Outcomes of sudden cardiac arrest in a state-wide integrated resuscitation program: Results from the Minnesota Resuscitation Consortium

Antiarrhythmic effects of metformin

Atrial fibrillation/flutter (AF) is a major public health problem and is associated with stroke, heart failure, dementia, and death. It is estimated that 20%-30% of Americans will develop AF at some point in their life. Current medications to prevent AF have limited efficacy and significant adverse effects. Newer and safer therapies to prevent AF are needed. Ventricular arrhythmias are less prevalent than AF but may have significant consequences including sudden cardiac death. Metformin is the most prescribed, first-line medication for treatment of diabetes mellitus (DM). It decreases hepatic glucose production but also reduces inflammation and oxidative stress. Experimental studies have shown that metformin improves metabolic, electrical, and histologic risk factors associated with AF and ventricular arrhythmias. Furthermore, in large clinical observational studies, metformin has been associated with a reduced risk of AF in people with DM. These data suggest that metformin may have antiarrhythmic properties and may be a candidate to be repurposed as a medication to prevent cardiac arrhythmias. In this article, we review the clinical observational and experimental evidence for the association between metformin and cardiac arrhythmias. We also discuss the potential antiarrhythmic mechanisms underlying this association. Repurposing a well-tolerated, safe, and inexpensive medication to prevent cardiac arrhythmias has significant positive public health implications.

QT prolongation predicts all-cause mortality above and beyond a validated risk score

INTRODUCTION

QT prolongation is a risk factor for life-threatening arrhythmias and sudden cardiac death. In large cohorts, QT interval was associated with all-cause mortality, but these analyses may contain residual confounding. Whether the QT interval provides prognostic information above and beyond a validated mortality risk score is unknown. We hypothesized that QT interval on ECG will independently predict mortality after adjustment for the Care Assessment Needs (CAN) score, which was validated to predict mortality nationwide at the Veterans Administration (VA) (c-index 0.86).

METHODS

Outpatients with an ECG at the Minneapolis VA from 2012 to 2016 were included in this retrospective cohort study. ECGs with ventricular rate < 50 or > 100 beats/min and those with QRS > 120 ms were excluded. QT intervals were corrected (QTc) using the Bazett's formula. CAN score, calculated within 1-week of the ECG, was obtained from the VA Corporate Data Warehouse.

RESULTS

Of the 31,201 patients, 427 (1.4%) had QTc ≥ 500 ms, 1799 (5.8%) had QTc 470-500 ms and 28,975 (92.9%) had QTc < 470 ms. Compared to those with QTc < 470 ms, CAN-adjusted odds ratios (OR) for 1-year mortality (1.76 for QTc 470-500 and 2.70 for QTc > 500 ms; p < 0.0001 for both) and for 5-year mortality (1.75 for QTc 470-500 and 2.48 for QTc > 500 ms; p < 0.0001 for both) were significantly higher in those with longer QTc. C-index for CAN score and QTc predicting 1-year mortality was 0.837.

CONCLUSIONS

QT prolongation predicts all-cause mortality independently of a validated mortality risk prediction score.

Statewide implementation of the cardiac arrest registry to enhance survival in Ohio

Objective

Public health surveillance is essential for improving community health. The Cardiac Arrest Registry to Enhance Survival (CARES) is a surveillance system for out-of-hospital cardiac arrest (OHCA). We describe results of the organized statewide implementation of Ohio CARES.

Methods

We performed a retrospective analysis of CARES enactment in Ohio. Key elements included: establishment of statewide leadership, appointment of a dedicated coordinator, conversion to a statewide subscription, statewide dissemination of information, fundraising from internal and external stakeholders, and conduct of resuscitation academies. We identified all adult (≥18 years) OHCA reported in the registry during 2013-2020. We evaluated OHCA characteristics before (2013-2015) and after (2016-2019) statewide implementation using chi-square test. We evaluated trends in OHCA outcomes using the Cochran-Armitage test of trend.

