Out-of-hospital Cardiac Arrest Survivors Research Articles

Extracorporeal cardiopulmonary resuscitation outcomes for children with out-of-hospital and emergency department cardiac arrest

ObjectiveData suggest extracorporeal cardiopulmonary resuscitation (ECPR) improves survival in adult patients with refractory cardiac arrest; however, ECPR outcomes in pediatric patients with out-of-hospital cardiac arrest (OHCA) is lacking. The primary aim of this study was to characterize pediatric patients who experience OHCA or cardiac arrest in the ED (EDCA). The secondary aim was to examine associations of cardiac arrest and location of ECPR cannulation with mortality. MethodsWe performed a retrospective analysis of the Extracorporeal Life Support Organization registry. We included pediatric patients (age > 28 days to <18 years) who received ECPR for refractory OHCA or EDCA between 2010 and 2019. Patient, cardiac arrest, and ECPR cannulation characteristics were summarized. We examined associations of location of cardiac arrest and ECPR cannulation with in-hospital mortality using multivariable logistic regression. ResultsWe analyzed data from 140 pediatric patients. 66 patients (47%) experienced OHCA and 74 patients (53%) experienced EDCA. Overall survival to hospital discharge was 31% (20% OHCA survival vs. 41% EDCA survival, p = 0.008). In adjusted analyses, OHCA was associated with 3.9 times greater odds of mortality (95% confidence interval [CI] 1.61, 9.81) when compared to compared to EDCA. The location of ECPR cannulation was not associated with mortality (odds ratio 1.8, 95% CI 0.75, 4.3). ConclusionsThe use of ECPR for pediatric patients with refractory OHCA is associated with poor survival compared to patients with EDCA. Location of ECPR cannulation does not appear to be associated with mortality.

Observer-reported cognitive decline in out-of-hospital cardiac arrest survivors and its association with long-term survivor and relative outcomes

AimLong-term cognitive decline after out-of-hospital cardiac arrest (OHCA) is still poorly understood. This study describes long-term observer-reported cognitive decline among Danish OHCA survivors, including differences in years since the event, and investigates characteristics and self-reported outcomes associated with observer-reported cognitive decline. MethodsAdults who survived an OHCA from 2016 to 2019, and their relatives, completed the national DANish Cardiac Arrest Survivorship survey. Relatives completed the Informant Questionnaire on Cognitive Decline in the Elderly, Cardiac Arrest version (IQCODE-CA), the Hospital Anxiety and Depression Scale (HADS) and the World Health Organisation-Five Well-being index; and survivors completed the Two Simple Questions (everyday activities and mental recovery), the Modified Fatigue Impact Scale, HADS, and the Short World Health Organisation Disability Assessment Schedule 2.0. Potential associations between survivor characteristics and the IQCODE-CA were investigated using a multivariable logistic regression model. Self-reported outcomes among survivors and relatives, and the association with IQCODE-CA scores were investigated using separate logistic regression models. ResultsTotal median IQCODE-CA score was 3.04 (IQR: 3.00–3.27), with 47% having possible cognitive decline (score ≥ 3.04), consistent across time groups. Increasing age (OR 0.98, 95% CI: 0.97–0.99) and worse self-reported mental and physical outcomes for survivors and relatives, except ‘everyday activities’ were significantly associated with possible cognitive decline among survivors. ConclusionsNearly half of OHCA survivors may suffer long-term cognitive decline. Worse self-reported mental and physical outcomes among survivors and their relatives are associated with potential cognitive decline emphasising the need for post-OHCA care to include systematic neurocognitive assessment, tailored support and effective rehabilitation.

Grey-to-white matter ratio values in early head CT as a predictor of neurological outcomes in survivors of out-of-hospital cardiac arrest based on severity of hypoxic-ischemic brain injury

