round, semi-structured consensus-seeking process with medical experts, followed each by exploratory feasibility investigations with intensive care unit survivors (n₁ = 5; n₂ = 5; n₃ = 7). Fourteen participants from nine stakeholder groups participated in the first and second consensus meeting. In the third consensus meeting, a core group of six clinical researchers refined the final outcome measurement instrument set proposal.

Results

We suggest an outcome measurement instrument set used in a two-step process. First step: Screening with brief tests covering PICS domains of (1) mental health (Patient Health Questionnaire-4 (PHQ-4)), (2) cognition (MiniCog, Animal Naming), (3) physical function (Timed Up-and-Go (TUG), handgrip strength), and (4) health-related quality of life (HRQoL) (EQ-5D-5L). Single items measure subjective health before and after the intensive care unit stay. If patients report new or worsened health problems after intensive care unit discharge and show relevant impairment in at least one of the screening tests, a second extended assessment follows: (1) Mental health (Patient Health Questionnaire-8 (PHQ-8), Generalized Anxiety Disorder Scale-7 (GAD-7), Impact of Event Scale - revised (IES-R)); (2) cognition (Repeatable Battery for the Assessment of Neuropsychological Status (RBANS), Trail Making Test (TMT) A and B); (3) physical function (2-Minute Walk Test (2-MWT), handgrip strength, Short Physical Performance Battery (SPPB)); and (4) HRQoL (EQ-5D-5L, 12-Item WHO Disability Assessment Schedule (WHODAS 2.0)).

Conclusions

We propose an outcome measurement instrument set used in a two-step measurement of PICS, combining performance-based and patient-reported outcome measures. First-step screening is brief, free-of-charge, and easily applicable by health care professionals across different sectors. If indicated, specialized healthcare providers can perform the extended, second-step assessment. Usage of the first-step screening of our suggested outcome measurement instrument set in outpatient clinics with subsequent transfer to specialists is recommended for all intensive care unit survivors. This may increase awareness and reduce the burden of PICS.

Trial registration

This study was registered at ClinicalTrials.gov (Identifier: NCT04175236; first posted 22 November 2019).

Perioperatively Acquired Weakness

BACKGROUND

Skeletal muscle failure in critical illness (intensive care unit-acquired weakness) is a well-known complication developing early during intensive care unit stay. However, muscle weakness during the perioperative setting has not yet been investigated.

METHODS

We performed a subgroup investigation of a prospective observational trial to investigate perioperative muscle weakness. Eighty-nine patients aged 65 years or older were assessed for handgrip strength preoperatively, on the first postoperative day, at intensive care unit discharge, at hospital discharge, and at 3-month follow-up. Functional status was evaluated perioperatively via Barthel index, instrumental activities of daily living, Timed Up and Go test, and functional independence measure. After exclusion of patients with intensive care unit-acquired weakness or intensive care unit stay of ≥72 hours, 59 patients were included into our analyses. Of these, 14 patients had additional pulmonary function tests preoperatively and on postoperative day 1. Blood glucose was measured intraoperatively every 20 minutes.

RESULTS

Handgrip strength significantly decreased after surgery on postoperative day 1 by 16.4% (P < .001). Postoperative pulmonary function significantly decreased by 13.1% for vital capacity (P = .022) and 12.6% for forced expiratory volume in 1 second (P = .001) on postoperative day 1. Handgrip strength remained significantly reduced at hospital discharge (P = .016) and at the 3-month follow-up (P = .012). Perioperative glucose levels showed no statistically significant impact on muscle weakness. Instrumental activities of daily living (P < .001) and functional independence measure (P < .001) were decreased at hospital discharge, while instrumental activities of daily living remained decreased at the 3-month follow-up (P = .026) compared to preoperative assessments.

CONCLUSIONS

Perioperatively acquired weakness occurred, indicated by a postoperatively decreased handgrip strength, decreased respiratory muscle function, and impaired functional status, which partly remained up to 3 months.