Results

Statewide CARES promotion increased participation from 2 (urban) to 136 (129 urban, 7 rural) EMS agencies. Covered population increased from 1.2 M (10% of state) to 4.8 M (41% of state). After statewide implementation, OHCA populations increased male (58.1% vs 60.8%, p < 0.01), white (50.1% vs 63.7%, p < 0.01), bystander witnessed (26.9% vs 32.9%, p < 0.01) OHCAs. Bystander CPR (34.7% vs 33.2%, p = 0.22), bystander AED (13.5% vs 12.3%, p = 0.55) and initial rhythm (shockable 18.0% vs 18.3%, p = 0.32) did not change. From 2013 to 2019 there were temporal increases in ROSC (29.7% to 31.9%, p-trend = 0.028), survival (7.4% to 12.3%, p-trend < 0.001) and survival with good neurologic outcome (5.6% to 8.6%, p-trend = 0.047).

Conclusion

The organized statewide implementation of CARES in Ohio was associated with marked increases in community uptake and concurrent observed improvements in patient outcomes. These results highlight key lessons for community-wide fostering of OHCA surveillance.

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.

The Impact of Head Position on Neurological and Histopathological Outcome Following Controlled Automated Reperfusion of the Whole Body (CARL) in a Pig Model

Introduction: Based on extracorporeal circulation, targeted reperfusion strategies have been developed to improve survival and neurologic recovery in refractory cardiac arrest: Controlled Automated Reperfusion of the whoLe Body (CARL). Furthermore, animal and human cadaver studies have shown beneficial effects on cerebral pressure due to head elevation during conventional cardiopulmonary resuscitation. Our aim was to evaluate the impact of head elevation on survival, neurologic recovery and histopathologic outcome in addition to CARL in an animal model. Methods: After 20 min of ventricular fibrillation, 46 domestic pigs underwent CARL, including high, pulsatile extracorporeal blood flow, pH-stat acid-base management, priming with a colloid, mannitol and citrate, targeted oxygen, carbon dioxide and blood pressure management, rapid cooling and slow rewarming. N = 25 were head-up (HUP) during CARL, and N = 21 were supine (SUP). After weaning from ECC, the pigs were extubated and followed up in the animal care facility for up to seven days. Neuronal density was evaluated in neurohistopathology. Results: More animals in the HUP group survived and achieved a favorable neurological recovery, 21/25 (84%) versus 6/21 (29%) in the SUP group. Head positioning was an independent factor in neurologically favorable survival (p < 0.00012). Neurohistopathology showed no significant structural differences between HUP and SUP. Distinct, partly transient clinical neurologic deficits were blindness and ataxia. Conclusions: Head elevation during CARL after 20 min of cardiac arrest independently improved survival and neurologic outcome in pigs. Clinical follow-up revealed transient neurologic deficits potentially attributable to functions localized in the posterior perfusion area, whereas histopathologic findings did not show corresponding differences between the groups. A possible explanation of our findings may be venous congestion and edema as modifiable contributing factors of neurologic injury following prolonged cardiac arrest.

A comparison between sudden cardiac arrest on military bases and non-military settings

INTRODUCTION

Out-of-hospital cardiac arrests contribute to significant morbidity and mortality in both non-military/civilian and military populations. Early CPR and AED use have been linked with improved outcomes. There is public health interest in identifying communities with high rates of both with the hopes of creating generalizable tactics for improving cardiac arrest survival.

METHODS

We examined a national registry of EMS activations in the United States (NEMSIS). Inclusion criteria were witnessed cardiac arrests from January 2020 to September 2022 where EMS providers documented the location of the arrest, whether CPR was provided prior to their arrival (yes/no), and whether an AED was applied prior to their arrival (yes/no). Cardiac arrests were then classified as occurring on a military base or in a non-military setting.

RESULTS

A total of 60 witnessed cardiac arrests on military bases and 202,605 witnessed cardiac arrests in non-military settings met inclusion criteria. Importantly, the prevalence of CPR and AED use prior to EMS arrival was significantly higher on military bases compared to non-military settings.

CONCLUSIONS

Reasons for the trends we observed may be a greater availability of CPR-trained individuals and AEDs on military bases, as well as a widespread willingness to provide aid to victims of cardiac arrest. Further research should examine cardiac arrests on military bases.

