Initial rhythm and survival in refractory out-of-hospital cardiac arrest. Post-hoc analysis of the Prague OHCA randomized trial

Association between increasing institutional experience with ECPR and outcomes in patients with out-of-hospital cardiac arrest: A nationwide multicenter observational study in Japan (the JAAM-OHCA registry)

AIM

To determine the association between institutional experience with extracorporeal cardiopulmonary resuscitation (ECPR) and outcomes after out-of-hospital cardiac arrest (OHCA).

METHODS

We analyzed data from the JAAM-OHCA registry, a nationwide multicenter database containing information on patients who experienced OHCA in Japan between June 2014 and December 2020. The study population consisted of patients with OHCA who were in cardiac arrest on hospital arrival and treated with extracorporeal membrane oxygenation (ECMO). Each patient was assigned a sequential number based on the order of initiation of ECPR at each facility. The primary outcome was 30-day survival and the secondary outcome was the interval between hospital admission and initiation of ECMO.

RESULTS

Data for a total of 2,315 patients with OHCA and cardiac arrest on hospital arrival who were treated with ECPR at any of 87 facilities were analyzed. On admission, 1,047 patients had shockable rhythm and 1,268 had non-shockable rhythm. The 30-day survival rate was not significantly associated with the accumulated case volume of ECPR. The interval between hospital arrival and initiation of ECMO decreased significantly with increasing experience of ECPR (p < 0.001, Jonckheere-Terpstra test). In non-shockable cases, 30-day survival tended to improve with increasing experience of ECPR (p = 0.04, Cochran-Armitage trend test).

CONCLUSION

Increasing institutional experience of ECPR did not significantly improve 30-day survival after OHCA but was associated with a shorter interval between hospital arrival and initiation of ECMO. In patients with non-shockable OHCA, increasing experience of ECPR improved 30-day survival. (246/250 words).

Signs of life as a favorable predictor for non-shockable cardiac arrest undergoing extracorporeal cardiopulmonary resuscitation post non-shockable cardiac arrest

BACKGROUND

When the initial rhythm of cardiac arrest is non-shockable, resuscitation outcomes tend to be unfavorable. However, signs of life (gasping, pupillary light reaction, or any form of body movement) have been suggested as favorable prognostic factors for patients with refractory cardiac arrest who are undergoing extracorporeal cardiopulmonary resuscitation (ECPR). This study determined whether signs of life are favorable neurological prognostic factors for patients undergoing ECPR post non-shockable cardiac arrest.

METHODS AND RESULTS

This single-center retrospective study included 227 refractory out-of-hospital cardiac-arrest patients who had undergone ECPR, divided into four groups according to shockability of initial cardiac rhythms and presence of signs of life. Initial cardiac rhythms were shockable in 154 patients (67.8 %) and non-shockable in 73 (32.2). Favorable neurological outcomes were observed in 4.1 %, 48.2 %, 0.0 %, and 38.7 % of patients with shockable rhythm without signs of life, shockable rhythm with signs of life, non-shockable rhythm without signs of life, and non-shockable rhythm with signs of life, respectively, with significant differences. Multivariate logistic regression analysis showed an independent association of signs of life during resuscitation with favorable neurological outcomes. The adjusted odds ratios for patients with shockable and non-shockable rhythm with signs of life were 34.33 and 96.51, respectively, compared with those without signs of life.

CONCLUSIONS

Signs of life during resuscitation were favorable prognostic factors in patients with refractory cardiac arrest and non-shockable rhythm. When these patients are considered for ECPR, the status of signs of life during resuscitation may facilitate the decision to perform ECPR.

Heart rhythm at hospital admission: A factor for survival and neurological outcome among ECPR recipients?

BACKGROUND

The initial rhythm is a known predictor of survival in extracorporeal cardiopulmonary resuscitation (ECPR) patients. However, the effect of the rhythm at hospital admission on outcomes in these patients is less clear.

METHODS

This observational, single-center study assessed the influence of the rhythm at hospital admission on 30-day survival and neurological outcomes at discharge in patients who underwent ECPR for out-of-hospital cardiac arrest (OHCA).

RESULTS

Between January 2012 and December 2023, 1,219 OHCA patients were admitted, and 210 received ECPR. Of these, 196 patients were analyzed. The average age was 52.9 years (±13), with 80.6 % male. The median time to ECPR initiation was 61 min (IQR 54-72). Patients with ventricular fibrillation as both the initial and admission rhythm had the highest 30-day survival rate (52 %: 35/67), while those with asystole in both instances had the lowest (6 %: 1/17, log-rank p < 0.00001). After adjusting for age, sex, initial rhythm, resuscitation time, location, bystander, and witnessed status, asystole at admission was linked to higher 30-day mortality (OR 4.03, 95 % CI 1.49-12.38, p = 0.009) and worse neurological outcomes (Cerebral Performance Category 3-5) at discharge (OR 4.61, 95 % CI 1.49-17.62, p = 0.013).

