Adult Out-of-hospital Cardiac Arrest Research Articles

The “invisible ceiling” of bystander CPR in three Asian countries: Descriptive study of national OHCA registry

BackgroundBystander cardiopulmonary resuscitation (CPR) for out-of-hospital cardiac arrest (OHCA) has increased in Singapore, Japan, and South Korea following the implementation of several public health, bystander-focused interventions, such as dispatcher-assisted CPR and community CPR training. It is unclear whether bystander CPR prevalence will continue on this trajectory over time. This study aimed to investigate the temporal trends of bystander CPR prevalence over a ten-year period in these three Asian countries. MethodUsing the national OHCA registries of Singapore, Japan and South Korea, we included witnessed, non-traumatic adult OHCA registered between 2010 and 2020 in Singapore and Japan, and between 2012 and 2020 in South Korea. We excluded those for whom resuscitation was not attempted or was terminated at scene. The study analysed the proportion of bystander CPR in the three countries, presenting the data annually and further breaking it down by age and gender. ResultsThis study included 491,067 patients in Japan [male 59 %, median, age 79 years (Q1-Q3, 69–87)], 13,143 patients in Singapore [male 66 %, median, age 69 years (Q1-Q3, 57–80)], and 87,997 patients in South Korea [male 64 %, median age 72 years (Q1-Q3, 59–81)]. The proportion of bystander CPR in each country had increased (Japan: 39 % in 2010 to 45 % in 2015, Singapore: 22 % in 2010 to 53 % in 2015, and South Korea: 37 % in 2012 to 56 % in 2015); however, these proportions have plateaued in 2020 (Japan: 46 %, Singapore: 54 %, and South Korea: 57 %) despite continued efforts. These trends were consistent across different age groups, gender and location. ConclusionThis study investigated the trend of bystander CPR over 10 years in three Asian countries. Although the proportion of bystander CPR has increased, it has now plateaued between 50–60 %. Further research is necessary to identify the contributing factors and advance beyond this “invisible ceiling”.

Ethical issues in termination of resuscitation decision-making: an interview study with paramedics and relatives of out-of-hospital cardiac arrest non-survivors

BackgroundIn out-of-hospital cardiac arrest (OHCA), decisions to terminate resuscitation or transport the patient to hospital are ethically fraught. However, little is known about paramedics’ ethical concerns in these decision-making processes.ObjectiveTo...

Abstract Su906: Patient and Arrest Characteristics Associated with Rearrest and Mortality Following Out of Hospital Cardiac Arrest

Background: Cardiac rearrest post-return of spontaneous circulation (ROSC) is a critical concern in emergency care, as it is associated with worse outcomes. Patient characteristics and arrest factors associated with rearrest remain poorly understood, making predicting rearrest after out of hospital cardiac arrest (OHCA) challenging. Aim: To examine rearrest patterns, identify patient-specific risk factors for rearrest, and assess the impact of rearrest on patient outcomes. Hypothesis: Patients that experience rearrest after OHCA will have greater cardiac comorbidities, unfavorable arrest characteristics, and greater mortality. Methods: We performed an observational single-site clinical trial of consecutive adult EMS OHCA patients with ROSC (1/01/2018 to 3/31/24). EMS reports, continuous EMS ECG recordings, and electronic health records were analyzed to determine rearrest occurrence at any time during EMS and ED care. Patient demographics, comorbidities, and arrest/rearrest characteristics were determined. The primary outcome was survival at 6 months. Statistical significance was determined using Chi-square and logistic regression (LR) analyses. Results: We examined 344 patients with OHCA and ROSC, of whom 173 patients rearrested and 171 did not. Patients experiencing rearrest were older (p<0.003) and more likely to be female (p<0.013). They were also more likely to have ED resuscitation medications and interventions (epinephrine, amiodarone, lidocaine, defibrillation, all p<0.001) and a higher incidence of underlying cardiovascular comorbidities, including HTN and CAD (p<0.03). Notably, PEA and asystole were the most common rearrest rhythms, and time from arrest to ROSC was greater (30±16 vs. 25±15 min, p<0.007) in rearrest patients vs. those who did not rearrest. Patients with rearrest were less likely to receive TTM (p<0.003) and importantly, had higher rates of in-hospital and six-month mortality (both p<0.001). In a LR model, no rearrest (OR 2.4, 1.1-5.2), shockable arrest rhythm (OR 9.3, 4-22), female sex (OR 3.3, 1.6-6.5), and therapeutic hypothermia (OR 3.3, 1.7-6.4), were associated with survival (all p<0.04). Conclusions: Rearrest is independently associated with mortality. Increased age, male sex, and underlying cardiac comorbidities were associated with rearrest. Patient and arrest characteristics may predict rearrest. Improved understanding of why these factors promote rearrest will be important to prevent rearrest to enhance OHCA outcomes.