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

BACKGROUND

The prognosis of refractory out-of-hospital cardiac arrest (OHCA) is generally poor. A recent Prague OHCA study has demonstrated that an invasive approach (including extracorporeal cardiopulmonary resuscitation, ECPR) is a feasible and effective treatment strategy in refractory OHCA. Here we present a post-hoc analysis of the role of initial rhythm on patient outcomes.

METHODS

The study enrolled patients who had a witnessed OHCA of presumed cardiac cause without early recovery of spontaneous circulation. The initial rhythm was classified as either a shockable or a non-shockable rhythm. The primary outcome was a composite of 180 day-survival with Cerebral Performance in Category 1 or 2.

RESULTS

256 (median age 58y, 17% females) patients were enrolled. The median (IQR) duration of resuscitation was 52 (33-68) minutes. 156 (61%) and 100 (39%) of patients manifested a shockable and non-shockable rhythm, respectively. The primary outcome was achieved in 63 (40%) patients with a shockable rhythm and in 5 (5%) patients with a non-shockable rhythm (p < 0.001). When patients were analyzed separately based on whether the treatment was invasive (n = 124) or standard (n = 132), the difference in the primary endpoint between shockable and non-shockable initial rhythms remained significant (35/72 (49%) vs 4/52 (8%) in the invasive arm and 28/84 (33%) vs 1/48 (2%) in the standard arm; p < 0.001).

CONCLUSION

An initial shockable rhythm and treatment with an invasive approach is associated with a reasonable neurologically favorable survival for 180 days despite refractory OHCA. Non-shockable initial rhythms bear a poor prognosis in refractory OHCA even when ECPR is readily available.

Predictors of Sudden Cardiac Arrest Among Patients With Post-Myocardial Infarction Ejection Fraction Greater Than 35

Background

Sudden cardiac arrest (SCA) risk increases after myocardial infarction (MI) in patients with a reduced ejection fraction (EF). However, the risk factors for SCA among patients with a post‐MI EF >35% remain poorly understood.

Methods and Results

Using the Optum de‐identified electronic health record data set from 2008 to 2017, we identified patients with an incident MI diagnosis and troponin elevation who had a post‐MI EF >35% and underwent coronary angiography. Primary outcome was SCA within 1 year post‐MI. The database was divided into derivation (70%) and validation (30%) cohorts by random selection. Cox proportional hazard regression was used to generate and validate a risk prediction model. Among 31 286 patients with an MI (median age 64.1; 39% female; 87% White), 499 experienced SCA within 1 year post‐MI (estimated probability 1.8%). Lack of revascularization at MI, post‐MI EF <50%, Black race, renal failure, chronic obstructive pulmonary disease, antiarrhythmic therapy, and absence of beta blocker therapy were independent predictors of SCA. A multivariable model consisting of these variables predicted SCA risk (C‐statistic 0.73). Based on this model, the estimated annual probability of SCA was 4.4% (95% CI, 3.9–4.9) in the highest quartile of risk versus 0.6% (95% CI, 0.4–0.8) in the lowest quartile.

Conclusions

Patients with a post‐MI EF >35% have a substantial annual risk of SCA. A risk model consisting of acute coronary revascularization, EF, race, renal failure, chronic obstructive pulmonary disease, antiarrhythmic therapy, and beta blocker therapy can identify patients with higher risk of SCA, who may benefit from further risk stratification and closer monitoring.

The effect of system performance improvement on patients with cardiac arrest: A systematic review

AIM

The aim of our review was to understand the effect of interventions to improve system-level performance on the clinical outcomes of patients with cardiac arrest.

METHODS

We searched PubMed, Ovid EMBASE, and the Cochrane Central Register of Controlled Trials (CENTRAL) databases to identify randomised controlled trials and non-randomised studies published before July 21, 2020 reporting systems interventions to improve outcomes. Characteristics, study design, evaluation methods and outcomes of included studies were extracted. (PROSPERO registration CRD42020161882).