CONCLUSIONS

The rhythm at hospital admission affects ECPR outcomes. Patients presenting with and maintaining ventricular fibrillation have a higher chance of favorable neurological survival, whereas those presenting with or converting to asystole have poor outcomes. The rhythm at hospital admission appears to be a valuable criterion for deciding on ECPR initiation.

Variability in patient selection criteria across extracorporeal cardiopulmonary resuscitation (ECPR) systems: A systematic review

BACKGROUND

Across the world, many systems have implemented extracorporeal cardiopulmonary resuscitation (ECPR) as a potential treatment strategy for patients in refractory cardiac arrest. To date, there are no universally accepted criteria for patient selection for ECPR. We conducted a systematic review to explore the variability in patient eligibility criteria for ECPR across systems.

METHODS

We searched the Cochrane Library(Wiley), EMBASE(OVID), and MEDLINE ALL (OVID) databases from inception to 5th February-2024 for all studies that described an ECPR system and where the system eligibility criteria was described. A combination of predetermined search terms was used to identify relevant articles. We conducted forward and backward citation tracking to identify any further relevant articles.

RESULTS

Our search identified 12,503 articles of which 167 articles were found to be potentially eligible. Seventy-seven articles were further excluded as they described the same ECPR system as another study. We finally included 90 studies describing a total of 93 ECPR systems. The eligibility criteria for ECPR differed among the included systems. Across systems, ECPR eligibility criteria included age (n=75, 80.7%), arrest witnessed status (n=64, 68.8%), any initial rhythm (n=55, 59.1%), and bystander CPR (n=33, 35.5%). Within criteria, we observed marked variability. The age cut-off varied from 50 to 80 years, with the most common age cut-off being 75 years and 18 (19.3%) systems having no cut-off. Whilst most systems limited ECPR to shockable rhythms (n=28,30.1%), some systems included shockable rhythms and/or PEA only (n=10,10.8%).

CONCLUSION

We observed marked variability across systems in the eligibility criteria for potential ECPR patients. There is a need for further work to identify the optimum ECPR selection criteria.

REVIEW REGISTRATION

PROSPERO (CRD42023451109).

Out-of-hospital cardiac arrest outcomes' determinants: an Italian retrospective cohort study based on Lombardia CARe

This study on the Lombardia Cardiac Arrest Registry (Lombardia CARe,) the most complete nationwide out-of-hospital cardiac arrest (OHCA) registry in Italy, aims at evaluating post-OHCA intra-hospital mortality risk according to patient's characteristics and emergency health service management (EMS), including level of care of first-admission hospital. Out of 12,581 patients included from 2015 to 2022, we considered 1382 OHCA patients admitted alive to hospital and survived more than 24 h. We estimated risk ratios (RRs) of intra-hospital mortality through log-binomial regression models adjusted by patients' and EMS characteristics. The study population consisted mainly of males (66.6%) most aged 60-69 years (24.7%) and 70-79 years (23.7%). Presenting rhythm was non-shockable in 49.9% of patients, EMS intervention time was less than 10 min for 30.3% of patients, and cardiopulmonary resuscitation (CPR) was performed for less than 15 min in 29.9%. Moreover, 61.6% of subjects (n = 852) died during hospital admission. Intra-hospital mortality is associated with non-shockable presenting rhythm (RR 1.27, 95% CI 1.19-1.35) and longer CPR time (RR 1.39, 95% CI 1.28-1.52 for 45 min or more). Patients who accessed to a secondary vs tertiary care hospital were more frequently older, with a non-shockable presenting rhythm and longer EMS intervention time. Non-shockable presenting rhythm accounts for 27% increased risk of intra-hospital death in OHCA patients, independently of first-access hospital level, thus demonstrating that patients' outcomes depend only by intrinsic OHCA characteristics and Health System's resources are utilised as efficiently as possible.

Mortality Predictors and Neurological Outcomes Following Extracorporeal Cardiopulmonary Resuscitation (eCPR): A Single-Center Retrospective Study

BACKGROUND

Extracorporeal cardiopulmonary resuscitation (eCPR) offers cardiorespiratory support to patients experiencing cardiac arrest. However, this technology is not yet considered a standard treatment, and the evidence on eCPR criteria and its association with survival and good neurological outcomes remains scarce. Therefore, we aimed to investigate the overall mortality and risk factors for mortality. Moreover, we provide a comparison of demographic, clinical, and laboratory characteristics of patients, including neurological outcomes and adverse events during support.

METHODS

This retrospective analysis included in-hospital and out-of-hospital cardiac arrest patients who received eCPR and were admitted between January 2008 and June 2022 at a tertiary and trauma one-level university hospital in Austria.

