Trends in utilization of mechanical circulatory support in patients hospitalized after out-of-hospital cardiac arrest

Critical Care Management of Patients After Cardiac Arrest: A Scientific Statement from the American Heart Association and Neurocritical Care Society

The critical care management of patients after cardiac arrest is burdened by a lack of high-quality clinical studies and the resultant lack of high-certainty evidence. This results in limited practice guideline recommendations, which may lead to uncertainty and variability in management. Critical care management is crucial in patients after cardiac arrest and affects outcome. Although guidelines address some relevant topics (including temperature control and neurological prognostication of comatose survivors, 2 topics for which there are more robust clinical studies), many important subject areas have limited or nonexistent clinical studies, leading to the absence of guidelines or low-certainty evidence. The American Heart Association Emergency Cardiovascular Care Committee and the Neurocritical Care Society collaborated to address this gap by organizing an expert consensus panel and conference. Twenty-four experienced practitioners (including physicians, nurses, pharmacists, and a respiratory therapist) from multiple medical specialties, levels, institutions, and countries made up the panel. Topics were identified and prioritized by the panel and arranged by organ system to facilitate discussion, debate, and consensus building. Statements related to postarrest management were generated, and 80% agreement was required to approve a statement. Voting was anonymous and web based. Topics addressed include neurological, cardiac, pulmonary, hematological, infectious, gastrointestinal, endocrine, and general critical care management. Areas of uncertainty, areas for which no consensus was reached, and future research directions are also included. Until high-quality studies that inform practice guidelines in these areas are available, the expert panel consensus statements that are provided can advise clinicians on the critical care management of patients after cardiac arrest.

Recovery and Survival of Patients After Out-of-Hospital Cardiac Arrest: A Literature Review Showcasing the Big Picture of Intensive Care Unit-Related Factors

As an important public health issue, out-of-hospital cardiac arrest (OHCA) requires several stages of high quality medical care, both on-field and after hospital admission. Post-cardiac arrest shock can lead to severe neurological injury, resulting in poor recovery outcome and increased risk of death. These characteristics make this condition one of the most important issues to deal with in post-OHCA patients hospitalized in intensive care units (ICUs). Also, the majority of initial post-resuscitation survivors have underlying coronary diseases making revascularization procedure another crucial step in early management of these patients. Besides keeping myocardial blood flow at a satisfactory level, other tissues must not be neglected as well, and maintaining mean arterial pressure within optimal range is also preferable. All these procedures can be simplified to a certain level along with using targeted temperature management methods in order to decrease metabolic demands in ICU-hospitalized post-OHCA patients. Additionally, withdrawal of life-sustaining therapy as a controversial ethical topic is under constant re-evaluation due to its possible influence on overall mortality rates in patients initially surviving OHCA. Focusing on all of these important points in process of managing ICU patients is an imperative towards better survival and complete recovery rates.

Critical Care Management of Patients After Cardiac Arrest: A Scientific Statement From the American Heart Association and Neurocritical Care Society

The critical care management of patients after cardiac arrest is burdened by a lack of high-quality clinical studies and the resultant lack of high-certainty evidence. This results in limited practice guideline recommendations, which may lead to uncertainty and variability in management. Critical care management is crucial in patients after cardiac arrest and affects outcome. Although guidelines address some relevant topics (including temperature control and neurological prognostication of comatose survivors, 2 topics for which there are more robust clinical studies), many important subject areas have limited or nonexistent clinical studies, leading to the absence of guidelines or low-certainty evidence. The American Heart Association Emergency Cardiovascular Care Committee and the Neurocritical Care Society collaborated to address this gap by organizing an expert consensus panel and conference. Twenty-four experienced practitioners (including physicians, nurses, pharmacists, and a respiratory therapist) from multiple medical specialties, levels, institutions, and countries made up the panel. Topics were identified and prioritized by the panel and arranged by organ system to facilitate discussion, debate, and consensus building. Statements related to postarrest management were generated, and 80% agreement was required to approve a statement. Voting was anonymous and web based. Topics addressed include neurological, cardiac, pulmonary, hematological, infectious, gastrointestinal, endocrine, and general critical care management. Areas of uncertainty, areas for which no consensus was reached, and future research directions are also included. Until high-quality studies that inform practice guidelines in these areas are available, the expert panel consensus statements that are provided can advise clinicians on the critical care management of patients after cardiac arrest.

