Prior Thrombectomy Does Not Affect the Surgical Complication Rate of Decompressive Hemicraniectomy in Patients with Malignant Ischemic Stroke

BACKGROUND

Even though mechanical recanalization techniques have dramatically improved acute stroke care since the pivotal trials of decompressive hemicraniectomy for malignant courses of ischemic stroke, decompressive hemicraniectomy remains a mainstay of malignant stroke treatment. However, it is still unclear whether prior thrombectomy, which in most cases is associated with application of antiplatelets and/or anticoagulants, affects the surgical complication rate of decompressive hemicraniectomy and whether conclusions derived from prior trials of decompressive hemicraniectomy are still valid in times of modern stroke care.

METHODS

A total of 103 consecutive patients who received a decompressive hemicraniectomy for malignant middle cerebral artery infarction were evaluated in this retrospective cohort study. Surgical and functional outcomes of patients who had received mechanical recanalization before surgery (thrombectomy group, n = 49) and of patients who had not received mechanical recanalization (medical group, n = 54) were compared.

RESULTS

The baseline characteristics of the two groups did significantly differ regarding preoperative systemic thrombolysis (63.3% in the thrombectomy group vs. 18.5% in the medical group, p < 0.001), the rate of hemorrhagic transformation (44.9% vs. 24.1%, p = 0.04) and the preoperative Glasgow Coma Score (median of 7 in the thrombectomy group vs. 12 in the medical group, p = 0.04) were similar to those of prior randomized controlled trials of decompressive hemicraniectomy. There was no significant difference in the rates of surgical complications (10.2% in the thrombectomy group vs. 11.1% in the medical group), revision surgery within the first 30 days after surgery (4.1% vs. 5.6%, respectively), and functional outcome (median modified Rankin Score of 4 at 5 and 14 months in both groups) between the two groups.

CONCLUSIONS

A prior mechanical recanalization with possibly associated systemic thrombolysis does not affect the early surgical complication rate and the functional outcome after decompressive hemicraniectomy for malignant ischemic stroke. Patient characteristics have not changed significantly since the introduction of mechanical recanalization; therefore, the results from former large randomized controlled trials are still valid in the modern era of stroke care.

Necrosectomy Versus Stand-Alone Suboccipital Decompressive Craniectomy for the Management of Space-Occupying Cerebellar Infarctions-A Retrospective Multicenter Study

BACKGROUND AND OBJECTIVES

Space-occupying cerebellar stroke (SOCS) when coupled with neurological deterioration represents a neurosurgical emergency. Although current evidence supports surgical intervention in such patients with SOCS and rapid neurological deterioration, the optimal surgical methods/techniques to be applied remain a matter of debate.

METHODS

We conducted a retrospective, multicenter study of patients undergoing surgery for SOCS. Patients were stratified according to the type of surgery as (1) suboccipital decompressive craniectomy (SDC) or (2) suboccipital craniotomy with concurrent necrosectomy. The primary end point examined was functional outcome using the modified Rankin Scale (mRS) at discharge and at 3 months (mRS 0-3 defined as favorable and mRS 4-6 as unfavorable outcome). Secondary end points included the analysis of in-house postoperative complications, mortality, and length of hospitalization.

RESULTS

Ninety-two patients were included in the final analysis: 49 underwent necrosectomy and 43 underwent SDC. Those with necrosectomy displayed significantly higher rate of favorable outcome at discharge as compared with those who underwent SDC alone: 65.3% vs 27.9%, respectively ( P < .001, odds ratios 4.9, 95% CI 2.0-11.8). This difference was also observed at 3 months: 65.3% vs 41.7% ( P = .030, odds ratios 2.7, 95% CI 1.1-6.7). No significant differences were observed in mortality and/or postoperative complications, such as hemorrhagic transformation, infection, and/or the development of cerebrospinal fluid leaks/fistulas.

CONCLUSION

In the setting of SOCS, patients treated with necrosectomy displayed better functional outcomes than those patients who underwent SDC alone. Ultimately, prospective, randomized studies will be needed to confirm this finding.

Functional Outcomes in Conservatively vs Surgically Treated Cerebellar Infarcts

Importance

According to the current American Heart Association/American Stroke Association guidelines, decompressive surgery is indicated in patients with cerebellar infarcts that demonstrate severe cerebellar swelling. However, there is no universal definition of swelling and/or infarct volume(s) available to support a decision for surgery.

Objective

To evaluate functional outcomes in surgically compared with conservatively managed patients with cerebellar infarcts.

Design, Setting, and Participants

In this retrospective multicenter cohort study, patients with cerebellar infarcts treated at 5 tertiary referral hospitals or stroke centers within Germany between 2008 and 2021 were included. Data were analyzed from November 2020 to November 2023.

Exposures

Surgical treatment (ie, posterior fossa decompression plus standard of care) vs conservative management (ie, medical standard of care).

Main Outcomes and Measures

The primary outcome examined was functional status evaluated by the modified Rankin Scale (mRS) at discharge and 1-year follow-up. Secondary outcomes included the predicted probabilities for favorable outcome (mRS score of 0 to 3) stratified by infarct volumes or Glasgow Coma Scale score at admission and treatment modality. Analyses included propensity score matching, with adjustments for age, sex, Glasgow Coma Scale score at admission, brainstem involvement, and infarct volume.

Results

Of 531 included patients with cerebellar infarcts, 301 (57%) were male, and the mean (SD) age was 68 (14.4) years. After propensity score matching, a total of 71 patients received surgical treatment and 71 patients conservative treatment. There was no significant difference in favorable outcomes (ie, mRS score of 0 to 3) at discharge for those treated surgically vs conservatively (47 [66%] vs 45 [65%]; odds ratio, 1.1; 95% CI, 0.5-2.2; P > .99) or at follow-up (35 [73%] vs 33 [61%]; odds ratio, 1.8; 95% CI, 0.7-4.2; P > .99). In patients with cerebellar infarct volumes of 35 mL or greater, surgical treatment was associated with a significant improvement in favorable outcomes at 1-year follow-up (38 [61%] vs 3 [25%]; odds ratio, 4.8; 95% CI, 1.2-19.3; P = .03), while conservative treatment was associated with favorable outcomes at 1-year follow-up in patients with infarct volumes of less than 25 mL (2 [34%] vs 218 [74%]; odds ratio, 0.2; 95% CI, 0-1.0; P = .047).

Conclusions and Relevance

Overall, surgery was not associated with improved outcomes compared with conservative management in patients with cerebellar infarcts. However, when stratifying based on infarct volume, surgical treatment appeared to be beneficial in patients with larger infarct volumes, while conservative management appeared favorable in patients with smaller infarct volumes.

The Stokes-Einstein-Sutherland Equation at the Nanoscale Revisited

The Stokes-Einstein-Sutherland (SES) equation is at the foundation of statistical physics, relating a particle's diffusion coefficient and size with the fluid viscosity, temperature, and the boundary condition for the particle-solvent interface. It is assumed that it relies on the separation of scales between the particle and the solvent, hence it is expected to break down for diffusive transport on the molecular scale. This assumption is however challenged by a number of experimental studies showing a remarkably small, if any, violation, while simulations systematically report the opposite. To understand these discrepancies, analytical ultracentrifugation experiments are combined with molecular simulations, both performed at unprecedented accuracies, to study the transport of buckminsterfullerene C60 in toluene at infinite dilution. This system is demonstrated to clearly violate the conditions of slow momentum relaxation. Yet, through a linear response to a constant force, the SES equation can be recovered in the long time limit with no more than 4% uncertainty both in experiments and in simulations. This nonetheless requires partial slip on the particle interface, extracted consistently from all the data. These results, thus, resolve a long-standing discussion on the validity and limits of the SES equation at the molecular scale.

Cerebellar Stroke Score and Grading Scale for the Prediction of Mortality and Outcomes in Ischemic Cerebellar Stroke

BACKGROUND

Several individual predictors for outcomes in patients with cerebellar stroke (CS) have been previously identified. There is, however, no established clinical score for CS. Therefore, the aim of this study was to develop simple and accurate grading scales for patients with CS in an effort to better estimate mortality and outcomes.

METHODS

This multicentric retrospective study included 531 patients with ischemic CS presenting to 5 different academic neurosurgical and neurological departments throughout Germany between 2008 and 2021. Logistic regression analysis was performed to determine independent predictors related to 30-day mortality and unfavorable outcome (modified Rankin Scale score of 4-6). By weighing each parameter via calculation of regression coefficients, an ischemic CS-score and CS-grading scale (CS-GS) were developed and internally validated.

RESULTS

Independent predictors for 30-day mortality were aged ≥70 years (odds ratio, 5.2), Glasgow Coma Scale score 3 to 4 at admission (odds ratio, 2.6), stroke volume ≥25 cm3 (odds ratio, 2.7), and involvement of the brain stem (odds ratio, 3.9). When integrating each parameter into the CS-score, age≥70 years and brain stem stroke were assigned 2 points, Glasgow Coma Scale score 3 to 4, and stroke volume≥25 cm3 1 point resulting in a score ranging from 0 to 6. CS-score of 0, 1, 2, 3, 4, 5, and 6 points resulted in 30-day mortality of 1%, 6%, 6%, 17%, 21%, 55%, and 67%, respectively. Independent predictors for 30-day unfavorable outcomes consisted of all components of the CS-score with an additional variable focused on comorbidities (CS-GS). Except for Glasgow Coma Scale score 3 to 4 at admission, which was assigned 3 points, all other parameters were assigned 1 point resulting in an overall score ranging from 0 to 7. CS-GS of 0, 1, 2, 3, 4, 5, 6, and 7 points resulted in 30-day unfavorable outcome of 1%, 17%, 33%, 40%, 50%, 80%, 77%, and 100%, respectively. Both 30-day mortality and unfavorable outcomes increased with increasing CS-score and CS-GS (P<0.001).