Abstract Su804: Use of Machine Learning Models to Predict Neurologically Intact Survival for Advanced Age Adults Following Out-of-hospital Cardiac Arrest

Background: We recently published a multivariable logistic regression model that successfully predicted neurologic outcomes in advanced age adults (≥ 65 years old) who achieve return of spontaneous circulation following out-of-hospital cardiac arrest (OHCA). Prior to externally validating this model, we sought to compare the predictive performance of our logistic regression model against common machine learning (ML) algorithms using the same dataset. Methods: We performed a retrospective observational analysis of the Cardiac Arrest Registry to Enhance Survival database from 2013-2021. All non-traumatic OHCA occurring in adults (≥65 years) who survived to hospital admission were included. The primary outcome measure was neurologically intact survival defined as a cerebral performance category (CPC) score of 1 or 2 at hospital discharge. Our original logistic regression model was compared to Boosted Trees and Decision Tree ML algorithms and assessed using accuracy, Area Under the Receiver Operating Characteristic Curve (AUC-ROC) and Area Under the Precision-Recall Curve (AUC-PR). The model variables included age, gender, race/ethnicity, location, witnessed status, who initiated cardiopulmonary resuscitation, whether an automated external defibrillator was applied prior to emergency medical services arrival, and first monitored rhythm. Results: A total of 83,561 OHCA were included. Median age was 75 years (IQR 69-82), 58.9% were male, 53% were White, 67% experienced an OHCA at home, 52% were witnessed by a bystander, 44% received bystander CPR, and 34% were found in shockable rhythm. Neurologically intact survival (CPC 1 or 2) occurred in 23% of patients. The logistic regression model had an accuracy of 79.6%, AUC-PR 0.542, and AUC-ROC of 0.774. The Boosted Trees model had an accuracy of 79.2%, AUC-PR 0.555, and AUC-ROC of 0.774. The Decision Tree Model had an accuracy of 79.3%, AUC-PR 0.490, and AUC-ROC of 0.717. Conclusion: Boosted Trees and Decision Tree ML models performed comparably to the logistic regression model in predicting favorable versus unfavorable neurological outcomes following successful resuscitation from OHCA in advanced-age adults. Given their similar performance, logistic regression may be preferred for its simplicity and interpretability over alternative ML models. Future efforts to improve and ultimately externally validate the model are warranted.

Abstract Sa1101: Association Between Changes in Hypoxic-Ischemic Brain Injury and Neurological Outcomes in Cardiac Arrest Survivors.

Aim: Quantitative analysis of hypoxic-ischemic brain injury (HIBI) using apparent diffusion coefficient (ADC) values from brain magnetic resonance imaging (MRI) is used to predict poor neurological outcomes in out-of-hospital cardiac arrest (OHCA) survivors. Our study aimed to determine the association between changes in HIBI and neurological outcomes in OHCA survivors using two types of MRI. Methods: This observational study used data collected prospectively from a tertiary academic hospital. The study included adult comatose OHCA survivors who underwent targeted temperature management (TTM) and brain MRI within 6 hours (first) and 72–96 hours (second) using the same MR scanner. We analyzed the neurological outcomes based on brain volumes below a specific ADC value using 10-step intervals within the range of 200–1200 × 10 -6 mm 2 /s for the first and second MRIs. ADC-R(x) represents the proportion of total brain volume occupied by voxels, with ADC values ranging from 200 × 10 -6 mm 2 /s to each threshold. Additionally, ADC(x) represents the proportion of total brain volume occupied by voxels that are “threshold - 10” at each threshold. Poor neurological outcomes were categorized as cerebral performance levels 3–5, observed 6 months after OHCA. Results: Overall, 122 patients (25% female) were included in the analysis, of whom 61 (50%) showed poor neurological outcomes. Higher ADC-R(x) were observed in the poor neurological outcome group on both the first and second MRI scans at all ADC intervals (all P < 0.05) (Figure 1). In the Good Neurological Outcome group, the ADC-R values ranged between 370 and 940, with the second MRI value being smaller than that of the first (right shift, P < 0.05). In contrast, the Poor Neurological Outcome group showed ADC-R values ranging between 340 and 1190, with the second MRI value being higher than that of the first (left shift, P < 0.05) (Figure 2). The difference in ADC(x) between the second and first MRI based on neurological outcome showed a positive change in ADC below 620 for a poor neurological outcome and a positive change in ADC above 740 for a good neurological outcome (Figure 3). Conclusions: In this cohort study, we observed that the initial HIBI that occurred during OHCA worsened or returned to normal depending on the neurological outcome after TTM. Prospective multicenter studies are required to generalize our findings.