Contemporary National Trends of Mechanical Circulatory Support Among Myocarditis Hospitalizations Before the Pandemic: A National In-patient Database (2005-2019) Study

According to the Global Burden of Disease Project, the morbidity and mortality of myocarditis continue to be a significant worldwide burden. On October 1, 2015, hospital administrative data started using the International Classification of Diseases (ICD)-10 codes instead of the ICD-9. To our knowledge, nationwide trends of myocarditis have not been studied after this update. The NIS database from 2005-2019 was analyzed using ICD-9 and 10 codes. Our search yielded 141,369 hospitalizations due to myocarditis, with 40.9% females. There were 6627 (4.68%) patients who required mechanical circulatory support (MCS) using left ventricular assisted devices (LVAD), intra-aortic balloon pump (IABP), or extracorporeal membrane oxygenation (ECMO). The use of LVAD and ECMO increased significantly during the study period (p-trend 0.003 and <0.001, respectively), whereas the use of IABP decreased during the same period (p-trend 0.025). Our study demonstrated an overall increase in the use of MCS overall in myocarditis, with increasing utilization of more advanced MCS in the forms of LVAD and ECMO.

Health Disparities in Extracorporeal Membrane Oxygenation Utilization and Outcomes: A Scoping Review and Methodologic Critique of the Literature

OBJECTIVES

To map the scope, methodological rigor, quality, and direction of associations between social determinants of health (SDoH) and extracorporeal membrane oxygenation (ECMO) utilization or outcomes.

DATA SOURCES

PubMed, Web of Science, Embase, and Cochrane Library databases were systematically searched for citations from January 2000 to January 2023, examining socioeconomic status (SES), race, ethnicity, hospital and ECMO program characteristics, transport, and geographic location (context) with utilization and outcomes (concept) in ECMO patients (population).

STUDY SELECTION

Methodology followed Preferred Reporting Items for Systematic Reviews and Meta-Analyses scoping review extension. Two reviewers independently evaluated abstracts and full text of identified publications. Exclusion criteria included non-English, unavailable, less than 40 patients, and periprocedural or mixed mechanical support.

DATA EXTRACTION

Content analysis used a standardized data extraction tool and inductive thematic analysis for author-proposed mediators of disparities. Risk of bias was assessed using the Quality in Prognosis Studies tool.

DATA SYNTHESIS

Of 8,214 citations screened, 219 studies were identified. Primary analysis focuses on 148 (68%) including race/ethnicity/SES/payer variables including investigation of ECMO outcomes 114 (77%) and utilization 43 (29%). SDoH were the primary predictor in 15 (10%). Overall quality and methodologic rigor was poor with advanced statistics in 7%. Direction of associations between ECMO outcomes or utilization according to race, ethnicity, SES, or payer varied. In 38% adverse outcomes or lower use was reported in underrepresented, under-resourced or diverse populations, while improved outcomes or greater use were observed in these populations in 7%, and 55% had no statistically significant result. Only 26 studies (18%) discussed mechanistic drivers of disparities, primarily focusing on individual- and hospital-level rather than systemic/structural factors.

CONCLUSIONS

Associations between ECMO utilization and outcomes with SDoH are inconsistent, complicated by population heterogeneity and analytic shortcomings with limited consideration of systemic contributors. Findings and research gaps have implications for measuring, analyzing, and interpreting SDoH in ECMO research and healthcare.

