Out-of-hospital Cardiac Arrest Group Research Articles

Out of hospital sudden cardiac arrest as a prognostic factor for in-hospital mortality in patients admitted with cardiogenic shock

Abstract Funding Acknowledgements None. Background The mortality in cardiogenic shock (CS) is still high despite new comprehensive therapies. Cardiac arrest (CA) frequently complicates CS which can have an unfavourable effect on the course after admission. Purpose The study aimed to analyse the clinical characteristics and prognosis of patients admitted with CS after out-of-hospital cardiac arrest (OHCA) compared to the group without OHCA. Methods The studied group consisted of a total of 80 patients with an average age of 62 ± 13 years (81 % male) admitted to tertiary hospital with CS in the period 2021-2022. The severity of the shock according to the Society for Cardiac Angiography and Interventions (SCAI) SHOCK classification among the whole population was from C to E: 7 (9%), 38 (48%), and 35 (43%), respectively. The cohort was divided into 2 subgroups: the OHCA group consisted of 23 individuals (29%) and the without OHCA (non-OHCA group) consisted of 57 individuals. Results The groups did not differ in terms of demographic parameters and comorbidities. There were no differences in baseline heart rate 95 [50;114] vs. 91 [77;105] beats per minute and mean artery pressure 75 [70;97] vs. 82 [70;97] mmHg for OHCA vs. non-OHCA, respectively, all p> 0.05. Patients from OHCA group had higher baseline creatinine level 1.65 [1.35;1.88] vs. 1.37 [1.08; 1.65] mg/dL, p=0.019, white blood cell count 12 [9;16] vs. 17 [12;23] × 109/L, p=0.015 and lower pH from blood gas analysis 7.0 [6.9;7.2] vs. 7.3 [7.2;7.4], p<0.001). In the OHCA group, 90% of cases of CS were caused by acute coronary syndrome (ACS), while in the group without OHCA, 76% were due to ACS and 20 % due to the progression of chronic heart failure, p=0.032. Mechanical Circulatory Support (MCS) was used in almost every patient (98% non-OHCA vs. 95% OHCA), however, the OHCA group was more often treated with V-A ECMO 14 (64%) vs. 16 (28%) in the non-OHCA, p=0.004. The overall number of in-hospital deaths was 57 (71%). The OHCA group had significantly higher in-hospital mortality 22 (96%) compared to the non-OHCA patients 35 (61%), p=0.002. Conclusion Patients experiencing CS complicated by OHCA have more often ischaemic ethology of shock, have a greater degree of organ damage and a lower pH in blood gas analysis at admission, and have extremely high in-hospital mortality rates when compared with patients facing CS but without prior OHCA, which underscores the urgent need for improved prevention methods, interventions, and public awareness.

Clinical features and outcomes of patients with refractory out-of-hospital cardiac arrest and an initial shockable rhythm

Abstract Background Clinical features of patients presenting with refractory out-of-hospital cardiac arrest (OHCA) and initial shockable rhythms of ventricular fibrillation/pulseless ventricular tachycardia (VF/pVT) remain poorly described. Purpose This study evaluated clinical characteristics, angiographic findings, and short-term outcomes among patients with refractory OHCA (defined as incessant VF/pVT after ≥3 direct-current shocks) compared to those without refractory OHCA. Methods Of 761 consecutive patients hospitalized for OHCA between 2014–2018 at two large tertiary health services in Victoria, Australia, 204 (27%) had an initial shockable rhythm and were stratified by the presence (n=74, 36%) or absence (n=130, 64%) of refractory OHCA. Primary outcome was in-hospital mortality. Multivariable logistic regression was performed to evaluate independent predictors of in-hospital mortality. Results The majority of patients were male (77%) and the median age was 62 years [IQR 52–72]. Refractory OHCA patients had longer cardiopulmonary resuscitation (23 vs 15 minutes), more frequently required ≥450 mg of amiodarone (34% vs 3.8%), had cardiogenic shock (80% vs 55%) necessitating higher adrenaline dose (4.0 vs 1.0 mg) and higher rates of mechanical ventilation (92% vs 74%) (all p<0.01). A total of 167 patients (82%) underwent coronary angiography, and refractory OHCA patients were less likely to be selected (74% vs 86%, p=0.035). No difference in door-to-needle times between those with and without refractory OHCA was noted (103 vs 99 minutes, p=0.586). Significant coronary artery disease (≥1 major vessel with >70% stenosis) was present in >70% of patients. Refractory OHCA group frequently had acute coronary occlusion (64% vs 47%), especially of the left circumflex artery (20% vs 6.4%) and graft vessel (7.3% vs 0.9%), and often had complex coronary lesions (type B2 or C) (57% vs 39%) compared to those without refractory OHCA (all p<0.05). Patients with both refractory OHCA and ST-elevation on electrocardiogram had the highest prevalence of acute coronary occlusion (85%, 22/26). Refractory OHCA group had higher rates of in-hospital mortality (45% vs 30%) and new requirement for dialysis (18% vs 6.3%) (all p<0.05). After adjustment, refractory OHCA heightened the risk of in-hospital mortality by over two-fold (OR 2.28, 95% CI 1.06–4.89, p=0.034) (Figure 1). Among those with refractory OHCA, higher cumulative prehospital adrenaline dose (OR 1.38, 95% CI 1.01–1.89 per 1 mg increase), and increased number of direct-current shocks (1.13, 1.00–1.27 per 1 additional shock) were independent predictors of in-hospital mortality, whereas undergoing coronary revascularization (0.28, 0.09–0.94) diminished this risk (all p<0.05) (Figure 2). Conclusion Refractory VF/pVT OHCA was associated with more intensive resuscitation, higher rates of acute coronary occlusion and poorer in-hospital outcomes, underscoring the need for future studies in this extreme-risk subgroup.Figure 1Figure 2