High-Sensitivity Cardiac Troponin T and Cognitive Function in Patients With Ischemic Stroke

Background and Purpose- Our study aim was to assess whether high-sensitivity cardiac troponin T (hs-cTnT), a specific biomarker for myocardial injury, is associated with cognitive function in patients after mild-to-moderate first-ever ischemic stroke. Methods- We used data from PROSCIS-B (Prospective Cohort With Incident Stroke Berlin). Cognitive function was assessed by Mini-Mental-State-Examination at baseline, and Telephone Interview for Cognitive Status-modified after 1 to 3 years of follow-up. Patients were categorized according to hs-cTnT quartiles. We performed generalized linear regression to calculate risk ratios of cognitive impairment (Mini-Mental-State-Examination <27; Telephone Interview for Cognitive Status-modified <32). Association of hs-cTnT with cognitive function over time was estimated using a linear mixed model. Results- We included 555 patients (mean age, 67 years, 62% male, median National Institutes of Health Stroke Scale 2 [interquartile range, 1-5], hs-cTnT above upper reference limit 40%, baseline cognitive impairment 28%). Baseline Mini-Mental-State-Examination score and rate of cognitive impairment were lower in patients in the highest versus lowest hs-cTnT quartile (median Mini-Mental-State-Examination 27 versus 29, and 15.3% versus 43.0%, adjusted risk ratio, 1.76 [95% CI, 1.07-2.90], respectively). If anything, cognition seemed to improve in all groups, yet Telephone Interview for Cognitive Status-modified scores were consistently lower in patients within the highest versus lowest hs-cTnT quartile (adjusted β, -1.33 [95% CI, -2.65 to -0.02]), without difference in the rate of change over time. Conclusions- In patients with mild-to-moderate first-ever ischemic stroke without dementia, higher hs-cTnT was associated with higher prevalence of cognitive impairment at baseline and lower Telephone Interview for Cognitive Status-modified during 3-year follow-up. Registration- URL: https://www.clinicaltrials.gov; Unique identifier: NCT01363856.

Fingolimod after a first unilateral episode of acute optic neuritis (MOVING) - preliminary results from a randomized, rater-blind, active-controlled, phase 2 trial

Background

Neuroprotection and promotion of remyelination represent important therapeutic gaps in multiple sclerosis (MS). Acute optic neuritis (ON) is a frequent MS manifestation. Based on the presence and properties of sphingosine-1-phosphate receptors (S1PR) on astrocytes and oligodendrocytes, we hypothesized that remyelination can be enhanced by treatment with fingolimod, a S1PR modulator currently licensed for relapsing-remitting MS.

Methods

MOVING was an investigator-driven, rater-blind, randomized clinical trial. Patients with acute unilateral ON, occurring as a clinically isolated syndrome or MS relapse, were randomized to 6 months of treatment with 0.5 mg oral fingolimod or subcutaneous IFN-β 1b 250 μg every other day. The change in multifocal visual evoked potential (mfVEP) latency of the qualifying eye was examined as the primary (month 6 vs. baseline) and secondary (months 3, 6 and 12 vs. baseline) outcome. In addition, full field visual evoked potentials, visual acuity, optical coherence tomography as well as clinical relapses and measures of disability, cerebral MRI, and self-reported visual quality of life were obtained for follow-up. The study was halted due to insufficient recruitment (n = 15), and available results are reported.

Results

Per protocol analysis of the primary endpoint revealed a significantly larger reduction of mfVEP latency at 6 months compared to baseline with fingolimod treatment (n = 5; median decrease, 15.7 ms) than with IFN-β 1b treatment (n = 4; median increase, 8.15 ms) (p <  0.001 for interaction). Statistical significance was maintained in the secondary endpoint analysis. Descriptive results are reported for other endpoints.

Conclusion

Preliminary results of the MOVING trial argue in support of a beneficial effect of fingolimod on optic nerve remyelination when compared to IFN-β treatment. Interpretation is limited by the small number of complete observations, an unexpected deterioration of the control group and a difference in baseline mfVEP latencies. The findings need to be confirmed in larger studies.

Trial registration

The trial was registered as EUDRA-CT 2011–004787-30 on October 26, 2012 and as NCT01647880 on July 24, 2012.

High-dose vitamin D supplementation in multiple sclerosis - results from the randomized EVIDIMS (efficacy of vitamin D supplementation in multiple sclerosis) trial

Background

Epidemiological, preclinical, and non-interventional studies link vitamin D (VD) serum levels and disease activity in multiple sclerosis (MS). It is unclear whether high-dose VD supplementation can be used as an intervention to reduce disease activity.

Objectives

The study aimed to compare the effects of every other day high- (20,400 IU) versus low-dose (400 IU) cholecalciferol supplementation on clinical and imaging markers of disease activity in patients with relapsing–remitting MS or clinically isolated syndrome.

Methods

The EVIDIMS (efficacy of vitamin D supplementation in multiple sclerosis) trial was a multicentre randomized/stratified actively controlled explorative phase 2a pilot trial with a double-blind intervention period of 18 months, add on to interferon-β1b.

