Cerebral Performance Category Research Articles

Economic burden of Cardiac Arrest in Spain: analyzing healthcare costs drivers and treatment strategies cost-effectiveness

BackgroundCardiac arrest is a major public health issue in Europe. Cardiac arrest seems to be associated with a large socioeconomic burden in terms of resource utilization and health care costs. The aim of this study is the analysis of the economic burden of cardiac arrest in Spain and a cost-effectiveness analysis of the key intervention identified, especially in relation to neurological outcome at discharge.MethodsThe data comes from the information provided by 115 intensive care and cardiology units from Spain, including information on the care of patients with out-of-hospital cardiac arrest who had a return of spontaneous circulation. The information reported by theses 115 units was collected by a nationwide survey conducted between March and September 2020. Along with number of patients (2631), we also collect information about the structure of the units, temperature management, and prognostication assessments. In this study we analyze the potential association of several factors with neurological outcome at discharge, and the cost associated with the different factors. The cost-effectiveness of using servo-control for temperature management is analyzed by means of a decision model, based on the results of the survey and data collected in the literature, for a one-year and a lifetime time horizon.ResultsA total of 109 cardiology units provided results on neurological outcome at discharge as evaluated with the cerebral performance category (CPC). The most relevant factor associated with neurological outcome at discharge was ‘servo-control use’, showing a 12.8% decrease in patients with unfavorable neurological outcomes (i.e., CPC3-4 vs. CPC1-2). The total cost per patient (2020 Euros) was €73,502. Only “servo-control use” was associated with an increased mean total cost per hospital. Patients treated with servo-control for temperature management gained in the short term (1 year) an average of 0.039 QALYs over those who were treated with other methods at an increased cost of €70.8, leading to an incremental cost-effectiveness ratio of 1,808 euros. For a lifetime time horizon, the use of servo-control is both more effective and less costly than the alternative.ConclusionsOur results suggest the implementation of servo-control techniques in all the units that are involved in managing the cardiac arrest patient from admission until discharge from hospital to minimize the neurological damage to patients and to reduce costs to the health and social security system.

Abstract 207: Soluble Urokinase-Type Plasminogen Activator Receptor in Comatose Survivors After Out-of-Hospital Cardiac Arrest Treated With Targeted Temperature Management

Introduction: Exposure to whole-body ischemia/reperfusion after out-of-hospital cardiac arrest (OHCA) triggers a systemic inflammatory response where soluble urokinase plasminogen activator receptor (suPAR) is released. Aims: This study investigated serial levels of suPAR in patients treated with differentiated target temperature management (TTM) and the associations with mortality and neurological outcome. Methods: In this single center sub-study of the randomized Targeted Temperature Management for 24 vs 48h (TTH-trial), we included 82 patients and measured serial levels of suPAR at 24, 48 and 72 h. We assessed all-cause mortality and neurological function evaluated by the Cerebral Performance Categories at six months after OHCA. Levels of suPAR between TTH groups were evaluated in repeated measures mixed models. Mortality was assessed by the Kaplan-Meier method. Good neurological outcome at six months was assessed by logistic regression analyses. The predictive value of suPAR was evaluated with the area under the receiver operating characteristic (ROC) curve. Results: Levels of suPAR were significantly different between TTH-groups (p interaction =0.04) with the highest difference at 48h, 4.7 ng/mL (95%CI: 4.1-5.4 ng/mL) in the TTH24 group compared to 2.8 ng/mL (95%CI: 2.2-3.5 ng/mL) in the TTH48 group, p<0.0001. Levels of suPAR above the median value (2.6 ng/mL) was significantly associated with increased all-cause mortality at any timepoint (p log-rank <0.05). The interaction of suPAR levels and TTH group was not significant (p interaction =NS). A two-fold increase in levels of suPAR were significantly associated with a decreased odds ratio of a good neurological outcome in both unadjusted and adjusted analyses without interaction of TTH group (p interaction =NS). AUC at 24h was 0.78 (95%CI: 0.67-88, p<0.0001). The optimal cutoff value for suPAR in predicting 180 mortality was 2.6 ng/mL (sensitivity: 0.75, specificity: 0.63). Conclusion: Prolonged TTM of 48 hours vs. 24 hours was associated with lower levels of suPAR. High levels of suPAR were associated with increased mortality and lower odds for good neurological outcome at six months with no significant interaction of TTH group. The biomarker suPAR was a modest predictor of outcome.

Presentation and Outcomes of Adults With Overdose-Related Out-of-Hospital Cardiac Arrest