RESULTS

One cluster randomised trial and 26 non-randomised studies were included. There were 18 studies focusing on interventions for patients with out-of-hospital cardiac arrest and 9 studies for patients with in-hospital cardiac arrest. Interventions included implementation of a bundle of care strategy, evaluation of cardiopulmonary resuscitation (CPR) quality with feedback/debriefing, data surveillance, and CPR training programs. Although improved survival with favorable neurologic outcome at discharge after the implementation of specific interventions was found in 13 studies, improved survival to hospital discharge in 14 studies and improved survival to admission in 3 studies, there were still 7 studies showing no significant improvement of clinical outcomes after interventions.

CONCLUSION

Although only moderate to very low certainty of evidence exists to support the effect of system-level performance improvement on the clinical outcomes of patients, we recommend that organisations or communities evaluate their performance and target key areas with the goal to improve performance because of no known risks and the potential for a large beneficial effect.

Education, Implementation, and Teams: 2020 International Consensus on Cardiopulmonary Resuscitation and Emergency Cardiovascular Care Science With Treatment Recommendations

For this 2020 International Consensus on Cardiopulmonary Resuscitation and Emergency Cardiovascular Care Science With Treatment Recommendations, the Education, Implementation, and Teams Task Force applied the population, intervention, comparator, outcome, study design, time frame format and performed 15 systematic reviews, applying the Grading of Recommendations, Assessment, Development, and Evaluation guidance. Furthermore, 4 scoping reviews and 7 evidence updates assessed any new evidence to determine if a change in any existing treatment recommendation was required. The topics covered included training for the treatment of opioid overdose; basic life support, including automated external defibrillator training; measuring implementation and performance in communities, and cardiac arrest centers; advanced life support training, including team and leadership training and rapid response teams; measuring cardiopulmonary resuscitation performance, feedback devices, and debriefing; and the use of social media to improve cardiopulmonary resuscitation application.

Education, Implementation, and Teams: 2020 International Consensus on Cardiopulmonary Resuscitation and Emergency Cardiovascular Care Science With Treatment Recommendations

For this 2020 International Consensus on Cardiopulmonary Resuscitation and Emergency Cardiovascular Care Science With Treatment Recommendations, the Education, Implementation, and Teams Task Force applied the population, intervention, comparator, outcome, study design, time frame format and performed 15 systematic reviews, applying the Grading of Recommendations, Assessment, Development, and Evaluation guidance. Furthermore, 4 scoping reviews and 7 evidence updates assessed any new evidence to determine if a change in any existing treatment recommendation was required. The topics covered included training for the treatment of opioid overdose; basic life support, including automated external defibrillator training; measuring implementation and performance in communities, and cardiac arrest centers; advanced life support training, including team and leadership training and rapid response teams; measuring cardiopulmonary resuscitation performance, feedback devices, and debriefing; and the use of social media to improve cardiopulmonary resuscitation application.

Nonsustained ventricular tachycardia in heart failure with preserved ejection fraction

BACKGROUND

Ventricular tachycardia (VT) is a common arrhythmia in heart failure with reduced ejection fraction but its incidence, predictors, and significance have not been determined in heart failure with preserved ejection fraction (HFpEF).

METHODS

We performed a retrospective review of arrhythmias in two cohorts of patients with an HFpEF diagnosis. Patients in cohort 1 (n = 40) underwent routine arrhythmia surveillance with a 14-day ambulatory electrocardiogram (ECG) monitor. Patients in cohort 2 (n = 85) had cardiac pacemakers and underwent routine device interrogations.

RESULTS

In cohort 1, 13 patients (32.5%) had one or more episodes of nonsustained VT (NSVT) on ambulatory ECG. In cohort 2, 38 patients (44.7%) had NSVT on cardiac pacemaker interrogations. During a median (interquartile range) follow-up of 3.0 (1.6 to 5.1) years, 15 (12%) patients died (20% of patients with NSVT versus 6.8% of those without NSVT; P = .03). In logistic regression analysis, NSVT was associated with a 3.4-fold higher odds of death (95% confidence interval 1.08 to 10.53; P = .04) in HFpEF.