Results

Fifty-three patients were randomized, and 41 patients completed the study. Cholecalciferol supplementation was well tolerated and safe in both arms. After 18 months, clinical (relapse rates, disability progression) and radiographical (T2-weighted lesion development, contrast-enhancing lesion development, brain atrophy) did not differ between both treatment arms. Post-study power calculations suggested that the sample size was too low to prove the hypothesis.

Conclusions

The results neither support nor disprove a therapeutic benefit of high-dose VD supplementation but provide a basis for sound sample size estimations in future confirmatory studies. www.clinicaltrials.gov/NCT01440062

Ketogenic diet and fasting diet as Nutritional Approaches in Multiple Sclerosis (NAMS): protocol of a randomized controlled study

BACKGROUND

Multiple sclerosis (MS) is the most common inflammatory disease of the central nervous system in young adults that may lead to progressive disability. Since pharmacological treatments may have substantial side effects, there is a need for complementary treatment options such as specific dietary approaches. Ketone bodies that are produced during fasting diets (FDs) and ketogenic diets (KDs) are an alternative and presumably more efficient energy source for the brain. Studies on mice with experimental autoimmune encephalomyelitis showed beneficial effects of KDs and FDs on disease progression, disability, cognition and inflammatory markers. However, clinical evidence on these diets is scarce. In the clinical study protocol presented here, we investigate whether a KD and a FD are superior to a standard diet (SD) in terms of therapeutic effects and disease progression.

METHODS

This study is a single-center, randomized, controlled, parallel-group study. One hundred and eleven patients with relapsing-remitting MS with current disease activity and stable immunomodulatory therapy or no disease-modifying therapy will be randomized to one of three 18-month dietary interventions: a KD with a restricted carbohydrate intake of 20-40 g/day; a FD with a 7-day fast every 6 months and 14-h daily intermittent fasting in between; and a fat-modified SD as recommended by the German Nutrition Society. The primary outcome measure is the number of new T2-weighted MRI lesions after 18 months. Secondary endpoints are safety, changes in relapse rate, disability progression, fatigue, depression, cognition, quality of life, changes of gut microbiome as well as markers of inflammation, oxidative stress and autophagy. Safety and feasibility will also be assessed.

DISCUSSION

Preclinical data suggest that a KD and a FD may modulate immunity, reduce disease severity and promote remyelination in the mouse model of MS. However, clinical evidence is lacking. This study is the first clinical study investigating the effects of a KD and a FD on disease progression of MS.

TRIAL REGISTRATION

ClinicalTrials.gov, NCT03508414. Retrospectively registered on 25 April 2018.

[Recommendations for the Detection and Specification of Perioperative Neurocognitive Disorders]

Perioperative neurocognitive disorders (pNCD) are relevant to long term treatment outcome after elective surgery. The detection of pNCD is challenging and based on extended neuropsychological testing that often is not feasible due to economy driven time constraints during preoperative risk assessment. Only recently new recommendations for the nomenclature of cognitive change associated with anaesthesia and surgery facilitated the transition of the former research diagnosis postoperative cognitive dysfunction (POCD) as a clinical diagnosis based on DSM-5 criteria. In our article we provide an overview of the new recommended diagnostic criteria for pNCD based on the publication by the Nomenclature Consensus Working Group in November 2018. We discuss ideas for the implementation of clinical routine pNCD screening in patients aged 70 years or older with elective surgery and possible options for further support of patients screened positively and their families and care givers.

Additive Value of Transrectal Systematic Ventral Biopsies in Combination with Magnet Resonance Imaging/Ultrasound Fusion-Guided Biopsy in Patients with 3 or More Negative Prostate Biopsies

INTRODUCTION

Patients with consistent suspicion for prostate cancer (PCa) and multiple negative prebiopsies prior to multiparametric magnetic resonance imaging (mpMRI) are still frequently evaluated for an image-guided biopsy and are reported with heterogeneous detection rates. The inclusion of a systematic biopsy (SB) is also still recommended with predominant sampling within the posterior/peripheral zone of the prostate. The aim of this study was (I) to evaluate PCa detection rates using a modified 10 core SB template including anterior biopsies in combination with mpMRI/ultrasound fusion-guided targeted biopsy (TB) in patients with 3 or more negative prebiopsies and (II) to compare mpMRI index lesion localization with histologically confirmed locali-zation from associated prostatectomy samples.