Drug overdose (OD) is a public health challenge and an important cause of out-of-hospital cardiac arrest (OHCA). Existing studies evaluating OD-related OHCA (OD-OHCA) either aggregate all drugs or focus on opioids. The epidemiology, presentation, and outcomes of drug-specific OHCA are largely unknown. To evaluate the temporal pattern, clinical presentation, care, and outcomes of adult patients with OHCA overall and according to the drug-specific profile. This cohort study of adults with OHCA in King County Washington was conducted between January 1, 2015, and December 31, 2021. Etiology of OHCA was determined using emergency medical service, hospital, and medical examiner records. Etiology was classified as non-OD OHCA or OD-OHCA, with drug-specific profiles categorized as (1) opioid without stimulant, (2) stimulant without opioid, (3) opioid and stimulant, or (4) all other nonstimulant, nonopioid drugs. Statistical analysis was performed on July 1, 2023. Out-of-hospital cardiac arrest. The primary outcome was survival to hospital discharge. The secondary outcome was survival with favorable functional status defined by Cerebral Performance Category 1 or 2 based on review of the hospital record. In this cohort study, there were 6790 adult patients with emergency medical services-treated OHCA from a US metropolitan system. During the 7-year study period, there were 702 patients with OD-OHCA (median age, 41 years [IQR, 29-53 years]; 64% male [n = 450] and 36% female [n = 252]) and 6088 patients with non-OD OHCA (median age, 66 years [IQR, 56-77 years]; 65% male [n = 3944] and 35% female [n = 2144]). The incidence of OD-OHCA increased from 5.2 (95% CI, 3.8-6.6) per 100 000 person-years in 2015 to 13.0 (95% CI, 10.9-15.1) per 100 000 person-years in 2021 (P < .001 for trend), whereas there was no significant temporal change in the incidence of non-OD OHCA (P = .30). OD-OHCA were more likely to be unwitnessed (66% [460 of 702] vs 41% [2515 of 6088]) and less likely to be shockable (8% [56 of 702] vs 25% [1529 of 6088]) compared with non-OD OHCA. Unadjusted survival was not different (20% [138 of 702] for OD vs 18% [1095 of 6088] for non-OD). When stratified by drug profile, combined opioid-stimulant OHCA demonstrated the greatest relative increase in incidence. Presentation and outcomes differed by drug profile. Patients with stimulant-only OHCA were more likely to have a shockable rhythm (24% [31 of 129]) compared with patients with opioid-only OHCA (4% [11 of 295]) or patients with combined stimulant-opioid OHCA 5% [10 of 205]), and they were more likely to have a witnessed arrest (50% [64 of 129]) compared with patients with OHCA due to other drugs (19% [14 of 73]) or patients with combined stimulant-opioid OHCA (23% [48 of 205]). Patients with a combined opioid-stimulant OHCA had the lowest survival to hospital discharge (10% [21 of 205]) compared with patients with stimulant-only OHCA (22% [29 of 129]) or patients with OHCA due to other drugs (26% [19 of 73]), a difference that persisted after multivariable adjustment. In a population-based cohort study, the incidence of OD-OHCA increased significantly from 2015 to 2021, with the greatest increase observed among patients with a combined stimulant-opioid OHCA. Presentation and outcome differed according to the drug-specific profile. The combination of increasing incidence and lower survival among among patients with a opioid-stimulant OHCA supports prevention and treatment initiatives that consider the drug-specific profile.

Abstract 407: The Efficacy and Frequency of Early Left Heart Catheterization After Out of Hospital Cardiac Arrest Over That Last Decade

Background: The efficacy of early coronary intervention after return of spontaneous circulation (ROSC) from out of hospital cardiac arrest, (OHCA) is debated. A recent review of the Wayne County, (Mi) CARES dataset from 2014-18 noted that early LHC maintained the strongest correlation to survival to discharge with good neurological outcome, for all-cause OHCA. Though the overall rate of LHC remained relatively stable, there was a sizable reduction in early LHC and a comparable increase in late LHC in those with CPC 1 and 2 at discharge [ 12 ] Our objective is to utilize the national CARES data to analyze the effect of early LHC on survival with good neurological outcome and to describe the frequency and timing of LHC in OHCA. Methods: This observational study included patients enrolled in the national CARES registry from 2013-21. For the outcome of LHC by year, chi square analysis was performed. Outcome was cerebral performance category, (CPC) (good &lt;3 vs. poor &gt; 3) at hospital discharge. A propensity score (PS) model was constructed using variables predictive of LHC and good outcome to determine probability of LHC. The PS was then used in an inverse weighted random effects logistic regression model to determine the independent effect of early LHC on outcome. Results: 132,758 individual cases were identified. Median age was 60.3 years (s.d. 16.6), 61.8% were male. Early coronary angiography was performed in 26,999 (20.3%) patients. Patients who underwent early angiography often had shockable rhythms (78.% vs 34%), suffered the OHCA in a public location (36.9% vs 26.1%%), and were witnessed cardiac arrests (80% vs 48%). For the full model the odds ratio for a good outcome after early LHC was 2.54 (95% CI 2.36 - 2.73). Only initial shockable rhythm was more predictive of a good outcome with an OR of 3.9. The proportion undergoing early catheterization declined from 27.6 % to 17.3% from 2013 to 2021; p &lt; 0.0001), though the overall catheterization rate remained the same. Conclusion: In patients with OHCA, early left heart catheterization retains a strong association with good neurological outcome at hospital discharge. The use of early left heart catheterization has declined significantly over the last 9 years.