CONCLUSIONS

The CS-score and CS-GS are simple and accurate grading scales for the prediction of 30-day mortality and unfavorable outcome in patients with CS. While the score systems proposed here may not directly impact treatment decisions, it may help discuss mortality and outcome with patients and caregivers.

Single-Molecule Pycnometry and Shape Analysis of Ions in the Gas Phase

The analysis of ions and clusters by mobility-classified mass spectrometry provides information on the mobility of analytes in the drift gas and the analyte mass. Mass equivalent and mobility equivalent diameters of globular analytes, such as ions, poly(ethylene glycol) (PEG), and ionic liquid nanodroplets, can be correlated with good accuracy by the Stokes-Millikan mobility model. A prerequisite to such an analysis is, however, the assumption of a globular analyte shape, which then allows determination of material density for globular ions. We show that the analyte density can be evaluated with high precision, independent of any assumptions on the analyte shape, by careful analysis of analyte-PEG-cluster ions following the concept of classical pycnometry. In particular, the analyte is entrapped in a globular PEG-analyte droplet. Based on the now independently derived mobility diameter and volume equivalent diameter, it is possible to attribute two parameters, size and shape, to the analyte molecule. We demonstrate the approach for lysozyme, cyano-cobalamin (vitamin B12), and glucose, which cover two orders of magnitude in analyte mass (180···14 300 Da). The derived densities for these analytes are highly accurate, i.e., they deviate less than 1% from literature values. Our method can be applied to newly synthesized molecules, supramolecular assemblies, isolated biomolecules, and molecular clusters, where only minor amounts of materials are available. The obtained shape parameters of lysozyme and cyano-cobalamin agree well with the expected molecular shapes. Data evaluation relies only on locations of the species in the mass-mobility plane and is in principle independent of any mobility theory. Our approach is thus robust with respect to experimental uncertainties and produces identical results irrespective of the type of mobility classification and drift gas.

The Single-Dose Application of Interleukin-4 Ameliorates Secondary Brain Damage in the Early Phase after Moderate Experimental Traumatic Brain Injury in Mice

Activation of the interleukin-4 (IL-4) pathway ameliorates secondary injury mechanisms after experimental traumatic brain injury (TBI); therefore, we assessed the effect of a therapeutic IL-4 administration on secondary brain damage after experimental TBI. We subjected 100 C57/Bl6 wildtype mice to controlled cortical impact (CCI) and administered IL-4 or a placebo control subcutaneously 15 min thereafter. Contusion volume (Nissl staining), neurological function (hole board, video open field, and CatWalkXT®), and the immune response (immunofluorescent staining) were analyzed up to 28 days post injury (dpi). Contusion volumes were significantly reduced after IL-4 treatment up to 14 dpi (e.g., 6.47 ± 0.41 mm3 vs. 3.80 ± 0.85 mm3, p = 0.011 3 dpi). Macrophage invasion and microglial response were significantly attenuated in the IL-4 group in the acute phase after CCI (e.g., 1.79 ± 0.15 Iba-1+/CD86+ cells/sROI vs. 1.06 ± 0.21 Iba-1/CD86+ cells/sROI, p = 0.030 in the penumbra 3 dpi), whereas we observed an increased neuroinflammation thereafter (e.g., mean GFAP intensity of 3296.04 ± 354.21 U vs. 6408.65 ± 999.54 U, p = 0.026 in the ipsilateral hippocampus 7 dpi). In terms of functional outcome, several gait parameters were improved in the acute phase following IL-4 treatment (e.g., a difference in max intensity of -7.58 ± 2.00 U vs. -2.71 ± 2.44 U, p = 0.041 3 dpi). In conclusion, the early single-dose administration of IL-4 significantly reduces secondary brain damage in the acute phase after experimental TBI in mice, which seems to be mediated by attenuation of macrophage and microglial invasion.

Efficient quenching sheds light on early stages of gold nanoparticle formation

The formation mechanism of plasmonic gold nanoparticles (Au NPs) by fast NaBH₄ induced reduction of the precursors is still under debate. In this work we introduce a simple method to access intermediate species of Au NPs by quenching the solid formation process at desired time periods. In this way, we take advantage of the covalent binding of glutathione on Au NPs to stop their growth. By applying a plethora of precise particle characterization techniques, we shed new light on the early stages of particle formation. The results of in situ UV/vis measurements, ex situ sedimentation coefficient analysis by analytical ultracentrifugation, size exclusion high performance liquid chromatography, electrospray ionization mass spectrometry supported by mobility classification and scanning transmission electron microscopy suggest an initial rapid formation of small non-plasmonic Au clusters with Au₁₀ as the main species followed by their growth to plasmonic Au NPs by agglomeration. The fast reduction of gold salts by NaBH₄ depends on mixing which is hard to control during the scale-up of batch processes. Thus, we transferred the Au NP synthesis to a continuous flow process with improved mixing. We observed that the mean volume particle sizes and the width of the particle size distribution decrease with increasing flow rate and thus higher energy input. Mixing- and reaction-controlled regimes are identified.

Magnetic in situ determination of surface coordination motifs by utilizing the degree of particle agglomeration

Most analytical techniques used to study the surface chemical properties of superparamagnetic iron oxide nanoparticles (SPIONs) are barely suitable for in situ investigations in liquids, where SPIONs are mostly applied for hyperthermia therapy, diagnostic biosensing, magnetic particle imaging or water purification. Magnetic particle spectroscopy (MPS) can resolve changes in magnetic interactions of SPIONs within seconds at ambient conditions. Herein, we show that by adding mono- and divalent cations to citric acid capped SPIONs, the degree of agglomeration can be utilized to study the selectivity of cations towards surface coordination motifs via MPS. A favored chelate agent, like ethylenediaminetetraacetic acid (EDTA) for divalent cations, removes cations from coordination sites on the SPION surface and causes redispersion of agglomerates. The magnetic determination thereof represents what we call a "magnetically indicated complexometric titration". The relevance of agglomerate sizes for the MPS signal response is studied on a model system of SPIONs and the surfactant cetrimonium bromide (CTAB). Analytical ultracentrifugation (AUC) and cryogenic transmission electron microscopy (cryo-TEM) reveal that large micron-sized agglomerates are required to significantly change the MPS signal response. With this work, a fast and easy-to-use characterization method to determine surface coordination motifs of magnetic nanoparticles in optically dense media is demonstrated.

Determination of 2D Particle Size Distributions in Plasmonic Nanoparticle Colloids via Analytical Ultracentrifugation: Application to Gold Bipyramids

Multidimensional particle properties determine the product properties in numerous advanced applications. Accurate and statistically meaningful measurements of complex particles and their multidimensional distributions are highly challenging but strongly needed. 2D particle size distributions of plasmonic nanoparticles of complex regular shape can be obtained from analytical ultracentrifugation experiments via the optical back coupling method. A workflow for the calculation of frictional properties of arbitrarily shaped nanoparticles was developed based on bead shell models and applied to gold bipyramids with a pentagonal cross-section. The obtained 2D particle length-diameter distributions and the reduced cumulative 1D length and diameter distributions were compared to transmission electron microscopy measurements. While we find very good agreement for most measurements, the obtained length and diameter distributions were shifted by a few nanometers for some samples. Transmission electron microscopy, energy-dispersive X-ray spectroscopy, electron tomography, and finite element modeling indicate that the shift originated from a slight mismatch between the assumed shape of the simulated perfect bipyramids and the real particle shape and composition due to the presence of silver in the particles. This study demonstrates the feasibility of the applied techniques for complex shape analysis of nanoparticle ensembles with unmatched particle count numbers.

Green room temperature synthesis of silver-gold alloy nanoparticles

Metallic alloy nanoparticles (NPs) exhibit interesting optical, electrical and catalytic properties, dependent on their size, shape and composition. In particular, silver-gold alloy NPs are widely applied as model systems to better understand the syntheses and formation (kinetics) of alloy NPs, as the two elements are fully miscible. Our study targets product design via environmentally friendly synthesis conditions. We use dextran as the reducing and stabilizing agent for the synthesis of homogeneous silver-gold alloy NPs at room temperature. Our approach is a one-pot, low temperature, reaction-controlled, green and scalable synthesis route of well-controlled composition and narrow particle size distribution. The composition over a broad range of molar gold contents is confirmed by scanning transmission electron microscopy-energy-dispersive X-ray spectroscopy (STEM-EDX) measurements and auxiliary inductively coupled plasma-optical emission spectroscopy measurements (ICP-OES). The distributions of the resulting particles in size and composition are obtained from multi-wavelength analytical ultracentrifugation using the optical back coupling method and further confirmed by high-pressure liquid chromatography. Finally, we provide insight into the reaction kinetics during the synthesis, discuss the reaction mechanism and demonstrate possibilities for scale-up by a factor of more than 250 by increasing the reactor volume and NP concentration.