Abstract Su605: Return of Spontaneous Circulation after Transport with Ongoing Cardiopulmonary Resuscitation: Is Transport Always Futile?

Introduction: Despite validated Termination of Resuscitation (TOR) rules for Out of Hospital Cardiac Arrest (OHCA) some OHCA patients are transported prior to Return of Spontaneous Circulation (ROSC), sometimes with long transport times. There are certain therapies unavailable in the prehospital setting which could make transport prior to ROSC beneficial for some OHCA patients. Hypothesis: We hypothesized that longer transport times for patients with ongoing Cardiopulmonary Resuscitation (CPR) would be associated with progressively lower probability of achieving ROSC. Aims: To determine if there is a transport time interval beyond which ROSC becomes so unlikely that transport time could be determinant factor for TOR. Methods: We performed a retrospective study of the 2020-2022 NEMSIS national prehospital dataset. We included adult OHCA patients that did not have ROSC prehospital, were transported to the hospital, and had outcome and timestamp data available. We calculated transport time for each encounter and stratified encounters into 5-minute transport time intervals. We defined our outcome as ROSC after transport. We used multivariable logistic regression evaluating the association between 5-minute increases in transport time and ROSC. We performed a secondary analysis of patients that met termination of resuscitation (TOR) criteria (unwitnessed OHCA with no CPR or AED placement prior to EMS arrival). Results: Of 1,409,692 OHCAs, we included 137,957 OHCAs that were transported without prehospital ROSC. The median transport time was 8.9 minutes (IQR 5.4-13.8), and 17,957 (13.1%) had ROSC after hospital arrival. In 5-minute intervals from 0-30 minutes, ROSC rates were 13.5%, 13.1%, 12.0%, 11.1%, 12.1%, and 13.9%. Odds of ROSC per 5-minute increase in transport time was 1.00 (95% CI 1.00-1.00). For patients that met field TOR criteria, rates of ROSC for each 5-minute interval from 0-30 minutes were 9.2%, 8.7%, 7.6%, 5.9%, 6.1%, 4.2%, 7.5%. Odds of ROSC per 5-minute increase in transport time was 0.93 (95% CI 0.88-0.98). Conclusion: In this dataset we were unable to identify a transport time interval up to 30 mins beyond which transport is futile, even in patients who were transported despite meeting the universal TOR rule. Decision to transport based on case-by-case OHCA characteristics could have influenced results. Further research is needed to identify the subset of patient in whom transport prior to ROSC may be beneficial.

The association between intra-arrest arterial blood pressure and return of spontaneous circulation in out-of-hospital cardiac arrest

BackgroundThe optimal haemodynamic parameter for goal-directed resuscitation in out-of-hospital cardiac arrest (OHCA) remains uncertain. This study aimed to characterise the association between invasive blood pressure (IBP) measurements and return of spontaneous circulation (ROSC) in adult OHCA patients, to identify this parameter. MethodsA retrospective observational study was conducted at East Anglian Air Ambulance (EAAA). Adult (≥18 years) medical OHCA patients attended by EAAA between 01/02/2015 and 01/02/2024, who had arterial IBP measurement during chest compressions were included. The initial, minimum, maximum, average (mean) and Δ (maximum-initial) were calculated for systolic (SBP), diastolic (DBP) and mean arterial (MAP) components of IBP. Logistic regression and receiver operating characteristic curves tested the association between IBP variables and ROSC. ResultsDuring the study period, 4363 OHCA patients were attended and 80 met inclusion criteria. Thirty-four patients (42.5 %) achieved ROSC and 4 (5.0 %) survived to discharge. The maximum, average and Δ DBP; and maximum and average MAP were positively associated with ROSC. Maximum DBP had an AUC of 0.83 (95 % CI 0.74–0.92) with an optimal cut-off of 35 mmHg (sensitivity 94.1 %; specificity 58.7 %) for predicting ROSC. The odds ratio for ROSC was 1.05 (95 % CI 1.03–1.08) for every 1 mmHg increase in maximum DBP. ConclusionsThis study supports the use of arterial DBP as an important haemodynamic parameter for goal-directed resuscitation in adult OHCA. Maximising DBP may increase the chances of ROSC. These data suggest that a DBP threshold of 35 mmHg is optimal for identifying patients who may achieve ROSC with continued resuscitation.