Clinical Features and Outcomes Among Patients With Refractory Out-of-Hospital Cardiac Arrest and an Initial Shockable Rhythm.

Clinical features among patients with refractory out-of-hospital cardiac arrest (OHCA) and initial shockable rhythms of ventricular fibrillation/pulseless ventricular tachycardia are not well-characterized. We compared clinical characteristics and coronary angiographic findings between patients with refractory OHCA (incessant ventricular fibrillation/pulseless ventricular tachycardia after ≥3 direct-current shocks) and those without refractory OHCA. Between 2014 and 2018, a total of 204 patients with ventricular fibrillation/pulseless ventricular tachycardia OHCA (median age 62; males 78%) were divided into groups with (36%, 74/204) and without refractory arrest (64%, 130/204). Refractory OHCA patients had longer cardiopulmonary resuscitation (23 versus 15 minutes), more frequently required ≥450 mg amiodarone (34% versus 3.8%), and had cardiogenic shock (80% versus 55%) necessitating higher adrenaline dose (4.0 versus 1.0 mg) and higher rates of mechanical ventilation (92% versus 74%; all P<0.01). Of 167 patients (82%) selected for coronary angiography, 33% (n=55) had refractory OHCA (P=0.035). Significant coronary artery disease (≥1 major vessel with >70% stenosis) was present in >70% of patients. Refractory OHCA patients frequently had acute coronary occlusion (64% versus 47%), especially left circumflex (20% versus 6.4%) and graft vessel (7.3% versus 0.9%; all P<0.05) compared with those without refractory OHCA. Refractory OHCA group had higher in-hospital mortality (45% versus 30%, P=0.036) and greater new requirement for dialysis (18% versus 6.3%, P=0.011). After adjustment, refractory OHCA was associated with over 2-fold higher odds of in-hospital mortality (odds ratio, 2.28 [95% CI, 1.06-4.89]; P=0.034). Refractory ventricular fibrillation/pulseless ventricular tachycardia OHCA was associated with more intensive resuscitation, higher rates of acute coronary occlusion, and poorer in-hospital outcomes, underscoring the need for future studies in this extreme-risk subgroup.

Rural versus urban out-of-hospital cardiac arrest response, treatment and outcomes in the North East of England from 2018 to 2019.

Out-of-hospital cardiac arrest (OHCA) is a time-sensitive medical emergency. There is international evidence to suggest that rural regions experience worse OHCA outcomes, such as reduced survival rates. The aim of this study was to quantitatively review and compare the OHCA response, treatment and pre-hospital outcomes in a single-centre ambulance service over a 1-year period in urban and rural areas. This study used retrospective OHCA audit data from the North East Ambulance Service NHS Foundation Trust, from April 2018 to April 2019, comparing OHCA response, treatment and return of spontaneous circulation (ROSC) data in relation to urban or rural classification status, using the UK government urban-rural classification tool. A total of 1295 urban cases and 319 rural cases were compared. Bystander public-access defibrillator (PAD) use was higher in rural areas in comparison to urban areas (20/319 (6.3%) vs 47/1295 (3.6%); p = 0.03). The mean ambulance response time was slower in rural areas (10:43 minutes (n = 319) (SD ± 8.2) vs 07:35 minutes (n = 1295) (SD ± 7.1); p = < 0.01). Despite this, overall ROSC rates at hospital were similar between the groups, with no statistically significant difference (rural: 87/319 (27.3%) vs urban: 409/1295 (31.6%); p = 0.14).A further sub-group analysis of initially shockable OHCA cases showed slower ambulance response times in rural areas (10:45 minutes (n = 68) (SD ± 12.3) vs 07:55 minutes (n = 245) (SD ± 5.5); p = < 0.01) and that rural cases experienced lower ROSC at hospital rates (31/68 (45.6%) vs 151/245 (61.6%); p = 0.02). This report showed differences in OHCA response and outcomes between rural and urban settings. In the shockable OHCA sub-group analysis, rural areas had slower ambulance response times and lower ROSC rates. The longer ambulance response times in the rural shockable OHCA group could be a factor in the reduced ROSC rates. Linking hospital survival data should be used in future research to explore this area further.

The effects of cardiopulmonary resuscitation (CPR) performed out-of-hospital and in-hospital with manual or automatic device methods and laboratory parameters on survival of patients with cardiac arrest.