Background: Hypoxic-ischemic brain injury (HIBI) is a common complication of out-of-hospital cardiac arrest (OHCA). Objectives: We investigated whether grey-to-white matter ratio (GWR) values, measured using early head computed tomography (HCT), were associated with neurological outcomes based on the severity of HIBI in survivors of OHCA. Methods: This retrospective multicenter study included adult comatose OHCA survivors who underwent an HCT scan within 2 hours after the return of spontaneous circulation. HIBI severity was assessed using the revised post-Cardiac Arrest Syndrome for Therapeutic hypothermia (rCAST) scale (low, moderate, and severe). Poor neurological outcomes were defined as Cerebral Performance Categories 3–5 at 6 months after OHCA. Results: Among 354 patients, 27% were women and 224 (63.3%) had poor neurological outcomes. The distribution of severity was 19.5% low, 47.5% moderate, and 33.1% severe. The area under the receiver operating curves of the GWR values for predicting rCAST severity (low, moderate, and severe) were 0.52, 0.62, and 0.79, respectively. The severe group had significantly higher predictive performance than the moderate group (p=0.02). Multivariate logistic regression analysis revealed a significant association between GWR values and poor neurological outcomes in the moderate group (adjusted odds ratio=0.012, 95% CI 0.0–0.54, p=0.02). Conclusions: In this cohort study, GWR values measured using early HCT demonstrated variations in predicting neurological outcomes based on HIBI severity. Furthermore, GWR in the moderate group was associated with poor neurological outcomes.

Extracorporeal Membrane Oxygenation Pathway for Management of Refractory Cardiac Arrest: A Retrospective Study from A National Center of Extracorporeal Cardiopulmonary Resuscitation.

Cardiac arrest remains a critical condition with high mortality and catastrophic neurological impact. Extracorporeal cardiopulmonary resuscitation (ECPR) has been introduced as an adjunct in cardiopulmonary resuscitation modalities. However, survival with good neurological outcomes remains a major concern. This study aims to explore our early experience with ECPR and identify the factors associated with survival in patients presenting with refractory cardiac arrest. A retrospective cohort study analyzing six-year data from a tertiary center, the country reference for ECPR. A national center of ECPR. Adult patients who experienced witnessed refractory cardiopulmonary arrest and were supported by ECPR. ECPR for eligible patients as per local service protocol. Data from 87 patients were analyzed; of this cohort, 62/87 patients presented with in-hospital cardiac arrest (IHCA), and 25/87 presented with out-of-hospital cardiac arrest (OHCA). Overall survival to decannulation and hospital discharge rates were 26.4% and 25.3%, respectively. Among survivors (n=22), 19 presented with IHCA (30.6%), whilst only 3 survivors presented with OHCA (12%). A total of 15/87 (17%) patients were alive at 6-month follow-up. All survivors had good neurological function assessed as Cerebral Performance Category 1 or 2. Multivariate logistic regression to predict survival to hospital discharge showed that IHCA was the only independent predictor (Odds Ratio 5.8, p =0.042), however, this positive association disappeared after adjusting for the first left ventricular ejection fraction after resuscitation. In this study, the use of ECPR for IHCA was associated with a higher survival to discharge compared to OHCA. This study demonstrated a comparable survival rate to other established centers, particularly for IHCA. Neurological outcomes were comparable in both IHCA and OHCA survivors. However, large multicenter studies are warranted for better under-standing and improving the outcomes.

The quality of care and long-term mortality of out of hospital cardiac arrest survivors after acute myocardial infarction: a nationwide cohort study.

The long-terms outcomes of out of hospital cardiac arrest (OHCA) survivors are not well known. Using the Myocardial Ischaemia National Audit Project (MINAP) registry, linked to Office for National Statistics (ONS) mortality data, we analysed 661326 England, Wales and Northern-Ireland AMI patients; 14127 (2%) suffered OHCA and survived beyond thirty-days of hospitalisation. Patients dying within thirty-days of admission were excluded. Mean follow-up for patients included was 1500 days. Cox regression models were fitted, adjusting for demographics and management strategy. OHCA survivors were younger (in years) (64 (interquartile range [IQR] 54-72) vs. 70 (IQR 59-80), P<0.001), more often underwent invasive coronary angiography (88%vs. 71%, P<0.001) and percutaneous coronary intervention (72%vs. 45%, P<0.001). Overall, risk of mortality for OHCA patients that survived past 30-days was lower than patients that did not suffer cardiac arrest (adjusted hazard ratio [HR] 0.91; 95% CI; 0.87-0.95, P<0.001). 'Excellent care' according to the mean opportunity-based quality indicator (OBQI) score compared to 'Poor care', predicted reduced risk of long-term mortality post OHCA, for all-patients (HR: 0.77, CI; 0.76-0.78, P<0.001), more for STEMI patients (HR: 0.73, CI; 0.71-0.75, P<0.001), but less significantly in NSTEMI patients (HR: 0.79, CI; 0.78-0.81, P<0.001). Out of hospital cardiac arrest (OHCA) patients remain at significant risk of mortality in-hospital. However, if surviving over thirty-days post arrest, OHCA survivors have good longer-term survival up to ten-years compared to the general AMI population. Higher quality inpatient care appears to improve long-term survival in all OHCA patients, more so in STEMI.