Out-of-hospital cardiac arrest in patients with psoriasis

Abstract Background Psoriasis is a complex autoinflammatory disease that has been associated with atherosclerosis, higher risks of cardiovascular diseases, and electrocardiographic changes. Whether these risk factors lead to higher risks of out-of-hospital cardiac arrest (OHCA) is undetermined. Purpose To investigate whether psoriasis is associated with OHCA. Method Using the nationwide Danish Cardiac Arrest Registry, we identified adult (≥18 years) OHCA patients of presumed cardiac cause with and without psoriasis between June 1st 2001 and December 31st 2019. The association of cardiac arrest was estimated using time-varying Cox regression fitted with a nested case-control design where we matched up to five controls per case on age, sex and year of OHCA and 4 comorbidities: ischemic heart disease, congestive heart failure, cardiovascular risk factors, and major extra cardiac organ disease. In subgroup analyses, the main analysis was repeated in patients with severe psoriasis (presence of inpatient hospital contact during the previous year) as compared to mild psoriasis. Results We included 43,967 OHCA cases and matched with 219,772 controls from the general population. The median age was 72 years, 68% were male and 26% had ischemic heart disease, 21% had congestive heart failure, 57% had cardiovascular risk factors, and 33% had extra cardiac organ disease (Table 1). We identified 1,145 (2.6%) cases and 4,971 (2.3%) controls who had psoriasis. Compared with cardiac arrest cases without psoriasis, cases with psoriasis had similar age and sex distribution, prevalence of ischemic heart disease, and congestive heart failure, but a higher prevalence of cardiovascular risk factors, major extra cardiac organ disease and Charlson score distribution. Psoriasis was significantly associated with higher hazard ratios of OHCA: HR 1.16 [95% confidence interval: 1.08 - 1.23] (Figure 1). Compared to no psoriasis, having severe psoriasis was significantly associated with higher hazard of OHCA: HR 1.98 [95% confidence interval: 1.10 - 3.61], while mild psoriasis was not (Figure 1). Conclusion In this nationwide nested case-control study, psoriasis was significantly associated with increased hazard of out-of-hospital cardiac arrest. Furthermore, the association was only significant with severe psoriasis compared to those without psoriasis, while mild psoriasis was not. This study highlights the importance of examining cardiovascular risk factors and prioritizing prevention of cardiovascular disease in patients with psoriasis.Figure 1Table 1

Valvular heart disease and out-of-hospital cardiac arrest

Abstract Background The prevalence of valvular heart disease is on the rise. Severe valvular diseases are generally associated with high mortality, and aortic stenosis (AS) is associated with halved survival after out-of-hospital cardiac arrest (OHCA). Despite the severity of the prognosis of valvular heart diseases, their association with the risk of OHCA is not well-elucidated. Purpose The study aimed to examine the association between valvular heart disease and OHCA. Method We conducted a study using data from the nationwide Danish Cardiac Arrest Registry. We included adult OHCA patients with presumed cardiac origin. We compared OHCA cases with and without valvular heart disease, stratified by valvular disease type (AS, aortic regurgitation (AR), mitral stenosis (MS), and mitral regurgitation (MR) or multiple valvular diseases (more than 1 concomitant type of valvular disease)). We calculated the hazard ratios of OHCA using time-varying Cox regression models fitted with a nested case-control design. For each case, we matched up to five controls based on age, sex, year of OHCA, and two comorbidities: ischemic heart disease and congestive heart failure. Results We included 43,967 OHCA cases and 219,772 controls matched from the general population. In the total case population, the median age was 72 years, 68% were male, 26% had ischemic heart disease, 21% had congestive heart failure, and 57% had cardiovascular risk factors. We identified 1862 (4.23%) cases with AS, 336 (<1%) with AR, 31 with MS (<1%), 710 with MR (1.6%), and 605 with multiple valvular diseases (1.4%). Compared with cardiac arrest cases without valvular disease, cases with valvular disease were more likely to have ischemic heart disease (e.g., AS vs controls: 6.5% vs 1.7%, p<0.001) and congestive heart failure (e.g., MR vs controls: 3.5% vs 1%, p<0,001; AS vs controls: 8.2% vs 2.8%, p<0.001). AS, MS (HR: 1.67 [95%CI: 1.12; 2.51]), MR (HR: 1.38 [95%CI: 1.27; 1.50]) and multiple valvular diseases (HR: 1.36 [95%CI: 1.24; 1.49]) were significantly associated with higher hazard of OHCA (Figure 1); the strongest association was seen for AS (HR: 1.66 [95% CI: 1.58; 1.76]) (Figure 1). AR was not significantly associated with OHCA (HR: 1.05 [95%CI: 0.94; 1.19]). Conclusion In this Danish nationwide cardiac arrest cohort, aortic stenosis, aortic regurgitation, and mitral regurgitation were associated with increased rates of OHCA. The association was strongest in aortic stenosis patients. Focus on risk factors of OHCA in patients with valvular heart disease is warranted.Figure 1

