Predicting symptomatic intracranial haemorrhage after mechanical thrombectomy: the TAG score

BACKGROUND

There is limited data on predictors of symptomatic intracranial haemorrhage (sICH) in patients who underwent mechanical thrombectomy. In this study, we aim to determine those predictors with external validation.

METHODS

We evaluated mechanical thrombectomy in a derivation cohort of patients at a comprehensive stroke centre over a 30-month period. Clinical and radiographic data on these patients were obtained from the prospective quality improvement database. sICH was defined using the European Cooperative Acute Stroke Study III. We compared clinical and radiographic characteristics between patients with and without sICH using χ² and t tests to identify independent predictors of sICH with p<0.1. Significant variables were then combined in a multivariate logistic regression model to derive an sICH prediction score. This score was then validated using data from the Blood Pressure After Endovascular Treatment multicentre prospective registry.

RESULTS

We identified 578 patients with acute ischaemic stroke who received thrombectomy, 19 had sICH (3.3%). Predictive factors of sICH were: thrombolysis in cerebral ischaemia (TICI) score, Alberta stroke program early CT score (ASPECTS), and glucose level, and from these predictors, we derived the weighted TICI-ASPECTS-glucose (TAG) score, which was associated with sICH in the derivation (OR per unit increase 1.98, 95% CI 1.48 to 2.66, p<0.001, area under curve ((AUC)=0.79) and validation (OR per unit increase 1.48, 95% CI 1.22 to 1.79, p<0.001, AUC=0.69) cohorts.

CONCLUSION

High TAG scores are associated with sICH in patients receiving mechanical thrombectomy. Larger studies are needed to validate this scoring system and test strategies to reduce sICH risk and make thrombectomy safer in patients with elevated TAG scores.

Possible Empirical Evidence of Glymphatic System on Computed Tomography After Endovascular Perforations

BACKGROUND

The glial-lymphatic pathway is a fluid-clearance pathway consisting of a para-arterial route for the flow of cerebrospinal fluid along perivascular spaces and subsequently toward the brain interstitium. In this case series, we aim to investigate an empirical demonstration of glymphatic clearance of extravasated iodine following perforation incurred during endovascular therapy on serial computed tomography.

METHODS

Six consecutive cases of endovascular perforation during thrombectomy performed between 2005 and 2018 were retrospectively collected by searching our internal database of total 446 thrombectomies. Two cases were excluded because care was withdrawn shortly following the procedure and no follow-up imaging was available. One case was excluded because a ventricular drain was placed. Three cases were hence included in this analysis.

RESULTS

All 3 cases demonstrated progressive absorption of contrast by the brain parenchyma with eventual contrast disappearance.

CONCLUSIONS

We described a likely in vivo computed tomography correlate of the glymphatic system in a cohort of patients who sustained intraprocedural extravasation during thrombectomy for acute ischemic stroke.

P686Cancer is not associated with increased cardiac and bleeding events after 2nd- and 3rd-generation drug-eluting stents implantation

Background

Previous studies demonstrated the impact of concomitant cancer on the increased risk of adverse cardiac and bleeding events after percutaneous coronary intervention (PCI). However, the impact in this 2nd- and 3rd-generation drug-eluting stent (DES) era remains to be elucidated.

Purpose

To clarify the impact of cancer on clinical outcomes in patients after 2nd- or 3rd -generation DES implantation.

Methods

A total of 932 patients who underwent PCI with 2nd- or 3rd -generation DES were included. Patients who were diagnosed with cancer after PCI were excluded from the present cohort. The incidence of major adverse cardiac events (MACE) including cardiac death, myocardial infarction and target or non-target vessel revascularization, and bleeding events was compared between the patients with cancer or the history of treatment for cancer (cancer group, n=140) and the patients without cancer (no cancer group, n=792). Bleeding events were evaluated according to the Thrombolysis in Myocardial Infarction definition. Further comparisons were performed between the 2 groups (cancer group, n=126; no cancer group, n=252) after the adjustment of baseline clinical characteristics using 1:2 propensity score-matching analysis.