CONCLUSIONS

In conclusion, patients with HFpEF have a relatively high, and possibly underappreciated, burden of NSVT, which confers a higher risk of mortality. The frequent episodes of NSVT in these patients may provide insight into the mechanism of sudden cardiac death in HFpEF.

Assessment of Community Interventions for Bystander Cardiopulmonary Resuscitation in Out-of-Hospital Cardiac Arrest: A Systematic Review and Meta-analysis

IMPORTANCE

Outcomes from out-of-hospital cardiac arrests (OHCAs) remain poor. Outcomes associated with community interventions that address bystander cardiopulmonary resuscitation (CPR) remain unclear and need further study.

OBJECTIVE

To examine community interventions and their association with bystander CPR and survival after OHCA.

DATA SOURCES

Literature search of the MEDLINE, Embase, and the Cochrane Library databases from database inception to December 31, 2018, was conducted. Key search terms included cardiopulmonary resuscitation, layperson, basic life support, education, cardiac arrest, and survival.

STUDY SELECTION

Community intervention studies that reported on comparisons with control and differences in survival following OHCA were included. Studies that focused only on in-hospital interventions, patients with in-hospital cardiac arrest, only dispatcher-assisted CPR, or provision of automated external defibrillators were excluded.

DATA EXTRACTION AND SYNTHESIS

Pooled odds ratios (ORs) and 95% CIs were estimated using a random-effects model. This study followed the Preferred Reporting Items for Systematic Reviews and Meta-analyses (PRISMA) reporting guideline.

MAIN OUTCOMES AND MEASURES

Thirty-day survival or survival to hospital discharge and bystander CPR rate.

RESULTS

A total of 4480 articles were identified; of these, 15 studies were included for analysis. There were broadly 2 types of interventions: community intervention alone (5 studies) and community intervention combined with changes in health services (10 studies). Four studies involved notification systems that alerted trained lay bystanders to the location of the OHCA in addition to CPR skills training. Meta-analysis of 9 studies including 21 266 patients with OHCA found that community interventions were associated with increased survival to discharge or 30-day survival (OR, 1.34; 95% CI, 1.14-1.57; I2 = 33%) and greater bystander CPR rate (OR, 1.28; 95% CI, 1.06-1.54; I2 = 82%). Compared with community intervention alone, community plus health service intervention was associated with a greater bystander CPR rate compared with community alone (community plus intervention: OR, 1.74; 95% CI, 1.26-2.40 vs community alone: OR, 1.06; 95% CI, 0.85-1.31) (P = .01). Survival rate, however, was not significantly different between intervention types: community plus health service intervention OR, 1.71; 95% CI, 1.09-2.68 vs community only OR, 1.26; 95% CI, 1.05-1.50 (P = .21).

CONCLUSIONS AND RELEVANCE

In this study, while the evidence base is limited, community-based interventions with a focus on improving bystander CPR appeared to be associated with improved survival following OHCA. Further evaluations in diverse settings are needed to enable widespread implementation of such interventions.

Study on the Improvement of Electrical Facility System of Automated External Defibrillators by Real-Time Measurement of Thoracic Impedance

Sudden Cardiac Arrest (SCA) is a serious emergency disease that has increased steadily every year. To this end, an Automated External Defibrillator (AED) is placed in a public place so that even non-professional medical personnel can respond to SCA. However, the thoracic impedance of patients changes due to CardioPulmonary Resuscitation (CPR) and artificial respiration during first aid treatment. In addition, changes in chest statues due to gender, age, and accidents cause changes in thoracic impedance in real time. The change in thoracic impedance caused by this has a negative effect on the intended electrical energy of the automatic heart shocker to the emergency patient. To prove this, we divided it into adult and pediatric modes and experimented with the energy error of the AED according to the same impedance change. When the first peak current was up to 56.4 (A) and at least 8.4 (A) in the adult mode, the first peak current was up to 32.2 (A) and at least 4.8 (A), respectively, when the impedance changed, the error of the current figure occurred. In this paper, the inverse relationship between thoracic impedance and electric shock energy according to the state of the cardiac arrest patient is demonstrated through the results of the experiment, and the need for an electric facility system that can revise for changes in thoracic impedance of the cardiac arrest patient by reflecting them on electric shock energy in real time is presented.