METHODS

Overall 1,337 consecutive patients underwent sensor-based registration TB of the prostate and a subsequent 10-core SB between January 2012 and December 2015 at our institution. For this study, 101 patients with ≥3 negative prebiopsies and prostate imaging - reporting data system lesions ≥3 were pooled prospectively and underwent TB and a modified SB including 2 ventral (anterior) biopsies. Detection rates were estimated for the modified SB, TB, and its combination. A subgroup analysis of 35 patients undergoing prostatectomy was performed by a head-to-head comparison of mpMRI index lesion and histologically confirmed PCa index lesion localization.

RESULTS

The overall detection rate for PCa was 54.5%. The combination of TB and SB detected 14 (25.4%) more cases missed by TB alone (p < 0.001) and 7 (12.7%) more cases missed by SB alone (p = 0.016), respectively. A postoperative Gleason upgrade was seen in 12/35 (34.3%) cases within the TB group and in 14/35 (40.0%) in the SB group, respectively. The subgroup analysis showed a predominant location of PCa index lesions anteriorly at the level of the midgland. The MRI detection rate of the anteriorly located index lesions was 70.4% (15/21 cases) with a clinically significant Gleason score (≥3 + 4 = 7a [International Society of Urological Pathology grade 2]) in 80.9%. Interestingly a modified SB template detected 90.5% (19/21) of the anteriorly located index lesions.

CONCLUSION

Our data suggest that in patients with multiple prebiopsies PCa seems to be predominantly located anteriorly. We suggest the general integration of anterior biopsies despite TB in repeat biopsy patients.

C-reactive protein for risk prediction of post-operative delirium and post-operative neurocognitive disorder

BACKGROUND

Post-operative delirium (POD) and post-operative neurocognitive disorder (NCD) are frequently seen in the elderly. Development of biomarkers for pre-operative risk prediction is of major relevance. As inflammation present before surgery might predispose to POD and post-operative NCD development, we aim to determine associations between pre-operative C-reactive protein (CRP) and the incidence of POD and post-operative NCD.

METHODS

In this observational study, we analyzed 314 patients enrolled in the SuDoCo trial, who had a pre-operative CRP measurement the day before surgery. Primary outcomes were POD assessed according DSM-4 from day 1 until day 7 after surgery and post-operative NCD assessed 3 months after surgery. We conducted multivariable logistic regression analysis adjusted for age, sex, randomization, body mass index, MMSE, ASA status, infection/autoimmune disease/malignoma and types of surgery to determine associations between CRP with POD and post-operative NCD, respectively.

RESULTS

Pre-operative CRP was independently associated with POD [OR 1.158 (95% CI 1.040, 1.291); P = .008]. Patients with CRP values ≥5 mg/dL had a 4.8-fold increased POD risk [OR 4.771 (95% CI 1.765, 12.899; P = .002)] compared to patients with lower CRP values. However, no association was seen between pre-operative CRP and post-operative NCD [OR 0.552 (95% CI 0.193, 1.581); P = .269].

CONCLUSIONS

Pre-operative CRP levels were independently associated with POD but not post-operative NCD after three months. Moreover, higher pre-operative CRP levels showed higher risk for POD. This strengthens the role of inflammation in the development of POD. Assessment of CRP before surgery might allow risk stratification of POD.

TRIAL REGISTRATION

This study was registered with ISRCTN Register 36437985 on 02 March 2009.

Diagnostic biomarkers for adult haemophagocytic lymphohistiocytosis in critically ill patients (HEMICU): a prospective observational study protocol

INTRODUCTION

Haemophagocytic lymphohistiocytosis (HLH) in adults is characterised by toxic immune activation and a sepsis-like syndrome, leading to high numbers of undiagnosed cases and mortality rates of up to 68%. Early diagnosis and specific immune suppressive treatment are mandatory to avoid fatal outcome, but the diagnostic criteria (HLH-2004) are adopted from paediatric HLH and have not been validated in adults. Experimental studies suggest biomarkers to sufficiently diagnose HLH. However, biomarkers for the diagnosis of adult HLH have not yet been investigated.