Determining the predictive factors for cardiac arrest may be helpful in the management of in-hospital cardiac arrest (IHCA) and out-of-hospital cardiac arrest (OHCA) and in estimating the outcome. Therefore, in the present study, we aimed to investigate the effect of demographic data, cardiopulmonary resuscitation (CPR) initiating setting, compression method, and laboratory parameters on survival from cardiac arrest. A total of 414 patients who met the inclusion criteria were included in the study. Patients were grouped into those who underwent out-of-hospital CPR and those who underwent CPR in the hospital and patients who received automatic compression and those who did not receive. In addition to pH, lactate and bicarbonate in arterial blood gas, CK-MB, troponin, urea, creatinine, calcium, potassium, and glucose were measured. The mean age of patients was 70.36±15.68 years, and 170 (41.1%) were female. Although the success rate of CPR in the OHCA group (22.2%) was lower than in the patients in the IHCA group (30.9%), the difference was not statistically significant. There was no difference between the two groups in the comparison of mechanical compression devices and manual compression. In the logistic regression analysis, high pH and low lactate values were found to be independent predictors of survival. The results of this study revealed no significant difference between IHCA and OHCA CPR applications and between manual and mechanical compressions in terms of survival in patients with cardiac arrest. In addition, higher pH levels and lower lactate levels measured during CPR were independent predictors of survival.

Impact of Lactate on 30-Day All-Cause Mortality in Patients with and without Out-of-Hospital Cardiac Arrest Due to Cardiogenic Shock.

In patients with cardiogenic shock (CS) due to myocardial infarction, elevated lactate levels are known to be negative predictors. Studies regarding the prognostic impact in patients with CS complicated by out-of-hospital cardiac arrest (OHCA) are limited. Two hundred and sixty-three consecutive patients with CS were included. The prognostic value of lactate on days 1, 2, 3, 4 and 8 was tested stratified by OHCA and non-OHCA. Statistical analyses included the univariable t-test, Spearman's correlation, C-statistics, Kaplan-Meier analyses, as well as multivariable mixed analysis of variance (ANOVA) and Cox proportional regression analyses. The primary endpoint of all-cause mortality occurred in 49.4% of the non-OHCA group and in 63.4% of the OHCA group. Multivariable regression models showed an association of lactate values with 30-day all-cause mortality in the non-OHCA (p = 0.024) and OHCA groups (p = 0.001). In Kaplan-Meier analyses, patients with lactate levels ≥ 4 mmol/L (log-rank p = 0.001) showed the highest risk for 30-day all-cause mortality in the non-OHCA as well as in the OHCA group. However, in C-statistics lactate on days 1 and 8 had a better discrimination for 30-day all-cause mortality in the OHCA group compared to the non-OHCA group. In conclusion, patients presenting with CS lactate levels showed a good prognostic performance, with and without OHCA. Especially, lactate levels on days 1 and 8 were more accurate in the discrimination for all-cause mortality in CS-patients with OHCA.

Quantitative measurement of the pupillary light reflex has independent prognostic value in patients resuscitated from cardiac arrest

Abstract Funding Acknowledgements Type of funding sources: Private grant(s) and/or Sponsorship. Main funding source(s): Novo Nordisk Foundation Background Patients resuscitated from cardiac arrest (CA) are at high risk of unfavourable neurological outcome or death caused by anoxic brain injury. Bedside quantitative pupillometry are a promising new entity as part of the multimodal neuroprognostication. We aimed to evaluate the prognostic value of quantitative assessment of the percentage change in pupil size (%CH) in unconscious critically ill cardiac patients, both with or without CA. Methods Patients admitted to our cardiac intensive care unit from April 2015 to June 2017, assessed with serial quantitative pupillometry until discharge or death, were included. Patients were divided into subgroups of out-of-hospital-cardiac arrest (OHCA), in-hospital cardiac arrest (IHCA), and of other unconscious critically ill non-CA cardiac patients. With median value as cut-off, we used Cox regression to assess the association between %CH and the hazard ratios (HR) of 30-day mortality. In all groups we used multivariable Cox models adjusted for age, sex, and event of ST elevation myocardial infarction (STEMI) and for OHCA and IHCA, we further adjusted for CA variables of shockable primary rhythm and time to return of spontaneous circulation (ROSC). Kaplan-Meier survival analysis were performed for all groups. Results We included 221 patients (OHCA n=135, IHCA =28, and non-CA n=58), predominantly males, admitted with a mean age of 63±12 years (61±12 years for OHCA, 65±12 years for IHCA and 67±11 years for non-CA). We estimated the median %CH at 9.5% for OHCA, 11.0 for IHCA, and 13.0% for non-CA. In both CA groups, a %CH lower than the median were significantly (p&amp;lt;0.05) associated with an increased HR of 30-day mortality in univariate analysis. For OHCA patients, Cox regression yielded a HR of 2.5 with a 95% confidence interval (95% CI) of 1.346-4.542 in the unadjusted model, and a HR at 2.4 with 95% CI: 1.3-4.5 in the adjusted model. When adjusting for shockable primary rhythm and time to ROSC in the OHCA group HR remained significant at 2.4 with 95% CI: 1.2-4.7. In the IHCA group we found HR at 3.7 with 95% CI: 1.0-14.1 in both the unadjusted and adjusted model. However, results were borderline significant (p=0.052 and p=0.078, respectively). When adjusting for shockable primary rhythm and time to ROSC in the IHCA group the HR was 4.5, however with 95% CI: 0.4-46.1 and p=0.208. The non-CA group HR was 0.7 with 95% CI: 0.3-1.8 (unadjusted) and HR 0.7 with CI: 0.3-1.9 (adjusted), with p=0.470 and p=0.483, respectively. Kaplan-Meier curves presented significantly higher mortality in patients with %CH lower than the median for OHCA and IHCA. No significant risk was found for non-CA (p=0.510). Conclusion A %CH below 9.5% is independently and significantly associated with increased risk of death in patients resuscitated from OHCA. Further analyses may focus on identifying optimal cut-offs and further compare the prognostic information of different parameters in quantitative pupillometry.