Implications of Initial Recorded Rhythm on Cardioverter-Defibrillator Insertion and Subsequent All-Cause Mortality in Sudden Cardiac Arrest Survivors

Sudden cardiac arrest (SCA) rhythms have been traditionally divided into shockable [ventricular tachycardia (VT)/ventricular fibrillation (VF)] and nonshockable [(asystole (ASY)/pulseless electrical activity (PEA)] rhythms. It is unclear if the specific rhythm has implications on patient management and outcomes. We evaluated 1,433 patients who were admitted with SCA from 2000 to 2012 and were discharged alive. Of those, 1,123 patients had a recorded initial SCA rhythm. Subjects included were >18 years of age, and without an implantable cardioverter-defibrillator (ICD) in place at the time of the event. The likelihood of receiving an ICD for each SCA rhythm and the time to death were analyzed. Of the overall cohort of 1,123 SCA survivors (age of 62 ± 15 years; 39.2% women; 56.3% in-hospital SCA; 83% white; 67% coronary artery disease), 355 (31.6%) received an ICD, and 493 (43.9%) died over a mean follow-up of 3.8 ± 3.2 years. Patients with VF (n = 254, 43.6%) or VT (n = 83, 43.9%) were more likely to receive ICD therapy compared with those with ASY (n = 9, 5.3%) or PEA (n = 9, 4.8%; p <0.001). All-cause mortality was lower in VF patients compared with the other groups (p <0.0001). ICD therapy was associated with lower risk of death in the VF group (hazard ratio [HR] 0.61 [0.45 to 0.83]; p = 0.002) and strong trends toward less mortality in patients with VT (HR 0.64 [0.40 to 1.03]; p = 0.07) and ASY (HR 0.39 [0.12 to 1.31]; p = 0.13) but not in those with PEA (HR 0.93 [0.39 to 2.23]; p = 0.88). In conclusion, long-term survival in post-SCA patients is influenced by initial SCA rhythm. Although SCA survivors with shockable rhythms were more likely to receive ICDs, the ICD was associated with lower risk of death in most patients, including those with ASY. In conclusion, our data suggest that a more detailed SCA rhythm classification has important implications to patient management and long-term survival in this population.

A simple decision rule predicts futile resuscitation of out-of-hospital cardiac arrest

AIM

Resuscitation of cardiac arrest involves invasive and traumatic interventions and places a large burden on limited EMS resources. Our aim was to identify prehospital cardiac arrests for which resuscitation is extremely unlikely to result in survival to hospital discharge.

METHODS

We performed a retrospective cohort analysis of all cardiac arrests in San Mateo County, California, for which paramedics were dispatched, from January 1, 2015 to December 31, 2018, using the Cardiac Arrest Registry to Enhance Survival (CARES) database. We described characteristics of patients, arrests, and EMS responses, and used recursive partitioning to develop decision rules to identify arrests unlikely to survive to hospital discharge, or to survive with good neurologic function.

RESULTS

From 2015-2018, 1750 patients received EMS dispatch for cardiac arrest in San Mateo County. We excluded 44 patients for whom resuscitation was terminated due to DNR directives. Median age was 69 years (IQR 57-81), 563 (33.0%) patients were female, 816 (47.8%) had witnessed arrests, 651 (38.2%) received bystander CPR, 421 (24.7%) had an initial shockable rhythm, and 1178 (69.1%) arrested at home. A simple rule (non-shockable initial rhythm, unwitnessed arrest, and age 80 or greater) excludes 223 (13.1%) arrests, of whom none survived to hospital discharge.

CONCLUSION

A simple decision rule (non-shockable rhythm, unwitnessed arrest, age ≥ 80) identifies arrests for which resuscitation is futile. If validated, this rule could be applied by EMS policymakers to identify cardiac arrests for which the trauma and expense of resuscitation are extremely unlikely to result in survival.