Association between Case Volumes of Extracorporeal Life Support and Clinical Outcome in Out-of-Hospital Cardiac Arrest

AIM

Extracorporeal life support (ECLS) for out-of-hospital cardiac arrest (OHCA) is increasing. There is little evidence identifying the association between hospital ECLS case volumes and outcomes in different populations receiving ECLS or conventional cardiopulmonary resuscitation (CPR). The goal of this investigation was to identify the association between ECLS case volumes and clinical outcomes of OHCA patients.

METHODS

This cross-sectional observational study used the National OHCA Registry for adult OHCA cases in Seoul, Korea between January 2015 and December 2019. If the ECLS volume during the study period was >20, the institution was defined as a high-volume ECLS center. Others were defined as low-volume ECLS centers. Outcomes were good neurologic recovery (cerebral performance category 1 or 2) and survival to discharge. We performed multivariate logistic regression and interaction analyses to assess the association between case volume and clinical outcome.

RESULTS

Of the 17,248 OHCA cases, 3,731 were transported to high-volume centers. Among the patients who underwent ECLS, those at high-volume centers had a higher neurologic recovery rate than those at low-volume centers (17.0% vs. 12.0%), and the adjusted OR for good neurologic recovery was 2.22 (95% confidence interval (CI): 1.15-4.28) in high-volume centers compared to low-volume centers. For patients who received conventional CPR, high-volume centers also showed higher survival-to-discharge rates (adjusted OR of 1.16, 95%CI: 1.01-1.34).

CONCLUSIONS

High-volume ECLS centers showed better neurological recovery in patients who underwent ECLS. High-volume centers also had better survival-to-discharge rates than low-volume centers for patients not receiving ECLS.

Impact of Hospital Safety-Net Burden on Outcomes of In-Hospital Cardiac Arrest in the United States

High safety-net burden hospitals (HBHs) treating large numbers of uninsured or Medicaid-insured patients have generally been linked to worse clinical outcomes. However, limited data exist on the impact of the hospitals' safety-net burden on in-hospital cardiac arrest (IHCA) outcomes in the United States.

OBJECTIVES

To compare the differences in survival to discharge, routine discharge home, and healthcare resource utilization between patients at HBH with those treated at low safety-net burden hospital (LBH).

DESIGN SETTING AND PARTICIPANTS

Retrospective cohort study across hospitals in the United States: Hospitalized patients greater than or equal to 18 years that underwent cardiopulmonary resuscitation (CPR) between 2008 and 2018 identified from the Nationwide Inpatient Database. Data analysis was conducted in January 2022.

EXPOSURE

IHCA.

MAIN OUTCOMES AND MEASURES

The primary outcome is survival to hospital discharge. Other outcomes are routine discharge home among survivors, length of hospital stay, and total hospitalization cost.

RESULTS

From 2008 to 2018, an estimated 555,016 patients were hospitalized with IHCA, of which 19.2% occurred at LBH and 55.2% at HBH. Compared with LBH, patients at HBH were younger (62 ± 20 yr vs 67 ± 17 yr) and predominantly in the lowest median household income (< 25th percentile). In multivariate analysis, HBH was associated with lower chances of survival to hospital discharge (adjusted odds ratio [aOR], 0.88; 95% CI, 0.85-0.96) and lower odds of routine discharge (aOR, 0.6; 95% CI, 0.47-0.75), compared with LBH. In addition, IHCA patients at publicly owned hospitals and those with medium and large hospital bed size were less likely to survive to hospital discharge, while patients with median household income greater than 25th percentile had better odds of hospital survival.

CONCLUSIONS AND RELEVANCE

Our study suggests that patients who experience IHCA at HBH may have lower rates and odds of in-hospital survival and are less likely to be routinely discharged home after CPR. Median household income and hospital-level characteristics appear to contribute to survival.