Early ICD implantation following out-of-hospital cardiac arrest: a retrospective cohort study from the Swedish Registry for Cardiopulmonary Resuscitation

BackgroundIt is unclear whether an implantable cardioverter-defibrillator (ICD) is generally beneficial in survivors of out-of-hospital cardiac arrest (OHCA).ObjectiveWe studied the association between ICD implantation prior to discharge and survival in...

Adverse Safety Events in Emergency Medical Services Care of Children With Out-of-Hospital Cardiac Arrest

Survival for children with out-of-hospital cardiac arrest (OHCA) remains poor despite improvements in adult OHCA survival. To characterize the frequency of and factors associated with adverse safety events (ASEs) in pediatric OHCA. This population-based retrospective cohort study examined patient care reports from 51 emergency medical services (EMS) agencies in California, Georgia, Oregon, Pennsylvania, Texas, and Wisconsin for children younger than 18 years with an OHCA in which resuscitation was attempted by EMS personnel between 2013 and 2019. Medical record review was conducted from January 2019 to April 2022 and data analysis from October 2022 to February 2023. Severe ASEs during the patient encounter (eg, failure to give an indicated medication, 10-fold medication overdose). A total of 1019 encounters of EMS-treated pediatric OHCA were evaluated; 465 patients (46%) were younger than 12 months. At least 1 severe ASE occurred in 610 patients (60%), and 310 patients (30%) had 2 or more. Neonates had the highest frequency of ASEs. The most common severe ASEs involved epinephrine administration (332 [30%]), vascular access (212 [19%]), and ventilation (160 [14%]). In multivariable logistic regression, the only factor associated with severe ASEs was young age. Neonates with birth-related and non-birth-related OHCA had greater odds of a severe ASE compared with adolescents (birth-related: odds ratio [OR], 7.0; 95% CI, 3.1-16.1; non-birth-related: OR, 3.4; 95% CI, 1.2-9.6). In this large geographically diverse cohort of children with EMS-treated OHCA, 60% of all patients experienced at least 1 severe ASE. The odds of a severe ASE were higher for neonates than adolescents and even higher when the cardiac arrest was birth related. Given the national increase in out-of-hospital births and ongoing poor outcomes of OHCA in young children, these findings represent an urgent call to action to improve care delivery and training for this population.

How do survivors after out-of-hospital cardiac arrest perceive their health compared to the norm population? A nationwide registry study from Norway

IntroductionSelf-perceived health status data is usually collected using patient-reported outcome measures. Information from the patients’ perspective is one of the important components in planning person-centred care. The study aimed to compare EQ-5D-5L in survivors after out-of-hospital cardiac arrest (OHCA) with data for Norwegian population controls. Secondary aim included comparing characteristics of respondents and non-respondents from the OHCA population. MethodsIn this cross-sectional survey, 714 OHCA survivors received an electronic EQ-5D-5L questionnaire 3–6 months following OHCA. EQ-5D-5L assesses for five dimensions of health (mobility, self-care, usual activities, pain/discomfort, and anxiety/depression) with five-point descriptive scales and overall health on a visual analogue scale from 0 (worst) to 100 (best) (EQ VAS). Results are used to calculate the EQ index ranging from −0.59 (worst) to 1 (best). Patient responses were matched for age and sex with existing data from controls, collected through a postal survey (response rate 26%), and compared with Chi-square tests or t-tests as appropriate. ResultsOf 784 OHCA survivors, 714 received the EQ-5D-5L, and 445 (62%) responded. Respondents had higher rates of shockable first rhythm and better cerebral performance category scores than the non-respondents. OHCA survivors reported poorer health compared to controls as assessed by EQ-5D-5L dimensions, the EQ index (0.76 ± 0.24 vs 0.82 ± 0.18), and EQ VAS (69 ± 21 vs 79 ± 17), except for the pain/discomfort dimension. ConclusionsNorwegian OHCA survivors reported poorer health than the general population as assessed by the EQ-5D-5L. PROMs use in this population can be used to inform follow-up and health care delivery.