Individualized decision making in on-scene resuscitation time for out-of-hospital cardiac arrest using reinforcement learning

On-scene resuscitation time is associated with out-of-hospital cardiac arrest (OHCA) outcomes. We developed and validated reinforcement learning models for individualized on-scene resuscitation times, leveraging nationwide Korean data. Adult OHCA patients with a medical cause of arrest were included (N = 73,905). The optimal policy was derived from conservative Q-learning to maximize survival. The on-scene return of spontaneous circulation hazard rates estimated from the Random Survival Forest were used as intermediate rewards to handle sparse rewards, while patients’ historical survival was reflected in the terminal rewards. The optimal policy increased the survival to hospital discharge rate from 9.6% to 12.5% (95% CI: 12.2–12.8) and the good neurological recovery rate from 5.4% to 7.5% (95% CI: 7.3–7.7). The recommended maximum on-scene resuscitation times for patients demonstrated a bimodal distribution, varying with patient, emergency medical services, and OHCA characteristics. Our survival analysis-based approach generates explainable rewards, reducing subjectivity in reinforcement learning.

Association of Prehospital Rearrest With Outcome Following Out-of-Hospital Cardiac Arrest: A Systematic Review and Meta-Analysis of Observational Studies

Objectives Exposure to prehospital rearrest has previously been associated with mortality following out-of-hospital cardiac arrest (OHCA). Our objective was to conduct a systematic review and meta-analysis examining the association between prehospital rearrest and survival in adults following OHCA resuscitation. Methods We searched the PubMed, Scopus, and Web of Science bibliographic databases for observational studies that included adult OHCA patients who achieved return of spontaneous circulation in the prehospital setting following OHCA and reported survival to hospital discharge data stratified by rearrest status. The primary exposure was prehospital rearrest. The primary outcome for this study was survival to hospital discharge. Secondary outcomes included survival with a favorable neurological outcome and rearrest prevalence. We pooled data using inverse heterogeneity modeling and presented effect sizes for the survival outcomes as odds ratios with 95% confidence intervals. We quantified heterogeneity using Cochran’s Q and the I2 statistic and examined small study effects using Doi plots and the LFK index. Results Of the 84 publications screened, we included 7 observational studies containing 27,045 patients with survival to hospital discharge data. Rearrest was common (30% [18–43%]; n = 7 studies; Q = 1086.1, p < 0.001; I2 = 99%; LFK index = 1.21) and associated with both decreased odds of survival to discharge (pooled aOR: 0.27 [0.22, 0.33]; n = 7 studies; Q = 32.2, p < 0.01, I2 = 81%, LFK index = −0.08) and decreased odds of survival to discharge with a favorable neurological outcome (pooled aOR: 0.25, [0.22, 0.28]; n = 4 studies; Q = 3.5, p = 0.3; I2 = 13%, LFK index = 1.30). Conclusions Rearrest is common and associated with decreased survival following OHCA. The pooled result of this meta-analysis suggests that preventing rearrest in five patients would be necessary to save one life.

Assessing variations in care delivered to rural out of hospital cardiac arrest patients in the interfacility transfer setting.

There is significant variation in out-of-hospital cardiac arrest (OHCA) outcomes between different regions. We sought to evaluate outcomes of OHCA patients in the interfacility transfer (IFT) setting, between critical care transport (LifeFlight) and community Emergency Medical Services (EMS), in the state of Maine. This was a retrospective analysis of our institution's electronic medical record and the Maine EMS database. Data were collected from January 1, 2019, to December 31, 2021. Only adult OHCA encounters requiring an IFT for definitive post-cardiac-arrest care were included. Demographics, EMS agency, IFT vital signs, targeted temperature management (TTM) medications, cerebral performance category (CPC) scores, survival to discharge, and other descriptive variables were collected. Ninety-three patients met inclusion criteria, with LifeFlight transferring 30 of them (32.3%). LifeFlight was more likely to initiate TTM compared to other EMS agencies (p=0.012), have run-sheets reported (p=0.001), and serve rural areas (p=0.036). LifeFlight was associated with more epinephrine (0.034) and norepinephrine (<0.001) use. Only 37% of IFTs had physician orders, with none (0.0%) of them defining vital sign targets. No difference in survival to discharge or CPC scores was observed between LifeFlight and other EMS agencies. No significant variation in comorbidities or vital signs was observed. There was no difference in survival to discharge or CPC scores between LifeFlight and ad hoc EMS agency. LifeFlight was associated with more TTM and vasopressor utilization during IFT. Most IFT encounters did not have dedicated physician orders, and none of the orders included vital sign targets.