Hypomorphic RAG deficiency: impact of disease burden on survival and thymic recovery argues for early diagnosis and HSCT

Patients with hypomorphic mutations in the RAG1 or RAG2 gene present with either Omenn syndrome or atypical combined immunodeficiency with a wide phenotypic range. Hematopoietic stem cell transplantation (HSCT) is potentially curative, but data are scarce. We report on a worldwide cohort of 60 patients with hypomorphic RAG variants who underwent HSCT, 78% of whom experienced infections (29% active at HSCT), 72% had autoimmunity, and 18% had granulomas pretransplant. These complications are frequently associated with organ damage. Eight individuals (13%) were diagnosed by newborn screening or family history. HSCT was performed at a median of 3.4 years (range 0.3-42.9 years) from matched unrelated donors, matched sibling or matched family donors, or mismatched donors in 48%, 22%, and 30% of the patients, respectively. Grafts were T-cell depleted in 15 cases (25%). Overall survival at 1 and 4 years was 77.5% and 67.5% (median follow-up of 39 months). Infection was the main cause of death. In univariable analysis, active infection, organ damage pre-HSCT, T-cell depletion of the graft, and transplant from a mismatched family donor were predictive of worse outcome, whereas organ damage and T-cell depletion remained significant in multivariable analysis (hazard ratio [HR] = 6.01, HR = 8.46, respectively). All patients diagnosed by newborn screening or family history survived. Cumulative incidences of acute and chronic graft-versus-host disease were 35% and 22%, respectively. Cumulative incidences of new-onset autoimmunity was 15%. Immune reconstitution, particularly recovery of naïve CD4+ T cells, was faster and more robust in patients transplanted before 3.5 years of age, and without organ damage. These findings support the indication for early transplantation.

Reappraisal of Intracerebral Hemorrhages and Intracerebral Hemorrhage Grading Scale Score in Surgically and Medically Managed Cerebellar Intracerebral Hemorrhage

BACKGROUND

As compared with supratentorial intracerebral hemorrhages (ICH), bleeds that occur within the cerebellum require special consideration given the nature of the posterior fossa.

OBJECTIVE

To validate ICH and ICH grading scale (ICH-GS) scores in patients with cerebellar hemorrhage and examine the outcomes of patients managed surgically as compared with those who underwent conservative treatment.

METHODS

This observational multicenter study included 475 patients with cerebellar hemorrhage from 9 different neurosurgical departments in Germany between 2005 and 2021. The prognostic accuracy of ICH and ICH-GS scores were calculated by the area under the curve of the receiver operating characteristic curves. Analyzed outcomes were the in-hospital mortality, mortality at 6 months, in-hospital outcome, and outcome at 6 months.

RESULTS

Of 403 patients, 252 patients (62.5%) underwent surgical treatment and 151 patients (37.5%) conservative treatment. Both ICH and ICH-GS scores demonstrated good prognostic accuracy regarding both overall mortality and functional outcomes. In those patients presenting with severe cerebellar hemorrhages, ie, ICH score >3 and ICH-GS score >11, overall mortality was significantly lower in surgically treated patients. Mortality was significantly higher in those patients managed surgically who presented with ICH scores ≤3; in such patients, improved outcomes were noted when the hematoma was treated conservatively.

CONCLUSION

ICH and ICH scores are useful tools for prediction of survival and outcome in patients with cerebellar ICH. Surgical management may be beneficial for those who present with severe cerebellar ICH as reflected by ICH scores >3, while conservative management seems reasonable in patients with lower ICH scores.

Assessment of hindlimb motor recovery after severe thoracic spinal cord injury in rats: classification of CatWalk XT® gait analysis parameters

Assessment of locomotion recovery in preclinical studies of experimental spinal cord injury remains challenging. We studied the CatWalk XT® gait analysis for evaluating hindlimb functional recovery in a widely used and clinically relevant thoracic contusion/compression spinal cord injury model in rats. Rats were randomly assigned to either a T9 spinal cord injury or sham laminectomy. Locomotion recovery was assessed using the Basso, Beattie, and Bresnahan open field rating scale and the CatWalk XT® gait analysis. To determine the potential bias from weight changes, corrected hindlimb (H) values (divided by the unaffected forelimb (F) values) were calculated. Six weeks after injury, cyst formation, astrogliosis, and the deposition of chondroitin sulfate glycosaminoglycans were assessed by immunohistochemistry staining. Compared with the baseline, a significant spontaneous recovery could be observed in the CatWalk XT® parameters max intensity, mean intensity, max intensity at%, and max contact mean intensity from 4 weeks after injury onwards. Of note, corrected values (H/F) of CatWalk XT® parameters showed a significantly less vulnerability to the weight changes than absolute values, specifically in static parameters. The corrected CatWalk XT® parameters were positively correlated with the Basso, Beattie, and Bresnahan rating scale scores, cyst formation, the immunointensity of astrogliosis and chondroitin sulfate glycosaminoglycan deposition. The CatWalk XT® gait analysis and especially its static parameters, therefore, seem to be highly useful in assessing spontaneous recovery of hindlimb function after severe thoracic spinal cord injury. Because many CatWalk XT® parameters of the hindlimbs seem to be affected by body weight changes, using their corrected values might be a valuable option to improve this dependency.

Differences in circulating cardiac troponin I and T in acute and chronic cardiac disease

Background

Clinical practice and guidelines assume that cardiac troponin I (cTnI) and cTnT are interchangeable, reflecting identical pathophysiological processes. However, it is unknown if cTnI and cTnT really are equivalent measures in different pathophysiological settings.

Purpose

To highlight potential differences in the release of cTnI and cTnT.

Methods

Large pooled cohort analysis including extensively characterized individuals, stratified into three groups: no cardiac disease (normal aging), chronic cardiac disease, and acute cardiac disease. Circulating cTnI and cTnT concentrations were measured blinded to clinical data using high-sensitivity assays (hs-cTnI-Architect, hs-cTnT-Elecsys) and their ratio calculated. Findings were validated using a second hs-cTnI assay (hs-cTnI-Clarity).

Results

Among 8719 individuals, 29% female, 10% had no known cardiac disease, 71% chronic cardiac disease, and 20% acute cardiac disease. Baseline characteristics including renal function were comparable between individuals with chronic and acute cardiac disease. Normal aging (without cardiac disease) was associated with a disproportional increase in cTnT versus cTnI (low cTnI/cTnT ratio, median 0.50, IQR 0.38–0.68). Although older, patients with chronic cardiac disease had a slightly higher cTnI/cTnT ratio (median 0.53, IQR 0.37–0.79, p&lt;0.05). In contrast, in patients with acute cardiac disease, cTnI concentrations were disproportionally elevated compared to cTnT concentrations, resulting in a cTnI/cTnT ratio of 1.96 (IQR 0.93–4.73, p&lt;0.001). Internal validation using a second hs-cTnI assay confirmed these findings.

Conclusion

These findings suggest relevant differences in the release of cTnI and cTnT with a greater release of cTnT versus cTnI in normal aging and a disproportional increase in cTnI versus cTnT in acute cardiac disease.

Funding Acknowledgement

Type of funding sources: Foundation. Main funding source(s): Swiss National Science Foundation

Detrimental effects of intense vasodilation in women with acute heart failure: novel insights from a prospective randomized controlled trial

Background

Guidelines recommend evaluating the risk/benefit ratio of novel therapies individually in women and men, as the pathophysiology and the response to treatment may differ according to sex. Among patients with acute heart failure (AHF), a strategy of intensive vasodilation, compared with usual care, overall did provide comparable outcomes. However, sex-specific differences in heart failure pathophysiology and the effect of the strategy in women with AHF remained unclear.

Purpose

To characterize sex-specific differences in heart failure pathophysiology and to evaluate the effect of a strategy that emphasized early intensive and sustained vasodilation in women with AHF.

Methods

In a randomized, open-label blinded-end-point trial patients hospitalized for AHF were enrolled in 10 hospitals in Switzerland, Bulgaria, Germany, Brazil, and Spain. Inclusion criteria were AHF expressed by acute dyspnea and increased plasma concentrations of natriuretic peptides, systolic blood pressure ≥100 mmHg, and a plan for treatment in a general ward. Patients were randomized 1:1 to a strategy of early intensive and sustained vasodilation throughout the hospitalization or usual care. The primary end point was a composite of all-cause mortality or rehospitalization for AHF at 180 days. The subgroup analysis according to sex was predefined.

Results

Among 781 patients who completed the trial, 288 (36.9%) were women. Women were significantly older, had a higher systolic blood pressure at presentation and a more common history of diastolic dysfunction (all ps&lt;0.05), whereas men had a significantly higher body surface area, a more common history of ischemic heart disease and a significant lower left ventricular ejection fraction (all ps&lt;0.05). The primary end point, a composite of all-cause mortality or rehospitalization for AHF at 180 days, occurred in 53 female patients (37.9%) in the intervention group (including 28 deaths [20.0%]) and in 35 female patients (23.6%) in the usual care group (including 22 deaths [14.9%]) (absolute difference for the primary end point, 14.3%; adjusted hazard ratio, 1.62 [95% CI, 1.05–2.50]; P=0.03).