Association between quantitative analysis of cerebral edema using CT imaging and neurological outcomes in cardiac arrest survivors

BackgroundTo determine if the density distribution proportion of Hounsfield unit (HUdp) in head computed tomography (HCT) images can be used to quantitatively measure cerebral edema in survivors of out-of-hospital cardiac arrest (OHCA). MethodsThis retrospective observational study included adult comatose OHCA survivors who underwent HCT within 6 h (first) and 72–96 h (second), all performed using the same CT scanner. Semi-automated quantitative analysis was used to identify differences in HUdp at specific HU ranges across the intracranial component based on neurological outcome. Cerebral edema was defined as the increased displacement of the sum of HUdp values (ΔHUdp) at a specific range between two HCT scans. Poor neurological outcome was defined as cerebral performance categories 3–5 at 6 months after OHCA. ResultsTwenty-three (42%) out of 55 patients had poor neurological outcome. Significant HUdp differences were observed between good and poor neurological outcomes in the second HCT scan at HU = 1–14, 23–35, and 39–56 (all P < 0.05). Only the ΔHUdp = 23–35 range showed a significant increase and correlation in the poor neurological outcome group (4.90 vs. -0.72, P < 0.001) with the sum of decreases in the other two ranges (r = 0.97, P < 0.001). Multivariate logistic regression analysis demonstrated a significant association between ΔHUdp = 23–35 range and poor neurological outcomes (adjusted OR, 1.12; 95% CI: 1.02–1.24; P = 0.02). ConclusionIn this cohort study, the increased displacement in ΔHUdp = 23–35 range is independently associated with poor neurological outcome and provides a quantitative assessment of cerebral edema formation in OHCA survivors.

A multidisciplinary guideline-based approach to improving the sudden cardiac arrest care pathway: The Copenhagen framework

Although recommended in the European Resuscitation Council (ERC) and European Society of Intensive Care Medicine (ESICM) Guidelines, a framework for delivering post-cardiac arrest care in a systematic manner in dedicated high-volume cardiac arrest centers is lacking in the existing literature.To our knowledge, the Copenhagen Framework is the only established framework of its kind. The framework comprises management of out-of-hospital cardiac arrest (OHCA) survivors, and follow-up, and rehabilitation. The framework also incorporates research projects on cardiac arrest survivors and their close family members. The overall aim of this paper is to describe a framework made in order to bridge the gaps between international recommendations and delivering high-quality post-resuscitation clinical care, improving the continuity of care for OHCA survivors, access to post-CA rehabilitation, a seamless transition to everyday life, and ultimately patient outcomes in the future.

Incidence and Long-Term Outcomes of Acute Myocardial Infarction Among Survivors of Out-of-Hospital Cardiac Arrest.

Despite the increasing long-term survival after out-of-hospital cardiac arrest (OHCA), the risk of subsequent acute myocardial infarction (AMI) remains poorly understood. We aimed to determine the incidence, predictors, and long-term outcomes of AMI among survivors of OHCA. We assembled a retrospective cohort of 882 patients with OHCA who survived to 30 days or discharge from the hospital between 2010 and 2019. Survivors of OHCA had an increased risk of subsequent AMI, defined as AMI occurring 30 days after index OHCA or following discharge from the hospital after OHCA, compared with the general population when matched for age and sex (standardized incidence ratio, 4.64 [95% CI, 3.52-6.01]). Age-specific risks of subsequent AMI for men (standardized incidence ratio, 3.29 [95% CI, 2.39-4.42]) and women (standardized incidence ratio, 6.15 [95% CI, 3.27-10.52]) were significantly increased. A total of 7.2%, 8.3%, and 14.3% of survivors of OHCA had a subsequent AMI at 3 years, 5 years, and end of follow-up, respectively. Age at OHCA (hazard ratio [HR], 1.04 [95% CI, 1.02-1.06]) and past medical history of prior AMI, defined as any AMI preceding or during the index OHCA event (HR, 1.84 [95% CI, 1.05-3.22]), were associated with subsequent AMI, while an initial shockable rhythm was not (HR, 1.00 [95% CI, 0.52-1.94]). Survivors of OHCA with subsequent AMI had a higher risk of death (HR, 1.58 [95% CI, 1.12-2.22]) than those without. Survivors of OHCA are at an increased risk of subsequent AMI compared with the general population. Prior AMI, but not an initial shockable rhythm, increases this risk, while subsequent AMI predicts death. Preventive measures for AMI including cardiovascular risk factor control and revascularization may thus improve outcomes in selected patients with cardiac pathogenesis.