METHODS AND ANALYSIS

The HEMICU (Diagnostic biomarkers for adult haemophagocytic lymphohistiocytosis in critically ill patients) study aims to estimate the incidence rate of adult HLH among suspected adult patients in intensive care units (ICUs). Screening for HLH will be performed in 16 ICUs of Charité - Universitätsmedizin Berlin. The inclusion criteria are bicytopaenia, hyperferritinaemia (≥500 µg/L), fever or when HLH is suspected by the clinician. Over a period of 2 years, we expect inclusion of about 100 patients with suspected HLH. HLH will be diagnosed if at least five of the HLH-2004 criteria are fulfilled, together with an expert review; all other included patients will serve as controls. Second, a panel of potential biomarker candidates will be explored. DNA, plasma and serum will be stored in a biobank. The primary endpoint of the study is the incidence rate of adult HLH among suspected adult patients during ICU stay. Out of a variety of measured biomarkers, this study furthermore aims to find highly potential biomarkers for the diagnosis of adult HLH in ICU. The results of this study will contribute to improved recognition and patient outcome of adult HLH in clinical routine.

ETHICS AND DISSEMINATION

The institutional ethics committee approved this study on 1 August 2018 (Ethics Committee of Charité - Universitätsmedizin Berlin, EA4/006/18). The results of the study will be disseminated in an international peer-reviewed journal and presented at international conferences.

TRIAL REGISTRATION NUMBER

NCT03510650.

Serum Anti-NMDA (N-Methyl-D-Aspartate)-Receptor Antibodies and Long-Term Clinical Outcome After Stroke (PROSCIS-B)

Background and Purpose- NMDAR1-abs (anti-N-Methyl-D-Aspartate receptor GluN1 antibodies), predominantly known in the context of autoimmune encephalitis, have been observed in serum of healthy individuals. A previous study found smaller stroke magnetic resonance imaging lesion growth in seropositive patients, suggesting a neuroprotective effect of these antibodies. The impact of NMDAR1-abs seropositivity on long-term functional outcome and recurrent vascular events and death after first-ever stroke remains unclear. Methods- Data from the Prospective Cohort with Incident Stroke-Berlin were used. NMDAR1-abs (ie, IgM, IgA, and IgG) were measured in serum within 7 days after first stroke. Outcomes of interest included modified Rankin Scale at one year and the time-to-event of a combined end point (recurrent stroke, myocardial infarction, and all-cause mortality) within 3 years. We calculated odds ratios from adjusted partial proportional odds models and subsequently compared outcome of patients with low titers (1:10; 1:32; and 1:100), and high titers (1:320; 1:1000) to seronegative patients. Furthermore, we estimated hazard ratios for a secondary vascular event or death in NMDAR1-abs seropositive compared to seronegative patients in models adjusted for confounders. Results- The analyses included 583 patients with antibody measurements (39% female, median National Institutes of Health Stroke Scale:2, IQR:1-4), and NMDAR1-abs were observed in 76 (13%) patients. NMDAR1-abs seroprevalence was not associated with functional outcome (odds ratio=1.27; 95% CI, 0.77-2.09); sub-group analyses, however, showed worse outcome in patients with high titers (odds ratio=3.47; 95% CI, 1.54-7.80). Seropositive patients had an increased risk for a secondary vascular event or death (hazard ratios =1.83, 95% CI, 1.10-3.05). Conclusions- In our study, NMDAR1-abs seropositivity was not associated with functional outcome at one year after stroke, however, high titers (≥1:320) were associated with poor functional outcome. Furthermore, NMDAR1-abs seropositivity was associated with increased cardiovascular risk within 3 years after first stroke, independently from other risk factors. Clinical Trial Registration- URL: https://www.clinicaltrials.gov. Unique identifier: NCT01363856.

Intraoperative hyperglycemia increases the incidence of postoperative delirium

BACKGROUND

Hyperglycemia frequently occurs during major surgery and is associated with adverse postoperative outcomes. This study aimed to investigate the influence of intraoperative hyperglycemia on incidences of postoperative delirium (POD) and postoperative cognitive dysfunction (POCD).

METHODS

Eighty-seven patients aged ≥65 years undergoing elective surgery were included in this prospective observational subproject of the BioCog study. Blood glucose (BG) levels were measured every 20 minutes intraoperatively. Hyperglycemia was defined as BG levels ≥150 mg·dL-1. Patients were assessed for POD twice daily until postoperative day 7. The occurrence of POCD was determined three months after surgery. Multivariable logistic regression was used to identify associations between hyperglycemia and POD as well as POCD. Secondary endpoints comprised duration of hyperglycemia, maximum glucose level (Glucosemax) and differences between diabetic and non-diabetic patients.