Contemporary Management of Concomitant Cardiac Arrest and Cardiogenic Shock Complicating Myocardial Infarction

Cardiogenic shock (CS) and cardiac arrest (CA) are the most life-threatening complications of acute myocardial infarction. Although there is a significant overlap in the pathophysiology with approximately half the patients with CS experiencing a CA and approximately two-thirds of patients with CA developing CS, comprehensive guideline recommendations for management of CA + CS are lacking. This paper summarizes the current evidence on the incidence, pathophysiology, and short- and long-term outcomes of patients with acute myocardial infarction complicated by concomitant CA + CS. We discuss the hemodynamic factors and unique challenges that need to be accounted for while developing treatment strategies for these patients. A summary of expert-based step-by-step recommendations to the approach and treatment of these patients, both in the field before admission and in-hospital management, are presented.

Survival and neurological outcome after out-of-hospital cardiac arrest treated with and without mechanical circulatory support

Aim

The aim of this study was to describe the survival and neurological outcome in patients with OHCA treated with and without mechanical circulatory support (MCS).

Methods

This was a retrospective observational cohort study on patients with OHCA admitted to Aarhus University Hospital, Denmark, between January 2015 and December 2019. Kaplan-Meier estimates were used to evaluate 30-day and 30–180-day survival. Cox regression analysis was used to assess the association between covariates and one-year mortality.

Results

Among 1,015 patients admitted, 698 achieved return of spontaneous circulation (ROSC) before admission, 101 patients with refractory OHCA received mechanical circulatory support (MCS) and the remaining 216 patients with refractory OHCA did not receive MCS treatment. Survival to hospital discharge was 47% (478/1015). Good neurological outcome defined as Cerebral Performance Categories 1–2 were seen among 92% (438/478) of the patients discharged from hospital. Median low-flow was 15 [8–22] minutes in the ROSC group and 105 [94–123] minutes in the MCS group. Mortality rates were high within the first 30 days, however; 30–180-day survival in patients discharged remained constant over time in both patients with ROSC on admission and patients admitted with MCS. Advanced age > 70 years (hazard ratio (HR) 1.98, 95% confidence interval (CI) 1.11–3.49), pulseless electrical activity (HR 2.39, 95% CI 1.25–4.60) and asystole HR 2.70, 95% CI 1.25–5.95) as initial rhythms were associated with one-year mortality in patients with ROSC.

Conclusions

Short-term survival rates were high among patients with ROSC and patients receiving MCS. Among patients who survived to day 30, landmark analyses showed comparable 180-day survival in the two groups despite long low-flow times in the MCS group. Advanced age and initial non-shockable rhythms were independent predictors of one-year mortality in patients with ROSC on admission.

Clinical and Economic Burden of Out-of-Hospital Cardiac Arrest in US Commercial Insurance Population (2014 to 2019)

Little is known about the economic burden incurred by out-of-hospital cardiac arrest (OHCA) in the US commercial insurance setting. We used IBM MarketScan Commercial Claims and Encounters Database (January 2014 to March 2019) to identify patients hospitalized with OHCA based on the International Classification of Diseases codes. Patients who survived the initial OHCA episode were stratified by prognosis based on discharge setting and classified into mild (discharged home), moderate (skilled nursing facility), severe (inpatient rehabilitation or long-term hospital), and very severe (hospice) prognosis groups, respectively. Patients were followed up for 12 months after discharge for health care resource utilization and medical costs, which were inflated to year 2020. Overall, 23,512 patients with OHCA hospitalization were identified, of whom 14,667 were <65 years and 60.5% were men. The incidence of OHCA per 100,000 was steady in patients <65 years over the years (17.9 in 2014; 17.5 in 2018) but among those ≥65 years, decreased from 139.7 in 2014 to 111.1 in 2018. Total medical costs 12 months after discharge generally increased with severity of prognosis, with an average for the mild, moderate, and severe prognosis group, respectively, estimated to be $52,746, $100,394, and $130,530 among patients <65 years, and $63,194, $65,794, and $70,973 among those ≥65 years. Costs were lower for those with very severe prognosis ($7,102 for <65 years; $2,553 for ≥65 years), possibly due to high mortality. In conclusion, OHCA continues to pose a substantial clinical and economic burden on patients and the US health care system, which increases with the severity of disease prognosis.