Abstract 266: Texas Out of Hospital Cardiac Arrest Gender Disparities From Statewide Out-of-Hospital Cardiac Arrest Data Registry - The Texas Cares Project

Introduction: Female out-of-hospital cardiac arrest (OHCA) victims experience differences in care and worse rates of survival compared to male victims. Gender differences in time spent by prehospital care teams on scene with patients has not been studied. Hypothesis: There are gender disparities in scene time and outcomes. Increased scene time is associated with worse outcomes for Males and Females. Methods: We performed a retrospective, cohort study of the Texas Cardiac Arrest Registry to Enhance Survival (CARES) from 2014-201. We included adult OHCAs not witnessed by prehospital personnel that included scene time data and did not result in return of spontaneous circulation in the field that were transferred to emergency departments for ongoing resuscitation. We described OHCA demographics. We evaluated the association between gender and scene time. Using multivariable logistic regression, we evaluated the association of scene time with favorable neurologic outcome, (cerebral performance category (CPC) of 1 or 2). Results: We include 11,782 encounters with OHCA not witnessed by prehospital personnel, of these 7,185 were male and 4,597 female. Female OHCAs were older than male (mean 63.7 vs 61.3, p &amp;lt; 0.01). Female patients had slightly longer scene times than males (mean 29.2 vs 27.9). Female patients were less likely to have favorable neurologic outcomes (12.5% women vs 17.3% men, p &lt; 0.01 by chi2). Adjusting for age, gender, race, initial rhythm and bystander CPR in the multivariable model, increased scene time remained associated with a lower odds of favorable neurologic outcome (OR 0.96, 95%CI 0.95-0.96). Conclusions: OHCAs with longer duration scene time were associated with a lower likelihood of favorable neurologic outcome. Female patients were likely to have longer scene time duration and worse rate of favorable neurologic outcome.

Abstract 256: Quantitative Assessment and Visualization of Hypoxic Ischemic Brain Injury in Survivors of Cardiac Arrest Using Unenhanced Computed Tomography Images

Aim: This study aimed to investigate whether the distribution of Hounsfield units (HU) values in head computed tomography (HCT) images can serve as an effective tool for assessing the severity of hypoxic ischemic brain injury (HIBI) in survivors of out-of-hospital cardiac arrest (OHCA). Methods: This retrospective study included adult comatose OHCA survivors who underwent first HCT scans within 6 hours and second HCT scans between 72-96 hours on the same CT machine after the return of spontaneous circulation. Automated quantitative analysis was used on CT images to eliminate artifacts and identify differences in the proportion of HU values (HUp) at specific intervals across the intracranial area based on neurological outcome. Additionally, correlation analysis was conducted between serum levels of neuron-specific enolase (NSE) at 48 hours post-ROSC and the sum of HUp values in the aforementioned intervals. Poor outcome was defined as cerebral performance categories 3-5 at 6 months post-ROSC. Results: Of the 55 included patients (84% male), 23 (42%) had poor outcome. Significant differences in HU values were observed between outcomes in the second HCT scan at HU=1-14, 23-35, and 39-56 (P&lt;0.05). Within the same HU interval, the poor outcome group showed a greater change between the first and second HCT scans compared to the good outcome group (Figure). The correlations between the sum of HUp and NSE levels within the range of HU=1-14, 23-35, and 39-56 in the second HCT were 0.34, 0.60, and 0.49, respectively (Figure). The second HCT scans demonstrated better prognostic performance than the first HCT scan for HU=1-14 (area under the curve 0.75 vs. 0.60), 23-35 (0.85 vs. 0.62), and 39-56 (0.75 vs. 0.59), while no significant difference was observed compared to GWR (0.78) (all P≥0.05). Conclusions: The proportional sum of HU values within specific intervals in the entire cerebral area on CT images can effectively assess and visualize the extent of HIBI in survivors of OHCA.

Abstract 146: Advanced Age and Neurological Recovery in Elderly Patients With Out-of-Hospital Cardiac Arrest Treated With Targeted Temperature Management: A Nationwide Population-Based Registry Study

Objectives: The chance of neurological recovery after out-of-hospital cardiac arrest (OHCA) can be influenced by advanced age, however further recent evidence will be need in elderly population. The purpose of this study is to evaluate the impact of advanced age on the neurological recovery in elderly OHCA survivors treated with targeted temperature management (TTM). Methods: This retrospective observational study, using a nationwide population-based OHCA registry, was conducted from January 2016 to December 2020. Non-traumatic elderly (≥ 65 years) comatose OHCA survivors treated with TTM were enrolled. The elderly patients were divided into four groups (65-69 years, 70-74 years, 75-79 years, and ≥ 80 years). The primary outcome was good neurological outcome, defined as Cerebral Performance Categories (CPC) of 1 or 2 at hospital discharge. Results: Among 23,336 OHCA patients who admitted to the hospital, 3,398 patients treated with TTM. Excluding 2,033 non-elderly patients, 1,365 patients were analyzed. In four elderly group, the rate of good neurological outcomes were decreased by advanced age (24.2%, 16.1%, 11.4%, and 5.9%). This was also observed after subgroup analysis based on the initial shockable (40.6%, 31.5%, 28.6%, and 14.9%) and non-shockable rhythm (10.6%, 7.2%, 4.1%, and 3.4%). Multivariate analysis showed the adjusted odds ratio (aOR) for good neurological outcome decreased as advanced age (65-69 years: reference, 70-74 years: aOR 0.70, 75-79 years: aOR 0.49, and ≥ 80: aOR 0.25). The optimal age cutoffs for good outcome in elderly OHCA survivors with shockable and non-shockable rhythm were 77 years and 72 years respectively. Conclusions: The neurologic recovery rate in OHCA survivors treated with TTM was gradually decreased with advanced age. However even with ≥ 80 years with shockable rhythm, had a good neurologic outcome of 14.9%, which is higher than 65-69 years of 10.6% in non-shockable rhythm.

Abstract 184: Blood Pressure Matters After Cardiac Arrest: Is Our Target Too Low?