RESULTS

In total, 90 patients fulfilled inclusion criteria, 41 (46%) patients survived until intensive care unit discharge, and 39 (43%) survived until hospital discharge. The most common cause of cardiac arrest was myocardial infarction (42, 47%), and non-shockable initial rhythm was reported in 50 patients (56%). Of 33 survivors with documented outcomes, 30 had a good recovery as measured with Cerebral Performance Category score, 2 suffered severe disability, and 1 remained in a persistent vegetative state. Finally, multivariate analysis identified asystole as initial rhythm (HR 2.88, p = 0.049), prolonged CPR (HR 1.02, p = 0.043), and CPR on the weekend (HR 2.57, p = 0.032) as factors with a higher risk of mortality.

CONCLUSIONS

eCPR-related decision-making could be additionally supported by the comprehension of the reported risk factors for mortality and severe disability. Further studies are needed to elucidate the impact of peri-arrest variables on outcomes, aiming to improve patient selection.

Health-related quality of life one year after refractory cardiac arrest treated with conventional or extracorporeal CPR; a secondary analysis of the INCEPTION-trial

Background

Prospective, trial-based data comparing health-related quality of life (HRQoL) in patients surviving out-of-hospital cardiac arrest (OHCA) through extracorporeal cardiopulmonary resuscitation (ECPR) or conventional CPR (CCPR) are scarce. We aimed to determine HRQoL during 1-year after refractory OHCA in patients treated with ECPR and CCPR.

Methods

We present a secondary analysis of the multicenter INCEPTION-trial, which studied the effectiveness of ECPR versus CCPR in patients with refractory OHCA. HRQoL was prospectively assessed using the EQ-5D-5L questionnaire. Poor HRQoL was pragmatically defined as an EQ-5D-5L health utility index (HUI) > 1 SD below the age-adjusted norm. We used mixed linear models to assess the difference in HRQoL over time and univariable analyses to assess factors potentially associated with poor HRQoL.

Results

A total of 134 patients were enrolled, and hospital survival was 20% (27 patients). EQ-5D-5L data were available for 25 patients (5 ECPR and 20 CCPR). One year after OHCA, the estimated mean HUI was 0.73 (0.05) in all patients, 0.84 (0.12) in ECPR survivors, and 0.71 (0.05) in CCPR survivors (p-value 0.31). Eight (32%) survivors had a poor HRQoL. HRQoL was good in 17 (68%) patients, with 100% in ECPR survivors versus 60% in CCPR survivors (p-value 0.14).

Conclusion

One year after refractory OHCA, 68% of the survivors had a good HRQoL. We found no statistically significant difference in HRQoL one year after OHCA in patients treated with ECPR compared to CCPR. However, numerical differences may be clinically relevant in favor of ECPR.

The short- and mid-term mortality trends in out-of-hospital cardiac arrest survivors: insights from a 5-year multicenter retrospective study in Taiwan

Background

The survival trend and factors influencing short- and mid-term mortality in Asian out-of-hospital cardiac arrest (OHCA) survivors should be elucidated. We performed survival analyses on days 3 and 30, hypothesizing decreased survival rates within the initial 3 days post-resuscitation. Additionally, variables linked to mortality at these two timepoints were examined.

Methods

We performed a retrospective analysis on adult nontraumatic OHCA survivors admitted to the National Taiwan University Hospital and its branches between 2017 and 2021. We collected the following variables from the NTUH-Integrative Medical Database: basic characteristics, cardiopulmonary resuscitation events, inotrope administration, and post-resuscitation management. The outcomes included 3- and 30-day mortality. Subgroup analyses with the Kaplan-Meier method explored the survival probability of the OHCA survivors and assessed differences in cumulative survival among subgroups. Cox proportional hazards model was used to estimate adjusted hazard ratios with 95% confidence interval.

Results

Of the 967 survivors, 273 (28.2%) and 604 (62.5%) died within 3 and 30 days, respectively. The 30-day survival curve after OHCA showed an uneven decline, with the most significant decrease within the first 3 days of admission. Various risk factors influence mortality at 3- and 30-day intervals. Although increased age, noncardiac etiology, and prolonged low-flow time increased mortality risks, bystander CPR, targeted temperature management, and continuous renal replacement therapy were associated with reduced mortality at 3- and 30-day timeframes.

Conclusion

Survival declined in most OHCA survivors within 3 days post-resuscitation. The risk factors associated with mortality at 3- and 30-day intervals varied in this population.

Machine Learning Identifies Higher Survival Profile In Extracorporeal Cardiopulmonary Resuscitation

OBJECTIVES

Extracorporeal cardiopulmonary resuscitation (ECPR) has been shown to improve neurologically favorable survival in patients with refractory out-of-hospital cardiac arrest (OHCA) caused by shockable rhythms. Further refinement of patient selection is needed to focus this resource-intensive therapy on those patients likely to benefit. This study sought to create a selection model using machine learning (ML) tools for refractory cardiac arrest patients undergoing ECPR.

DESIGN

Retrospective cohort study.

SETTING

Cardiac ICU in a Quaternary Care Center.

PATIENTS

Adults 18-75 years old with refractory OHCA caused by a shockable rhythm.