Results

The incidence of MACE at median 577 [340–1043] days after the PCI was comparable between the 2 groups in both unadjusted (15.0% vs. 15.0%, p=0.984) (Panel A) and adjusted cohorts (14.3 vs. 13.1%, p=0.796), although the incidence of all cause death in the cancer group was significantly greater than the no cancer group (15.1 vs. 9.5%, p=0.007, in the adjusted cohort). The increased risk of MACE was not observed in any types of cancer or treatment (Panel B). The incidence of bleeding events was also comparable between the 2 groups (4.0 vs. 2.0%, p=0.297, in the adjusted cohort).

Conclusion

The increased incidence of MACE and bleeding events in patients with cancer was not demonstrated after the 2nd- or 3rd-generation DES implantation. Further studies are required to clarify the safety and efficacy of PCI in patients with cancer.

Impacts of climate change on snow accumulation and melting processes over mountainous regions in Northern California during the 21st century

A point-location-based analysis of future climate change impacts on snow accumulation and melting processes was conducted over three study watersheds in Northern California during a 90-year future period by means of snow regime projections. The snow regime projections were obtained by means of a physically-based snow model with dynamically downscaled future climate projections. Then, atmospheric and snow-related variables, and their interrelations during the 21st century were investigated to reveal future climate change impacts on snow accumulation and melting processes. The analysis shows large reductions in snow water equivalent (SWE), snowfall to precipitation (S/P) ratio, and snowmelt through the 21st century. Timing of the peak of the SWE and snowmelt will also change in the future. Meanwhile, the analysis in this study shows that air temperature rise will affect, but will not dominate the future change in snowmelt over the study watersheds. This result implies the importance of considering atmospheric variables other than air temperature, such as precipitation, shortwave radiation, relative humidity, and wind speed even if these variables will not clearly change during the 21st century.

P6339Sequential organ failure assessment score on admission predicts long-time mortality of the patients with acute heart failure

Background

Despite the remarkable advances in the treatment options of acute heart failure (HF), prognosis assessment remains an ongoing challenge. Previous studies revealed only a moderate accuracy of models predicting mortality. Sequential Organ Failure Assessment (SOFA) Score are widely used in the intensive care unit (ICU) to predict outcome and predicted higher long-time mortality in unselected patients in cardiac ICU. In addition, the American Heart Association Get With the Guidelines–Heart Failure (GWTG-HF) risk score allows for risk stratification of 30-day outcome for patients hospitalized with HF. The purpose of this study was to evaluate whether SOFA score on admission is useful for long-time mortality prediction in acute HF patients and also to assess the discriminative performance as compared with GWTG-HF risk score.

Methods

This was a single-centre, retrospective cohort study. Between January 2007 and December 2016, we screened eligible 661 consecutive patients with acute HF administered at our hospital. SOFA score on admission of 294 patients was able to calculate retrospectively. We enrolled 269 patients who could complete follow up evaluation for more than 1 year. Endpoint was all-cause mortality after admission. Additive information of SOFA score was evaluated by area under the curve (AUC), net reclassification improvement (NRI), integrated discrimination improvement (IDI) and decision curve analysis (DCA).

Results

The 269 patients were included in this study (78.5±10.9 years; 136 men; left ventricular ejection fraction [EF], 49.8±16.6%) during a mean follow-up of 32.1±22.3 months. Patients with all-cause death had higher SOFA score (4.2±2.3 versus 2.8±1.8, p<0.001; AUC, 0.689) and GWTG-HF risk score (44.0±7.6 versus 38.1±7.9, P<0.001, AUC, 0.692).

Kaplan-Meier survival analysis demonstrated higher SOFA scores (P<0.001) and GWTG-HF risk scores (P<0.001) appears to be related to increase probabilities of all cause death. A multivariate Cox proportional hazard model were made with adjustment for SOFA score, GWTG-HF risk score, age, gender and ejection fraction. As a result, SOFA score (hazard ratio [HR] 1.227; 95% confidence interval [CI], 1.130 to 1.326; P<0.001), GWTG-HF (HR, 1.054; 95% CI, 1.029 to 1.078; P<0.001) and age (HR, 1.069; 95% CI 1.048 to 1.092; P<0.001) were independent predictors of all cause death and HR of SOFA score was the highest in these parameters. Incorporating SOFA score into GWTG-HF score yielded a significant NRI (0.528 (95% CI 0.291 to 0.765) and IDI (0.046 (95% CI 0.020 to 0.072). In DCA, compared with the reference model, the net benefit for SOFA score model was greater across the range of threshold probabilities.