Heat loss augmented by extracorporeal circulation is associated with overcooling in cardiac arrest survivors who underwent targeted temperature management

We investigated the association of extracorporeal circuit-based devices with temperature management and neurological outcome in out-of-hospital cardiac arrest survivors who underwent targeted temperature management. Patients with extracorporeal membrane oxygenation and/or continuous renal replacement therapy were classified as the extracorporeal group. We calculated the cooling rate during the induction period and time-weighted core temperatures (TWCT) during the maintenance period. We defined the sum of TWCT above or below 33 °C as positive and negative TWCT, respectively, and the sum of TWCT above 33.5 °C or below 32.5 °C as undercooling or overcooling, respectively. The primary outcome was the negative TWCT. The secondary outcomes were positive TWCT, cooling rate, undercooling, overcooling, and poor neurological outcomes, defined as Cerebral Performance Category 3–5. Among 235 patients, 150 (63.8%) had poor neurological outcomes and 52 (22.1%) were assigned to the extracorporeal group. The extracorporeal group (β, 0.307; p < 0.001) had increased negative TWCT, rapid cooling rate (1.77 °C/h [1.22–4.20] vs. 1.24 °C/h [0.77–1.79]; p = 0.005), lower positive TWCT (33.4 °C∙min [24.9–46.2] vs. 54.6 °C∙min [29.9–87.0]), and higher overcooling (5.01 °C min [0.00–10.08] vs. 0.33 °C min [0.00–3.78]). However, the neurological outcome was not associated with the use of extracorporeal devices (odds ratio, 1.675; 95% confidence interval, 0.685–4.094).

A Comprehensive Review of Mechanical Circulatory Support Devices

Treatment strategies to combat cardiogenic shock (CS) have remained stagnant over the past decade. Mortality rates among patients who suffer CS after acute myocardial infarction (AMI) remain high at 50%. Mechanical circulatory support (MCS) devices have evolved as novel treatment strategies to restore systemic perfusion to allow cardiac recovery in the short term, or as durable support devices in refractory heart failure in the long term. Haemodynamic parameters derived from right heart catheterization assist in the selection of an appropriate MCS device and escalation of mechanical support where needed. Evidence favouring the use of one MCS device over another is scant. An intra-aortic balloon pump is the most commonly used short-term MCS device, despite providing only modest haemodynamic support. Impella CP® has been increasingly used for CS in recent times and remains an important focus of research for patients with AMI-CS. Among durable devices, Heartmate® 3 is the most widely used in the USA. Adequately powered randomized controlled trials are needed to compare these MCS devices and to guide the operator for their use in CS. This article provides a brief overview of the types of currently available MCS devices and the indications for their use.

How effective is extracorporeal cardiopulmonary resuscitation (ECPR) for out-of-hospital cardiac arrest? A systematic review and meta-analysis

BACKGROUND

Extracorporeal cardiopulmonary resuscitation (ECPR) has gained increasing as a promising but resource-intensive intervention for out-of-hospital cardiac arrest (OHCA). There is little data to quantify the impact of this intervention and the patients likely to benefit from its use. We conducted a meta-analysis of the literature to assess the survival benefit associated with ECPR for OHCA.

METHODS

We searched PubMed, Embase, and Scopus databases to identify relevant observational studies and randomized control trials. We used the Newcastle-Ottawa Scale and Cochrane risk-of-bias tool to assess studies' quality. We performed random-effects meta-analysis for the primary outcome of survival to hospital discharge and used meta-regressions to assess heterogeneity.

RESULTS

We identified 1287 articles, reviewed the full text of 209 and included 44 in our meta-analysis. Our analysis included 3097 patients with OHCA. Patients' mean age was 52, 79% were male, and 60% had primary ventricular fibrillation/ventricular tachycardia arrest. We identified a survival-to-discharge rate of 24%; 18% survived with favorable neurologic function. 30- and 90-days survival rates were both around 18%. The majority of included articles were high quality studies.