RESULTS

POD occurred in 41 (47.1%), POCD in five (15.2%) patients. In two separate multivariable logistic regression models, hyperglycemia was significantly associated with POD (OR 3.86 [CI 95% 1.13, 39.49], P=0.044) but not POCD (3.59 [NaN, NaN], P=0.157). Relative duration of hyperglycemia was higher in POD patients compared to patients without POD (20 [0; 71] % versus 0 [0; 55] %, P=0.075), whereas the maximum glucose levels during surgery were similar between the two groups. Considering only non-diabetic patients, relative duration of hyperglycemia (P=0.003) and Glucosemax (P=0.015) were significantly higher in patients with POD.

CONCLUSIONS

Intraoperative hyperglycemia was independently associated with POD but not POCD. Relative duration of hyperglycemia appeared thereby to also play a role. Especially hyperglycemic non-diabetic patients might be at high risk for POD.

Biomarkers of immune capacity, infection and inflammation are associated with poor outcome and mortality after stroke - the PREDICT study

Background

Almost 40% of stroke patients have a poor outcome at 3 months after the index event. Predictors for stroke outcome in the early acute phase may help to tailor stroke treatment. Infection and inflammation are considered to influence stroke outcome.

Methods

In a prospective multicenter study in Germany and Spain, including 486 patients with acute ischemic stroke, we used multivariable regression analysis to investigate the association of poor outcome with monocytic HLA-DR (mHLA-DR) expression, interleukin 6 (IL-6), interleukin 10 (IL-10), tumor necrosis factor alpha (TNF-alpha) and lipopolysaccharide-binding protein (LBP) as markers for immunodepression, inflammation and infection. Outcome was assessed at 3 months after stroke via a structured telephone interview using the modified Rankin Scale (mRS). Poor outcome was defined as a mRS score of 3 or higher which included death. Furthermore, a time-to-event analysis for death within 3 months was performed.

Results

Three-month outcome data was available for 391 patients. Female sex, older age, diabetes mellitus, atrial fibrillation, stroke-associated pneumonia (SAP) and higher National Institute of Health Stroke Scale (NIHSS) score as well as lower mHLA-DR levels, higher IL-6 and LBP-levels at day 1 were associated with poor outcome at 3 months in bivariate analysis. Furthermore, multivariable analysis revealed that lower mHLA-DR expression was associated with poor outcome.

Female sex, older age, atrial fibrillation, SAP, higher NIHSS score, lower mHLA-DR expression and higher IL-6 levels were associated with shorter survival time in bivariate analysis. In multivariable analysis, SAP and higher IL-6 levels on day 1 were associated with shorter survival time.

Conclusions

SAP, lower mHLA-DR-expression and higher IL-6 levels on day one are associated with poor outcome and shorter survival time at 3 months after stroke onset.

Trial registration

www.clinicaltrials.gov, NCT01079728, March 3, 2010.

Diagnostic and prognostic benefit of arterial spin labeling in subacute stroke

BACKGROUND AND PURPOSE

Brain perfusion measurement in the subacute phase of stroke may support therapeutic decisions. We evaluated whether arterial spin labeling (ASL), a noninvasive perfusion imaging technique based on magnetic resonance imaging (MRI), adds diagnostic and prognostic benefit to diffusion-weighted imaging (DWI) in subacute stroke.

METHODS

In a single-center imaging study, patients with DWI lesion(s) in the middle cerebral artery (MCA) territory were included. Onset to imaging time was ≤7 days and imaging included ASL and DWI sequences. Qualitative (standardized visual analysis) and quantitative perfusion analyses (region of interest analysis) were performed. Dichotomized early outcome (modified Rankin Scale [mRS] 0-2 vs. 3-6) was analyzed in two logistic regression models. Model 1 included DWI lesion volume, age, vascular pathology, admission NIHSS, and acute stroke treatment as covariates. Model 2 added the ASL-based perfusion pattern to Model 1. Receiver-operating-characteristic (ROC) and area-under-the-curve (AUC) were calculated for both models to assess their predictive power. The likelihood-ratio-test compared both models.

RESULTS

Thirty-eight patients were included (median age 70 years, admission NIHSS 4, onset to imaging time 67 hr, discharge mRS 2). Qualitative perfusion analysis yielded additional diagnostic information in 84% of the patients. In the quantitative analysis, AUC for outcome prediction was 0.88 (95% CI 0.77-0.99) for Model 1 and 0.97 (95% CI 0.91-1.00) for Model 2. Inclusion of perfusion data significantly improved performance and outcome prediction (p = 0.002) of stroke imaging.

CONCLUSIONS

In patients with subacute stroke, our study showed that adding perfusion imaging to structural imaging and clinical data significantly improved outcome prediction. This highlights the usefulness of ASL and noninvasive perfusion biomarkers in stroke diagnosis and management.