Conclusion

Among women with AHF, a strategy of early intensive and sustained vasodilation, compared with usual care, had a detrimental effect on a composite outcome of all-cause mortality and AHF rehospitalization at 180 days.

Funding Acknowledgement

Type of funding sources: Public hospital(s). Main funding source(s): University Hospital Basel

Prognostic value of a disease-specific health-related quality score in acute heart failure

Background

Despite the striking therapeutic progress made in the treatment of heart failure (HF), rehospitalization rate and mortality remain a major and often unpredictable problem. Previous studies have shown the prognostic value of Kansas City Cardiomyopathy Questionnaire (KCCQ), a score assessing disease-specific health-related quality of life in stable chronic HF patients. Recently, a large study including 4898 patients with acute HF (AHF) enrolled in China reported the incremental predictive ability of KCCQ for a composite outcome of death and rehospitalization. However, these findings were not yet confirmed. In order to address this unmet need, the aim of this study was to examine the prognostic value of KCCQ in another AHF cohort.

Purpose

To validate the prognostic value of the KCCQ in AHF.

Methods

Goal-directed AfterLoad Reduction in Acute Congestive Cardiac Decompensation Study (GALACTIC) was a prospective, multicenter (n=10), randomized, interventional controlled trial enrolling adult patients presenting with AHF. KCCQ was assessed shortly after admission. We focused on the prognostic value of the short version KCCQ-12, explored the association with the composite of all-cause mortality and AHF rehospitalization within 30- and 180-day follow-up and compared it to the original score. Patients were grouped into quartiles according their KCCQ: high-risk (0–&lt;25), moderate- to high-risk (25–&lt;50), low- to moderate-risk (50–&lt;75) and low-risk group (75–100). Cumulative incidence of assessed endpoints was displayed in Kaplan-Meier curves. Covariate adjustments were made using Cox regression. Prognostic accuracy over N-terminal pro-B-type natriuretic peptide (NT-proBNP) was evaluated by time-dependent area under the curve.

Results

Among 781 patients, 419 (median age 78, 35% female, 32% new onset of HF) had a complete set of variables to calculate KCCQ. Follow-up was available in all patients up to 180 days. 29 (7%) and 122 (29%) patients died or were rehospitalized for AHF within 30- and 180-days, respectively. Median KCCQ-12 was 37.5 with 25% of patients attaining the high- and 8% the low-risk group. After adjustment, each 10-point decrease in the KCCQ was associated with a 10% increase in 180-day risk regardless of new onset or acute decompensated chronic HF, age, sex, comorbidities, systolic blood pressure, creatinine, NT-proBNP and sodium levels. The prognostic ability for a 30-day risk was not significant. Using the same adjustments, a 10-point decrease in the original KCCQ was significant for a 20% and a 11% increase in risk for the short- and long-term composite outcome. The prognostic accuracy of KCCQ was comparable to NT-proBNP.

Conclusions

Health status, measured by the KCCQ-12 among patients with AHF, is significantly associated with a long-term composite outcome of all-cause mortality and AHF rehospitalization. The original KCCQ overall score is an independent predictor for both, the 30- and 180-day composite outcome.

Funding Acknowledgement

Type of funding sources: Public grant(s) – EU funding. Main funding source(s): European Union, the Swiss National Science Foundation

Using high-sensitivity cardiac troponin for the exclusion of inducible myocardial ischemia in patients without previously known coronary artery disease

Background

The rapid and safe exclusion of functionally relevant coronary artery disease (CAD) is a crucial, yet unmet clinical need. High-sensitivity cardiac troponin (hs-cTn) may be an attractive strategy, particularly in patients without previously known CAD.

Purpose

To derive and internally validate optimal rule-out cutoffs for an early and safe exclusion of functionally relevant CAD in symptomatic patients without previously known CAD.

Methods

In an ongoing single-center, prospective, cohort study, we enrolled consecutive patients without previously known CAD that were referred with symptoms possibly related to functionally relevant CAD. Cardiac troponin concentrations were measured at presentation using two high-sensitivity assays (Elecsys hs-cTnT and Architect hs-cTnI). Presence of functionally relevant CAD was adjudicated by 2 independent cardiologists, blinded to hs-cTn measurements, using MPI-SPECT/CT in all patients, as well as coronary angiography and fractional flow reserve measurements, whenever available. The primary diagnostic outcome was safety for early rule-out of functionally relevant CAD, quantified by sensitivity and the negative predictive value (NPV). The co-primary prognostic outcomes were cumulative incidences of cardiovascular death and all-cause death after 5 years. A NPV ≥90% and sensitivity ≥90% were predefined as acceptable performance criteria. The derived cutoffs were further evaluated in pre-specified subgroups. Internal validity was assessed with a bootstrapping procedure for a realistic estimate in similar future patients. Cumulative incidence curves stratified by the presence of functionally relevant CAD and hs-cTn concentrations below and above the derived cutoffs were constructed.

Results

Among 2111 eligible patients, 498 (23.6%) had a final diagnosis of functionally relevant CAD. Median age was 68 years and 938 (44.4%) were female. For ruling out functionally relevant CAD, a hs-cTnT concentration &lt;5 ng/L resulted in a sensitivity of 90.8% (95% CI: 87.9–93.0%) and a NPV of 90.2% (95% CI: 87.1–92.5), triaging 468 (22.2%) patients towards rule-out. Similarly, a hs-cTnI concentration &lt;2 ng/L resulted in a sensitivity of 91.6% (95% CI: 88.8–93.7%) and a NPV of 90.0% (95% CI: 86.8–92.6), triaging 422 (20.0%) patients. Internal validation showed robustness of these findings. The diagnostic performance of the derived cutoffs did not significantly vary across the subgroups. Hs-cTn concentrations above the derived cutoffs were associated with a substantially higher cumulative event rate of cardiovascular death (hs-cTnT: 7.0% vs. 0.8%; hs-cTnI: 6.6% vs. 1.2%) and all-cause death (hs-cTnT: 14.3% vs. 2.4%; hs-cTnI: 13.1% vs. 4.4%) during 5-years follow-up (log rank p&lt;0.001 for all).

Conclusion

In symptomatic patients without previously known CAD, very low hs-cTn concentrations may generally allow to safely and effectively exclude functionally relevant CAD.

Funding Acknowledgement

Type of funding sources: Public grant(s) – National budget only. Main funding source(s): Swiss National Science FoundationSwiss Heart Foundation

Multidimensional characterization of noble metal alloy nanoparticles by multiwavelength analytical ultracentrifugation

In this study, we introduce a method for the simultaneous retrieval of two-dimensional size-composition distributions of noble metal Ag-Au alloy nanoparticles utilizing an analytical ultracentrifuge equipped with a multiwavelength extinction detector (MWL-AUC). MWL-AUC is used to measure coupled optical and sedimentation properties of the particles. The optical response of the nanoparticles is calculated using Mie's theory, where the particles' complex refractive index is corrected due to the effect of reduced mean free path of electrons. Using a combined analysis of the hydrodynamic and spectral data captured by MWL-AUC, the size and composition of the alloy particles is retrieved. Our method is validated through the analysis of synthetic data and by the very good agreement between experimental scanning transmission electron microscopy and our AUC data. The presented comprehensive characterization approach contributes to improved synthesis, scale-up and production of particulate systems as it provides a simple, fast and direct method to determine noble metal alloy nanoparticle size and composition distributions simultaneously.

Determination of specific and non-specific protein-protein interactions for beta-lactoglobulin by analytical ultracentrifugation and membrane osmometry experiments

Protein-protein interactions are essential for the understanding of biological processes. Specific protein aggregation is an important aspect for many biological systems. In particular, electrostatic interactions play the key role for protein-protein interactions, as many amino acids have pH-dependent charge states. Moreover, protein dissociation is directly related to the solution pH, ionic strength, temperature and protein concentration. The subtle interplay between different specific and non-specific interactions is demonstrated for beta-lactoglobulin (BLG) with a focus on low salt concentrations, thus mimicking technically relevant processing conditions. BLG is a well-characterized model system, proven to attain its monomer-dimer equilibrium strongly dependent upon the pH of the solution. In this manuscript, we present a unique combination of analytical ultracentrifugation and membrane osmometry experiments, which quantifies specific and non-specific interactions, i.e. in terms of the dimer dissociation constants and the second osmotic virial coefficient, at pH 3 and 7 and sodium chloride concentrations of 10 mM and 100 mM. This provides direct insight to protein-protein interactions for a system with a concentration-dependent monomer-dimer equilibrium. Moreover, using a coarse-grained extended DLVO model in combination with molecular dynamics simulations, we quantify non-specific monomer-monomer, monomer-dimer and dimer-dimer interactions as well as the binding free energy of BLG dimerization from theoretical calculations. The experimentally determined interactions are shown to be mainly governed by electrostatic interactions and further agree with free energy calculations. Our experimental protocol aims to determine non-specific and specific interactions for a dynamically interacting system and provides an understanding of protein-protein interactions for BLG at low salt concentrations.