CONCLUSIONS

Extracorporeal cardiopulmonary resuscitation is a promising but resource-intensive intervention that may increase rates of survival to hospital discharge among patients who experience OHCA.

Acute kidney injury and cardiac arrest in the modern era: an updated systematic review and meta-analysis

Objective: Acute kidney injury (AKI) is associated with higher morbidity and mortality in cardiac arrest (CA). There are limited contemporary data on the incidence and outcomes of AKI in CA.Methods: We comprehensively searched the databases of MEDLINE, EMBASE, PUBMED, and the Cochrane from inception to November 2020. Observational studies that reported the incidence of AKI in CA survivors were included. Data from each study were combined using the random effects to calculate pooled incidence and risk ratios with 95% confidence intervals (CIs). The primary outcome was short-term mortality and secondary outcomes included long-term mortality, incidence of AKI, and use of renal replacement therapy (RRT). Subgroup and meta-regression analyses were performed to explore heterogeneity.Main results: A total of 25 observational studies comprising 8,165 patients were included. The incidence of AKI in CA survivors was 40.3% (range 32.9-47.8%). In stage 3 AKI, one-fourth of patients required RRT. AKI was associated with an increased risk of both short-term (OR 2.27 [95% CI 1.74-2.96]; p < 0.001) and long-term mortality (OR 1.51 [95% CI 1.93-3.25]; p < 0.001). Meta-regression and subgroup analyses did not suggest any effect of hypothermia on incidence of AKI.Conclusion: AKI complicates the care of 40% of CA survivors and is associated with significantly increased short- and long-term mortality.

The 2018 adult heart allocation policy change benefits low-volume transplant centers

INTRODUCTION

The effect of the 2018 adult heart allocation policy change at an institution-level remains unclear. The present study assessed the impact of the policy change by transplant center volume.

METHODS

The United Network for Organ Sharing database was queried for all adults undergoing isolated heart transplantation from November 2016 to September 2020. Era 1 was defined as the period before the policy change and Era 2 afterwards. Hospitals were divided into low-(LVC) medium-(MVC) and high-volume (HVC) tertiles based on annual transplant center volume. Competing-risks regressions were used to determine changes in waitlist death/deterioration, while post-transplant mortality was assessed using multivariable Cox proportional-hazards models.

RESULTS

A total of 3531 (47.0%) patients underwent heart transplantation in Era 1 and 3988 (53.0%) in Era 2. At LVC, Era 2 patients were less likely to experience death/deterioration on the waitlist (subhazard ratio .74, 95% CI .63-.88), while MVC and HVC patients experienced similar waitlist death/deterioration across eras. After adjustment, transplantation in Era 2 was associated with worse 1-year mortality at MVC (hazard ratio, HR, 1.42 95% CI 1.02-1.96) and HVC (HR 1.42, 95% CI 1.02-1.98) but not at LVC.

CONCLUSION

Early analysis shows that LVC may be benefitting under the new allocation scheme.

Sociodemographic differences in utilization and outcomes for temporary cardiovascular mechanical support in the setting of cardiogenic shock

BACKGROUND

Temporary mechanical circulatory support (MCS) devices are increasingly used in cardiogenic shock, but whether sociodemographic differences by sex, race and/or ethnicity, insurance status, and neighborhood poverty exist in the utilization of these devices is unknown.

METHODS

Retrospective cross-sectional study using the National Inpatient Sample for 2012-2017. Logistic regression models were used to examine predictors of use of temporary MCS devices and for in-hospital mortality, clustering by hospital-year.