Conclusions

The SOFA score, simple and validated mortality risk score can predict long-term all-cause mortality in patients with acute HF. Discriminative performance metrics such as NRI, IDI and DCA were improved on incorporation of the SOFA score for prediction of mortality.

Development and validation of the comprehensive assessment scale for chemotherapy-induced peripheral neuropathy in survivors of cancer

Background

Appropriate assessment is essential for the management of chemotherapy-induced peripheral neuropathy (CIPN), an intractable symptom that cannot yet be palliated, which is high on the list of causes of distress for cancer patients. However, objective assessment by medical staff makes it easy to underestimate the symptoms and effects of CIPN in cancer survivors. As a result, divergence from subjective evaluation of cancer survivors is a significant problem. Therefore, there is an urgent need to develop a subjective scale with high accuracy and applicability that reflects the experiences of cancer patients. We developed a comprehensive assessment scale for CIPN in cancer survivors, named the Comprehensive Assessment Scale for Chemotherapy-Induced Peripheral Neuropathy in Survivors of Cancer (CAS-CIPN), and demonstrated its reliability and validity.

Methods

We developed a questionnaire based on qualitative studies of peripheral neuropathy in Japanese cancer patients and literature review. Twelve cancer experts confirmed the content validity of the questionnaire. A draft version comprising 40 items was finalized by a pilot test on 100 subjects. The participants in the present study were 327 Japanese cancer survivors. Construct validity was determined by factor analysis, and internal validity by confirmation factor analysis and Cronbach’s α.

Results

Factor analysis showed that the structure consisted of 15 items in four dimensions: “Threatened interference in daily life by negative feelings”, “Impaired hand fine motor skills”, “Confidence in choice of treatment/management,” and “Dysesthesia of the palms and soles.” The CAS-CIPN internal consistency reliability was 0.826, and the reliability coefficient calculated using the Spearman-Brown formula [q = 2r/(1 + r)] was 0.713, confirming high internal consistency and stability. Scores on this scale were strongly correlated with Gynecologic Oncology Group-Neurotoxicity scores (r = 0.714, p < 0.01), confirming its criterion-related validity.

Conclusions

The CAS-CIPN is an assessment tool with high reliability and validity for the comprehensive evaluation of CIPN in cancer survivors. The CAS-CIPN is simple to use, and can be used by medical professionals for appropriate situational assessment and intervention.

New precise measurements of muonium hyperfine structure at J-PARC MUSE

High precision measurements of the ground state hyperfine structure (HFS) of muonium is a stringent tool for testing bound-state quantum electrodynamics (QED) theory, determining fundamental constants of the muon magnetic moment and mass, and searches for new physics. Muonium is the most suitable system to test QED because both theoretical and experimental values can be precisely determined. Previous measurements were performed decades ago at LAMPF with uncertainties mostly dominated by statistical errors. At the J-PARC Muon Science Facility (MUSE), the MuSEUM collaboration is planning complementary measurements of muonium HFS both at zero and high magnetic field. The new high-intensity muon beam that will soon be available at H-Line will provide an opportunity to improve the precision of these measurements by one order of magnitude. An overview of the different aspects of these new muonium HFS measurements, the current status of the preparation for high-field measurements, and the latest results at zero field are presented.

Analysis of future climate change impacts on snow distribution over mountainous watersheds in Northern California by means of a physically-based snow distribution model