Abstract 12069: Long-Term Trends in the Incidence and Outcome of Refractory and Non-Refractory Ventricular Fibrillation Cardiac Arrest

Introduction: Although many developed countries are reporting temporal improvements in out-of-hospital cardiac arrest (OHCA) outcomes from initial shockable rhythms, trends in the incidence and outcome of refractory ventricular fibrillation are not well understood. Methods: Between 2010 and 2019, we performed a retrospective observational study of OHCA from a population-based registry in Victoria, Australia. We included all adult, non-traumatic OHCA with an initial shockable rhythm. Temporal trends in incidence and survival to hospital discharge were compared across non-refractory and refractory OHCA, defined as cases receiving 3 or more consecutive shocks for a persistent shockable rhythm. Risk-adjusted logistic regression models were used to describe the year-on-year change in the likelihood of refractory OHCA and survival to hospital discharge. Results: Of the 7,267 initial shockable OHCA with an attempted resuscitation, 4168 (57.4%) and 3,099 (42.6%) were non-refractory and refractory OHCA, respectively. The proportion of cases with refractory OHCA declined over the study period from 48.4% in 2010 to 40.2% in 2019 (p trend &lt;0.001). Unadjusted survival to hospital discharge was higher in non-refractory OHCA (46.3% vs. 25.8%, p&lt;0.001), although both populations experienced increases in survival over time (p trend &lt;0.05 for both). After adjustment for arrest confounders, the likelihood of refractory VF decreased by 4.4% every year (adjusted odds ratio [AOR]: 0.96, 95% CI: 0.94, 0.97; p&lt;0.001). Factors reducing the likelihood of refractory OHCA were female sex, bystander CPR, arrest witnessed by emergency medical services, and public location. In the survival model, refractory OHCA was independently associated with a reduction in survival to hospital discharge (AOR 0.50, 95% CI: 0.45, 0.56; p&lt;0.001). Temporal improvements in survival were observed year-on-year (AOR 1.03, 95% CI: 1.02, 1.05; p&lt;0.001) and this did not differ between non-refractory and refractory OHCA (group interaction, p = 0.51). Conclusions: The incidence of refractory OHCA is declining in our region and survival outcomes are improving. Further research identifying factors contributing to the decline in refractory OHCA may help to improve outcomes further.

Impact of a Modified Institutional Protocol on Outcomes After Extracorporeal Cardiopulmonary Resuscitation for Refractory Out-Of-Hospital Cardiac Arrest

To analyze the impact of the modification of the authors' institutional protocol on outcomes after extracorporeal cardiopulmonary resuscitation (ECPR) for out-of-hospital cardiac arrest (OHCA). An observational analysis. The protocol complied with national recommendations. A further eligibility criterion was added since January 2015: the presence of sustained shockable rhythm at extracorporeal life support (ECLS) implantation. To assess the impact of this change, patients were divided into two groups: (1) from January 2010 to December 2014 (group A) and (2) from January 2015 to December 2019 (group B). The primary endpoint was survival to hospital discharge with good neurologic outcome. Predictors of survival were searched with multivariate analyses. University hospital. Adult patients supported with ECPR for refractory OHCA. None. From January 2010 to December 2019, 85 patients had ECLS for OHCA (group A, n=68, 80%; group B, n=17, 20%). The mean age was 42.4 years, 78.8% were male. The rate of implantation of ECLS was significantly lower in group B (p=0.01). Mortality during ECLS support was significantly lower (58.8 v 86.8%; p=0.008), and the weaning rate was significantly higher (41.2 v 13.2%; p=0.008) in group B. Survival to discharge with good neurologic outcome was significantly improved (23.5 v 4.4%; p=0.027) in group B. A sustained shockable rhythm was the only independent predictor of survival to hospital discharge with good neurologic outcome. The modification of the authors' institutional protocol throughout the further criterion of sustained shockable rhythm yielded a favorable impact on outcomes after ECPR for OHCA.