Exact replication: Foundation of science or game of chance?

The need for replication of initial results has been rediscovered only recently in many fields of research. In preclinical biomedical research, it is common practice to conduct exact replications with the same sample sizes as those used in the initial experiments. Such replication attempts, however, have lower probability of replication than is generally appreciated. Indeed, in the common scenario of an effect just reaching statistical significance, the statistical power of the replication experiment assuming the same effect size is approximately 50%-in essence, a coin toss. Accordingly, we use the provocative analogy of "replicating" a neuroprotective drug animal study with a coin flip to highlight the need for larger sample sizes in replication experiments. Additionally, we provide detailed background for the probability of obtaining a significant p value in a replication experiment and discuss the variability of p values as well as pitfalls of simple binary significance testing in both initial preclinical experiments and replication studies with small sample sizes. We conclude that power analysis for determining the sample size for a replication study is obligatory within the currently dominant hypothesis testing framework. Moreover, publications should include effect size point estimates and corresponding measures of precision, e.g., confidence intervals, to allow readers to assess the magnitude and direction of reported effects and to potentially combine the results of initial and replication study later through Bayesian or meta-analytic approaches.

Impact of pre-admission oral anticoagulation on ischaemic stroke volume, lesion pattern, and frequency of intracranial arterial occlusion in patients with atrial fibrillation

Aims

Therapeutic oral anticoagulation on hospital admission reduces morbidity and mortality after acute ischaemic stroke in patients with atrial fibrillation (AF). The underlying mechanism is not fully understood. In order to assess the impact of INR-level on admission on stroke volume, lesion pattern and the frequency of intracranial arterial occlusion, we analysed serial MRI measurements in AF patients suffering acute ischaemic stroke.

Methods and results

This subgroup analysis of the prospective '1000Plus' study included patients with acute ischaemic stroke and known AF or a first episode of AF in hospital. All patients underwent serial brain magnetic resonance imaging. Stroke patients were categorized as follows: Group1, phenprocoumon intake, international normalized ratio (INR) ≥1.7 on admission, no thrombolysis; Group2, INR < 1.7 on admission, thrombolysis; and Group3, INR < 1.7, no thrombolysis. In 98 AF patients {77 ± 9 years, 60% male; median National Institute of Health Stroke Scale [NIHSS] score on admission 5 (interquartile range [IQR] 2-8)} with known AF before admission, territorial infarction was less often found in Group 1 (n = 20) compared with Group 2 + 3 (20% vs. 47%, P = 0.022). Arterial occlusion rate on admission differed among groups (30%, 75%, and 35%, respectively, P = 0.004) but not between Group 1 vs. Group 2 + 3 (30% vs. 45%, P = 0.31). Median FLAIR volume on Days 5-7 was lower in Group1 compared with Group 2 (n = 20) [3.2 cm3 (IQR 1.1-11.3) vs. 18.6 cm3 (IQR 8.2-49.4); P = 0.009] but not compared with Group 2 + 3 [7.8 cm3 (IQR 1.6-25.9); P = 0.23]. An INR ≥ 1.7 on admission was not associated with smaller stroke volume in multivariable regression analysis. Adding 57 patients with a first AF episode during the in-hospital stay, similar results were observed in 155 AF patients.

Conclusion

In this AF cohort, an INR ≥ 1.7 at stroke onset affects lesion pattern but does not affect significantly lower stroke volume and the frequency of arterial occlusion on admission.

Association of obesity, diabetes and hypertension with cognitive impairment in older age

Background

Age-related cognitive impairment is rising in prevalence but is not yet fully characterized in terms of its epidemiology. Here, we aimed to elucidate the role of obesity, diabetes and hypertension as candidate risk factors.

Methods

Original baseline data from 3 studies (OCTOPUS, DECS, SuDoCo) were obtained for secondary analysis of cross-sectional associations of diabetes, hypertension, blood pressure, obesity (body mass index [BMI] ≥30 kg/m²) and BMI with presence of cognitive impairment in log-binomial regression analyses. Cognitive impairment was defined as scoring more than 2 standard deviations below controls on at least one of 5–11 cognitive tests. Underweight participants (BMI<18.5 kg/m²) were excluded. Results were pooled across studies in fixed-effects inverse variance models.