The prognostic value of the phosphate-to-albumin ratio in patients with OHCA: A multicenter observational study

PurposeIn patients with out-of-hospital cardiac arrest (OHCA), early and accurate outcome prediction is crucial for making treatment decisions and informing their relatives. A previous study reported an association between high phosphate levels and unfavorable neurological outcomes after return of spontaneous circulation (ROSC); however, its prognostic value was insufficient when used independently. Therefore, this study aimed to validate the usefulness of the phosphate-to-albumin ratio (PAR) in predicting neurological outcomes and in-hospital mortality by incorporating albumin, another known prognostic indicator. Materials and methodsThis multicenter observational study included adult OHCA survivors from October 2015 to June 2021. The primary endpoint was an unfavorable neurological outcome at hospital discharge, defined as a cerebral performance category score of 3–5. The in-hospital mortality rates were also evaluated. ResultsOf the 2397 adult OHCA survivors, PAR differed significantly between the unfavorable and favorable neurological outcome groups, as well as between the non-survival and survival to hospital discharge groups (2.4 vs 1.4, 2.5 vs 1.6, respectively). The area under the receiver operating characteristic curve (AUROC) value of the PAR for predicting unfavorable neurological outcome was 0.81 (95% confidence interval [CI], 0.79–0.83), and the AUROC value for predicting in-hospital mortality was 0.76 (95% CI, 0.74–0.78). In multivariable analysis, the PAR was independently associated with unfavorable neurological outcome (odds ratio [OR] 1.30, 95% CI 1.15–1.37; p < 0.001) and in-hospital mortality (OR 1.24, 95% CI 1.12–1.38; p < 0.001). ConclusionThe PAR is a readily obtainable and independent prognostic indicator for patients with ROSC after OHCA, helping healthcare providers in predicting outcomes.

Joint Modeling of Social Determinants and Clinical Factors to Define Subphenotypes in Out-of-Hospital Cardiac Arrest Survival: Cluster Analysis.

Machine learning clustering offers an unbiased approach to better understand the interactions of complex social and clinical variables via integrative subphenotypes, an approach not studied in out-of-hospital cardiac arrest (OHCA). We conducted a cluster analysis for a cohort of OHCA survivors to examine the association of clinical and social factors for mortality at 1 year. We used a retrospective observational OHCA cohort identified from Medicare claims data, including area-level social determinants of health (SDOH) features and hospital-level data sets. We applied k-means clustering algorithms to identify subphenotypes of beneficiaries who had survived an OHCA and examined associations of outcomes by subphenotype. We identified 27,028 unique beneficiaries who survived to discharge after OHCA. We derived 4 distinct subphenotypes. Subphenotype 1 included a distribution of more urban, female, and Black beneficiaries with the least robust area-level SDOH measures and the highest 1-year mortality (2375/4417, 53.8%). Subphenotype 2 was characterized by a greater distribution of male, White beneficiaries and had the strongest zip code-level SDOH measures, with 1-year mortality at 49.9% (4577/9165). Subphenotype 3 had the highest rates of cardiac catheterization at 34.7% (1342/3866) and the greatest distribution with a driving distance to the index OHCA hospital from their primary residence >16.1 km at 85.4% (8179/9580); more were also discharged to a skilled nursing facility after index hospitalization. Subphenotype 4 had moderate median household income at US $51,659.50 (IQR US $41,295 to $67,081) and moderate to high median unemployment at 5.5% (IQR 4.2%-7.1%), with the lowest 1-year mortality (1207/3866, 31.2%). Joint modeling of these features demonstrated an increased hazard of death for subphenotypes 1 to 3 but not for subphenotype 4 when compared to reference. We identified 4 distinct subphenotypes with differences in outcomes by clinical and area-level SDOH features for OHCA. Further work is needed to determine if individual or other SDOH domains are specifically tied to long-term survival after OHCA.

Association between distance to nearest automated external defibrillator and socioeconomic deprivation in Great Britain