Cognitive dysfunction after out-of-hospital cardiac arrest: Rate of impairment and clinical predictors

BackgroundThe purpose of this study was to evaluate the rate and domains of cognitive impairment in out-of-hospital cardiac arrest (OHCA) survivors, as compared to patients who experienced a myocardial infarction (MI), and to explore mechanisms and predictors of this impairment. Methods and resultsOHCA survivors with “good” neurological recovery (i.e., Cerebral Performance Categories Scale ≤ 2) (n = 79), as well as a control group of MI patients (n = 69), underwent a comprehensive neuropsychological assessment. Forty-three percent of OHCA survivors were cognitively impaired (in the lowest decile on a global measure of cognitive functioning). Rates of impairment were approximately six times higher in the OHCA group than the MI group. Attention, memory, language and executive function were affected. Downtime was a significant predictor of cognitive impairment; the interaction between downtime and immediate intervention was significant such that, at short downtimes, receiving cardiopulmonary resuscitation (CPR) or defibrillation within 1 min of collapse predicted less cognitive impairment. ConclusionsOHCA survivors – even those with seemingly good neurological recovery – are at risk for cognitive impairment. Cognitive rehabilitation may be an important consideration post-OHCA.

Early predictors of mortality in refractory cardiogenic shock following acute coronary syndrome treated with extracorporeal membrane oxygenator.

We aimed to analyze the outcome and identify predictors of hospital mortality in patients with refractory cardiac arrest (CA) complicating acute coronary syndromes (ACS) and requiring veno-arterial extracorporeal membrane oxygenation (VA-ECMO) treatment. Between Jan-2005 and Dec-2019, 51 patients underwent urgent VA-ECMO implantation for CA in ACS. Patients were divided in two groups: "in-hospital" cardiac arrest (IHCA) and "out-of-hospital" cardiac arrest (OHCA). Prospectively collected data were retrospectively analyzed and compared between groups. Predictors for hospital mortality were investigated. IHCA and OHCA patients were 32 (62.7%) and 19 (37.3%), respectively. The groups differed for: male gender (72% vs 95%; p = 0.070), lactate peak level (8.5 ± 4.3vs10.7 ± 2.9; p = 0.023), total elapsed time from CA to VA-ECMO implantation in both groups (p < 0.001) and elapsed time from CA (IHCA group) or hospital arrival (OHCA group) to VA-ECMO implantation (38min vs 80min; p = 0.001). At logistic regression analysis, concomitant lactate level greater than 8.0mmol/L and elapsed time from CA to VA-ECMO ≥ 30min were predictors of increased mortality (OR 3.9; 95% CI 1.19-12.79; p = 0.025) for the entire population. In-hospital mortality was 60.8% (31/51 patients): 68.4% in OHCA group and 56.2% in IHCA group. No risk factors related to 30-day mortality resulted significant at univariable analysis. When rapidly instituted, VA-ECMO improves survival in patients with refractory cardiac arrest allowing coronary syndrome treatment. The association of an elapsed time from CA to VA-ECMO implantation longer than 30min and a preoperative lactate peak level over 8.0mmol/L predict a poor outcome, independently from being IHCA or OHCA.

Impact of Coronavirus Disease 2019 Pandemic on the Incidence and Management of Out-of-Hospital Cardiac Arrest in Patients Presenting With Acute Myocardial Infarction in England.

BackgroundStudies have reported significant reduction in acute myocardial infarction–related hospitalizations during the coronavirus disease 2019 (COVID‐19) pandemic. However, whether these trends are associated with increased incidence of out‐of‐hospital cardiac arrest (OHCA) in this population is unknown.Methods and ResultsAcute myocardial infarction hospitalizations with OHCA during the COVID‐19 period (February 1–May 14, 2020) from the Myocardial Ischaemia National Audit Project and British Cardiovascular Intervention Society data sets were analyzed. Temporal trends were assessed using Poisson models with equivalent pre–COVID‐19 period (February 1–May 14, 2019) as reference. Acute myocardial infarction hospitalizations during COVID‐19 period were reduced by >50% (n=20 310 versus n=9325). OHCA was more prevalent during the COVID‐19 period compared with the pre–COVID‐19 period (5.6% versus 3.6%), with a 56% increase in the incidence of OHCA (incidence rate ratio, 1.56; 95% CI, 1.39–1.74). Patients experiencing OHCA during COVID‐19 period were likely to be older, likely to be women, likely to be of Asian ethnicity, and more likely to present with ST‐segment–elevation myocardial infarction. The overall rates of invasive coronary angiography (58.4% versus 71.6%; P<0.001) were significantly lower among the OHCA group during COVID‐19 period with increased time to reperfusion (mean, 2.1 versus 1.1 hours; P=0.05) in those with ST‐segment–elevation myocardial infarction. The adjusted in‐hospital mortality probability increased from 27.7% in February 2020 to 35.8% in May 2020 in the COVID‐19 group (P<.001).ConclusionsIn this national cohort of hospitalized patients with acute myocardial infarction, we observed a significant increase in incidence of OHCA during COVID‐19 period paralleled with reduced access to guideline‐recommended care and increased in‐hospital mortality.