Results

Analyses totaled 1545 participants with a mean age of 61 years (OCTOPUS) to 70 years (SuDoCo). Cognitive impairment was found in 29.0% of participants in DECS, 8.2% in SuDoCo and 45.6% in OCTOPUS. In pooled analyses, after adjustment for age, sex, diabetes and hypertension, obesity was associated with a 1.29-fold increased prevalence of cognitive impairment (risk ratio [RR] 1.29; 95% CI 0.98, 1.72). Each 1 kg/m² increment in BMI was associated with 3% increased prevalence (RR 1.03; 95% CI 1.00, 1.06). None of the remaining risk factors were associated with impairment.

Conclusion

Our results show that older people who are obese have higher prevalence of cognitive impairment compared with normal weight and overweight individuals, and independently of co-morbid hypertension or diabetes. Prospective studies are needed to investigate the temporal relationship of the association.

The ratio between cerebral blood flow and Tmax predicts the quality of collaterals in acute ischemic stroke

Background

In acute ischemic stroke the status of collateral circulation is a critical factor in determining outcome. We propose a less invasive alternative to digital subtraction angiography for evaluating collaterals based on dynamic-susceptibility contrast magnetic resonance imaging.

Methods

Perfusion maps of Tmax and cerebral blood flow (CBF) were created for 35 patients with baseline occlusion of a major cerebral artery. Volumes of hypoperfusion were defined as having a Tmax delay of > 4 seconds (Tmax4s) and > 6 seconds (Tmax6s) and a CBF drop below 80% of healthy, contralateral tissue. For each patient a ratio between the volume of the CBF and the Tmax based perfusion deficit was calculated. Associations with collateral status and radiological outcome were assessed with the Mann-Whitney-U test, uni- and multivariable logistic regression analyses as well as area under the receiver-operator-characteristic (ROC) curve.

Results

The CBF/Tmax volume ratios were significantly associated with bad collateral status in crude logistic regression analysis as well as with adjustment for NIHSS at admission and baseline infarct volume (OR = 2.5 95% CI[1.2–5.4] p = 0.020 for CBF/Tmax 4s volume ratio and OR = 1.6 95% CI[1.0–2.6] p = 0.031 for CBF/Tmax6s volume ratio). Moreover, the ratios were significantly correlated to final infarct size (Spearman’s rho = 0.711 and 0.619, respectively for the CBF/Tmax4s volume ratio and CBF/Tmax6s volume ration, all p<0.001). The ratios also had a high area under the ROC curve of 0.93 95%CI[0.86–1.00]) and 0.90 95%CI[0.80–1.00]respectively for predicting poor radiological outcome.

Conclusions

In the setting of acute ischemic stroke the CBF/Tmax volume ratio can be used to differentiate between good and insufficient collateral circulation without the need for invasive procedures like conventional angiography.

The first night effect in multiple sclerosis patients undergoing home-based polysomnography

BACKGROUND

The first night effect (FNE) is a polysomnography (PSG) habituation effect in the first of several consecutive in-laboratory PSGs (I-PSGs). The FNE is caused by the discomfort provoked by electrodes and cables and the exposure to an unfamiliar environment. A reverse FNE (RFNE) with an improved sleep in the first night is characteristic of insomnia, presumably because the video PSG in the sleep laboratory leads to a decrease in the negatively toned cognitive activity. Therefore, two or more I-PSGs are required for an accurate diagnosis. Although the FNE is well documented in I-PSG, little is known about the FNE and the RFNE in home-based PSGs (H-PSGs).

METHODS

This is a retrospective analysis of a recently published cross-sectional study using H-PSG. Sixty-three consecutive patients suffering from multiple sclerosis (MS) were investigated by two consecutive H-PSGs without video. The differences between the first and second H-PSGs were analyzed. The patients were classified into four subgroups: no sleep disorder, insomnia, sleep-related breathing disorders (SRBDs), and periodic limb movement disorder or restless legs syndrome (PLMD/RLS).

RESULTS

MS patients suffering from insomnia showed no RFNE. MS patients with SRBD or PLMD/RLS showed no reduced sleep efficiency but significantly less slow wave sleep. Furthermore, SRBD patients showed significantly less non-rapid eye movement (NREM) sleep, and PLMD/RLS patients were significantly awake longer in the first night after sleep onset (increased wake-after-sleep-onset time) and showed a higher rapid eye movement (REM) latency.

CONCLUSION

SRBD and PLMD/RLS patients showed a significant FNE. Two consecutive H-PSGs are required in these patients to obtain a precise hypnogram even in the ambulatory field. In MS patients suffering from insomnia, no RFNE was found, and in insomnia patients one H-PSG seems to be sufficient.