OP0038 VITAMIN D AND MARINE n-3 FATTY ACID SUPPLEMENTATION FOR PREVENTION OF AUTOIMMUNE DISEASE IN THE VITAL RANDOMIZED CONTROLLED TRIAL: OUTCOMES OVER 7 YEARS

Background

Strong biologic rationale supports both vitamin D and marine omega-3 (n-3) fatty acids for prevention of autoimmune disease (AD). Within the randomized, double-blind, placebo-controlled VITamin D and OmegA-3 TriaL (VITAL), we tested the effects of these supplements on AD incidence. We previously reported results after 5.3 years of randomized follow-up showing overall protective effects for vitamin D on AD incidence (HR 0.78, 95% CI 0.61-0.99) and suggestive results for n-3 fatty acids (HR 0.85, 95%CI 0.67-1.08)1.

Objectives

We aimed to test effects of these supplements with two more years of post-intervention follow-up in VITAL.

Methods

VITAL enrolled and randomized men and women (age ≥50 and ≥55 years, respectively) in a 2-by-2 factorial design to vitamin D3 (2000 IU/d) and/or n-3 fatty acids (1000 mg/d) or placebo and followed for median 5.3 years. Here, we followed participants for another 2 years of observation to assess for sustained effects. Incident AD diagnoses were reported by participants annually and confirmed by medical record review by expert physicians using existing classification criteria. The primary endpoint was total incident AD, including rheumatoid arthritis (RA), polymyalgia rheumatica (PMR), autoimmune thyroid disease (AITD), psoriasis, and all others. Pre-specified secondary endpoints included individual common AD; and probable AD. Cox models calcuated hazard ratios (HR) for incident ADs.

Results

Of 25,871 participants randomized, 71% self-reported non-Hispanic Whites, 20% Black, 9% other racial/ethnic groups, 51% women, mean age was 67.1 years. During 7.5 years median follow-up, confirmed AD was diagnosed in 156 participants in vitamin D arm vs 198 in vitamin D placebo arm, HR 0.79 (0.64-0.97). Incident AD was confirmed in 167 participants in n-3 fatty acid arm and 187 in n-3 fatty acid placebo arm, HR 0.89 (0.72-1.10). For vitamin D, HRs trended toward reduction for RA 0.67 (0.37- 1.21), PMR 0.69 (0.46-1.03) and psoriasis 0.57 (0.33-0.99). For n-3 fatty acids, HRs trended toward reduction for RA 0.55 (0.30-1.10) and AITD 0.61 (0.33-1.12). Vitamin D’s effect on AD incidence was stronger in those with body mass index (BMI) < 25 (HR 0.65, 0.44-0.96) than ≥ 25 kg/m2 (p interaction 0.01).

Conclusion

Supplementation for 5.3 years with 2000 IU/day vitamin D (compared to placebo), followed by 2 years of observational follow-up, significantly reduced overall incident AD by 21% in older adults. HRs for RA, PMR and psoriasis trended toward reduction with vitamin D, with stronger effect in those with normal BMI. Supplementation with 1000 mg/day n-3 fatty acids did not significantly reduce total AD.

References

[1]Hahn J et al, BMJ, 2022 Jan 26;376: e066452.

Table 1.

Hazard Ratios for Primary and Secondary Endpoints, by Randomized Assignment to Vitamin D/Placebo (Left), N-3 Fatty Acids/Placebo (Right)a

EndpointVitamin D3(N=12,927)Placebo (N=12,944)Hazard Ratio (95% CI)pN-3 Fatty Acids (N=12,933)Placebo (N=12,938)Hazard Ratio (95% CI)pPrimary: Confirmed AD1561980.79 (0.64-0.97)0.031671870.89 (0.72-1.10)0.27Secondary:Confirmed + probable AD2653210.83 (0.70-0.97)0.022713150.86 (0.73-1.01)0.06Excluding subjects with any pre-randomization AD Confirmed AD1271620. 79 (0.62-0.99)0.041411480.95 (0.75-1.20)0.66 Confirmed + probable AD2112700. 78 (0.65-0.94)0.0072322490.93 (0.78-1.11)0.41Excluding first 2 years follow-up Confirmed AD861300.66 (0.50-0.87)0.0031041120.92 (0.71-1.21)0.56 Confirmed + probable AD1472050.72 (0.58-0.89)0.0021721800.95 (0.77-1.17)0.63Individual ADb RA18270.67 (0.37-1.21)0.1816290.55 (0.30-1.01)0.06 PMR39570.69 (0.46-1.03)0.0746500.92 (0.61-1.37)0.67 AITD27181.50 (0.82-2.71)0.1917280.61 (0.33-1.12)0.11 Psoriasis20350.57 (0.33-0.99)0.0534211.62 (0.94-2.79)0.08

aAnalyses from Cox regression models controlled for age, sex, race, and other (n-3 fatty acid or vitamin D) randomization group bConfirmed AD.

Figure 1.

Disclosure of Interests

Karen Costenbader Consultant of: Astra Zeneca, Glaxo Smith Kline, Neutrolis, Grant/research support from: Merck, Exagen, Gilead, Nancy Cook: None declared, I-min Lee: None declared, Jill Hahn: None declared, Joseph Walter: None declared, Vadim Bubes: None declared, Gregory Kotler: None declared, Nicole Yang: None declared, Sonia Friedman: None declared, Erik Alexander: None declared, JoAnn Manson: None declared.

Interleukin-4 reduces lesion volume and improves neurological function in the acute phase after experimental traumatic brain injury in mice

Little is known about the impact of Interleukin-4 (IL-4) on secondary brain damage in the acute phase after experimental traumatic brain injury (TBI). Therefore, we evaluated the effect of IL-4-Knockout on structural damage as well as functional impairment in the acute phase after experimental TBI in mice. 28 C57Bl/6 wildtype and 20 C57BL/6-Il4tm1Nnt/J Interleukin-4-Knockout (IL-4-KO) mice were subjected to Controlled Cortical Impact (CCI). Contusion volumes, body weight and functional outcome (Video Open Field Test (VOF), Hole Board Test (HB), CatWalkXT®) were determined on postoperative days one (D1), three (D3) and seven (D7). Contusion volume (13.45 +/- 0.88 mm³ vs. 9.50 +/- 0.97 mm³, p=0.015) and weight loss (-2.92 +/- 0.52% vs. -0.85 +/- 0.67%, p=0.027) were significantly higher and exploration behavior significantly more impaired (e.g., 150.44 +/- 18.71 fields explored vs. 211.56 +/- 18.90 fields explored, p=0.028 in the VOF; 23.31 +/- 2.03 holes explored vs. 35.65 +/- 1.93 holes explored, p<0.001 in the HB) in IL-4-KO mice on D1. Gait impairment was significantly more pronounced in IL-4-KO mice throughout the first week after CCI (e.g., 0.07 +/- 0.01s vs. 0.00 +/- 0.01s, p=0.047 for right hindpaw Swing on D1; -1.76 +/- 1.34 U vs. 2.53 +/- 0.90 U, p=0.01 for right forepaw Mean Intensity on D3; -0.01 +/- 0.01cm² vs. 0.05 +/- 0.01cm², p=0.015 for left forepaw Mean Area on D7). In conclusion, IL-4 reduces structural damage and improves functional outcome in the acute phase after CCI. Neurobehavioral outcome assessment in IL-4-related studies should focus on motor function on the first three days after trauma induction.

The Local Intraarterial Administration of Nimodipine Might Positively Affect Clinical Outcome in Patients with Aneurysmal Subarachnoid Hemorrhage and Delayed Cerebral Ischemia

The effect of the intraarterial administration of nimodipine as a rescue measure to treat delayed vasospasm after aSAH remains understudied; therefore, we evaluated its effect on short- and long-term functional and neuropsychological outcomes after aSAH. In this prospective observational study, a total of 107 consecutive patients treated for aSAH of WFNS grades I−V were recruited. At follow-up visits 3-, 12- and 24-months after the hemorrhage, functional outcome was assessed using the Extended Glasgow Outcome (GOSE) and modified Rankin (mRS) scales, while neurocognitive function was evaluated using the screening module of the Neuropsychological Assessment Battery (NAB-S). The outcome of patients, who had received rescue therapy according to the local standard treatment protocol (interventional group, n = 37), and those, who had been treated conservatively (conservative group, n = 70), were compared. Even though significantly more patients in the interventional treatment group suffered from high-grade aSAH (WFNS Grades IV and V, 54.1% vs. 31.4%, p = 0.04) and required continuous drainage of cerebrospinal fluid at discharge (67.7% vs. 37.7%, p = 0.02) compared to the control group, significant differences in functional outcome were present only at discharge and three months after the bleeding (GOSE > 4 in 8.1% vs. 41.4% and 28.6% vs. 72.7%, p < 0.001 and p = 0.01 for the interventional and control group, respectively). Thereafter, group differences were no longer significant. While significantly more patients in the intervention group had severe neuropsychological deficits (76.3% vs. 36.0% and 66.7% vs. 29.2%, p = 0.04 and 0.05, respectively) and were unable to work (5.9% vs. 38.1%, p = 0.03 at twelve months) at three and twelve months after the hemorrhage, no significant differences between the two groups could be detected at long-term follow-up. The presence of moderate neuropsychological impairments did not significantly differ between the groups at any timepoint. In conclusion, despite initially being significantly more impaired, patients treated with intraarterial administration of nimodipine reached the same functional and neuropsychological outcomes at medium- and long-term follow-up as conservatively treated patients suggesting a potential beneficial effect of intraarterial nimodipine treatment for delayed vasospasm after aSAH.