METHODS

Three hundred seventy-six consecutive patients with refractory OHCA and a shockable presenting rhythm were analyzed, of which 301 underwent ECPR and cannulation for venoarterial extracorporeal membrane oxygenation. Clinical variables that were widely available at the time of cannulation were analyzed and ranked on their ability to predict neurologically favorable survival.

INTERVENTIONS

ML was used to train supervised models and predict favorable neurologic outcomes of ECPR. The best-performing models were internally validated using a holdout test set.

MEASUREMENTS AND MAIN RESULTS

Neurologically favorable survival occurred in 119 of 301 patients (40%) receiving ECPR. Rhythm at the time of cannulation, intermittent or sustained return of spontaneous circulation, arrest to extracorporeal membrane oxygenation perfusion time, and lactic acid levels were the most predictive of the 11 variables analyzed. All variables were integrated into a training model that yielded an in-sample area under the receiver-operating characteristic curve (AUC) of 0.89 and a misclassification rate of 0.19. Out-of-sample validation of the model yielded an AUC of 0.80 and a misclassification rate of 0.23, demonstrating acceptable prediction ability.

CONCLUSIONS

ML can develop a tiered risk model to guide ECPR patient selection with tailored arrest profiles.

Current trends in the management of out of hospital cardiac arrest (OHCA)

Sudden cardiac arrest remains a relevant problem with a significant number of deaths worldwide. Although survival rates have more than tripled over the last 20 years (4% in 2001 vs. 14% in 2020), survival rates with good neurological outcomes remain persistently low, representing a major socioeconomic problem. Every minute of delay from patient collapse to start cardiopulmonary resuscitation (CPR) and early defibrillation reduces the chance of survival by approximately 10-12%. Therefore, the time to treatment is a crucial factor in the prognosis of patients with out-of-hospital cardiac arrest (OHCA). Research teams working in the pre-hospital setting are therefore looking for ways to improve the transmission of information from the site of an emergency event and to make it easier for emergency medical dispatch centres (EMDC) to recognise life-threatening conditions with minimal deviation. For emergency unit procedures already at the scene of the event, methods are being sought to efficiently and temporarily replace a non-functioning cardiopulmonary system. In the case of traumatic cardiac arrest (TCA), the focus is mainly on effective affecting non-compressible haemorrhage.

A national multi centre pre-hospital ECPR stepped wedge study; design and rationale of the ON-SCENE study

BACKGROUND

The likelihood of return of spontaneous circulation with conventional advanced life support is known to have an exponential decline and therefore neurological outcome after 20 min in patients with a cardiac arrest is poor. Initiation of venoarterial ExtraCorporeal Membrane Oxygenation (ECMO) during resuscitation might improve outcomes if used in time and in a selected patient category. However, previous studies have failed to significantly reduce the time from cardiac arrest to ECMO flow to less than 60 min. We hypothesize that the initiation of Extracorporeal Cardiopulmonary Resuscitation (ECPR) by a Helicopter Emergency Medical Services System (HEMS) will reduce the low flow time and improve outcomes in refractory Out of Hospital Cardiac Arrest (OHCA) patients.

METHODS

The ON-SCENE study will use a non-randomised stepped wedge design to implement ECPR in patients with witnessed OHCA between the ages of 18-50 years old, with an initial presentation of shockable rhythm or pulseless electrical activity with a high suspicion of pulmonary embolism, lasting more than 20, but less than 45 min. Patients will be treated by the ambulance crew and HEMS with prehospital ECPR capabilities and will be compared with treatment by ambulance crew and HEMS without prehospital ECPR capabilities. The primary outcome measure will be survival at hospital discharge. The secondary outcome measure will be good neurological outcome defined as a cerebral performance categories scale score of 1 or 2 at 6 and 12 months.

DISCUSSION

The ON-SCENE study focuses on initiating ECPR at the scene of OHCA using HEMS. The current in-hospital ECPR for OHCA obstacles encompassing low survival rates in refractory arrests, extended low-flow durations during transportation, and the critical time sensitivity of initiating ECPR, which could potentially be addressed through the implementation of the HEMS system. When successful, implementing on-scene ECPR could significantly enhance survival rates and minimize neurological impairment.

TRIAL REGISTRATION

Clinicaltyrials.gov under NCT04620070, registration date 3 November 2020.