Association between pre-arrest left ventricular ejection fraction and survival in nontraumatic out-of-hospital cardiac arrest.

Out-of-hospital cardiac arrest (OHCA) poses major public health issues. Pre-arrest heart function is a prognostic factor, but the specific contribution of pre-arrest echocardiographic evaluation in predicting OHCA outcome remains limited. The primary objective was to investigate the association between left ventricular ejection fraction (LVEF) measured in echocardiography prior to OHCA and survival to hospital discharge. This multicenter retrospective cohort study analyzed data from the National Taiwan University Hospital and its affiliated hospitals. We included adult nontraumatic OHCA patients who were treated by the emergency medical services (EMS) and underwent echocardiography within 6 months prior to the OHCA event from January 2016 to December 2022. Data included demographics, preexisting diseases, resuscitation events, and echocardiographic reports. The primary outcome was the survival to hospital discharge after post-arrest care. Statistical analysis involved multivariable logistic regression to modify potential confounders, reported as adjusted odds ratio (aOR) and 95% confidence interval (CI), and evaluate the association between echocardiographic findings and survival to hospital discharge. This study analyzed 950 patients, with 33.6% surviving to discharge. A higher pre-arrest LVEF was independently associated with increased survival. Compared to patients with LVEF < 40%, those with LVEF between 40% and 60% had significantly higher odds of survival (aOR = 3.68, 95% CI = 2.14-6.35, P < 0.001), and those with LVEF > 60% had even greater odds of survival (aOR = 5.46, 95% CI = 3.09-9.66, P < 0.001). There was also an association between lower tricuspid regurgitation pressure gradient and survival (aOR = 0.98, 95% CI = 0.97-1.00, P = 0.015). Younger age, male gender, dyslipidemia, stroke, cancer, witnessed arrest, initial shockable rhythm, and shorter low-flow time are other significant predictors of survival. In adult, nontraumatic, EMS-treated OHCA patients, a higher LVEF 6 months prior to OHCA was associated with improved survival at hospital discharge.

Characteristics of Out-of-Hospital Cardiac Arrest Trials Registered in ClinicalTrials.gov.

Background/Objective: Out-of-hospital cardiac arrest (OHCA) poses a substantial public health concern. A collective evaluation of clinical trials is crucial for understanding systemic trends and progress within a specific research area of interest, ultimately shaping future directions. We performed a comprehensive analysis of the characteristics of trials in the adult OHCA population registered on ClinicalTrials.gov. Methods: Aided by medical subject headings (MeSH), we systematically searched the ClinicalTrials.gov database. Trends over time were assessed with the Cochran-Mantel-Haenszel test. The association between publication year and annual number was assessed with the Pearson correlation coefficient. Results: Out of 152 trials spanning the 2003-2023 period, 29.6% were observational and 70.4% were interventional. Compared with the observational trials, interventional trials were more often randomized (RCT) and achieved full publication status in 84% of cases (p = 0.03). The primary focus of interventional trials was "procedures" (43%), "devices" (23%), and "drugs" (21%). Observational studies focused on "biomarkers" (16%) and "diagnostic test" (13%) (p < 0.001). A decrement in the number of interventional trials with a sample size ≥100 patients across three temporal study points was observed. Nevertheless, published studies predominantly had a sample size ≥100 patients (76%), in contrast to unpublished trials (p ≤ 0.001). An increase in the number of interventional studies funded by the "academic/university" sector was also recorded. Conclusions: Clinical trials on OHCA primarily involved interventions aimed at treatment and were more often randomized, single-center, with small (<100) sample sizes, and funded by the "academic/university" sector.

Compression-only versus standard cardiopulmonary resuscitation in out-of-hospital cardiac arrest: A meta-analysis of randomized controlled trials.

Bystander-initiated cardiopulmonary resuscitation (CPR) can improve survival rates in individuals with out-of-hospital cardiac arrest (OHCA). Two CPR approaches are commonly utilized, standard (S-CPR) with mouth-to-mouth breathing and compression-only (CO-CPR). We conducted a systematic review and meta-analysis to compare clinical outcomes associated with S-CPR versus CO-CPR in OHCA. A systematic literature search was conducted using PubMed, EMBASE, and the Cochrane Library. Eligible studies included randomized controlled trials (RCTs) focused on adult OHCA patients receiving CO-CPR or S-CPR. Forest plots were generated for pooled data analysis using Review Manager version 5.4. Random-effect analyses were used, and statistical significance was set at p < .05. Four randomized controlled trials were included in the final analysis, encompassing a total sample size of 4987 patients (2482 in the CO-CPR group and 2505 in the S-CPR group). CO-CPR was associated with significantly improved 1-day survival compared with S-CPR (OR = 1.15; 95% CI: 1.02-1.31; p = .03) and survival to hospital discharge (OR = 1.25; 95% CI: 1.01-1.55; p = .04). No heterogeneity was observed among the studies for either outcome. CO-CPR emerges as a promising strategy for improving outcomes in OHCA compared to S-CPR. However, further large-scale RCTs are required to generate more robust evidence.