Hydrodynamic simulations of sedimenting dilute particle suspensions under repulsive DLVO interactions

We present guidelines to estimate the effect of electrostatic repulsion in sedimenting dilute particle suspensions. Our results are based on combined Langevin dynamics and lattice Boltzmann simulations for a range of particle radii, Debye lengths and particle concentrations. They show a simple relationship between the slope K of the concentration-dependent sedimentation velocity and the range χ of the electrostatic repulsion normalized by the average particle-particle distance. When χ → 0, the particles are too far away from each other to interact electrostatically and K = 6.55 as predicted by the theory of Batchelor. As χ increases, K likewise increases as if the particle radius increased in proportion to χ up to a maximum around χ = 0.4. Over the range χ = 0.4-1, K relaxes exponentially to a concentration-dependent constant consistent with known results for ordered particle distributions. Meanwhile the radial distribution function transitions from a disordered gas-like to a liquid-like form. Power law fits to the concentration-dependent sedimentation velocity similarly yield a simple master curve for the exponent as a function of χ, with a step-like transition from 1 to 1/3 centered around χ = 0.6.

Focal lesion size poorly correlates with motor function after experimental traumatic brain injury in mice

Background

It remains unclear whether neurobehavioral testing adds significant information to histologic assessment of experimental traumatic brain injury (TBI) and if automated gait assessment using the CatWalk XT^®, while shown to be effective in in the acute phase, is also effective in the chronic phase after experimental TBI. Therefore, we evaluated the correlation of CatWalk XT^® parameters with histologic lesion volume and analyzed their temporal and spatial patterns over four weeks after trauma induction.

Methods

C57Bl/6 mice were subjected to controlled cortical impact (CCI). CatWalk XT^® analysis was performed one day prior to surgery and together with the histological evaluation of lesion volume on postoperative days one, three, seven, 14 and 28. Temporal and spatial profiles of gait impairment were analyzed and a total of 100 CatWalk XT^® parameters were correlated to lesion size.

Results

While in the first week after CCI, there was significant impairment of nearly all CatWalk XT^® parameters, impairment of paw prints, intensities and dynamic movement parameters resolved thereafter; however, impairment of dynamic single paw parameters persisted up to four weeks. Correlation of the CatWalk XT^® parameters with lesion volume was poor at all timepoints.

Conclusion

As CatWalk XT^® parameters do not correlate with focal lesion size after CCI, gait assessment using the CatWalk XT^® might add valuable information to solitary histologic evaluation of the injury site. While all CatWalk XT^® parameters can be used for gait assessments in the first week after CCI, dynamic single paw parameters might be more relevant in the chronic phase after experimental TBI.

Derivation and validation of a novel 3-hour pathway for the observe-zone of the ESC 0/1h-algorithm

Background

The latest non-ST elevation myocardial infarction (NSTEMI) guidelines from the European Society of Cardiology (ESC) recommend a 3h cardiac troponin determination in patients triaged to the observe-zone of the ESC 0/1h-algorithm; however, no specific cut-off for further triage is endorsed.

Purpose

To derive and internally, as well as externally, validate a novel 3-hour pathway for the observe-zone of the ESC 0/1h-algorithm.

Methods

In an ongoing multicentre international diagnostic study, we prospectively enrolled unselected patients presenting to the emergency department with symptoms suggestive of myocardial infarction (MI). Final diagnoses were centrally adjudicated by two independent cardiologists applying the 4th universal definition of MI, based on complete cardiac work-up including cardiac imaging, serial high sensitivity cardiac troponin T (hs-cTnT) sampling and 90-day follow-up information. High sensitivity-cTnT concentrations were measured at presentation and after 1 and 3 hours. The primary outcome was safety, quantified by the sensitivity and NPV for early rule out of NSTEMI. External validation was performed in an independent multicentre international study.

Results

Among 2076 eligible patients, application of the ESC 0/1h-algorithm triaged 1512 patients (72.8%) to either rule-out or rule-in of NSTEMI, remaining 564 patients (27.2%) in the observe-zone (adjudicated NSTEMI prevalence 120/564 patients, 21.3%). The novel derived 3h-pathway for the observe-zone patients ruled-out NSTEMI with a 3h hs-cTnT concentration &lt;15 ng/L and a 0/3h-hs-cTnT absolute change &lt;4 ng/L, triaging 138 patients (25%) towards rule-out, resulting in a sensitivity of 99.2% (95% CI 96.0–99.9) and a NPV of 99.3% (95% CI 95.4–99.9). A 0/3h-hs-cTnT absolute change ≥6 ng/L ruled-in 63 patients (11.2%), resulting in a specificity of 98% (95% CI 96.2–98.9) and a PPV of 85.7% (95% CI75.0–92.3). The novel 3h-pathway reduced the number of patients in the observe zone by 36%, and the number of T1MI by 50% (Figure 1). Findings were confirmed in both internal and external validation.

Conclusions

A novel derived pathway combining a 3h hs-cTnT concentration &lt;15 ng/L and a 0/3h absolute change &lt;4 ng/L allowed to very safely rule-out NSTEMI in patients remaining in the observe-zone of the ESC 0/1h-algorithm.

Funding Acknowledgement

Type of funding sources: Public grant(s) – National budget only. Main funding source(s): The Swiss Heart FoundationThe Swiss National Science Foundation Figure 1

Discordance in prognostic ability between physician assessed NYHA classification and self-reported health status in patients with acute heart failure

Background

Especially in patients with acute heart failure (AHF) the NYHA classification remains of uncertain representation of patients' actual health state. Alternatively, patient's subjective well-being, in terms of health-related quality of life (HRQL), showed to have an excellent prognostic ability in out clinic patients with chronic heart failure.

Objectives

It is unknown whether HRQL instruments can assess a more reliable prognostication in patients hospitalized due to AHF than the NYHA classification.

Methods

Goal Directed Afterload Reduction in Acute Congestive Cardiac Decompensation Study (GALACTIC) was a multicenter, randomized, open-label blinded-end-point trial that emphasized early intensive and sustained vasodilation in adult patients hospitalized due to AHF with NYHA functional class III/IV, however provided neutral findings. HRQL was assessed by the generic EQ-5D-3L which is a 3-leveled 5-item instrument and the disease-specific Kansas City Cardiomyopathy Questionnaire (KCCQ). Unadjusted and adjusted Cox regression models were performed after patients were grouped into low (EQ-5D −0.074&lt;0.25; KCCQ 0&lt;25), moderately low (0.25&lt;0.5; 25&lt;50), moderately high (0.5&lt;0.75; 50&lt;75) and high HRQL (0.75–1.0; 75–100).

Results

781 patients were enrolled in 10 centres in 5 countries over 2 continents among which 536 (69%) patientshad completed theEQ-5D and 419 (54%) the KCCQ shortly after admission. Within 180 days of follow-up69 (13%) and 54 (13%) patients died and 151 (28%) and 122 (29%) died or were rehospitalized due to AHF, respectively. Cumulative incidence as well as HRs in patients grouped according to NYHA (n=536) indicated a comparable or significantly lower risk in patients with NYHA IV: e.g. for the combined outcome HR 1.07 (95% CI 0.777–1.473) and aHR 0.463 (95% CI 0.245–0.875). Whereas HRs in patients grouped according to both, EQ-5D (n=536) and KCCQ (n=419), increased from the group with highest to the group with the lowest HRQL: e.g. aHR for moderately high 1.11 (95% CI 0.718–1.715), for moderately low 1.721 (95% CI 1.102–2.688) and for low EQ-5D index 1.891 (95% CI 1.136–3.149) referenced to high HRQL (EQ-5D index 0.75–1.0).

Conclusions

These findings corroborate and extend previous work suggesting that NYHA classification poorly discriminates AHF patients' prognosis and challenge its' extensive application. HRQL might be a possible alternative to easily assess these patients' heath state.

Funding Acknowledgement

Type of funding sources: Public grant(s) – National budget only. Main funding source(s): Swiss National Science Foundation, the Swiss Heart Foundation A. 180-day mortality; B. composite outcome

Determination of the yield, mass and structure of silver patches on colloidal silica using multiwavelength analytical ultracentrifugation

Anisotropic nanoparticles offer considerable promise for applications but also present significant challenges in terms of their characterization. Recent developments in the electroless deposition of silver patches directly onto colloidal silica particles have opened up a simple and scalable synthesis method for patchy particles with tunable optical properties. Due to the reliance on patch nucleation and growth, however, the resulting coatings are distributed in coverage and thickness and some core particles remain uncoated. To support process optimization, new methods are required to rapidly determine patch yield, thickness and coverage. Here we present a novel approach based on multiwavelength analytical ultracentrifugation (MWL-AUC) which permits simultaneous hydrodynamic and spectroscopic characterization. The patchy particle colloids are produced in a continuous flow mixing process that makes use of a KM-type micromixer. By varying the process flow rate or metal precursor concentration we show how the silver to silica mass ratio distribution derived from the AUC-measured sedimentation coefficient distribution can be influenced. Moreover, through reasoned assumptions we arrive at an estimation of the patch yield that is close to that determined by arduous analysis of scanning electron microscopy (SEM) images. Finally, combining MWL-AUC, electrodynamic simulations and SEM image analysis we establish a procedure to estimate the patch thickness and coverage.