The link between initial cardiac rhythm and survival outcomes in in-hospital cardiac arrest using propensity score matching, adjustment, and weighting

The association between the initial cardiac rhythm and short-term survival in patients with in-hospital cardiac arrest (IHCA) has not been extensively studied despite the fact that it is thought to be a prognostic factor in patients with out-of-hospital cardiac arrest. This study aimed to look at the relationship between initial shockable rhythm and survival to hospital discharge in individuals with IHCA. 1516 adults with IHCA who received chest compressions lasting at least two minutes at the National Taiwan University Hospital between 2006 and 2014 made up the study population. Propensity scores were estimated using a fitted multivariate logistic regression model. Various statistical methodologies were employed to investigate the association between shockable rhythm and the probability of survival to discharge in patients experiencing IHCA, including multivariate adjustment, propensity score adjustment, propensity score matching, and logistic regression based on propensity score weighting. In the original cohort, the multivariate-adjusted odds ratio (OR) was 2.312 (95% confidence interval [CI]: 1.515-3.531, P < 0.001). In additional propensity score adjustment, the OR between shockable rhythm and the probability of survival to hospital discharge in IHCA patients was 2.282 (95% CI: 1.486, 3.504, P < 0.001). The multivariate-adjusted logistic regression model analysis revealed that patients with shockable rhythm had a 1.761-fold higher likelihood of surviving to hospital release in the propensity score-matched cohort (OR = 2.761, 95% CI: 1.084-7.028, P = 0.033). The multivariate-adjusted OR of the inverse probability for the treatment-weighted cohort was 1.901 (95% CI: 1.507-2.397, P < 0.001), and the standardized mortality ratio-weighted cohort was 2.692 (95% CI: 1.511-4.795, P < 0.001). In patients with in-hospital cardiac arrest, Initial cardiac rhythm is an independent predictor of survival to hospital discharge. Depending on various statistical methods, patients with IHCA who have a shockable rhythm have a one to two fold higher probability of survival to discharge than those who have a non-shockable rhythm. This provides a reference for optimizing resuscitation decisions for IHCA patients and facilitating clinical communication.

Differences in Pathophysiology and Treatment Efficacy Based on Heterogeneous Out-of-Hospital Cardiac Arrest

Out-of-hospital cardiac arrest (OHCA) is heterogeneous in terms of etiology and severity. Owing to this heterogeneity, differences in outcome and treatment efficacy have been reported from case to case; however, few reviews have focused on the heterogeneity of OHCA. We conducted a literature review to identify differences in the prognosis and treatment efficacy in terms of CA-related waveforms (shockable or non-shockable), age (adult or pediatric), and post-CA syndrome severity and to determine the preferred treatment for patients with OHCA to improve outcomes.

Role of low-density lipoprotein electronegativity and sexual dimorphism in contributing early ventricular tachyarrhythmias following ST-elevation myocardial infarction

Background

Early ventricular tachycardia/fibrillation (VT/VF) in patients with ST-elevation myocardial infarction (STEMI) has higher morbidity and mortality. This study examines gender-differentiated risk factors and underlying mechanisms for early onset VT/VF in STEMI.

Methods

We analyzed data from 2,964 consecutive STEMI patients between January 1, 2008 and December 31, 2021. Early VT/VF was defined as occurrence of spontaneous VT/VF of ≥30 s or requirement of immediate cardioversion/defibrillation within the first 48 h after symptoms. An ex vivo ischemic-reperfusion experiments were conducted in 8-week-old ApoE-/- mice fed a high-fat diet to explore the underlying mechanisms of early VT/VF.

Results

In 255 of out 2,964 STEMI patients who experienced early VT/VF, the age was younger (58.6 ± 13.8 vs. 61.0 ± 13.0 years old, P = 0.008) with a male predominance. The plasma levels of L5, the most electronegative subclass of low-density lipoprotein, was higher in early VT/VF patients compared to those without early VT/VF (n = 21, L5: 14.1 ± 22.6% vs. n = 46, L5: 4.3 ± 9.9%, P = 0.016). In the experimental setup, all male mice (n = 4) developed VT/VF post sham operation, whereas no such incidence was observed in the female mice (n = 3). Significantly, male mice exhibited considerably slower cardiac conduction velocity as compared to their female counterparts in whole heart preparations (25.01 ± 0.93 cm/s vs.42.32 ± 5.70 cm/s, P < 0.001), despite analogous action potential durations. Furthermore, isolated ventricular myocytes from male mice showed a distinctly lower sodium current density (-29.20 ± 3.04 pA/pF, n = 6) in comparison to female mice (-114.05 ± 6.41 pA/pF, n = 6, P < 0.001). This decreased sodium current density was paralleled by a reduced membrane expression of Nav1.5 protein (0.38 ± 0.06 vs. 0.89 ± 0.09 A.U., P < 0.001) and increased cytosolic Nav1.5 levels (0.59 ± 0.06 vs. 0.29 ± 0.04 A.U., P = 0.001) in male mice. Furthermore, it was observed that the overall expressions of sorting nexin 27 (SNX27) and vacuolar protein sorting 26 (VPS26) were significantly diminished in male mice as compared to female littermates (0.91 ± 0.15 vs. 1.70 ± 0.28, P = 0.02 and 0.74 ± 0.09 vs. 1.57 ± 0.13, P < 0.01, respectively).

Conclusions

Our findings reveal that male STEMI patients with early VT/VF are associated with elevated L5 levels. The gender-based discrepancy in early VT/VF predisposition might be due to compromised sodium channel trafficking, possibly linked with increased LDL electronegativity.