Exploratory Analyses of Cerebral Gray Matter Volumes After Out-of-Hospital Cardiac Arrest in Good Outcome Survivors.

BackgroundSurvival rates of cardiac arrest have increased over recent years, however, survivors may still be left with significant morbidity and functional impairment. A primary concern in cardiac arrest survivors is the effect of prolonged hypoxia/ischemia on the brain. The objectives of the present study were threefold: (1) to explore the effect of cardiac arrest on brain gray matter volumes (GMV) in “good outcome” survivors of out-of-hospital cardiac arrest (OHCA), (2) to examine the relationship between GMV, cognitive functioning and arrest factors, and (3) to explore whether OHCA patients differ from a group of patients with myocardial infarction (MI) uncomplicated by cardiac arrest and a group of healthy controls in terms of GMV.MethodsMedically stable OHCA survivors with preserved neurological function and who were eligible for magnetic resonance imaging scanning (MRI; n = 9), were compared to: (1) patients who had experienced a MI (n = 19) and (2) healthy controls (n = 12). Participants underwent brain MRI on a 3T Siemens Trio MRI scanner and GMV was measured by voxel-based morphometry. A comprehensive neuropsychological assessment was also conducted. Global GMV was compared in the three samples using analyses of variance. The relationships between cognition and GMV were examined within group using correlations.ResultsThe OHCA and MI groups showed a similar pattern of differences compared to the healthy control group. Both groups had decreased GMV in the anterior cingulate cortex, bilateral hippocampus, right dorsolateral prefrontal cortex, right putamen, and bilateral cerebellum. There were no significant differences in global or regional GMV between the OHCA and MI groups. Cognitive functioning was correlated with global GMV in the OHCA group; no such correlation was observed in the MI group.ConclusionRegional atrophy was observed in OHCA and MI survivors, compared to a healthy control group, suggesting a common mechanism, presumably preexisting cardiovascular disease. Although similar regional volume differences were observed between the MI and OHCA groups, the relationship between GMV and cognition was only observed in OHCA survivors. We suggest the acute hypoxia/ischemia ensuing from the arrest may interact with diminished neural reserve in select brain areas to expose occult cognitive dysfunction.

Infections in out-of-hospital and in-hospital post-cardiac arrest patients.

This study aims to describe infectious complications in both out-of-hospital cardiac arrest (OHCA) and in-hospital cardiac arrest (IHCA) patients with sustained return of spontaneous circulation (ROSC) and to compare differences in antimicrobial treatment and outcomes between the two groups. This was a retrospective, single-center, observational study. Adult patients (≥ 18years) with OHCA or IHCA who had sustained ROSC between December 2007 to March 2015 were included. Blood, urine, sputum, and other fluid cultures, as well as radiologic imaging, were obtained at the discretion of the treating clinical teams. 275 IHCA and 318 OHCA patients were included in the analysis. We found evidence of infection in 181 IHCA and 168 OHCA patients. Significant differences were found between the IHCA and OHCA group in terms of initial rhythm, duration of arrest (10min vs. 20, p = < 0.001), targeted temperature management (30% vs. 73%, p = < 0.001), and post-arrest infection rates (66% vs 53%, p = 0.001). 95% of IHCA and 82% of OHCA patients received antimicrobial treatment in the post-cardiac arrest period. The source of infection in both groups was largely respiratory, followed by urinary. Gram-positive cocci and gram-negative rods were the most common organisms identified among subjects with culture-proven bacteremia. Infections in the post-arrest period were common in both OHCA and IHCA. We found significantly more infections in IHCA compared to OHCA patients. The most common infection category was respiratory and the most common organism isolated from sputum cultures was Staphylococcus aureus coagulase-positive. The incidence of culture-positive bacteremia was similar in both OHCA and IHCA cohorts but overall lower than previously reported.

P1728Cardiogenic shock patients: those with and those without out-of-hospital cardiac arrest are different clinical entities

Abstract Introduction Cardiogenic shock (CS) due to myocardial infarction (MI) carries 30-day mortality rates as high as 50%. The vast majority of study cohorts assessing mortality in CS comprise both patients presenting with and without out-of-hospital cardiac arrest (OHCA). Patients with and without OHCA are likely to represent two distinctive entities, which may be problematic to combine in an intervention trial. Purpose The aim of the study was to compare CS due to MI patients presenting with and without OHCA in terms of patient characteristics and outcome. Methods In the period from 2010–2017 all patients admitted at two tertiary heart centres in Denmark with CS following MI were individually identified and validated through patient records. The two centres have a catchment area of 3.9 million citizens corresponding to two-thirds of the Danish population. Results A total of 1716 CS patients were identified, of which 42% presented with OHCA. OHCA patients were younger (mean 63 vs 67 years), more frequently male (85 vs 67%), had higher lactate concentration (median 6.2 vs 5.0 mmol/L) on admission and higher left ventricular ejection fraction (median 30 vs 25%) compared to patients without OHCA (p&lt;0.0001 for all). Patients presenting with OHCA had lower 30-day mortality compared to patients without OHCA (49% vs. 57%, respectively, plogrank&lt;0.0001, Figure). Cause of in hospital death differed markedly between the two groups. Not surprisingly, anoxic brain damage was the leading cause of in hospital death in the OHCA group (56%) and only seen in 4% of patients without OHCA. In contrast, cardiac failure was the main cause of death in hospital death among patients without OHCA (60%), compared to 27% in patients with OHCA (p&lt;0.0001). Figure 1 Conclusion Among patients with CS due to MI, overall 30-day mortality was significantly lower in patients presenting with OHCA. Anoxic brain damage was the main cause of in hospital death among OHCA patients, whereas fatal heart failure prevailed in patients without OHCA. Combining these two groups in a single trial with one specific intervention seems inappropriate and likely to cause an imbalance in the signal-to-noise ratio. Acknowledgement/Funding The Danish Heart Foundation and a research grant from Abiomed

