The use of prehospital variables to predict acute coronary artery disease in failed resuscitation attempts for out-of-hospital cardiac arrest

The state of emergency department extracorporeal cardiopulmonary resuscitation: Where are we now, and where are we going?

Extracorporeal cardiopulmonary resuscitation (ECPR) has emerged in the context of the emergency department as a life-saving therapy for patients with refractory cardiac arrest. This review examines the utility of ECPR based on current evidence gleaned from three pivotal trials: the ARREST trial, the Prague study, and the INCEPTION trial. We also discuss several considerations in the care of these complex patients, including prehospital strategy, patient selection, and postcardiac arrest management. Collectively, the evidence from these trials emphasizes the growing significance of ECPR as a viable intervention, highlighting its potential for improved outcomes and survival rates in patients with refractory cardiac arrest when employed judiciously. As such, these findings advocate the need for further research and protocol development to optimize its use in diverse clinical scenarios.

Extracorporeal membrane oxygenation for cardiac arrest: what, when, why, and how

INTRODUCTION

Extracorporeal membrane oxygenation (ECMO) facilitated resuscitation was first described in the 1960s, but only recently garnered increased attention with large observational studies and randomized trials evaluating its use.

AREAS COVERED

In this comprehensive review of extracorporeal cardiopulmonary resuscitation (ECPR), we report the history of resuscitative ECMO, terminology, circuit configuration and cannulation considerations, complications, selection criteria, implementation and management, and important considerations for the provider. We review the relevant guidelines, different approaches to cannulation, postresuscitation management, and expected outcomes, including neurologic, cardiac, and hospital survival. Finally, we advocate for the participation in national/international Registries in order to facilitate continuous quality improvement and support scientific discovery in this evolving area.

EXPERT OPINION

ECPR is the most disruptive technology in cardiac arrest resuscitation since high-quality CPR itself. ECPR has demonstrated that it can provide up to 30% increased odds of survival for refractory cardiac arrest, in tightly restricted systems and for select patients. It is also clear, though, from recent trials that ECPR will not confer this high survival when implemented in less tightly protocoled settings and within lower volume environments. Over the next 10 years, ECPR research will explore the optimal initiation thresholds, best practices for implementation, and postresuscitation care.

Exploratory analysis of myocardial function after extracorporeal cardiopulmonary resuscitation vs conventional cardiopulmonary resuscitation

Objective

Ventricular unloading is associated with myocardial recovery. We sought to evaluate the association of extracorporeal cardiopulmonary resuscitation (ECPR) on myocardial function after cardiac arrest. We conducted a retrospective exploratory analysis, comparing ejection fraction (EF) after adult cardiac arrest, between ECPR and conventional CPR.

Results

Among 1119 cases of cardiac arrest, 116 had an echocardiogram post-return of spontaneous circulation (ROSC) and were included. Thirty-eight patients had ≥ 2 echocardiograms. ECPR patients had differences in age, hypertension and chronic heart failure. ECPR patients had a lower EF post-ROSC (24% vs 45%; p < 0.01) and were more likely to undergo percutaneous coronary intervention (25% vs 3%; p < 0.01). In multivariate analysis, only ECPR use (β-coeff: 10.4 [95% CI 3.68–17.13]; p < 0.01) independently predicted improved myocardial function. In this exploratory study, EF after cardiac arrest may be more likely to improve among ECPR patients than CCPR patients. Our methodology should be replicated to confirm or refute the validity of our findings.

Predictors of In-Hospital Mortality after Recovered Out-of-Hospital Cardiac Arrest in Patients with Proven Significant Coronary Artery Disease: A Retrospective Study

INTRODUCTION

Recovered Out-of-Hospital Cardiac Arrest (rOHCA) population is heterogenous. Few studies focused on outcomes in the rOHCA subgroup with proven significant coronary artery disease (SigCAD). We aimed to characterize this subgroup and study the determinants of in-hospital mortality.

METHODS

Retrospective study of consecutive rOHCA patients submitted to coronary angiography. Only patients with SigCAD were included.

