Publications by authors named "Simon Mahler"

Using our recently developed laser speckle contrast imaging (LSCI) to visualize blood vessels and monitor blood flow noninvasively, we test the utility of the developing chick heart as a functional model for drug screening. To this end, we examined the effects of antihypertensive agents Nifedipine and Amlodipine, belonging to the L-type calcium channel antagonist family, on blood flow visualized noninvasively through the intact shell. Guided by the live view mode, the drugs were injected through the shell and ventral to HH16-19 chick embryos.

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In regional cerebrovascular monitoring, cerebral blood flow (CBF) and cerebral blood volume (CBV) are key metrics. Simultaneous, non-invasive measurement of CBF and CBV at different brain locations would advance cerebrovascular monitoring and pave the way for brain injury detection, as current brain injury diagnostic methods are often constrained by high costs, limited sensitivity, and reliance on subjective symptom reporting. This study's aim is to develop a multi-channel non-invasive optical system for measuring CBF and CBV at different regions of the brain simultaneously with a cost-effective, reliable, and scalable system capable of detecting potential differences in CBF and CBV across different regions of the brain.

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Background: We evaluated the Vitros® Immunodiagnostic Products N-terminal pro B-type natriuretic peptide (NT-proBNP) II assay for aiding in diagnosis of heart failure (HF) in patients with acute dyspnea.

Methods: Serum concentrations of NT-proBNP were measured in patient samples from 20 emergency departments across the United States. Study endpoints included sensitivity, specificity, likelihood ratios, and predictive values for diagnosis of acute HF according to age-stratified cutoffs (450, 900, and 1800 pg/mL), and a rule-out age-independent cutoff (300 pg/mL).

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Because 20-30% of patients with sepsis deteriorate to critical illness, biomarkers that provide accurate early prognosis may identify which patients need more intensive treatment versus safe early discharge. The objective was to test the performance of sVEGFR2, suPAR and PCT, alone or combined with clinical signs and symptoms, for the prediction of clinical deterioration. This prospective observational study enrolled patients with suspected infection who met SIRS criteria without organ dysfunction (delta SOFA <2 from baseline) from 16 emergency departments.

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Stroke poses a significant global health threat, with millions affected annually, leading to substantial morbidity and mortality. Current stroke risk assessment for the general population relies on markers such as demographics, blood tests, and comorbidities. A minimally invasive, clinically scalable, and cost-effective way to directly measure cerebral blood flow presents an opportunity.

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Background: The high-sensitivity HEART pathway (hs-HP) risk stratifies emergency department (ED) patients with chest pain. It is unknown if its safety and effectiveness vary by sex or race.

Methods: We conducted a subgroup analysis of the hs-HP implementation study, a pre-post interrupted time series at five US EDs.

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Imaging blood vessels in early-stage avian embryos has a wide range of practical applications for developmental biology studies, drug and vaccine testing, and early sex determination. Optical imaging, such as brightfield transmission imaging, offers a compelling solution due to its safe non-ionizing radiation, and operational benefits. However, it comes with challenges, such as eggshell opacity and light scattering.

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Unlabelled: Using our recently developed laser speckle contrast imaging (LSCI) to visualize blood vessels and monitor blood flow, here we test the utility of the chick embryo for drug screening. To this end, we examined the effects of antihypertensive agents Nifedipine and Amlodipine, belonging to the L-type calcium channel antagonist family, on blood flow visualized noninvasively through the intact shell. Guided by the live view mode, the drugs were injected through the shell and ventral to HH16-19 chick embryos.

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Background: Chest pain, a common emergency department 35 (ED) presentation, requires rapid evaluation. Optical technology-based non-invasive wearable devices (Infrasensor, RCE, Carlsbad, CA) rapidly and transcutaneously assesses cardiac Troponin I (cTnI).

Objectives: To perform a pilot study describing the performance of the Infrasensor in cTnI defined cohorts.

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Background: Data comparing the performance of sex-specific to overall (non-sex-specific) high-sensitivity cardiac troponin (hs-cTn) cut-points for diagnosing acute coronary syndrome (ACS) are limited. This study aims to compare the safety and efficacy of sex-specific versus overall 99th percentile high-sensitivity cardiac troponin T (hs-cTnT) cut-points.

Methods: We conducted a secondary analysis of the STOP-CP cohort, which prospectively enrolled emergency department patients ≥ 21 years old with symptoms suggestive of ACS without ST-elevation on initial electrocardiogram across eight U.

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Stroke poses a significant global health threat, with millions affected annually, leading to substantial morbidity and mortality. Current stroke risk assessment for the general population relies on markers such as demographics, blood tests, and comorbidities. A minimally invasive, clinically scalable, and cost-effective way to directly measure cerebral blood flow presents an opportunity.

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Background: Emergent reperfusion by percutaneous coronary intervention (PCI) within 90 minutes of first medical contact (FMC) is indicated in patients with ST-segment elevation myocardial infarction (STEMI). However, long transport times in rural areas in the Southeast US make meeting this goal difficult. The objective of this study was to determine the number of Southeast US residents with prolonged transport times to the nearest 24/7 primary PCI (PPCI) center.

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Study Objective: The real-world effectiveness and safety of a 0/1-hour accelerated protocol using high-sensitivity cardiac troponin (hs-cTn) to exclude myocardial infarction (MI) compared to routine care in the United States is uncertain. The objective was to compare a 0/1-hour accelerated protocol for evaluation of MI to a 0/3-hour standard care protocol.