Impact of a national initiative to provide civilian cardiopulmonary resuscitation training courses on the rates of bystander intervention by citizens and survival after out-of-hospital cardiac arrest

BACKGROUND

The impact of a national initiative to provide cardiopulmonary resuscitation (CPR) education to the public on the rates of citizen-initiated CPR and survival following out-of-hospital cardiac arrest (OHCA) remains uncertain.

METHODS

We examined 358,025 cases of citizen-witnessed OHCA with presumed cardiac origin, recorded in the Japanese nationwide registry from 2005 to 2020. We assessed the relationship between the number of individuals certified in CPR courses, citizen interventions, and neurologically favorable survival at one month.

RESULTS

The cumulative number of certified citizens has linearly increased from 9,930,327 in 2005 to 34,938,322 in 2020 (incidence rate ratio for annual number = 1.03, p < 0.001), encompassing 32.3% of the Japanese population aged 15 and above. Similarly, the prevalence of citizen-initiated CPR has consistently increased from 40.6% in 2005 to 56.8% in 2020 (P for trend < 0.001). Greater citizen CPR engagement was significantly associated with better outcome in initial shockable rhythm patients [chest compression only: odds ratio (OR) 1.24; 95% confidence interval (CI) 1.02-1.51; P = 0.029; chest compression with rescue breathing: OR 1.33; 95% CI 1.08-1.62; P = 0.006; defibrillation with chest compression: OR 2.27; 95% CI 1.83-2.83; P < 0.001; defibrillation with chest compression and rescue breathing: OR 2.15; 95% CI 1.70-2.73; P < 0.001 vs. no citizen CPR].

CONCLUSIONS

The incidence of citizen-initiated CPR across Japan has consistently and proportionately increased with the rising number of individuals certified in CPR courses. Greater citizen CPR involvement has been linked to neurologically favorable survival, particularly in cases with an initial shockable rhythm.

Association between eGFR and neurological outcomes among patients with out-of-hospital cardiac arrest: A nationwide prospective study in Japan

Aim

We aimed to investigate the association between estimated glomerular filtration rate and prognosis in out-of-hospital cardiac arrest patients and explore the heterogeneity of the association.

Methods

Patients experiencing out-of-hospital cardiac arrest due to medical causes and registered in the JAAM-OHCA Registry between June 2014 and December 2019 were stratified into shockable rhythm, pulseless electrical activity, and asystole groups according to the cardiac rhythm at the scene. The primary outcome was a 1-month favorable neurological status. Adjusted odds ratios with 95% confidence intervals were calculated to investigate the association between estimated glomerular filtration rate and outcomes using a logistic model.

Results

Of the 19,443 patients included, 2769 had initial shockable rhythm at the scene, 5339 had pulseless electrical activity, and 11,335 had asystole. As the estimated glomerular filtration rate decreased, the adjusted odds ratio for a 1-month favorable neurological status decreased among those with initial shockable rhythm (estimated glomerular filtration rate, adjusted odds ratio [95% CI]: 45-59 mL/min/1.73 m2, 0.61 [0.47-0.79]; 30-44 mL/min/1.73 m2, 0.45 [0.32-0.62]; 15-29 mL/min/1.73 m2, 0.35 [0.20-0.63]; and <15 mL/min/1.73 m2, 0.14 [0.07-0.27]). Estimated glomerular filtration rate was associated with neurological outcomes in patients aged <65 years with initial shockable rhythm but not in those aged >65 years or patients with initial pulseless electrical activity or asystole.

Conclusion

The estimated glomerular filtration rate is associated with neurological prognosis in out-of-hospital cardiac arrest patients with initial shockable rhythm at the scene but not in those with initial non-shockable rhythm.

Early extracorporeal CPR for refractory out-of-hospital cardiac arrest - A pre-planned per-protocol analysis of the INCEPTION-trial

BACKGROUND

Evidence for extracorporeal cardiopulmonary resuscitation (CPR) in refractory out-of-hospital cardiac arrest (OHCA) remains inconclusive. Recently, the INCEPTION-trial, comparing extracorporeal with conventional CPR, found no statistically significant difference in neurologically favorable survival. Since protocol deviations were anticipated, a pre-specified per-protocol analysis was foreseen.

METHODS

The per-protocol analysis of the INCEPTION trial excluded patients not meeting inclusion or exclusion criteria, amongst which time-to-cannulation of >60 minutes, and achieving a return of spontaneous circulation before hospital arrival. Crossovers were excluded as well. The primary outcome (30-day survival in a neurologically favorable condition; cerebral performance category [CPC] 1-2) was primarily analyzed under a frequentist statistical framework. In addition, Bayesian analysis under a minimally informative prior was performed.