Early standardized clinical judgement for syncope diagnosis in the emergency department

BACKGROUND

The diagnosis of cardiac syncope remains a challenge in the emergency department (ED).

OBJECTIVE

Assessing the diagnostic accuracy of the early standardized clinical judgement (ESCJ) including a standardized syncope-specific case report form (CRF) in comparison with a recommended multivariable diagnostic score.

METHODS

In a prospective international observational multicentre study, diagnostic accuracy for cardiac syncope of ESCJ by the ED physician amongst patients ≥ 40 years presenting with syncope to the ED was directly compared with that of the Evaluation of Guidelines in Syncope Study (EGSYS) diagnostic score. Cardiac syncope was centrally adjudicated independently of the ESCJ or conducted workup by two ED specialists based on all information available up to 1-year follow-up. Secondary aims included direct comparison with high-sensitivity cardiac troponin I (hs-cTnI) and B-type natriuretic peptide (BNP) concentrations and a Lasso regression to identify variables contributing most to ESCJ.

RESULTS

Cardiac syncope was adjudicated in 252/1494 patients (15.2%). The diagnostic accuracy of ESCJ for cardiac syncope as quantified by the area under the curve (AUC) was 0.87 (95% CI: 0.84-0.89), and higher compared with the EGSYS diagnostic score (0.73 (95% CI: 0.70-0.76)), hs-cTnI (0.77 (95% CI: 0.73-0.80)) and BNP (0.77 (95% CI: 0.74-0.80)), all P < 0.001. Both biomarkers (alone or in combination) on top of the ESCJ significantly improved diagnostic accuracy.

CONCLUSION

ESCJ including a standardized syncope-specific CRF has very high diagnostic accuracy and outperforms the EGSYS score, hs-cTnI and BNP.

Probing sedimentation non-ideality of particulate systems using analytical centrifugation

Analytical centrifugation is a versatile technique for the quantitative characterization of colloidal systems including colloidal stability. The recent developments in data acquisition and evaluation allow the accurate determination of particle size, shape anisotropy and particle density. High precision analytical centrifugation is in particular suited for the study of particle interactions and concentration-dependent sedimentation coefficients. We present a holistic approach for the quantitative determination of sedimentation non-ideality via analytical centrifugation for polydisperse, plain and amino-functionalized silica particles spanning over one order of magnitude in particle size between 100 nm and 1200 nm. These systems typically behave as neutral hard spheres as predicted by auxiliary lattice Boltzmann simulations. The extent of electrostatic interactions and their impact on sedimentation non-ideality can be quantified by the repulsion range, which is the ratio of the Debye length and the average interparticle distance. Experimental access to the repulsion range is provided through conductivity measurements. With the experimental repulsion range at hand, we estimate the effect of polydispersity on concentration-dependent sedimentation properties through a combination of lattice Boltzmann and Brownian dynamics simulations. Finally, we determine the concentration-dependent sedimentation properties of charge-stabilized, fluorescently-labeled silica particles with a nominal particle size of 30 nm and reduced interparticle distance, hence an elevated repulsion range. Overall, our results demonstrate how the influence of hard-sphere type and electrostatic interactions can be quantified when probing sedimentation non-ideality of particulate systems using analytical centrifugation even for systems exhibiting moderate sample heterogeneity and complex interactions.

A16 FIBER SUPPLEMENTATION DIFFERENTIALLY MODULATES RESPONSES TO FECAL MICROBIAL TRANSPLANTATION IN PATIENTS WITH METABOLIC SYNDROME AND SEVERE OBESITY: A RANDOMIZED, DOUBLE-BLIND, PLACEBO-CONTROLLED PILOT TRIAL

Background

Fecal microbial transplantation (FMT) from lean donors to obese patients with metabolic syndrome (MS) has been associated with promising yet short-term metabolic improvements. The concept of using dietary or fiber supplementation to enhance effects induced by FMT has been much discussed in the literature, but to date no human trials have examined this concept.

Aims

The aim of this study was to determine if fiber supplementation following FMT was able to enhance or sustain FMT-mediated metabolic benefits.

Methods

We performed a 12-wk double-blind randomized placebo-controlled trial in patients with severe obesity and MS recruited from Edmonton’s Bariatric Clinic from 2018 to 2019. Patients were stratified by sex and block randomized 1:1:1:1 amongst one of four groups: (1) Placebo FMT and a non-fermentable fiber (NF) (2) Placebo FMT and fermentable fiber (FF); (3) FMT and non-fermentable fiber (FMT-NF); and (4) FMT and fermentable fiber (FMT-FF). Patients received a single dose of FMT (50g donor stool) with 20 oral capsules followed by a 6-wk period of daily fiber. The primary outcome was evaluating mean differences (MD) in insulin sensitivity from baseline to 6-wks using the homeostatic model assessment of insulin resistance (HOMA2-IR).

Results

Sixty-eight patients were randomized with 61 completing the primary outcome (NF = 17; FF = 15; FMT-NF = 14; FMT-FF = 15) and evaluated using a modified intent-to-treat analysis. Baseline characteristics were similar with a mean BMI 45 ± 7 kg/m2, a female predominance (83.6%), and a HOMA2-IR of 3.43 ± 2.2. There were no baseline differences in clinical characteristics, metabolic parameters, medications, or dietary intake. FMT-NF had improvements in HOMA2-IR (MD -24.0% ± 12.0%; p=0.02), insulin sensitivity (MD 27.6% ± 12.3%; p=0.02), and insulinemia (MD -25.4% ± 12.3%; p=0.02) from baseline to 6-wks (Figure 1). These benefits were associated with increased microbial richness and improvements in GLP-1 metabolism. Linear mixed model regression revealed that select bacterial taxa including Phascolarctobacterium, Ruminococcaeceae, and B. stercoris correlated with increased insulin sensitivity. Findings occurred in the absence of changes in anthropometric parameters, dietary intake, medication regimen and were not observed in groups receiving fermentable fiber or in any group following cessation of fiber.

Conclusions

This proof-of-concept trial provides evidence that a single FMT dose combined with daily non-fermentable fiber supplementation can successfully improve insulin resistance in patients with metabolic syndrome and severe obesity on optimized medical therapy.

Funding Agencies

W. Garfield Weston Foundation

The neuropsychological assessment battery (NAB) is a valuable tool for evaluating neuropsychological outcome after aneurysmatic subarachnoid hemorrhage

Background

Detecting and treating neuropsychological deficits after aneurysmatic subarachnoid hemorrhage (aSAH) play a key role in regaining independence; however, detecting deficits relevant to social and professional reintegration has been difficult and optimal timing of assessments remains unclear. Therefore, we evaluated the feasibility of administering the Neuropsychological Assessment Battery screening module (NAB-S) to patients with aSAH, assessed its value in predicting the ability to return to work and characterized clinical as well as neuropsychological recovery over the period of 24 months.

Methods

A total of 104 consecutive patients treated for aSAH were recruited. After acute treatment, follow up visits were conducted at 3, 12 and 24 months after the hemorrhage. NAB-S, Montreal Cognitive Assessment (MoCA) and physical examination were performed at each follow up visit.

Results

The NAB-S could be administered to 64.9, 75.9 and 88.9% of the patients at 3, 12 and 24 months, respectively. Moderate impairment of two or more neuropsychological domains (e.g speech, executive function, etc.) significantly correlated with inability to return to work at 12 and 24 months as well as poor outcome assessed by the extended Glasgow Outcome Scale (GOSE) at 3, 12 and 24 months. The number of patients with favorable outcomes significantly increased from 25.5% at discharge to 56.5 and 57.1% at 3 and 12 months, respectively, and further increased to 74.1% after 24 months.

Conclusion

The NAB-S can be administered to the majority of patients with aSAH and can effectively detect clinically relevant neuropsychological deficits. Clinical recovery after aSAH continues for at least 24 months after the hemorrhage which should be considered in the design of future clinical trials.

Validation of the Canadian syncope risk score in a large prospective international multicenter study

Background

Management and risk stratification of patients with syncope in the emergency department (ED) is often challenging. In an effort to support ED physicians in disposition decisions, the Canadian Syncope Risk Score (CSRS) was developed to predict 30-day serious outcomes.

Methods

The CSRS was developed in a Canadian multicenter study and contains nine predictors: predisposition to vasovagal syncope, heart disease, systolic pressure &lt;90 or &gt;180mmHg in the ED, troponin level &gt;99th percentile, abnormal QRS axis, QRS duration &gt;130ms, QTc interval &gt;480ms and an ED diagnosis of vasovagal or cardiac syncope. Patients can achieve a CSRS score between −3 and +11 points. We validated the CSRS in a large prospective international multicenter study recruiting patients 40 years or older presenting to the ED with a syncopal event within the last 12 hours. Recruitment centers contained smaller provincial hospitals, as well as big University Hospitals in eight countries on three continents. Primary outcome measure were 30-day serious arrhythmic and non-arrhythmic adverse events, as defined by the authors of the original score.