Introduction: Blood pressure is an important therapeutic target after cardiac arrest (CA), crucial for maintaining cerebral blood flow and preventing secondary brain injury. However, the optimal blood pressure during the post-resuscitation period remains unknown. Hypothesis: Proportion of time with mean arterial pressure (MAP) below a specific threshold will be associated with worse clinical outcomes. Methods: We assessed a retrospective cohort of CA patients admitted to an academic center between January 2014 - August 2022. Patients without a documented initial MAP, those who progressed to brain death, or who died within 96 hours were excluded. Multivariable logistic regression was used to test associations between proportion of time with MAP &lt; 65mmHg or &lt; 80mmHg and outcomes [survival and good neurologic outcome (Cerebral Performance Category 1-2) at hospital discharge]. We adjusted for age, sex, Charlson Comorbidity Score, CA location, initial rhythm, Pittsburgh Cardiac Arrest Category, and peak 24h norepinephrine equivalent. We evaluated the initial 96 hours from CA and the following sub-periods: 1) 0-24h, 2) 25-72h, and 3) 73-96h. Results: Of 817 patients with CA, 411 were included. Over the initial 96 hours, the proportion of time with MAP &lt; 80 was inversely associated with survival and good neurologic outcome (adjusted OR [95% CI] per 10% time 0.83 [0.75 - 0.93] and 0.78 [0.69 - 0.89], respectively); no such association was found for MAP &lt; 65. This inverse association held in period 2 (0.85 [0.78-0.93] and 0.79 [0.71-9.88], respectively) and period 3 (0.87 [0.80-0.94] and 0.85 [0.78-0.93], respectively), but not in period 1 (Figure 1). Conclusion: The proportion of time spent with MAP &lt; 80mmHg was associated with worse outcomes, independent of disease severity. The neuroprotective effect of higher MAP appears to occur between 25-96h from CA. Future prospective studies are needed to further characterize the differential clinical impact of MAP across time.

Abstract 103: Quantitative Analysis of Apparent Diffusion Coefficients to Predict Neurological Prognosis in Cardiac Arrest Survivors: An Observational Derivation and Internal-External Validation Study

Aim: Our study aimed to develop apparent diffusion coefficient (ADC) values and thresholds to predict poor outcomes in out-of-hospital cardiac arrest (OHCA) survivors by quantitatively analyzing ADC values in brain MRI. Methods: This observational study utilized prospectively collected data two tertiary academic hospitals. The derivation cohort comprised 70% of patients randomly selected from one hospital, whereas the internal validation cohort comprised the remaining 30%. The external validation cohort used data from the other hospital. MRI data were restricted to scans conducted at 3T within 72-96 h after OHCA. We analyzed the % voxels of ADC thresholds (percentage of voxels below ADC thresholds per total voxel [PV]) at 50-step intervals ranging from 200 to 1200 х 10 -6 mm/s. Poor neurological outcomes were defined as cerebral performance categories 3-5 at 6 months after OHCA. Results: In total, 448 brain MRI scans were evaluated, including a derivation cohort (n=224) and internal/external validation cohorts (n=96 and 128, respectively). The PV values of 500, 550, 600, 650 and 700 х 10 -6 mm/s were determined using the area under the curve (AUC) and demonstrated better performance than higher values in predicting poor neurological outcomes across the derivation (AUC 0.90-0.91), internal validation (AUC 0.87-0.91), and external validation cohorts (AUC 0.91-0.92), showing similar performance levels. A PV of 600х10 -6 mm/s predicted a poor outcome with 100% specificity at a threshold of &gt;13.2% in the derivation cohort, with a sensitivity of 74% (95% CI 66-81) at 100% specificity. In both the internal and external validation cohorts, when using the same threshold, a specificity of 100% corresponded to sensitivities of 75% (95% CI 63-85) and 78% (95% CI 66-87), respectively (Figure). Conclusions: Quantitative analysis of ADC values in brain MRI is a promising tool for predicting poor neurological outcomes in OHCA survivors, with high sensitivity at a specificity of 100%.

Abstract 210: The Relationship Between Serum Free Fatty Acid Levels After the Return of Spontaneous Circulation and Neurological Outcomes in Out-of-Hospital Cardiac Arrest Patients

Background: Free fatty acids (FFA) are a known risk factor in the development of sudden cardiac death. However, the relationship between FFA and the outcome of out-of-hospital cardiac arrest (OHCA) patients remains unclear. We aimed to examine the association between FFA and neurological outcomes in OHCA patients. Methods: This prospective observational study included adult (≥ 18 years) OHCA patients between February 2016 and December 2022. We measured serial FFA levels within 1 h after ROSC and at 6 h, 12 h, 24 h, 48 h, and 72 h after the return of spontaneous circulation (ROSC). The primary outcome was neurological outcome at 6 months. A poor neurological outcome was defined by cerebral performance categories 3, 4, and 5. Results: A total of 147 patients were included. Of them, 104 (70.7%) had poor neurological outcomes, whereby the median FFA levels within 1 h after ROSC (0.72 vs. 1.01 mol/L), at 6 h (1.19 vs. 1.90 mol/L), 12 h (1.20 vs. 1.66 mol/L), and 24 h (1.20 vs. 1.95 mol/L) after ROSC were significantly lower than in good outcome group. The FFA levels at 6 h (odds ratio [OR], 0.583; 95% confidence interval [CI], 0.370-0.919; P = 0.020), and 12 h (OR, 0.509; 95% CI, 0.303-0.854; P = 0.011) after ROSC were independently associated with poor neurological outcomes. Conclusions: The lower FFA levels at 6 h and 12 h after ROSC were associated with poor neurological outcomes in patients with OHCA. FFA may reflect oxidative metabolism as well as oxidative stress.