B-09 Cerebral Grey Matter After Out-Of-Hospital Cardiac Arrest In Good Outcome Survivors

Abstract Objective The purpose of this study was to evaluate the impact of out-of-hospital cardiac arrest (OHCA) on cognitive functioning and brain volumes, in good outcome survivors. Method Participants were medically stable OHCA survivors. Two control groups were also recruited: patients who experienced myocardial infarction (MI), and healthy controls (HC) with no history of cardiovascular disease. Neuropsychological assessment was conducted using the Neuropsychological Assessment Battery (NAB). Imaging was performed on a 3T Siemens Trio MRI scanner. Cerebral grey matter volume (GM; measured by voxel-based morphometry in SPM12) results are presented. Results Participants (nOHCA = 9, nMI = 19, nHC = 13) ranged in age from 30 to 85 years. When controlling for age, whole-brain analyses revealed decreased GM in anterior cingulate cortex, bilateral hippocampus in the OHCA and in the MI group compared to the HC group. In addition, the MI group had decreased GM compared to the HC in the thalamus and the right dorsolateral prefrontal cortex (p &lt; .001). No significant differences in GM were observed between the MI and OHCA groups. The hippocampus was selected as a region-of-interest for further analyses. The Total NAB Index was correlated with hippocampal GM in the OHCA group but not in the MI group (rOHCA = .78, p = .014). Conclusions Results revealed select areas of GM reduction in OHCA and MI groups, suggesting a contribution of cardiovascular disease to observed atrophy. Reductions are related to cognitive performance only in the cardiac arrest group which may suggest that these volume losses represent clinically meaningful changes.

Cortical Thickness and Cognitive Performance After Out-of-Hospital Cardiac Arrest

Background. Cognitive impairment is common in long-term survivors of out-of-hospital cardiac arrest (OHCA) but corresponding neuroimaging data are lacking. Objectives. This study explored the relationship among the cortical brain structure, cognitive performance, and clinical variables after OHCA. Methods. Three months after resuscitation, 13 OHCA survivors who had recovered from a coma to living independently and 19 healthy controls were assessed by cerebral magnetic resonance imaging and neuropsychological tests quantifying memory, fine-motor coordination, and attention/executive functions. Cortical thickness (Cth) and surface area (SA) were compared between groups and analyzed for relationships with cognitive performance as well as the clinical variables of coma duration and the time to return of spontaneous circulation (ROSC). All analyses were controlled for age and sex. Results. Analyses of SA revealed no significant differences. Compared with controls, survivors had significantly reduced memory and fine-motor coordination and significantly thinner cortex in large clusters in the frontal, parietal, and inferior temporal cortices, with additional regions in the left occipital lobe and the left temporal lobe. Widespread thinner cortical regions were significantly associated with decreased memory performance in survivors when compared with those in controls and were significantly associated with an increased time to ROSC and increased coma duration in the OHCA group. Increased coma duration, but not increased time to ROSC, was significantly correlated with cognitive test performance. Conclusions. The results suggest that widespread Cth reductions correspond to the cognitive impairments observed after OHCA. Neuroimaging studies of long-term OHCA survivors are warranted to guide the development of diagnostics and treatment options.

Platelet dysfunction after Out of Hospital Cardiac Arrest. Results from POHCAR: A prospective observational, cohort study

AimCoagulation and platelet function following out of hospital cardiac arrest (OHCA) at admission to a UK cardiology centre were investigated prospectively in this observational feasibility study, and compared to that of patients receiving percutaneous coronary intervention (PCI) for ST segment elevation myocardial infarction (STEMI). MethodBlood samples taken immediately at emergency department admission from patients after OHCA of probable cardiac origin were analysed using near-patient thromboelastometry and a platelet function analyser. Physiological parameters, demographic information, bleeding rates and 30-day survival were recorded, and compared to that of patients undergoing PCI for STEMI. ResultsThirty patients were enrolled into each group. Platelet activation with thrombin receptor stimulation was reduced in OHCA patients compared to STEMI patients; mean TRAP AUC OHCA 79.3 (95% CI 63.7–94.9) vs STEMI 101.6 (95% CI 87.4–115.8), p = 0.03. The maximum clot firmness time was prolonged in the OHCA group compared to the STEMI group; 1718s (1545s–1906s) vs 1544s (1387s–1709s), p = 0.01. Other measures of clot formation and strength were comparable between groups. Hyperfibrinolysis (maximum lysis > = 15%) was common in both groups (57% in STEMI; 50% in OHCA) but did not increase 30-day bleeding risk. ConclusionOHCA patients demonstrated reduced thrombin receptor function at hospital admission but overall clot formation dynamics comparable to STEMI patients, indicating no gross coagulopathy post OHCA in our cohort. Hyperfibrinolysis was common both post OHCA and after STEMI. The results of this small feasibility study cannot draw clinical conclusions but will inform power calculations for future studies.