Association of acute myocardial infarction cardiac arrest patient volume and in-hospital mortality in the United States: Insights from the National Cardiovascular Data Registry Acute Coronary Treatment And Intervention Outcomes Network Registry

BACKGROUND

Little is known about how differences in out of hospital cardiac arrest patient volume affect in-hospital myocardial infarction (MI) mortality.

HYPOTHESIS

Hospitals accepting cardiac arrest transfers will have increased hospital MI mortality.

METHODS

MI patients (ST elevation MI [STEMI] and non-ST elevation MI [NSTEMI]) in the Acute Coronary Treatment Intervention Outcomes Network Registry were included. Hospital variation of cardiac arrest and temporal trend of the proportion of cardiac arrest MI patients were explored. Hospitals were divided into tertiles based on the proportion of cardiac arrest MI patients, and association between in-hospital mortality and hospital tertiles of cardiac arrest was compared using logistic regression adjusting for case mix.

RESULTS

A total of 252 882 patients from 224 hospitals were included, of whom 9682 (3.8%) had cardiac arrest (1.6% of NSTEMI and 7.5% of STEMI patients). The proportion of MI patients who had cardiac arrest admitted to each hospital was relatively low (median 3.7% [25th, 75th percentiles: 3.0%, 4.5%]).with a range of 4.2% to 12.4% in the high-volume tertiles. Unadjusted in-hospital mortality increased with tertile: low 3.8%, intermediate 4.6%, and high 4.7% (P < 0.001); this was no longer significantly different after adjustment (intermediate vs high tertile odds ratio (OR) = 1.02; 95% confidence interval [0.90-1.16], low vs high tertile OR = 0.93 [0.83, 1.05]).

CONCLUSIONS

The proportion of MI patients who have cardiac arrest is low. In-hospital mortality among all MI patients did not differ significantly between hospitals that had increased proportions of cardiac arrest MI patients. For most hospitals, overall MI mortality is unlikely to be adversely affected by treating cardiac arrest patients with MI.

Ideal (i) CPR: Looking beyond shadows in a cave

Survival rates after cardiac arrest have shown minimal improvement in the last 60 years. However, in some forward-thinking cities and hospitals, out-of and in-hospital cardiac arrest survival rates exceed 20% and 40% respectively. These beacons of hope can enlighten us, providing a clearer vision of what it takes to provide Ideal cardiopulmonary resuscitation. To make progress in a field that has seemingly stagnated for too many decades, we must be open to new ideas and develop bundles of care that work in communities with varying EMS systems and various existing infrastructure to bring the best practices to the rest of the country.

Regional Variation in Outcomes of Hospitalized Patients Having Out-of-Hospital Cardiac Arrest

The aim of this study was to investigate patient outcomes after hospitalization for out-of-hospital cardiac arrest in the United States. We used the 2002 to 2013 Nationwide Inpatient Sample database to identify adults ≥18 years with an International Classification of Diseases, Ninth Revision, Clinical Modification, principal diagnosis code of cardiorespiratory arrest (427.5) or ventricular fibrillation (VF) (427.41). In 4 predefined federal geographic regions: Northeast, Midwest, South, and West, means and proportions of survival, survival stratified by initial rhythm, hospital charges, and cost were estimated. Multiple linear and logistic regression models were conducted. Of the 154,177 patients with out-of-hospital cardiac arrest hospitalized in the United States, 25,873 (16.8%) were in the Northeast, 38,296 (24.8%) in the Midwest, 57,305 (37.2%) in the South, and 32,703 (21.2%) in the West. Variability in survival was noted in VF arrests; compared with the Northeast, survival was higher in the Midwest and South (adjusted odds ratio [AOR] 1.16, 95% confidence interval [CI] 1.02 to 1.32 and AOR 1.24, 95% CI 1.09 to 1.40, respectively), with no difference detected in the West (AOR 0.93, 95% CI 0.82 to 1.06). No variability in survival was noted after non-VF arrests (p >0.05). Hospital charges rose significantly across all regions of the United States (p-trend < 0.001) and were higher in the West compared with the Northeast (hospital charges >$109,000/admission, AOR 1.76; 95% CI 1.50 to 2.06). In conclusion, nationwide, we observed significant regional variability in survival of hospitalized patients after out of hospital VF cardiac arrest, no survival variability after non-VF arrests, and a steady increase in hospital charges.