Results

1581 patients were eligible for this analysis. The population in this validation cohort was older (mean age 68 vs 54 years) and had a considerably higher rate of serious outcomes compared to the derivation cohort (n=186 (11.8%) vs n=147 (3.6%)). The area under the receiver operating characteristic curve (AUC) for the CSRS was 0.88 (95% confidence interval (CI) 0.86–0.91) and significantly higher compared to the validated OESIL score (AUC 0.75, 95% CI 0.71–0.78, p&lt;0.001). Calibration curve analysis showed an underestimation of risk in patients with a low CSRS and an overestimation in patients with a high CSRS. The rate of observed serious outcomes within 30d increased from 0.8% in the very low risk group (CSRS equal to or below −2) to 48% in the (very) high risk group (CSRS equal to or above 4, Hazard ratio 79.4, 95% CI 11.1–570.9). A Kaplan-Meier plot was used to visualize rates of serious outcomes in three different risk groups (Figure).

Conclusion

This is the first validation of the Canadian Syncope Risk Score in a large international syncope cohort. The prognostic discrimination of the CSRS for 30-day serious outcomes was very good in our validation cohort and comparable to that of the Canadian derivation study. Despite suboptimal calibration, prognostic analysis showed a high rate of serious outcomes in the CSRS (very) high risk group and a low rate of serious outcomes in the very low risk group. Allowing the clinical judgement of the ED physician in the form of suspected syncope etiology to be a part of the score seems to largely contribute to the high performance of the CSRS. Additional validation studies might be needed to further increase the accuracy of the CSRS in different patient populations with a different incidence of outcomes in settings outside of Canada.

Figure 1

Funding Acknowledgement

Type of funding source: Public grant(s) – National budget only. Main funding source(s): Swiss National Science Foundation; Swiss Heart Foundation

Influence of Organic Solvents on Secondary Brain Damage after Experimental Traumatic Brain Injury

Many compounds tested for a possible neuroprotective effect after traumatic brain injury (TBI) are not readily soluble and therefore organic solvents need to be used as a vehicle. It is, however, unclear whether these organic solvents have intrinsic pharmacological effects on secondary brain damage and may therefore interfere with experimental results. Thus, the aim of the current study was to evaluate the effect of four widely used organic solvents, dimethylsulfoxide (DMSO), Miglyol 812 (Miglyol^®), polyethyleneglycol 40 (PEG 40), and N-2-methyl-pyrrolidone (NMP) on outcome after TBI in mice. A total of 143 male C57Bl/6 mice were subjected to controlled cortical impact (CCI). Contusion volume, brain edema formation, and neurological function were assessed 24 h after TBI. Test substances or saline were injected intraperitoneally (i.p.) 10 min before CCI. DMSO, Miglyol, and PEG 40 had no effect on post-traumatic contusion volume after CCI; NMP, however, significantly reduced contusion volume and brain edema formation at different concentrations. The use of DMSO, Miglyol, and PEG 40 is unproblematic for studies investigating neuroprotective treatment strategies as they do not influence post-traumatic brain damage. NMP seems to have an intrinsic neuroprotective effect that should be considered when using this agent in pharmacological experiments; further, a putative therapeutic effect of NMP needs to be elucidated in future studies.

Development and validation of an ECG-based cardiac syncope risk calculator

Background

The early diagnosis of cardiac syncope is often challenging. We therefore developed an ECG-based risk calculator as an aid for rapid rule-out or rule-in of cardiac syncope and aimed to validate this decision tool.

Methods

In a prospective diagnostic international multicenter study (derivation cohort), 2007 patients, 40 years or older, presenting with syncope to the emergency department were recruited. The primary diagnostic outcome, cardiac syncope, was centrally adjudicated by two independent cardiologists using all clinical information obtained during syncope work-up including 12-month follow up. 12-lead ECG was recorded at presentation and read by residents blinded to clinical information. Significant ECG predictors of cardiac syncope were identified using penalized backward selection. Findings were validated in an independent US multicenter cohort with 2'269 syncope patients.

Results

In the derivation cohort (median age 71 years, 40% women), centrally adjudicated cardiac syncope was present in 267 patients (16%). Seven ECG criteria (rhythm, heart rate, corrected QT-interval, ST-segment depression, atrioventricular-block, bundle-branch-block and ventricular extrasystole/non-sustained ventricular tachycardia) were identified as significant predictors for cardiac syncope and combined into the bAseL Ecg Risk calculaTor for Cardiac Syncope (ALERT-CS). Diagnostic accuracy of ALERT-CS for cardiac syncope, as quantified by the area under the receiver-operating characteristics curve (AUC), was high (0.80, 95%-confidence interval (CI) 0.77–0.83) and significantly higher compared to the EGSYS score (0.73, 95% CI 0.70–0.76, p&lt;0.001). In combination, ALERT-CS significantly increased the AUC of BNP (0.82, 95% CI 0.79–0.85 vs 0.77, 95% CI 0.74–0.81, p=0.003), hs-cTnT (0.84, 95% CI 0.0.81–0.87 vs 0.77, 95% CI 0.74–0.80, p&lt;0.001) and integrated clinical judgment in the ED (0.90, 95% CI 0.89–0.92 vs 0.87, 95% CI 0.84–0.90, p&lt;0.001).

A predicted probability for cardiac syncope below 5.5% by ALERT-CS identified 138 patients (8%) eligible for triage towards rapid rule-out of cardiac syncope with a sensitivity of 99%. A predicted probability above 37.5% identified 181 patients (11%) eligible for triage towards rapid rule-in of cardiac syncope with a specificity of 95%. Prognostic verification for 30-day major adverse cardiac events (MACE) showed a high rate of MACE in the rule-in group and a very low rate of MACE in the rule-out group (Figure).

External validation (median age 72 years, 48% women) showed similar diagnostic accuracy (AUC 0.76, 95% CI 0.73–0.79) and prognostic results.

Conclusion

Combining seven ECG criteria within the simple ALERT-CS may aid ED physicians in the early rule-out or rule-in of cardiac syncope.

Figure 1

Funding Acknowledgement

Type of funding source: Public grant(s) – National budget only. Main funding source(s): Swiss National Science Foundation, Swiss Heart Foundation

Early diagnosis of acute myocardial infarction in patients with a history of percutaneous coronary intervention

Background

Recurrence of acute chest pain after percutaneous coronary intervention (PCI) is common. The early detection of acute myocardial infarction (AMI) as a possible cause of acute chest pain can be challenging in patients with a history of PCI due to e.g. pre-existing electrocardiographic abnormalities. It is unknown, whether high-sensitivity cardiac troponin T (hs-cTnT) concentrations and hs-cTnT-based rapid algorithms perform equally well in patients with a history of PCI.

Purpose

To investigate the impact of prior PCI on the diagnostic performance of hs-cTnT concentrations for early rule-out and rule-in of AMI.

Methods

In an ongoing multicentre international study, we prospectively enrolled unselected patients presenting to the emergency department (ED) with symptoms suggestive of AMI. Final diagnoses were centrally adjudicated by two independent cardiologists using all available medical records obtained during clinical care including 90 day follow-up information and cardiac imaging. High-sensitivity cTnT concentrations at presentation and after 1h were compared against the adjudicated final diagnosis. Patients were stratified according to the presence or absence of previous PCI.

Results

Among 5536 patients (1313 with and 4223 without previous PCI), incidence of AMI was significantly higher in patients with previous PCI (26.3% versus 21.4%; p&lt;0.001). Patients with prior PCI and a final diagnoses other than AMI had significantly higher concentrations of hs-cTnT at presentation to the ED (median 9ng/l [IQR 6 to 15.8] vs 5.5ng/l [IQR 3 to 10]; p&lt;0.001). However, in patients with final adjudicated diagnosis of AMI, hs-TnT concentrations at presentation were lower in patients with previous PCI (median 46ng/l [IQR 23 to 94] vs 55ng/l [IQR 25 to 175]; p=0.003). The diagnostic accuracy of hs-cTnT was high in patients with history of PCI, but significantly lower compared to patients without PCI (AUC 0.91 [95% CI 0.89–0.92] versus AUC 0.94 [95% CI 0.94–0.95]; p&lt;0.001, respectively). When applying the ESC 0/1-algorithm among patients with previous history of PCI, the rule out pathway showed also very high safety in patients with a history of PCI (sensitivity 99.2 [95% CI 97.2–99.8] and negative predictive value 99.6 [95% CI 98.5–99.9]). However, the efficacy of the ESC 0/1h-algorithm for early rule out of NSTEMI was lower in the PCI group compared to no PCI (45.2% vs 65.1%; P&lt;0.001, respectively), triaging more patients to the observe zone (36.8% versus 18.8%; p&lt;0.001). Time to discharge from the ED was significantly longer in patients with prior PCI (334 min vs 290 min; p&lt;0.001). When stratified for index AMI, patients with history of PCI waited longer for a final diagnoses of AMI (285 vs 217 min; p&lt;0.001).

Conclusions

History of PCI impacts on the diagnostic performance of hs-cTnT. Although the ESC 0/1h-algorithm still performs very safe when applied to patients with a history of PCI, its efficacy is significantly reduced.

Funding Acknowledgement

Type of funding source: Public grant(s) – National budget only. Main funding source(s): Swiss National Science Foundation, the Swiss Heart Foundation, the KTI, the Stiftung für kardiovaskuläre Forschung Basel the University of Basel and the University Hospital Basel