Abstract 150: Non-Linear Association Between the Time of Reaching the Targeted Temperature and the Neurological Outcome in Patients Undergoing Targeted Temperature Management After Out-of-Hospital Cardiac Arrest Observational Multicenter Cohort Study

Background: We aimed to identify the most favourable time from the introduction of targeted temperature management (TTM) to achieving the targeted temperature in patients experiencing out-of-hospital cardiac arrest. Methods: This multicenter cohort study was performed using the Comprehensive Registry of Intensive Care for OHCA Survival study, we collected patients’ information, including that on in-hospital care. We enrolled all consecutive patients transported to participating institutions in Osaka, Japan from 1 July 2012 through 31 December 2017. Eligible were persons aged ≥18 years whose cardiac arrest was of cardiac etiology and who received in-hospital TTM. Primary outcome was favourable neurological survival with a Cerebral Performance Category scale of 1 or 2 one-month after cardiac arrest, which was designated as “one-month favourable neurological survival”. After adjusting for several factors, a non-linear multivariable logistic regression analysis assessed the time from the introduction of TTM to reaching the targeted temperature and the probability of the primary outcome. Also, we subdivided patients according to five quintiles based on the time from the introduction of TTM to achieving the targeted temperature. To compare the probability of the primary outcome among quintiles, a multivariable logistic regression analysis calculated adjusted odds ratios and 95% confidence intervals. Results: We analyzed 483 patients. p for non-linearity was &lt;0.01 in the non-linear multivariable logistic regression analysis. In the first quintile (&lt;26.7 minutes), second quintile (26.8-89.9 minutes), third quintile (90.0-175.1 minutes), fourth quintile (175.2-352.1 minutes), and fifth quintile (≥352.2 minutes), one-month favourable neurological survival was 32.6% (31/95), 40.0% (36/90), 53.5% (53/99), 57.4% (54/94), and 37.9% (36/95), respectively. Adjusted odds ratios with 95% CI for the primary outcome in the first, second, third, and fifth quintiles, compared with the fourth quintile as the reference, were 0.38 (0.20 to 0.72), 0.43 (0.23 to 0.81), 0.77 (0.41 to 1.44), and 0.46 (0.25 to 0.87), respectively. Conclusions: Time to reaching the targeted temperature was associated with favourable outcome in patients with cardiac arrest.

Abstract 351: Novel Quantitative Imaging Biomarkers From Acute Brain CT Using Artificial Intelligence for Predicting Neurological Prognosis in Cardiac Arrest Patients: A Pilot Study

Background: Effective use of information extracted from medical images has attracted attention for decision support in primary care of patients with cardiac arrest (CA). Hypothesis and Aims: This study aimed to predict the neurological prognosis of patients with cardiac arrest by quantitative imaging biomarkers (QIBs) extracted from acute CT brain images before admission using artificial intelligence. Methods: Eighty-six CA patients (good prognosis; Glasgow-Pittsburgh cerebral performance categories [CPC]=1 or 2 at 90 days after the CA : 32 patients, poor prognosis; CPC=3, 4, or 5 at 90 days after the CA : 54 patients) treated at three hospitals between 2017 and 2019 were retrospectively analyzed. None of the CA patients caused by trauma or brain damage were included in the database. The data were divided into training and test data, and the training data were used to select informative QIBs for classification between the good and poor neurological prognosis in this analysis. Results: Seven CA patients’ data were excluded from the study due to severe metal and bone artifacts broadly spreading on the brain image, and 1170 QIBs were extracted from whole brain and regional brain interest volumes on CT images of each patient. The QIBs were composed of first-order histogram and texture features and informative QIBs for the classification were selected by feature selection algorithms using the training dataset. The feature corresponding to the gray level having a maximum gradient in the image histogram from the brain region of interest on CT images showed the strongest significant difference between the good and poor neurological prognosis of the test data set with p=0.009 and AUC=0.775 (95% CI; 0.590-0.960). Conclusions: We have shown that QIB can be used to predict neurological prognosis in patients with CA. Because this is a pilot study for methodological development and there are limitations in sample size and outcomes, new studies on a larger number of patients are required.

Abstract 390: Pre-Hospital Administered Adrenaline in the Presence of a Physician and Neurological Status of Patients With Out-of-Hospital Cardiac Arrest: A Multi-Center Prospective Cohort Study