RESULTS

60 patients were studied, 85% were male, mean age was 62.6 ± 12.1 years. In-hospital mortality rate was 43.3%. Patients with diabetes and history of stroke were less likely to survive. Significant univariate predictors of in-hospital mortality were further analysed separately, according to whether they were present at hospital admission or developed during hospital evolution. At hospital admission, initial non-shockable rhythm, low-flow time>12min, pH<7.25mmol/L and lactates >4.75mmol/L were the most relevant predictors and therefore included in a score tested by Kaplan-Meyer. Patients who had 0/4 criteria had 100% chance of survival till hospital discharge, 1/4 had 77%, 2/4 had 50%, 3/4 had 25%. Patients with all 4 criteria had 0% survival. During in-hospital evolution, a pH<7.35 at 24h, lactates>2mmol/L at 24h, anoxic brain injury and persistent hemodynamic instability proved significant. Patients who had 0/4 of these in-hospital criteria had 100% chance of survival till hospital discharge, 1/4 had 94%, 2/4 had 47%, 3/4 had 25%. Patients with all 4 criteria had 0% survival. Contrarily, CAD severity and ventricular dysfunction didn't significantly correlate to the outcome.

CONCLUSION

Classic prehospital variables retain their value in predicting mortality in the specific group of OHCA with SigCAD. In-hospital evolution variables proved to add value in mortality prediction. Combining these simple variables in risk scores might help refining prognostic prediction in these patients's subset.

Clinical Factors Associated with Obstructive Coronary Artery Disease in Patients with Out-of-Hospital Cardiac Arrest: Data from the Korean Cardiac Arrest Research Consortium (KoCARC) Registry

BACKGROUND

Although coronary artery disease (CAD) is a major cause of out-of-hospital cardiac arrest (OHCA), there has been no convinced data on the necessity of routine invasive coronary angiography (ICA) in OHCA. We investigated clinical factors associated with obstructive CAD in OHCA.

METHODS

Data from 516 OHCA patients (mean age 58 years, 83% men) who underwent ICA after resuscitation was obtained from a nation-wide OHCA registry. Obstructive CAD was defined as the lesions with diameter stenosis ≥ 50% on ICA. Independent clinical predictors for obstructive CAD were evaluated using multiple logistic regression analysis, and their prediction performance was compared using area under the receiver operating characteristic curve with 10,000 repeated random permutations.

RESULTS

Among study patients, 254 (49%) had obstructive CAD. Those with obstructive CAD were older (61 vs. 55 years, P < 0.001) and had higher prevalence of hypertension (54% vs. 36%, P < 0.001), diabetes mellitus (29% vs. 21%, P = 0.032), positive cardiac enzyme (84% vs. 74%, P = 0.010) and initial shockable rhythm (70% vs. 61%, P = 0.033). In multiple logistic regression analysis, old age (≥ 60 years) (odds ratio [OR], 2.01; 95% confidence interval [CI], 1.36-3.00; P = 0.001), hypertension (OR, 1.74; 95% CI, 1.18-2.57; P = 0.005), positive cardiac enzyme (OR, 1.72; 95% CI, 1.09-2.70; P = 0.019), and initial shockable rhythm (OR, 1.71; 95% CI, 1.16-2.54; P = 0.007) were associated with obstructive CAD. Prediction ability for obstructive CAD increased proportionally when these 4 factors were sequentially combined (P < 0.001).

CONCLUSION

In patients with OHCA, those with old age, hypertension, positive cardiac enzyme and initial shockable rhythm were associated with obstructive CAD. Early ICA should be considered in these patients.

Emerging and Future Technologies in Out-of-Hospital Cardiac Arrest Care

The care for victims of out-of-hospital cardiac arrest is evolving and will be influenced by future and emerging technologies that will play a role in the systems of care for these patients. Recent advances in extracorporeal life support and point-of-care ultrasound imaging, both in-hospital and out-of-hospital, may offer a therapeutic solution in some systems for patients with refractory or recurrent cardiac arrest. Drones capable of delivering automated external defibrillators to the scene of an out-of-hospital cardiac arrest, advances in digital and mobile technologies to notify and leverage bystander response, and wearable life detection technologies may improve survival.

Supportive technology in the resuscitation of out-of-hospital cardiac arrest patients

PURPOSE OF REVIEW

To discuss the increasing value of technological tools to assess and augment the quality of cardiopulmonary resuscitation (CPR) and, in turn, improve chances of surviving out-of-hospital cardiac arrest (OHCA).

RECENT FINDINGS

After decades of disappointing survival rates, various emergency medical services systems worldwide are now seeing a steady rise in OHCA survival rates guided by newly identified 'sweet spots' for chest compression rate and chest compression depth, aided by monitoring for unnecessary pauses in chest compressions as well as methods to better ensure full-chest recoil after compressions. Quality-assurance programs facilitated by new technologies that monitor chest compression rate, chest compression depth, and/or frequent pauses have been shown to improve the quality of CPR. Further aided by other technologies that enhance flow or better identify the best location for hand placement, the future outlook for better survival is even more promising, particularly with the potential use of another technology - extracorporeal membrane oxygenation for OHCA.