The impacts of climate change on snow distribution through the 21st century were investigated over three mountainous watersheds in Northern California by means of a physically-based snow distribution model. The future climate conditions during a 90-year future period from water year 2010 to 2100 were obtained from 13 future climate projection realizations from two GCMs (ECHAM5 and CCSM3) based on four SRES scenarios (A1B, A1FI, A2, and B1). The 13 future climate projection realizations were dynamically downscaled at 9 km resolution by a regional climate model. Using the downscaled variables based on the 13 future climate projection realizations, snow distribution over the Feather, Yuba, and American River watersheds (FRW, YRW, and ARW) was projected by means of the physically-based snow model. FRW and YRW watersheds cover the main source areas of the California State Water Project (SWP), and ARW is one of the key watersheds in the California Central Valley Project (CVP). SWP and CVP are of great importance as they provide and regulate much of the California's water for drinking, irrigation, flood control, environmental, and hydro-power generation purposes. Ensemble average snow distribution over the study watersheds was calculated over the 13 realizations and for each scenario, revealing differences among the scenarios. While the snow reduction through the 21st century was similar between A1B and A2, the snow reduction was milder for B1, and more severe for A1FI. A significant downward trend was detected in the snowpack over nearly the entire watershed areas for all the ensemble average results.

How Does Preexisting Hypertension Affect Patients with Intracerebral Hemorrhage?

BACKGROUND AND PURPOSE

Patients with intracerebral hemorrhage (ICH) frequently present with hypertension, but it is unclear if this is due to pre-existing hypertension (prHTN) or to the bleed itself or associated pain. We sought to assess the relationship between prHTN and admission systolic blood pressure (aBP) and bleed severity.

METHODS

We retrospectively assessed the relationship between prHTN and aBP and NIHSS in patients with ICH at 3 institutions.

RESULTS

Of 251 patients, 170 (68%) had prHTN based on history of hypertension/antihypertensive use. Median aBP was significantly higher in those with prHTN (155 mm Hg (IQR 135-181) versus 139 mm Hg (IQR 124-158), P < .001). Patients with left ventricular hypertrophy (LVH) on electrocardiogram (ECG) or transthoracic echocardiogram (TTE) had significantly higher aBP than those without LVH (median aBP 195 mm Hg (IQR 155-216) for patients with LVH on ECG versus 147 mm Hg (IQR 129-163) for patients with no LVH on ECG, P < .001; median aBP 181 mm Hg (IQR 153-214) for patients with LVH on TTE versus 152 mm Hg (IQR 137-169) for patients with no LVH on TTE, P = .01). prHTN was associated with a higher median NIHSS (11 (IQR 3-20) for patients with history of hypertension/antihypertensive use versus 6 (IQR 1-14) for patients without this history (P = .02); 9 (IQR 3-19) versus 5 (IQR 2-13) for patients with/without LVH on ECG (P = .085); and 10 (IQR 5-18) versus 5 (IQR 1-13) for patients with/without LVH on TTE (P = .046).

CONCLUSIONS

Patients with ICH who have prHTN have higher aBP and NIHSS, suggesting that prHTN may worsen reactive hypertension in the setting of ICH.

Muons at ISIS

For the last 30 years, muon experiments at ISIS pulsed neutron and muon facility at the Rutherford Appleton Laboratory, Oxfordshire have been making a significant contribution to a number of scientific fields. The muon facilities at ISIS consist of eight experimental areas. The European Commission Muon facility consists of three experimental areas with a fixed momentum (28 MeV c^-1). The RIKEN-RAL facility has a variable momentum (17-90 MeV c^-1) and a choice of negative or positive muons delivering muons to four experimental areas. There is also an area recently used for a muon ionization cooling experiment. In this paper, the ISIS pulsed muon facilities are reviewed, including the beam characteristics that could be useful for muography experiments.This article is part of the Theo Murphy meeting issue 'Cosmic-ray muography'.

Depth dependant element analysis of PbMg1/3Nb2/3O3 using muonic x-rays

The relaxor PbMg_1/3Nb_2/3O₃ (PMN) has received attention due to its potential applications as a piezoelectric when doped with PbTiO₃ (PT). Previous results have found that there are two phases existing in the system, one linked to the near-surface regions of the sample, the other in the bulk. However, the exact origin of these two phases is unclear. In this paper, depth dependant analysis results from negative muon implantation experiments are presented. It is shown that the Pb content is constant throughout all depths probed in the sample, but the Mg and Nb content changes in the near-surface region below 100 μm. At an implantation depth of 60 μm, it is found that there is a 25% increase in Mg content, with a simultaneous 5% decrease in Nb content in order to maintain charge neutrality. These results show that the previously observed skin effects in PMN are due to a change in concentration and unit cell.