Abstract Background Disparities in socioeconomic status manifest in death from out of hospital cardiac arrest (OHCA). Inequalities in access to automated external defibrillators (AED) due to socioeconomically determined location of AEDs may be associated with OHCA survival. Purpose To investigate distances between nearest AED location and postcode by socioeconomic deprivation for the population of Great Britain (GB). Methods AED location data for 2022 were drawn from the British Heart Foundation The Circuit registry. All 1,677,466 unit postcodes in Great Britain were linked to the Index of Deprivation for the corresponding Lower Layer Super Output Area using the 2019 Ministry of Housing Communities and Local Government tool. The median distance by road from the centre of each postcode to the nearest AED was calculated using geographic information systems. The proportion available 24/7 was also reported. Multilevel linear mixed regression models fit by country and adjusted for urban/rural status and clustering to calculate predicted marginal mean distances to the nearest active AED, and nearest AED accessible 24/7 by deprivation decile. Results 78,425 unique AED locations were included in the analysis (Table 1). The median distance to nearest AED was 762.1m (IQR 410.8 - 1221.0) in GB; 742.7m (407.2 - 1340.7) in Scotland, 738.8m (422.6 - 1223.5) in England, and 511.5m (282.9 - 937.3) in Wales. For 24/7 access AEDs, median distances were greater: 964.0m (524.7 - 1667.5), 994.1m (538.5 – 1832.3), 990.8m (544.9 - 1683.3), and 569.7m (316.8 - 1033.4), respectively. Overall, there was little evidence of a trend in nearest AED distance by deprivation (fig 1). In Scotland the nearest AED was, on average, 108m further away in the most compared with the least deprived areas. In England, the nearest AED was closer to postcodes in the least deprived areas of England (predicted mean 20m) and Wales (predicted mean 95m). In England, AEDs with 24/7 access were further from postcodes with increasing deprivation (predicted mean 99m further than least deprived areas). In Scotland, nearest 24/7 access AEDs were 317m further away in the most deprived areas, and 62m closer in Wales, but with no evidence of a linear trend. At a typical walking speed (1.31m/sec), on average in GB it would take 17 minutes to retrieve an AED and 21 minutes out of hours. In England and Scotland out of hours, those in the most deprived areas would be delayed access to an AED by 2.5 and 8 minutes respectively compared the least deprived. Conclusions Overall, the median distance to nearest AED across postcodes in GB is at odds with the likelihood of successful resuscitation. Graded social inequalities were not observed in AED access across GB. However, substantive differences were observed in 24/7 AED access between most and least deprived areas of England and Scotland. Greater and more equitable access to AEDs has the potential to save lives and improve outcomes for people with OHCA.

Neurofilament Light Chain levels during admission after out-of-hospital cardiac arrest is associated with cognitive performance at 3-months follow-up

Abstract Background Patients who are resuscitated from out-of-hospital cardiac arrest (OHCA) and hospitalized in coma are at high risk of mortality or brain injury with consequent cognitive impairment, and new therapy are wanted. Biomarkers of brain injury, including Neuron-specific enolase (NSE) and Neurofilament light chain (NfL), predict mortality from cerebral injury. However, prognostication of cognitive dysfunction after discharge in OHCA survivors is challenging. Montreal Cognitive Assessment (MoCA) is a recommended standardized cognitive function testing which is used in the months following OHCA. Nevertheless, prognostic methods assessed in the initial phase of admittance which identify patients at risk of developing cognitive impairment are needed. Purpose To investigate the effect of tocilizumab administered at admission after OHCA on cognitive performance assessed by MoCA at 3-month follow-up, and to investigate the association to time-to-ROSC, and NSE as well as NfL levels during index admission with MoCA at follow-up. Methods The IMICA trial evaluated tocilizumab for reducing systemic inflammation after OHCA and randomized 80 comatose adult patients at admission to an infusion of either tocilizumab (8mg/kg, maximum 800mg) or placebo. NSE at 48 hours was measured as part of routine biochemistry based on serum samples, and NFL at 48 hours was measured in serum samples from the biobank. Time-to-ROSC was reported from pre-hospital data and cognitive performance at 3 months follow-up were assessed by the MoCA test. The association between MoCA and time-to-ROSC, NSE and NfL was assessed by Spearman’s correlation analyses. Results At follow-up, 35 patients had a MoCA test performed, while 28 patients were deceased, and 17 were alive without having an available MoCA score. There was no difference in MoCA scores at follow-up in the tocilizumab group compared to placebo group (p=0.72), and therefore results for both groups were pooled for analyses. NfL was found to be inversely correlated with MoCA score, r = -0.49, p = 0.003 (Figure), while there were no correlations with MoCA for time-to-ROSC or NSE (p = 0.46 and p = 0.34). Conclusions NfL measured at 48 hours after admission was inversely correlated with cognitive performance at 3 months for survivors of OHCA.