Incidence, characteristics, and prehospital outcomes of out-of-hospital cardiac arrest in Qatar: a nationwide gender-based investigation

BackgroundResearch on incidence and characteristics of Out-of-Hospital Cardiac Arrest (OHCA) in the Middle East is limited. We assessed the incidence, prehospital characteristics, and outcomes of OHCA in Qatar, a Middle Eastern country. Subsequently, we performed gender-specific analysis.MethodsThis was a retrospective examination of data obtained from the OHCA registry at Hamad Medical Corporation (HMC) in Qatar from 2017 to 2022. We included adults, non-traumatic, EMS-treatment OHCA. We calculated the incidence of adult OHCA and conducted descriptive analyses for prehospital characteristics, and prehospital outcomes presented by return of spontaneous circulation (ROSC). We evaluated gender differences in prehospital characteristics and ROSC using Student’s t-test and the Chi-Square test as appropriate. Furthermore, we conducted a multivariable logistic regression analysis to investigate the correlation between gender and achieving ROSC.ResultsWe included 4,306 adult OHCA patients, with 869 (20.2%) being females. The mean annual incidence of adult OHCA was 27.4 per 100,000 population-year. Males had a higher annual incidence of OHCA than females. Among all cases, 36.3% occurred in a public location, 25.8% had an initial shockable rhythm, and 28.8% achieved ROSC. Males had a higher proportion of bystander CPR, arrests in public locations, and initial shockable rhythms. While unadjusted analysis showed no significant gender differences in achieving ROSC, adjusted analysis revealed that male gender was associated with higher odds of achieving ROSC (adjusted OR male vs. female 1.38, 95% CI 1.15–1.66, p < 0.001).ConclusionsApproximately 720 adults undergo non-traumatic OHCA in Qatar every year, with a higher incidence observed in males. Male gender was associated with higher odds of achieving ROSC. Further gender-specific research in OHCA intervention and outcome in the Middle East is required.

The association of intravenous vs. humeral-intraosseous vascular access with patient outcomes in adult out-of-hospital cardiac arrests

AimWhile intravenous (IV) vascular access for out-of-hospital cardiac arrest (OHCA) resuscitation is standard, humeral-intraosseous (IO) access is commonly used, despite few supporting data. We investigated the association between IV vs. humeral-IO and outcomes. MethodsWe utilized BC Cardiac Arrest Registry data, including adult OHCA where the first-attempted intra-arrest vascular access route performed by advanced life support (ALS)-trained paramedics was IV or humeral-IO. We fit a propensity-score adjusted model with inverse probability treatment weighting to estimate the association between IV vs. humeral-IO routes and favorable neurological outcomes (CPC 1–2) and survival at hospital discharge. We repeated models within subgroups defined by initial cardiac rhythm. ResultsWe included 2,112 cases; the first-attempted route was IV (n = 1,575) or humeral-IO (n = 537). Time intervals from ALS-paramedic on-scene arrival to vascular access (6.6 vs. 6.9 min) and epinephrine administration (9.0 vs. 9.3 min) were similar between IV and IO groups, respectively. Among IV and humeral-IO groups, 98 (6.2%) and 20 (3.7%) had favorable neurological outcomes. Compared to humeral-IO, an IV-first approach was associated with improved hospital-discharge favorable neurological outcomes (AOR 1.7; 95% CI 1.1–2.7) and survival (AOR 1.5; 95% CI 1.0–2.3). Among shockable rhythm cases, an IV-first approach was associated with improved favorable neurological outcomes (AOR 4.2; 95% CI 2.1–8.2), but not among non-shockable rhythm cases (AOR 0.73; 95% CI 0.39–1.4). ConclusionAn IV-first approach, compared to humeral-IO, for intra-arrest resuscitation was associated with an improved odds of favorable neurological outcomes and survival to hospital discharge. This association was seen among an initial shockable rhythm, but not non-shockable rhythm, subgroups.