RESULTS

Our study population included 109,327 admissions for cardiogenic shock. Overall, 14.3% of admissions received an intra-aortic balloon pump, 4.2% a percutaneous ventricular assist device, and 1.8% extracorporeal membranous oxygenation (ECMO). After adjusting for age, comorbidities, and hospital characteristics, use of temporary MCS was lower in women compared to men (adjusted odds ratio [aOR] = 0.76, P < .001), Black patients compared to white ones (aOR = 0.73, P < .001), those insured by Medicare (aOR = 0.75, P < .001), Medicaid (aOR = 0.74, P < .001), or uninsured (aOR = 0.90, P = .015) compared to privately insured, and those in the lowest income neighborhoods (aOR = 0.94, P = .003) versus other neighborhoods. Women, admissions covered by Medicare, Medicaid, or uninsured, and those from low-income neighborhoods also had higher mortality rates even after adjustment for MCS implantation.

CONCLUSIONS

There are differences in the use of temporary MCS in the setting of cardiogenic shock among specific populations within the United States. The growing use of MCS for treating cardiogenic shock highlights the need to better understand its impact on outcomes.

Extracorporeal life support programme for out-of-hospital cardiac arrest during competitive sport events: the experience of the Volleyball Men's World Championship Final Six in Turin (Italy)

The high incidence of out-of-hospital cardiac arrest refractory to standard resuscitation protocols, despite precompetitive screening, demonstrated the need for a prehospital team to provide an effective system for life support and resuscitation at the Volleyball Men's World Championship. The evolution of mechanical circulatory support suggests that current advanced cardiovascular life support protocols no longer represent the highest standard of care at competitive sporting events with large spectator numbers. Extracorporeal life support (ECLS) improves resuscitation strategies and offers a rescue therapy for refractory cardiac arrest that can no longer be ignored. We present our operational experience of an out-of-hospital ECLS cardiopulmonary resuscitation team at an international sporting event.

A review of ECMO for cardiac arrest

Cardiac arrest is an important public health concern, affecting an estimated 356,500 people in the out-of-hospital setting and 209,000 people in the in-hospital setting each year. The causes of cardiac arrest include acute coronary syndromes, pulmonary embolism, dyskalemia, respiratory failure, hypovolemia, sepsis, and poisoning among many others. In order to tackle the enormous issue of high mortality among sufferers of cardiac arrest, ongoing research has been seeking improved treatment protocols and novel therapies. One of the mechanical devices that has been increasingly utilized for cardiac arrest is venoarterial extracorporeal membrane oxygenation (VA-ECMO). Presently there is only one published randomized controlled trial examining the use of VA-ECMO as part of cardiopulmonary resuscitation (CPR), a process referred to as extracorporeal cardiopulmonary resuscitation (ECPR). Recently there has been significant progress in providing ECPR for refractory cardiac arrest patients. This narrative review seeks to outline the use of ECPR for both in-hospital and out-of-hospital cardiac arrest, as well as provide information on the expected outcomes associated with its use.

Association between Extracorporeal Membrane Oxygenation (ECMO) and Mortality in the Patients with Cardiac Arrest: A Nation-Wide Population-Based Study with Propensity Score Matched Analysis

We attempted to determine the impact of extracorporeal membrane oxygenation (ECMO) on short-term and long-term outcomes and find potential resource utilization differences between the ECMO and non-ECMO groups, using the National Health Insurance Service database. We selected adult patients (≥20 years old) with non-traumatic cardiac arrest from 2007 to 2015. Data on age, sex, insurance status, hospital volume, residential area urbanization, and pre-existing diseases were extracted from the database. A total of 1.5% (n = 3859) of 253,806 patients were categorized into the ECMO group. The ECMO-supported patients were more likely to be younger, men, more covered by national health insurance, and showed, higher usage of tertiary level and large volume hospitals, and a lower rate of pre-existing comorbidities, compared to the non-ECMO group. After propensity score-matching demographic data, hospital factors, and pre-existing diseases, the odds ratio (ORs) of the ECMO group were 0.76 (confidence interval, (CI) 0.68–0.85) for 30-day mortality and 0.66 (CI 0.58–0.79) for 1-year mortality using logistic regression. The index hospitalization was longer, and the 30-day and 1-year hospital costs were greater in the matched ECMO group. Although ECMO support needed longer hospitalization days and higher hospital costs, the ECMO support reduced the risk of 30-day and 1-year mortality compared to the non-ECMO patients.