Methods: The RACE-IT trial was a stepped-wedge, randomized trial across 9 emergency departments (EDs) that enrolled 32,609 patients evaluated for possible MI from July 2020 through April 2021.

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Significance: In the realm of cerebrovascular monitoring, primary metrics typically include blood pressure, which influences cerebral blood flow (CBF) and is contingent upon vessel radius. Measuring CBF noninvasively poses a persistent challenge, primarily attributed to the difficulty of accessing and obtaining signal from the brain.

Aim: Our study aims to introduce a compact speckle contrast optical spectroscopy device for noninvasive CBF measurements at long source-to-detector distances, offering cost-effectiveness, and scalability while tracking blood flow (BF) with remarkable sensitivity and temporal resolution.

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Background: A single dose epinephrine protocol (SDEP) for out-of-hospital cardiac arrest (OHCA) achieves similar survival to hospital discharge (SHD) rates as a multidose epinephrine protocol (MDEP). However, it is unknown if a SDEP improves SHD rates among patients with a shockable rhythm or those receiving bystander cardiopulmonary resuscitation (CPR).

Methods: This pre-post study, spanning 11/01/2016-10/29/2019 at 5 North Carolina EMS systems, compared pre-implementation MDEP and post-implementation SDEP in patients ≥18 years old with non-traumatic OHCA.

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Background: Diagnosing ischemia in emergency department (ED) patients with suspected acute coronary syndrome (sACS) is challenging with equivocal disposition of intermediate risk patients.

Objective: Compare sensitivity and specificity of magnetocardiography (MCG) versus standard of care (SOC) stress testing in diagnosing myocardial ischemia.

Methods: Multicenter, prospective, observational cohort study.

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Article Synopsis
  • The study evaluates the economic impact of an accelerated protocol (AP) for diagnosing myocardial infarction (MI) using high-sensitivity cardiac troponin (hs-cTn) compared to conventional testing methods.
  • Conducted across nine emergency departments, the research analyzed costs and length of stay for nearly 32,450 patients suspected of having MI.
  • Results showed that the AP did not significantly increase treatment costs or length of stay overall, but some lower acuity emergency departments experienced shorter stays and lower health system costs with the AP.
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Background: The American College of Cardiology (ACC) recently published an Expert Consensus Decision Pathway for chest pain.

Objectives: The purpose of this study was to validate the ACC Pathway in a multisite U.S.

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Article Synopsis
  • The study evaluated the effectiveness of the ESC 0/1-hour algorithm using high-sensitivity cardiac troponin T to predict 30-day cardiac death or myocardial infarction (MI) among different age groups in emergency patients with chest pain.
  • It involved a subgroup analysis of 1,430 patients, showing that lower percentages of older patients were ruled out compared to middle-aged and young patients (35.6% vs. 62.1% vs. 79.9%).
  • While the algorithm demonstrated a high negative predictive value (NPV) for predicting adverse events across all age groups, it only reached the 99% NPV safety threshold when combined with the HEART score for older and middle-aged adults.
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Brain metastases can occur in nearly half of patients with early and locally advanced (stage I-III) non-small cell lung cancer (NSCLC). There are no reliable histopathologic or molecular means to identify those who are likely to develop brain metastases. We sought to determine if deep learning (DL) could be applied to routine H&E-stained primary tumor tissue sections from stage I-III NSCLC patients to predict the development of brain metastasis.

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Background: The European Society of Cardiology (ESC) 0/1-h high sensitivity troponin T (hs-cTnT) algorithm does not differentiate risk based on known coronary artery disease (CAD: prior myocardial infarction [MI], coronary revascularization, or ≥ 70% coronary stenosis). We recently evaluated its performance among patients with known CAD at 30-days, but little is known about its longer-term risk prediction. The objective of this study is to determine and compare the performance of the algorithm at 90-days among patients with and without known CAD.

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In the realm of cerebrovascular monitoring, primary metrics typically include blood pressure, which influences cerebral blood flow (CBF) and is contingent upon vessel radius. Measuring CBF non-invasively poses a persistent challenge, primarily attributed to the difficulty of accessing and obtaining signal from the brain. This study aims to introduce a compact speckle visibility spectroscopy (SVS) device designed for non-invasive CBF measurements, offering cost-effectiveness and scalability while tracking CBF with remarkable sensitivity and temporal resolution.

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Objectives: To assess the in vitro IntelliSep test, a microfluidic assay that quantifies the state of immune activation by evaluating the biophysical properties of leukocytes, as a rapid diagnostic for sepsis.

Design: Prospective cohort study.

Setting: Five emergency departments (EDs) in Louisiana, Missouri, North Carolina, and Washington.

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Background: The HEART Pathway (History, Electrocardiogram, Age, Risk factors, Troponin) can be used with high-sensitivity cardiac troponin to risk stratify emergency department patients with possible acute coronary syndrome. However, data on whether a high-sensitivity HEART Pathway (hs-HP) are safe and effective is lacking.

Methods: An interrupted time series study was conducted at 5 North Carolina sites in 26 126 adult emergency department patients being investigated for possible acute coronary syndrome and without ST-segment-elevation myocardial infarction.

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