Early ICD implantation and survival after out-of-hospital cardiac arrest

Abstract Background It is unclear whether an implantable cardioverter-defibrillator (ICD) is generally beneficial in survivors of out-of-hospital cardiac arrest (OHCA) of cardiac etiology. Aim We studied the association between ICD implantation and survival in patients with cardiac etiology or initial shockable rhythm in OHCA, using the Swedish Registry for Cardiopulmonary Resuscitation (SRCR). Methods All cases in the SRCR during 2010 to 2020 with cardiac etiology or initial shockable rhythm who were discharged alive included. We examined the association between ICD and survival using propensity score. Propensity scores (919 candidate predictors before feature selection) were estimated using gradient boosting, Bayesian additive regression trees, neural networks, extreme gradient boosting and logistic regression. Cox regression was used to model survival. The primary outcome was death or recurrent cardiac arrest. Results The 90-days event rate was 25% in the ICD group, compared with 52% in those without ICD. With regards to the average treatment effect (ATE) the overall hazard ratio 0.38 (95% CI 0.26-0.56) for ICD vs. no ICD. The overall average treatment effect on those treated (ATT) was 0.31 (95% CI 0.22-0.44). In the 15 subgroup analyses, every point estimate were below 1, with the most pronounced association noted in those with a history of acute myocardial infarction (HR 0.07 [95% CI 0.02-0.32]). All ATE and ATE estimates were aligned. Conclusions Mortality in survivors of OHCA occurs early after discharge, and prompt implantation of an ICD is associated with 62% lower probability of death and recurrent cardiac arrest overall.

STEMI patients after out-of-hospital cardiac arrest: should we cool?

Abstract Introduction Patients who have been successfully resuscitated after out-of-hospital cardiac arrest (OHCA) due to ST-segment elevation myocardial infarction (STEMI) have a high risk of death and poor neurological outcome. Application of therapeutic hypothermia (TTM) is recommended in addition to the reperfusion strategies in patients who remain comatose after resuscitation. However, data analysis in STEMI patients successfully resuscitated after OHCA who remain comatose are inconsistent and still a subject of discussion. Objective The aim of this research was to examine the impact of TTM on in-hospital survival and neurological outcome in comatose STEMI patients after OHCA. Methods The study was conducted as a retrospective observational analysis of data taken from a hospital OHCA registry. The examined sample consisted of 141 patients hospitalized from January 2007 to December 2021 due to STEMI complicated by OHCA and who remained comatose upon admission. Inclusion criteria for analysis were STEMI of any localisation and unresponsiveness on admission defined as Glasgow Coma Score (GCS) ≤ 8. Favorable neurological outcome was defined as Cerebral Performance Category Score (CPC) ≤ 2. Results Our research included 141 comatose survivors of OHCA due to STEMI, among whom 91 (64.5%) were men, and TTM was applied in 82 (58.2%) patients. Witnessed cardiac arrest (48.7% vs. 23.1%, p = 0.027), duration of resuscitation ≤ 20 minutes (66.1% vs. 28.4%, p &amp;lt; 0.0005), initial shockable rhythm (55.2% vs. 22.9%, p = 0.001) and performed urgent percutaneous coronary intervention (PCI) (56.2% vs. 23.1%, p &amp;lt; 0.0005) had a statistically significant influence on in-hospital survival, while good neurological recovery was influenced only by the duration of resuscitation ≤ 20 minutes (69.2% vs. 36.7%, p = 0.008). TTM was applied more often when the resuscitation lasted ≤ 20 minutes (51.2% vs. 29.3%, p = 0.015), with an initial shockable rhythm (85.4% vs. 14.6%, p &amp;lt; 0.0005) and when urgent PCI was performed (82.9% vs. 35.6%, p &amp;lt; 0.0005). TTM had a statistically significant effect on in-hospital survival (58.5% vs. 23.7%, p &amp;lt; 0.0005), while it had no effect on favorable neurological outcome (54.7% vs. 56.3%, p = 1.000). Conclusion In our examined group of STEMI patients successfully resuscitated after OHCA who remained comatose at admission, TTM significantly improved in-hospital survival, but had no effect on favorable neurological outcome.

Bystander defibrillation increases 30-day survival even with short emergency medical service response time