RESULTS

Eighty-one patients were included in the per-protocol analysis (extracorporeal CPR n = 33, conventional CPR n = 48). Thirty-day survival with CPC1-2 was 15% in the extracorporeal CPR group versus 9% in the conventional CPR group (adjusted OR 1.9; 95% CI 0.4-9.3; p-value 0.393). Bayesian analysis showed an 84% posterior probability of any ECPR benefit and a 61% posterior probability of a 5% absolute risk reduction for the primary outcome.

CONCLUSION

A pre-planned, pre-specified per-protocol analysis of the INCEPTION-trial, found a higher survival with favorable neurological in patients undergoing ECPR versus CCPR for refractory shockable OHCA. This difference did not reach statistical significance, but results should be interpreted with care, in the light of the small remaining sample size.

Wolf Creek XVII Part 7: Mechanical circulatory support

Introduction

Failure to restore spontaneous circulation remains a major cause of death for cardiac arrest (CA) patients. Mechanical circulatory support, specifically extracorporeal cardiopulmonary resuscitation (ECPR), has emerged as a feasible and efficacious rescue strategy for selected refractory CA patients.

Methods

Mechanical Circulatory Support was one of six focus topics for the Wolf Creek XVII Conference held on June 14-17, 2023 in Ann Arbor, Michigan, USA. Conference invitees included international thought leaders and scientists in the field of CA resuscitation from academia and industry. Participants submitted via online survey knowledge gaps, barriers to translation and research priorities for each focus topic. Expert panels used the survey results and their own perspectives and insights to create and present a preliminary unranked list for each category that was debated, revised and ranked by all attendees to identify the top 5 for each category.

Results

Top 5 knowledge gaps included optimal patient selection, pre-ECPR treatments, logistical and programmatic characteristics of ECPR programs, generalizability and effectiveness of ECPR, and prevention of reperfusion injury. Top 5 barriers to translation included cost/resource limitations, technical challenges, collaboration across multiple disciplines, limited patient population, and early identification of eligible patients. Top 5 research priorities focused on comparing the outcomes of prehospital/rapid transport strategies vs in-hospital ECPR initiation, implementation of high-performing ECPR system vs standard care, rapid patient identification tools vs standard clinical judgment, post-cardiac arrest bundled care vs no bundled care, and standardized ECPR clinical protocol vs routine care.

Conclusion

This overview can serve as an innovative guide to transform the care and outcome of patients with refractory CA.

Extracorporeal cardiopulmonary resuscitation in out-of-hospital cardiac arrest - current status

PURPOSE OF REVIEW

Extracorporeal cardiopulmonary resuscitation (ECPR) is an emerging treatment for refractory cardiac arrest. In recent years, several randomized controlled trials have been published that aimed to address the efficacy and effectiveness of ECPR for out-of-hospital cardiac arrest (OHCA). Despite the lack of high-quality evidence concerning clinical effectiveness and cost-effectiveness, ECPR is increasingly implemented throughout the world. In this review, we aim to provide an overview of the current status of ECPR for OHCA.

RECENT FINDINGS

Randomized controlled trials showed diverging results, largely due to differences in selection criteria and study design. Single-center studies, performed in centers with extraordinary expertise and dedication consistently achieve a low-flow time of around 60 min, but such achievements are rarely reproduced outside these centers. Strict patient selection can improve outcome but simultaneously limits the caseload. Preliminary data suggest that outcome may also be improved by avoiding hyperoxia postresuscitation.

SUMMARY

The potential of ECPR to increase survival in selected patients in highly dedicated systems seems to be proven, the question remains whether ECPR for OHCA can be widely implemented successfully and can develop into a sustainable, commonplace resource-effective treatment.

Trend of Outcome Metrics in Recent Out-of-Hospital-Cardiac-Arrest Research: A Narrative Review of Clinical Trials

Cardiopulmonary resuscitation (CPR) research traditionally focuses on survival. In 2018, the International Liaison Committee on Resuscitation (ILCOR) proposed more patient-centered outcomes. Our narrative review assessed clinical trials after 2018 to identify the trends of outcome metrics in the field OHCA research. We performed a search of the PubMed database from 1 January 2019 to 22 September 2023. Prospective clinical trials involving adult humans were eligible. Studies that did not report any patient-related outcomes or were not available in full-text or English language were excluded. The articles were assessed for demographic information and primary and secondary outcomes. We included 89 studies for analysis. For the primary outcome, 31 (35%) studies assessed neurocognitive functions, and 27 (30%) used survival. For secondary outcomes, neurocognitive function was present in 20 (22%) studies, and survival was present in 10 (11%) studies. Twenty-six (29%) studies used both survival and neurocognitive function. Since the publication of the COSCA guidelines in 2018, there has been an increased focus on neurologic outcomes. Although survival outcomes are used frequently, we observed a trend toward fewer studies with ROSC as a primary outcome. There were no quality-of-life assessments, suggesting a need for more studies with patient-centered outcomes that can inform the guidelines for cardiac-arrest management.