Long-term survival in patients presenting with STEMI complicated by out of hospital cardiac arrest

BackgroundThere is limited data regarding long-term survival in patients who present with STEMI and out of hospital cardiac arrest (OHCA). MethodsWe prospectively analysed outcomes in 3521 consecutive patients who were diagnosed with STEMI and underwent primary percutaneous coronary intervention (PPCI) or coronary artery bypass surgery from 2004 to 2017. They were divided into two groups according to the presence of cardiac arrest (group I, patients with cardiac arrest; n = 156 group II, patients without cardiac arrest; n = 3365). ResultsPatients with OHCA had higher in hospital mortality (27.7% vs 2.9%, p < 0.01), sustained VT or VF (44.6% vs 4.3%, p < 0.01) and cardiogenic shock (22.9% vs 6.8%, p < 0.01). 30-day mortality (excluding death within first 24 h) was also higher in the OHCA group (24.6% vs 3.3%, p < 0.01). There was no significant difference in recurrent AMI, TVR, stroke, major bleeds or new onset heart failure. After a mean follow-up of 18.6 months, mortality was higher in patients with OHCA (7.9% vs 3.8%, p 0.04). This was driven mainly by an increase in cardiac mortality (5% vs 1.1%, p < 0.01). OHCA was a significant predictor of mortality beyond 30 days (HR – 2.5, 95% CI 0.99–6.3). Kaplan–Meier curves and the log-rank test revealed that patients with OHCA had significantly lower survival (p < 0.01). ConclusionsPatients with STEMI complicated by OHCA remain a high-risk group associated with high in hospital mortality. Beyond 30 days the occurrence of cardiac arrest was a significant predictor of all-cause and cardiac mortality.

Effects between chest-compression-only cardiopulmonary resuscitation and standard cardiopulmonary resuscitation for patients with out-of-hospital cardiac arrest: a Meta-analysis

To comprehensively evaluate and compare the resuscitation efficacy of chest-compression-only cardiopulmonary resuscitation (CCPR) and standard cardiopulmonary resuscitation (SCPR) for patients with out-of-hospital cardiac arrest (OHCA). Databases such as PubMed, Embase, Ovid, Cochrane Library, Wanfang, CNKI, VIP, CBM were searched from the date of their foundation to March 2nd 2018, and the studies on the difference of effects between CCPR and SCPR for patients with OHCA were retrieved. The outcomes included the return of spontaneous circulation (ROSC) rate, survival to hospital discharge, neurological function completion rate. Two reviewers independently screened the literature meeting the inclusion criteria, independently collected information and evaluated the literature quality. Meta-analysis was conducted using RevMan 5.3 software, and sensitivity analysis was conducted by selecting model analysis method and removing single research method. Funnel plot was used to evaluate publication bias. A total of 10 cohort studies were included, including 174 163 patients with OHCA, of which 95 157 undergone CCPR and 79 006 undergone SCPR. The scores of the Newcastle-Ottawa scale (NOS) were 8-9, indicating that the quality of the literatures included was high. It was shown by the Meta-analysis that CCPR had the higher rate of survival to hospital discharge [relative risk (RR) = 1.04, 95% confidence interval (95%CI) = 1.00-1.08, P = 0.04] and neurological function completion (RR = 1.11, 95%CI = 1.06-1.17, P < 0.000 1) than SCPR, but there was no significant difference in ROSC rate between the two groups (RR = 1.01, 95%CI = 0.98-1.04, P = 0.52). In the subgroup, there was no statistical significance between CCPR and SCPR in the rate of survival to hospital discharge in cardiac OHCA patients (RR = 1.13, 95%CI = 0.82-1.57, P = 0.45). However, in non-cardiac OHCA group, SCPR showed more benefits than CCPR in improving the rate of survival to hospital discharge (RR = 0.88, 95%CI = 0.80-0.96, P = 0.004). The above analysis results were consistent in the fixed effect model and random effect model, indicating that the results were reliable and stable. It was shown by the funnel plot that most of the studies were left-right inverted funnel type, indicating a low publication bias. However, the bias could not be completely excluded due to the small number of included literatures. For patients without OHCA etiological classification, CCPR was not less than SCPR in improving ROSC rate, discharge survival rate and good neurological function, and CCPR was more advantageous in learning and the willingness of bystanders to implement. However, when non-cardiogenic OHCA could be identified, SCPR should be recommended when conditions permit.