A Pre-Hospital Extracorporeal Cardio Pulmonary Resuscitation (ECPR) strategy for treatment of refractory out hospital cardiac arrest: An observational study and propensity analysis

BACKGROUND

Out of hospital cardiac arrest (OHCA) mortality rates remain very high with poor neurological outcome in survivors. Extracorporeal cardiopulmonary resuscitation (ECPR) is one of the treatments of refractory OHCA. This study used data from the mobile intensive care unit (MOICU) as part of the emergency medical system of Paris, and included all consecutive patients treated with ECPR (including pre-hospital ECPR) from 2011 to 2015 for the treatment of refractory OHCA, comparing two historical ECPR management strategies.

METHODS

We consecutively included refractory OHCA patients. In Period 1, ECPR was indicated in selected patients after 30min of advanced life support; in- or pre-hospital implementation depended on estimated transportation time and ECPR team availability. In Period 2, patient care relied on early ECPR initiation after 20min of resuscitation, stringent patient selection, epinephrine dose limitation and deployment of ECPR team with initial response team. Primary outcome was survival with good neurological function Cerebral Performance Category score (CPC score) 1 and 2 at ICU discharge or day 28.

FINDINGS

A total of 156 patients were included. (114 in Period 1 and 42 in Period 2). Baseline characteristics were similar. Mean low-flow duration was shorter by 20min (p<0.001) in Period 2. Survival was significantly higher in Period 2: 29% vs 8% (P<0.001), as confirmed by the multivariate analysis and propensity score. When combining stringent patient selection with an aggressive strategy, the survival rate increased to 38%. Pre-hospital ECPR implementation in itself was not an independent predictor of improved survival, but it was part of the strategy in Period 2.

INTERPRETATION

Our data suggest that ECPR in specific settings in the management of refractory OHCA is feasible and can lead to a significant increase in neurological intact survivors. These data, however, need to be confirmed by a large RCT.

Sodium nitroprusside enhanced cardiopulmonary resuscitation improves short term survival in a porcine model of ischemic refractory ventricular fibrillation

INTRODUCTION

Sodium nitroprusside (SNP) enhanced CPR (SNPeCPR) demonstrates increased vital organ blood flow and survival in multiple porcine models. We developed a new, coronary occlusion/ischemia model of prolonged resuscitation, mimicking the majority of out-of-hospital cardiac arrests presenting with shockable rhythms.

HYPOTHESIS

SNPeCPR will increase short term (4-h) survival compared to standard 2015 Advanced Cardiac Life Support (ACLS) guidelines in an ischemic refractory ventricular fibrillation (VF), prolonged CPR model.

METHODS

Sixteen anesthetized pigs had the ostial left anterior descending artery occluded leading to ischemic VF arrest. VF was untreated for 5min. Basic life support was performed for 10min. At minute 10 (EMS arrival), animals received either SNPeCPR (n=8) or standard ACLS (n=8). Defibrillation (200J) occurred every 3min. CPR continued for a total of 45min, then the balloon was deflated simulating revascularization. CPR continued until return of spontaneous circulation (ROSC) or a total of 60min, if unsuccessful. SNPeCPR animals received 2mg of SNP at minute 10 followed by 1mg every 5min until ROSC. Standard ACLS animals received 0.5mg epinephrine every 5min until ROSC. Primary endpoints were ROSC and 4-h survival.

RESULTS

All SNPeCPR animals (8/8) achieved sustained ROSC versus 2/8 standard ACLS animals within one hour of resuscitation (p=0.04). The 4-h survival was significantly improved with SNPeCPR compared to standard ACLS, 7/8 versus 1/8 respectively, p=0.0019.

CONCLUSION

SNPeCPR significantly improved ROSC and 4-h survival compared with standard ACLS CPR in a porcine model of prolonged ischemic, refractory VF cardiac arrest.