Background: Little is known about whether pre-hospital administered adrenaline with a physician present could improve the outcome of patients with cardiac arrest. Hypothesis and Aim: We aimed to test the hypothesis that pre-hospital administered adrenaline provided in the presence of a physician could improve neurological survival of patients with a specific type of first-confirmed cardiac rhythm following cardiac arrest compared with pre-hospital administered adrenaline provided in the absence of a physician. Methods: This prospective multi-center cohort study enrolled consecutive patients who were transported to 95 participating hospitals in Japan after out-of-hospital cardiac arrest and later underwent resuscitation at a hospital between June 1 2014 and December 31 2020. We included patients who were administered pre-hospital adrenaline under the presence or absence of a physician, and who were ≥18 years of age with cardiac arrest of a medical etiology. Primary outcome was a favorable neurological outcome (Cerebral Performance Category score of 1 or 2) one month after cardiac arrest. Whether the carotid artery was pulsating and 3-lead electrocardiogram monitor confirmed the first cardiac rhythm. Based on previous findings, those with the first-confirmed cardiac rhythm were subdivided into the non-shockable and shockable groups. Multivariable logistic regression analysis was performed on propensity score-matched patients. Results: We analyzed 11,711 patients. Among the 10,113 patients in the non-shockable group, 0.6% (N = 64) had a favorable neurological outcome. The adjusted odds ratio for a favorable neurologic outcome of pre-hospital administered adrenaline under the presence of a physician was 3.94 (95% confidence interval (CI): 1.58-11.4), compared with the absence of a physician. Of 1,598 patients in the shockable group, 10.3% (N = 164) had a favorable neurological outcome with an adjusted odds ratio of 1.30 (95% CI: 0.73-2.35). Conclusion: This prospective multi-center cohort study showed that pre-hospital administered adrenaline in the presence of a physician was significantly associated with a higher favorable neurological outcome in non-shockable patients with cardiac arrest.

Abstract 264: Impact of Receiving Hospital on Disparities in Out-of-Hospital Cardiac Arrest

Background: Minority out-of-hospital cardiac arrest (OHCA) victims suffer from worse outcomes. The factors contributing to these disparities are not completely understood, and little is known about the impact of receiving hospital on OHCA. Hypothesis: Receiving hospital plays an important role in OHCA outcome disparities. Methods: We performed a retrospective, cohort study of the national Cardiac Arrest Registry to Enhance Survival (CARES). We included OHCAs from 2014- 2021 that survived to hospital admission. Based on census tract data, we stratified OHCAs based on majority race/ethnicity: &gt;50% White, &gt;50% Black, and &gt;50% Hispanic/Latino. We stratified hospitals into quartiles based on hospital rate of the outcome, survival with favorable neurologic outcome, cerebral performance category of 1 of 2. We evaluated the association between race/ethnicity and care at increasing hospital performance quartile. We compared four models evaluating the association between race/ethnicity and outcome: 1) omitting receiving hospital and bystander CPR (B-CPR), 2) adjusting for B-CPR, 2) additionally adjusting for receiving hospital as a random intercept, and 3) adjusting for hospital performance quartile. We adjusted all models for possible confounders. Results: We include 124,908 OHCAs that survived to hospital admission; 90,034 majority White, 20,600 majority Black, and 14,338 majority Hispanic. Compared to White, Black (OR 0.1, 95% CI 0.1-0.1) and Hispanic OHCAs were less likely to be cared for at high performing hospitals. Ignoring receiving hospital, outcomes were worse for Black (19.7%, aOR 0.43, 95% CI 0.40-0.46) and Hispanic (22.1%, aOR 0.49, 95% CI 0.45-0.54) than White (33.5%). While adjusting for B-CPR did not change survival odds, adjusting for receiving hospital as a random intercept improved outcome odds for Black (aOR 0.60, 95% CI 0.54-0.67) and Hispanic (aOR 0.61, 95% CI 0.53-0.69). Adjusting for hospital performance quartile also improved outcome odds for Black (aOR 0.79, 95% CI 0.73-0.85) and Hispanic/Latino (aOR 0.78, 95% CI 0.70-0.86). Conclusion: OHCAs from minority communities were less likely to be cared for at higher performing hospitals, and adjusting for receiving hospital significantly diminished OHCA outcome disparities.

Abstract 18326: The Association of s Shockable Rhythm and Automated External Defibrillator Use With Outcomes in Infants With Out of Hospital Cardiac Arrest: A Study From the Cardiac Arrest Registry to Enhance Survival

Introduction: Defibrillation with an automated external defibrillator (AED) is critical in the chain of survival following a cardiac arrest caused by pulseless ventricular tachycardia and ventricular fibrillation. However, in 2022 the International Liaison Committee on Resuscitation could not make a recommendation for or against the use of AEDs in infants. Hypothesis: We aimed to describe the association of a shockable rhythm with outcomes in infants with out of hospital cardiac arrest (OHCA) and test the hypothesis that a shockable rhythm and AED use with defibrillation would be associated with improved neurologically favorable survival at hospital discharge by analyzing data from a large cardiac arrest registry in the United States Methods: We conducted an analysis of the Cardiac Arrest Registry to Enhance Survival database. Inclusion criteria were age &lt; 1 year of age and non-traumatic OHCA from January 1, 2013 through December 31, 2021. The primary outcome was neurologically favorable survival defined as a Cerebral Performance Category Scale of 1 or 2. Results: A total of 10,108 infants with OHCA were evaluated of which 308 (3%) had a shockable rhythm and 9,800 (97%) had a non-shockable rhythm. Compared to infants with non-shockable rhythms infants with shockable rhythms were more likely to be white (37.7% white, 25.6% black, 7.5% Hispanic), have a witnessed arrest (44.5% vs. 16%), a non-home/public arrest (16.9% vs. 6.7%), and bystander AED application with defibrillation (19.4% vs. 0.18%) (p&lt;0.05 for all). Neurologically favorable survival (19.2% shockable vs. 4.2% non-shockable was higher in arrests with a shockable rhythm compared to non-shockable arrests, p&lt;0.001). AEDs were applied by bystanders in 1479 (14.5%) arrests and were associated with neurologically favorable survival (11% AED with defibrillation vs. 3.5% AED without defibrillation, p=0.002) Conclusions: Although infants infrequently had an OHCA with a shockable rhythm survival outcomes were superior in arrests with a shockable rhythm and in arrests where there was bystander AED use with defibrillation. These results emphasize the importance of AED use in infants with shockable rhythms following an OHCA.