Prognostic value of grey-white matter ratio obtained within two hours after return of spontaneous circulation in out-of-hospital cardiac arrest survivors: A multicenter, observational study

BackgroundGrey-white matter ratio (GWR) measured by head computed tomography (CT) scan is known as a neurological prognostication tool for out-of-hospital cardiac arrest (OHCA) survivors. The prognostic value of GWR obtained early (within two hours after return of spontaneous circulation [ROSC]) remains a matter of debate. MethodsWe conducted a multicenter, retrospective, observational study at five hospitals. We included adult OHCA survivors who underwent head CT within two hours following ROSC. GWR values were measured using head CT. Average GWR values were calculated by the mean of the GWR-basal ganglia and GWR-Cerebrum. We divided the patients into poor or favorable neurological outcome groups defined by Glasgow-Pittsburgh Cerebral Performance Category scores. The predictive accuracy of GWR performance was assessed using the area under the curve (AUC). The sensitivities and specificities for predicting poor outcome were examined. ResultsOf 377 eligible patients, 281 (74.5%) showed poor neurological outcomes at one month after ROSC. Average GWR values of the poor neurological outcome group were significantly lower than those of the favorable neurological outcome. The average GWR value to predict neurological outcome with Youden index was 1.24 with AUC of 0.799. When average GWR values were 1.15 or lower, poor neurological outcomes could be predicted with 100% specificity. ConclusionsGWR values measured by head CT scans early (within two hours after ROSC) demonstrated moderate predictive performance for overall ROSC patients. When limited to the patients with GWR values of 1.15 or lower, poor neurological outcomes could be predicted with high specificity.

A Simple Scoring System for Identifying Favorable Neurologic Outcomes Among Out-of-Hospital Cardiac Arrest Patients With Asystole

Study objectiveAsystole is the most common initial rhythm in out-of-hospital cardiac arrest (OHCA), but indicates a low likelihood of neurological recovery. This study aimed to develop a novel scoring system to be easily applied at the time of emergency department arrival for identifying favorable neurological outcomes in OHCA survivors with an asystole rhythm. MethodsThis study is a secondary analysis based on a previously collected nationwide database, targeting non-traumatic adult OHCA patients aged ≥ 18 years with an asystole rhythm who achieved Return of Spontaneous Circulation (ROSC) between January 2016 and December 2020. The primary outcome was a favorable neurological outcome defined as Cerebral Performance Categories scores of 1 or 2 at hospital discharge. A prediction model was developed through multivariable logistic regression analysis in a derivation cohort in the form of a scoring system (WBC-ASystole). The performance and calibration of the model were tested using an internal validation cohort. ResultsAmong 19,803 OHCA patients with survival to hospital admission, 6,322 had asystole, and 285 (4.5%) achieved good neurological outcomes. Factors associated with favorable outcomes included age, witness arrest, bystander cardiopulmonary resuscitation, time from call to hospital arrival, and prehospital ROSC achievement. The WBC-ASystole score, totaling 11 points, exhibited a predictive performance with an area under the receiver operating characteristic curve of 0.80 (95% confidence interval [CI]: 0.76–0.83) and 0.79 (95% CI: 0.74–0.83) in the derivation and validation cohorts, respectively. After categorizing patients into three groups based on probability for good neurological outcomes, the sensitivity and specificity were as follows: 0.98 (95% CI: 0.97–0.99) and 0.09 (95% CI: 0.09–0.10) for the very low (WBC-ASystole: ≤2), 0.85 (95% CI: 0.82–0.89) and 0.54 (95% CI: 0.53–0.55) for the low (WBC-ASystole: 3–4), and 0.36 (95% CI: 0.34–0.39) and 0.93 (95% CI: 0.92–0.93) for fair predicted probability group (WBC-ASystole: ≥5). ConclusionsAlthough external validation studies must be performed, among OHCA with asystole, the WBC-ASystole scoring system may identify those patients who are likely to have a favorable neurological outcome.

The association between serum free fatty acid levels and neurological outcomes in out-of-hospital cardiac arrest patients: A prospective observational study.

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. This prospective observational study included adult (≥18 years) OHCA patients between February 2016 and December 2022. We measured serial FFA levels within 1 hour after ROSC and at 6, 12, 24, 48, and 72 hours 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. A total of 147 patients were included. Of them, 104 (70.7%) had poor neurological outcomes, whereby the median FFA levels within 1 hour after ROSC (0.72 vs 1.01 mol/L), at 6 hours (1.19 vs 1.90 mol/L), 12 hours (1.20 vs 1.66 mol/L), and 24 hours (1.20 vs 1.95 mol/L) after ROSC were significantly lower than in good outcome group. The FFA levels at 6 hours (odds ratio, 0.583; 95% confidence interval, 0.370-0.919; P = .020), and 12 hours (odds ratio, 0.509; 95% confidence interval, 0.303-0.854; P = .011) after ROSC were independently associated with poor neurological outcomes. The lower FFA levels at 6 hours and 12 hours after ROSC were associated with poor neurological outcomes in patients with OHCA. FFA may reflect oxidative metabolism as well as oxidative stress.