SUMMARY

After 5 decades of focus on manual chest compressions for CPR, new technologies for monitoring, guiding, and enhancing CPR performance may enhance outcomes from OHCA significantly in the coming years.

Recent developments in the management of patients resuscitated from cardiac arrest

Cardiac arrest is the leading cause of death in Europe and the United States. Many patients who are initially resuscitated die in the hospital, and hospital survivors often have substantial neurologic dysfunction. Most cardiac arrests are caused by coronary artery disease; patients with coronary artery disease likely benefit from early coronary angiography and intervention. After resuscitation, cardiac arrest patients remain critically ill and frequently suffer cardiogenic shock and multiorgan failure. Early cardiopulmonary stabilization is important to prevent worsening organ injury. To achieve best patient outcomes, comprehensive critical care management is needed, with primary goals of stabilizing hemodynamics and preventing progressive brain injury. Targeted temperature management is frequently recommended for comatose survivors of cardiac arrest to mitigate the neurologic injury that drives outcomes. Accurate neurologic assessment is central to managing care of cardiac arrest survivors and should combine physical examination with objective neurologic testing, with the caveat that delaying neurologic prognosis is essential to avoid premature withdrawal of supportive care. A combination of clinical findings and diagnostic results should be used to estimate the likelihood of functional recovery. This review focuses on recent advances in care and specific cardiac intensive care strategies that may improve morbidity and mortality for patients after cardiac arrest.

Development and Implementation of a Comprehensive, Multidisciplinary Emergency Department Extracorporeal Membrane Oxygenation Program

Despite advances in the medical and surgical management of cardiovascular disease, greater than 350,000 patients experience out-of-hospital cardiac arrest in the United States annually, with only a 12% neurologically favorable survival rate. Of these patients, 23% have an initial shockable rhythm of ventricular fibrillation/pulseless ventricular tachycardia (VF/VT), a marker of high probability of acute coronary ischemia (80%) as the precipitating factor. However, few patients (22%) will experience return of spontaneous circulation and sufficient hemodynamic stability to undergo cardiac catheterization and revascularization. Previous case series and observational studies have demonstrated the successful application of intra-arrest extracorporeal life support, including to out-of-hospital cardiac arrest victims, with a neurologically favorable survival rate of up to 53%. For patients with refractory cardiac arrest, strategies are needed to bridge them from out-of-hospital cardiac arrest to the catheterization laboratory and revascularization. To address this gap, we expanded our ICU and perioperative extracorporeal membrane oxygenation (ECMO) program to the emergency department (ED) to reach this cohort of patients to improve survival. In this report, we illustrate our process and initial experience of developing a multidisciplinary team for rapid deployment of ED ECMO as a template for institutions interested in building their own ED ECMO programs.

Ventricular fibrillation waveform measures and the etiology of cardiac arrest

BACKGROUND

Early determination of the acute etiology of cardiac arrest could help guide resuscitation or post-resuscitation care. In experimental studies, quantitative measures of the ventricular fibrillation waveform distinguish ischemic from non-ischemic etiology.

METHODS

We investigated whether waveform measures distinguished arrest etiology among adults treated by EMS for out-of-hospital ventricular fibrillation between January 1, 2006-December 31, 2014. Etiology was classified using hospital information into three exclusive groups: acute coronary syndrome (ACS) with ST elevation myocardial infarction (STEMI), ACS without ST elevation (non-STEMI), or non-ischemic arrest. Waveform measures included amplitude spectrum area (AMSA), centroid frequency (CF), mean frequency (MF), and median slope (MS) assessed during CPR-free epochs immediately prior to the initial and second shock. Waveform measures prior to the initial shock and the changes between first and second shock were compared by etiology group. We a priori chose a significance level of 0.01 due to multiple comparisons.

RESULTS

Of the 430 patients, 35% (n=150) were classified as STEMI, 29% (n=123) as non-STEMI, and 37% (n=157) with non-ischemic arrest. We did not observe differences by etiology in any of the waveform measures prior to shock 1 (Kruskal-Wallis Test) (p=0.28 for AMSA, p=0.07 for CF, p=0.63 for MF, and p=0.39 for MS). We also did not observe differences for change in waveform between shock 1 and 2, or when the two acute ischemia groups (STEMI and non-STEMI) were combined and compared to the non-ischemic group.

CONCLUSION

This clinical investigation suggests that waveform measures may not be useful in distinguishing cardiac arrest etiology.