Abstract 147: Is Effect Size of Targeted Temperature Management Different for Pediatric Post-Cardiac Arrest Syndrome According to the Severity?

Introduction: The beneficial effect of target temperature management (TTM) for pediatric post-cardiac arrest syndrome (PCAS) patients is controversial, and there are few studies on the differential effects of TTM according to the risk classification. Objective: The aim of this study was to evaluate the differential effects of TTM for pediatric PCAS patients according to a risk classification tool we previously developed, rCAST. Methods: We used data from the Japanese nationwide out-of-hospital cardiac arrest (OHCA) registry of the Japanese Association for Acute Medicine. We classified eligible pediatric PCAS patients (aged ≤18 years) who achieved return of spontaneous circulation (ROSC) according to the quintile of score points on the rCAST. The effect of TTM for their neurological outcome was evaluated for each severity group. And then, focusing on the severity group that appeared to benefit from TTM, we also evaluated the effect of TTM by the propensity score analysis with several adjustment factors. Good neurological outcome was defined as a Cerebral Performance Categories score or Pediatric Cerebral Performance Categories score ≤2 at 30 days. Results: Among 1,526 OHCA pediatric patients in the registry, data of 307 PCAS patients who achieved ROSC were analyzed. The proportion of patients with a good neurological outcome was higher among those who underwent TTM compared to those who did not in the first to forth quintile (TTM vs non-TTM; 81% [21/26] vs 58% [21/36] [p=0.10] in the first, 11% [2/19] vs 7% [2/31] [p=0.63] in the second, 12% [2/17] vs 0% [0/55] [p=0.053] in the third, and 11% [1/9] vs 0% [0/21] [p=0.30] in the fourth). In the group of the fifth quantile (rCAST ≥ 18.5), no patients showed good neurological outcome regardless of TTM (0% [0/20] vs 0% [0/73]). The propensity score analysis showed that TTM was significantly associated with their good neurological outcome in the patients classified into the first to fourth quantile group (Odds ratio; 1.21 [1.04-1.40], p = 0.014). Conclusions: TTM was significantly associated with a good neurological outcome in the pediatric PCAS patients with rCAST ≤ 18.0. All patients with rCAST ≥ 18.5 showed poor neurological outcomes even if they underwent TTM.

Abstract 396: A Novel Machine Learning Approach for Identifying Subgroups With Differential Responses to Amiodarone in Patients With Cardiac Arrest With Shockable Rhythm

Introduction: Although there is a possibility that the effectiveness of amiodarone may differ among a particular subgroup, there are few studies on the differential effects of amiodarone for the out-of-hospital cardiac arrest (OHCA) patients with a shockable rhythm. Objective: To identify subgroups with differential responses to amiodarone in OHCA with shockable rhythm by a novel machine learning approach. Methods: We used data from the Japanese nationwide OHCA registry of the Japanese Association for Acute Medicine. The OHCA patients who had initial shockable rhythm upon hospital arrival were included. The primary outcome was a good neurological outcome at 30 days, defined as a Cerebral Performance Categories score ≤2. We developed a linear score by outcome weighting learning (OWL) method with logistic loss to identify subgroups with differential effects of amiodarone. The difference in the effect of amiodarone between subgroups based on the developed score was evaluated by repeated cross-validation (RCV), and hypothesis testing was performed by the permutation method. Results: Among 68,111 OHCA patients in the registry, data of 2333 patients with initial shockable rhythm upon hospital arrival were analyzed. Our developed score showed that the longer duration from call to EMS to hospital arrival, hypothermia at hospital arrival, and no defibrillation until hospital arrival were important variables that had a trend of increasing the beneficial effect of amiodarone (Table). The effect of amiodarone on neurological outcomes varied significantly among the subgroups identified by the developed scores (OR: 1.05 (95%CI: 0.99-1.13), P [RCV] = 0.038). Conclusions: We successfully developed a model that discriminates between the patients for whom amiodarone had a harmful effect on their neurological outcome from those for whom amiodarone had a beneficial effect. In the patients for whom amiodarone had a harmful effect, the other treatment approaches may be needed.

Abstract 170: Late CCL23 Response is Associated With Poor Outcomes After Cardiac Arrest