Prehospital Predictors of Survival in Patients with Out-of-Hospital Cardiac Arrest

Background and Objectives: Despite advances in the treatment of heart diseases, the outcome of patients experiencing sudden cardiac arrest remains poor. The aim of our study was to determine the prehospital variables as predictors of survival outcomes in out-of-hospital cardiac arrest (OHCA) victims. Materials and Methods: This was a retrospective observational cohort study of OHCA cases. EMS protocols created in accordance with the Utstein style reporting for OHCA, first responder intervention reports, medical dispatch center dispatch protocols and hospital medical reports were all reviewed. Multivariate logistic regression was performed with the following variables: age, gender, witnessed status, location, bystander CPR, first rhythm, and etiology. Results: A total of 381 interventions with resuscitation attempts were analyzed. In more than half (55%) of them, bystander CPR was performed. Thirty percent of all patients achieved return of spontaneous circulation (ROSC), 22% of those achieved 30-day survival (7% of all OHCA victims), and 73% of those survived with Cerebral Performance Score 1 or 2. The logistic regression model of adjustment confirms that shockable initial rhythm was a predictor of ROSC [OR: 4.5 (95% CI: 2.5-8.1)] and 30-day survival [OR: 9.3 (95% CI: 2.9-29.2)]. Age was also associated (≤67 years) [OR: 3.9 (95% CI: 1.3-11.9)] with better survival. Conclusions: Elderly patients have a lower survival rate. The occurrence of bystander CPR in cardiac arrest remains alarmingly low. Shockable initial rhythm is associated with a better survival rate and neurological outcome compared with non-shockable rhythm.

Benefits, key protocol components, and considerations for successful implementation of extracorporeal cardiopulmonary resuscitation: a review of the recent literature

The application of venoarterial extracorporeal membrane oxygenation (ECMO) in patients unresponsive to conventional cardiopulmonary resuscitation (CPR) has significantly increased in recent years. To date, three published randomized trials have investigated the use of extracorporeal CPR (ECPR) in adults with refractory out-of-hospital cardiac arrest. Although these trials reported inconsistent results, they suggest that ECPR may have a significant survival benefit over conventional CPR in selected patients only when performed with strict protocol adherence in experienced emergency medical services-hospital systems. Several studies suggest that identifying suitable ECPR candidates and reducing the time from cardiac arrest to ECMO initiation are key to successful outcomes. Prehospital ECPR or the rendezvous approach may allow more patients to receive ECPR within acceptable timeframes than ECPR initiation on arrival at a capable hospital. ECPR is only one part of the system of care for resuscitation of cardiac arrest victims. Optimizing the chain of survival is critical to improving outcomes of patients receiving ECPR. Further studies are needed to find the optimal strategy for the use of ECPR.

Extracorporeal cardiopulmonary resuscitation for refractory OHCA: lessons from three randomized controlled trials-the trialists' view

Extracorporeal cardiopulmonary resuscitation is a promising treatment for refractory out-of-hospital cardiac arrest. Three recent randomized trials (ARREST trial, Prague OHCA study, and INCEPTION trial) that addressed the clinical benefit of extracorporeal cardiopulmonary resuscitation in out-of-hospital cardiac arrest yielded seemingly diverging results. The evidence for extracorporeal cardiopulmonary resuscitation in out-of-hospital cardiac arrest, derived from three recent randomized controlled trials, is not contradictory but rather complementary. Excellent results can be achieved with a very high level of dedication, provided that strict selection criteria are applied. However, pragmatic implementation of extracorporeal cardiopulmonary resuscitation does not necessarily lead to improved outcome of refractory out-of-hospital cardiac arrest. Centres that are performing extracorporeal cardiopulmonary resuscitation for out-of-hospital cardiac arrest or aspire to do so should critically evaluate whether they are able to meet the pre-requisites that are needed to conduct an effective extracorporeal cardiopulmonary resuscitation programme.

One-Year Review in Cardiac Arrest: The 2022 Randomized Controlled Trials

Cardiac arrest, one of the leading causes of death, accounts for numerous clinical studies published each year. This review summarizes the findings of all the randomized controlled clinical trials (RCT) on cardiac arrest published in the year 2022. The RCTs are presented according to the following categories: out-of- and in-hospital cardiac arrest (OHCA, IHCA) and post-cardiac arrest care. Interestingly, more than 80% of the RCTs encompassed advanced life support and post-cardiac arrest care, while no studies focused on the treatment of IHCA, except for one that, however, explored the temperature control after resuscitation in this population. Surprisingly, 9 out of 11 RCTs led to neutral results demonstrating equivalency between the newly tested interventions compared to current practice. One trial was negative, showing that oxygen titration in the immediate pre-hospital post-resuscitation period decreased survival compared to a more liberal approach. One RCT was positive and introduced new defibrillation strategies for refractory cardiac arrest. Overall, data from the 2022 RCTs discussed here provide a solid basis to generate new hypotheses to be tested in future clinical studies.