Postarrest Interventions that Save Lives

Patients resuscitated from cardiac arrest require complex management. An organized approach to early postarrest care can improve patient outcomes. Priorities include completing a focused diagnostic work-up to identify and reverse the inciting cause of arrest, stabilizing cardiorespiratory instability to prevent rearrest, minimizing secondary brain injury, evaluating the risk and benefits of transfer to a specialty care center, and avoiding early neurologic prognostication.

Relationship Between Institutional Volume of Out-of-Hospital Cardiac Arrest Cases and 1-Month Neurologic Outcomes: A Post Hoc Analysis of a Prospective Observational Study

BACKGROUND

The influence of institutional volume of out-of-hospital cardiac arrest (OHCA) cases on outcomes remains unclear.

OBJECTIVES

This study evaluated the relationship between institutional volume of adult, nontraumatic OHCA cases and 1-month favorable neurologic outcomes.

METHODS

This study retrospectively analyzed data between January 2012 and March 2013 from a prospective observational study in the Kanto area of Japan. We analyzed adult patients with nontraumatic OHCA who underwent cardiopulmonary resuscitation by emergency medical service personnel and in whom spontaneous circulation was restored. Based on the institutional volume of OHCA cases, we divided institutions into low-, middle-, or high-volume groups. The primary and secondary outcomes were 1-month favorable neurologic outcomes and 1-month survival, respectively. A multivariate logistic regression analysis adjusted for propensity score and in-hospital variables was performed.

RESULTS

Of 2699 eligible patients, 889, 898, and 912 patients were transported to low-volume (40 institutions), middle-volume (14 institutions), and high-volume (9 institutions) centers, respectively. Using low-volume centers as the reference, transport to a middle- or high-volume center was not significantly associated with a favorable 1-month neurologic outcome (adjusted odds ratio [OR] 1.21 [95% confidence interval {CI} 0.84-1.75] and adjusted OR 0.77 [95% CI 0.53-1.12], respectively) or 1-month survival (adjusted OR 1.10 [95% CI 0.82-1.47] and adjusted OR 0.76 [95% CI 0.56-1.02], respectively).

CONCLUSIONS

Institutional volume was not significantly associated with favorable 1-month neurologic outcomes or 1-month survival in OHCA. Further investigation is needed to determine the association between hospital characteristics and outcomes in patients with OHCA.

Intra-aortic Balloon Counterpulsation for High-Risk Percutaneous Coronary Intervention: Defining Coronary Responders

The effect of intra-aortic balloon counterpulsation (IABC) varies, and it is unknown whether this is due to a heterogeneous coronary physiological response. This study aimed to characterise the coronary and left ventricular (LV) effects of IABC and define responders in terms of their invasive physiology. Twenty-seven patients (LVEF 31 ± 9%) underwent coronary pressure and Doppler flow measurements in the target vessel and acquisition of LV pressure volume loops after IABC supported PCI, with and without IABC assistance. Through coronary wave intensity analysis, perfusion efficiency (PE) was calculated as the proportion of total wave energy comprised of accelerating waves, with responders defined as those with an increase in PE with IABC. The myocardial supply/demand ratio was defined as the ratio between coronary flow and LV pressure volume area (PVA). Responders (44.4%) were more likely to have undergone complex PCI (p = 0.03) with a higher pre-PCI disease burden (p = 0.02) and had lower unassisted mean arterial (87.4 ± 11.0 vs. 77.8 ± 11.6 mmHg, p = 0.04) and distal coronary pressures (88.0 ± 11.0 vs. 71.6 ± 12.4 mmHg, p < 0.001). There was no effect overall of IABC on the myocardial supply/demand ratio (p = 0.34). IABC has minimal effect on demand, but there is marked heterogeneity in the coronary response to IABC, with the greatest response observed in those patients with the most disordered autoregulation.