Introduction: Chemokines mediate the entrance and migration of leukocytes to inflamed tissue areas, contributing to the intensity of local inflammation. We found a high level of circulating chemokines, CCL2, CCL4, and CCL23, in patients resuscitated after cardiac arrest (CA). Hypothesis: The level of circulating chemokines is associated with systemic immune cell response, neurologic injury, and outcome after cardiac arrest. Goal: To characterize temporal chemokine and immune cell responses to cardiac arrest. Methods: A total of 42 patients after CA and 22 control subjects who underwent coronary artery bypass grafting (CABG) were enrolled. ELISA was used to determine chemokines in plasma at 6 hr, 24 hr, 48 hr, and 72 hr after CA and in CABG patients pre-operatively. Flow cytometry was used to determine subpopulations of immune cells. We measured changes in chemokines over time and the association of chemokine levels with outcome, markers of inflammation, and brain injury. A mouse model of CA was employed to assess the activation of human neutrophils locally in brain tissue. Results: Temporal dynamics were different for each chemokine, with early increases in CCL2 and CCL4, followed by a late elevation in CCL23 at 48 hours after resuscitation. A higher level of CCL23 was associated with a worse cerebral performance category score (r s =0.3, p=0.042) and higher mortality (r s =0.3, p=0.039). Positive correlations were found between CCL23 and an increased number of neutrophils, cellular mediators of inflammation, and levels of neuron-specific enolase. To study the potential role of neutrophil activation locally in injured brain tissue, we injected human post-CA neutrophils into the bloodstream of successfully resuscitated mice and measured the CCL23 in human neutrophils in mouse blood and brain 24 hours after resuscitation. An increased level of CCL23 production was found in mouse brain neutrophils compared to those in the peripheral circulation. Conclusion: It is well known that an early intense inflammatory response is associated with poor outcomes after CA. Our new data indicate that late activation of neutrophils in brain tissue may represent an additional mechanism contributing to ongoing brain tissue injury via the production of CCL23 after cardiac arrest.

Abstract 385: Comparison of Rapid Implementation of Automated Head and Thorax Elevation With Active Compression Decompression Cardiopulmonary Resuscitation and an Impedance Threshold Device versus National Outcome Data: A Prospective Observational Study

Background: Pre-clinical work has shown automated head and thorax elevation with active compression decompression CPR and an impedance threshold device (AHUP-CPR) improved 24-hour neurological survival. Propensity matched studies of out-of-hospital-cardiac arrest (OHCA) patients have shown a time dependent association between survival to hospital discharge (SHD) and application of AHUP CPR.Hypothesis: Rapid application of AHUP CPR for OHCA will have a higher incidence of SHD compared to national data. Methods: This is an ongoing prospective observational study of patients from an AHUP-CPR registry of non-traumatic adult OHCA receiving AHUP CPR as part of first responder care. OHCA patients from pre-hospital sites that consistently implemented rapid AHUP CPR were included. Patient demographics, arrest characteristics, ROSC, SHD, and SHD with favorable neurological function, defined as a Cerebral Performance Category score of 1 or 2, were recorded. Data are reported as means ± SD. Combined 2021 and 2022 data from the Cardiac Arrest Registry to Enhance Survival (CARES) were used for comparison of the primary study endpoint, SHD, and secondary endpoints. Chi-square testing was used to compare outcomes. Results: Of 11 registry sites, 7 (US States AL, FL, IL, MN, OK, TN, VA) met inclusion criteria and 1457 patients from January 2020 to June 2023 were enrolled. Average age was 65 ± 16.4 years, 61.8% (901) were male, and 71% (1035) received AHUP CPR. Average time (mm:ss) from 9-1-1 call to start of CPR was 9:52 (6:47) and time to start of AHUP CPR was 12:59 (5:51). Presenting rhythms were: asystole 47.8% (696), PEA 25.8% (376), and VF 20.5% (298). For all AHUP patients, SHD was 13.6% (198) versus 9.2% (26316/286525) for CARES (p &lt; 0.0001). SHD with favorable neurological function was higher for AHUP (10.3% (150) versus 7.3% for CARES (20889), p &lt; 0.0001) and ROSC (29.4% (428) vs 27.0% (77301), p = 0.039). Conclusions: In an unadjusted analysis, the incidence of SHD, ROSC, and neurologically favorable SHD with rapid implementation of AHUP-CPR was higher than nationally reported data. These results support prior findings of a time sensitive association between survival and time to AHUP-CPR. Additional analyses and study are needed for confirmation.

Abstract 212: Association of Glycocalyx Shedding and Outcomes in Patients After Cardiac Arrest: A Prospective Observational Study

Background: The glycocalyx sheds early after cardiac arrest (CA). However, the potential value of elevated serum glycocalyx components remains unknown. Methods: This prospective observational study included patients who suffered CA and survived over 24 hours in the ICU of the Affiliated Hospital of Xuzhou Medical University from September 2021 to October 2022. Serum samples were collected 24 hours post CA to assess the concentration of glycocalyx shedding, including Heparan Sulfate (HS), Hyaluronic Acid (HA) and Syndecan-1 (Sdc-1). Patients were followed for 30 days or until death after CA. Outcome measures were 30-day Cerebral Performance Categories scale (CPC≤2, good function group; CPC&gt;2, poor function group), and 30-day mortality. Logistic regression was used to assess the association of glycocalyx shedding with the 30-day CPC scale. COX regression was used to assess the association of glycocalyx shedding with 30-day mortality. Results: we included 71 patients. Compared with good function group (n=22), poor function group (n=49) had significantly higher levels of HS. Adjusted logistic regression showed that the high level of HS was associated with poor functional outcome (Figure1A, OR=0.41, 95% CI=0.21-0.79, p&lt;0.01). Compared with the survival group (n=39), non-survival group (n=32) had higher levels of HA. Adjusted Cox regression indicated that high levels of HA was associated with mortality (Figure1B,Figure2, HA: HR=1.69,95%, CI=1.13-2.56, p&lt;0.05). Conclusions: Elevated serum HS levels in the early stages post-CA have an association with poor functional outcomes. Increased levels of serum HA post-CA are associated with a higher 30-day mortality.