Abstract Background Rates of bystander initiated defibrillation are increasing in many areas of the world (1-4), but the effect of defibrillation at different time points after recognition of out-of-hospital cardiac arrest (OHCA) remains largely unknown. Purpose To assess the effect on 30-day survival of bystander defibrillation at different intervals of emergency medical service (EMS) response time. Methods We included OHCAs from 2016 through 2020 from the Danish Cardiac Arrest Registry. Cases were included if they were ≥18 years of age, bystander witnessed, received bystander cardiopulmonary resuscitation (CPR), had EMS response time of 25 minutes or less and only the first OHCA for each subject was considered. We excluded cases witnessed by EMS or if they had missing values of OHCA-related variables. Crude survival proportions were calculated for each minute of EMS response time. Relative risks (RR) and corresponding 95 % confidence intervals (95 % CI) of the outcome (30-day survival) for eight different intervals of EMS response time were estimated using a causal inference framework utilizing Targeted Maximum Likelihood Estimation (TMLE) with ensemble Super Learning, adjusting for age, sex, place of arrest (public/private), initial cardiac rhythm (shockable/not shockable), and comorbidities (prior acute myocardial infarction, ischemic heart disease, heart failure, chronic obstructive pulmonary disease, stroke, cancer). Results We included 7,471 cases of bystander witnessed OHCA receiving CPR before EMS arrival. Of these, 14.7 % (1,098/7,471) received bystander defibrillation before arrival of EMS. Overall, 44.5 % (489/1,098) survived to 30 days when bystander defibrillation was performed versus 18.8 % (1,200/6,373) when no bystander defibrillation was performed. When examining the crude survival proportion for each minute of EMS response time, we found that 30-day survival was consistently higher in the group receiving bystander defibrillation for the first 20 minutes after which the survival was approximately the same for the two groups (Figure 1). When adjusting for confounders, we found statistically significantly increased relative risks of 30-day survival for patients receiving bystander defibrillation, compared to patients not bystander defibrillated, for all intervals of EMS response time, except for response times of 0-2 min., where the increase did not reach statistical significance (0-2 min: RR; 1.34 [95 % CI: 0.88-2.05], 2-4 min: RR; 1.37 [95 % CI: 1.10-1.70], 4-6 min: RR; 1.55 [95 % CI: 1.33-1.80], 6-8 min: RR; 2.23 [95 % CI: 1.86-2.67], 8-10 min: RR; 1.99 [95 % CI: 1.55-2.55], 10-12 min: RR; 1.89 [95 % CI: 1.34-2.68], 12-15 min: RR; 1.86 [95 CI: 1.22-2.84], &amp;gt;15 min: RR; 1.98 [95 % CI: 1.16-3.38]) (Figure 2). Conclusion For all intervals of EMS response time, bystander defibrillation increased 30-day survival of OHCA. The effect was significant for EMS response times as short as 2-4 minutes.

Abstract 156: Incidence and Long-Term Outcomes of Acute Myocardial Infarction Among Survivors of Out-of-Hospital Cardiac Arrest

Introduction: Despite the increasing long-term survival after out-of-hospital cardiac arrest (OHCA), the risk of subsequent acute myocardial infarction (AMI) remains poorly understood. We aimed to determine the incidence, predictors, and long-term outcomes of AMI among OHCA survivors. Methods: We assembled a retrospective cohort of patients with OHCA who survived to 30 days or discharge from hospital regardless of time from index event between 2010-2019 by linking the Pan-Asian Resuscitation Outcomes Study (Singapore participants), Singapore Myocardial Infarction Registry, and the Singapore Registry of Births and Deaths. We calculated the risk of subsequent AMI defined as AMI occurring 30 days after index OHCA or following discharge from hospital post-OHCA, among OHCA survivors compared to the general population using age- and sex-specific standardised incidence ratios (SIR) and the cumulative incidence of subsequent AMI among OHCA survivors. We investigated predictors of subsequent AMI among OHCA survivors and whether AMI predicted mortality using Cox regression hazard ratios for time-to-event analyses. Results: In total, 882 OHCA survivors were analysed. OHCA survivors had an increased risk of subsequent AMI compared to the general population when matched for age and sex (SIR 4.64, 95% CI: 3.52-6.01). Age-specific risks of subsequent AMI for males (SIR 3.29, 95%CI: 2.39-4.42) and females (SIR 6.15, 95%CI: 3.27-10.52) were significantly increased. 7.2%, 8.3%, and 14.3% of OHCA survivors had subsequent AMI at 3 years, 5 years, and end of follow-up respectively. Age at OHCA (HR 1.04, 95%CI: 1.02-1.06) and past medical history of prior AMI, defined as any AMI preceding or during the index OHCA event (HR 1.84, 95%CI: 1.05-3.22), were associated with subsequent AMI. OHCA survivors with subsequent AMI had a higher risk of mortality (HR 1.58, 95%CI: 1.12-2.22) than those without. Conclusion: Long-term OHCA survivors have an increased risk of subsequent AMI, compared to the general population. Prior AMI significantly increases this risk and subsequent AMI predicts mortality. Intensive cardiovascular risk factor control and revascularisation may improve outcomes in selected patients with a cardiac etiology.

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.