Abstract WP290: A Resident-Driven Intervention to Decrease Door-to-Needle Time and Increase Resident Satisfaction in a Resource-Limited Setting

Introduction: Neurology residents are often the first-line responders to emergency department (ED) stroke codes, however their role in initiating stroke systems changes is not well established. At a large, resource-limited public hospital, neurology residents developed a protocol for acute stroke codes focused on improved interdisciplinary communication.

Methods: Process mapping was used to identify current state deficiencies. Poor communication between neurology residents and ED physicians, nurses, and radiology techs and role redundancy were identified as core deficiencies. Ideal and future state maps were used to create a stroke code workflow diagram (the “protocol”). Changes included assigning specific responsibilities to each team member, and forcing interdisciplinary communication at specific points in the process (i.e. ED physician calls tech when patient goes to CT). The protocol was implemented in May 2016. Median door-to-needle (DTN) times were compared in the pre-intervention (January 1, 2014 - April 30, 2016) and post-intervention (May 1, 2016 - June 15, 2017) periods using non-parametric tests. Resident satisfaction with communication during stroke codes was measured using pre- and post-intervention surveys; responses were compared with t-test.

Results: A total of 66 patients received tPA, 20 (30%) in the post-intervention period. Baseline demographics and NIHSS did not differ in the pre- and post-intervention periods, however median DTN decreased (58 vs. 40 min, p=0.02) and proportion of DTN≤45 minutes doubled (30% vs. 60%, p=0.03) in the post-intervention period. Twenty-three residents (79%) completed pre-intervention surveys; 19 residents (64%) completed post-intervention surveys. Resident satisfaction was greater in the post-intervention period with respect to stroke team communication (2.8 vs. 3.6, p=0.01), understanding multidisciplinary roles (3.8 vs. 4.3, p=0.03), and interaction between team members (3.2 vs. 3.8, p=0.03) measured using a five-point scale (higher being better).

Conclusion: In a resource-limited setting, neurology residents are capable of implementing acute stroke workflow changes using basic process improvement methods that have a measurable impact on DTN and resident satisfaction.

Maximizing T c by tuning nematicity and magnetism in FeSe1-x S x superconductors

A fundamental issue concerning iron-based superconductivity is the roles of electronic nematicity and magnetism in realising high transition temperature (T c). To address this issue, FeSe is a key material, as it exhibits a unique pressure phase diagram involving non-magnetic nematic and pressure-induced antiferromagnetic ordered phases. However, as these two phases in FeSe have considerable overlap, how each order affects superconductivity remains perplexing. Here we construct the three-dimensional electronic phase diagram, temperature (T) against pressure (P) and isovalent S-substitution (x), for FeSe1-x S x . By simultaneously tuning chemical and physical pressures, against which the chalcogen height shows a contrasting variation, we achieve a complete separation of nematic and antiferromagnetic phases. In between, an extended non-magnetic tetragonal phase emerges, where T c shows a striking enhancement. The completed phase diagram uncovers that high-T c superconductivity lies near both ends of the dome-shaped antiferromagnetic phase, whereas T c remains low near the nematic critical point.

Trend analysis of watershed-scale precipitation over Northern California by means of dynamically-downscaled CMIP5 future climate projections

The impacts of climate change on watershed-scale precipitation through the 21st century were investigated over eight study watersheds in Northern California based on dynamically downscaled CMIP5 future climate projections from three GCMs (CCSM4, HadGEM2-ES, and MIROC5) under the RCP4.5 and RCP8.5 future climate scenarios. After evaluating the modeling capability of the WRF model, the six future climate projections were dynamically downscaled by means of the WRF model over Northern California at 9km grid resolution and hourly temporal resolution during a 94-year period (2006-2100). The biases in the model simulations were corrected, and basin-average precipitation over the eight study watersheds was calculated from the dynamically downscaled precipitation data. Based on the dynamically downscaled basin-average precipitation, trends in annual depth and annual peaks of basin-average precipitation during the 21st century were analyzed over the eight study watersheds. The analyses in this study indicate that there may be differences between trends of annual depths and annual peaks of watershed-scale precipitation during the 21st century. Furthermore, trends in watershed-scale precipitation under future climate conditions may be different for different watersheds depending on their location and topography even if they are in the same region.