Post-cardiac Arrest Research Articles

Postarrest Neuroprognostication: Practices and Opinions of Canadian Physicians.

Objective, evidence-based neuroprognostication of postarrest patients is crucial to avoid inappropriate withdrawal of life-sustaining therapies or prolonged, invasive, and costly therapies that could perpetuate suffering when there is no chance of an acceptable recovery. Postarrest prognostication guidelines exist; however, guideline adherence and practice variability are unknown. To investigate Canadian practices and opinions regarding assessment of neurological prognosis in postarrest patients. An anonymous electronic survey was distributed to physicians who care for adult postarrest patients. Of the 134 physicians who responded to the survey, 63% had no institutional protocols for neuroprognostication. While the use of targeted temperature management did not affect the timing of neuroprognostication, an increasing number of clinical findings suggestive of a poor prognosis affected the timing of when physicians were comfortable concluding patients had a poor prognosis. Variability existed in what factors clinicians' thought were confounders. Physicians identified bilaterally absent pupillary light reflexes (85%), bilaterally absent corneal reflexes (80%), and status myoclonus (75%) as useful in determining poor prognosis. Computed tomography, magnetic resonance imaging, and spot electroencephalography were the most useful and accessible tests. Somatosensory evoked potentials were useful, but logistically challenging. Serum biomarkers were unavailable at most centers. Most (79%) physicians agreed ≥2 definitive findings on neurologic exam, electrophysiologic tests, neuroimaging, and/or biomarkers are required to determine a poor prognosis with a high degree of certainty. Distress during the process of neuroprognostication was reported by 70% of physicians and 51% request a second opinion from an external expert. Significant variability exists in post-cardiac arrest neuroprognostication practices among Canadian physicians.

Indoleamine 2,3-Dioxygenase Deletion to Modulate Kynurenine Pathway and to Prevent Brain Injury after Cardiac Arrest in Mice.

The catabolism of the essential amino acid tryptophan to kynurenine is emerging as a potential key pathway involved in post-cardiac arrest brain injury. The aim of this study was to evaluate the effects of the modulation of kynurenine pathway on cardiac arrest outcome through genetic deletion of the rate-limiting enzyme of the pathway, indoleamine 2,3-dioxygenase. Wild-type and indoleamine 2,3-dioxygenase-deleted (IDO-/-) mice were subjected to 8-min cardiac arrest. Survival, neurologic outcome, and locomotor activity were evaluated after resuscitation. Brain magnetic resonance imaging with diffusion tensor and diffusion-weighted imaging sequences was performed, together with microglia and macrophage activation and neurofilament light chain measurements. IDO-/- mice showed higher survival compared to wild-type mice (IDO-/- 11 of 16, wild-type 6 of 16, log-rank P = 0.036). Neurologic function was higher in IDO-/- mice than in wild-type mice after cardiac arrest (IDO-/- 9 ± 1, wild-type 7 ± 1, P = 0.012, n = 16). Indoleamine 2,3-dioxygenase deletion preserved locomotor function while maintaining physiologic circadian rhythm after cardiac arrest. Brain magnetic resonance imaging with diffusion tensor imaging showed an increase in mean fractional anisotropy in the corpus callosum (IDO-/- 0.68 ± 0.01, wild-type 0.65 ± 0.01, P = 0.010, n = 4 to 5) and in the external capsule (IDO-/- 0.47 ± 0.01, wild-type 0.45 ± 0.01, P = 0.006, n = 4 to 5) in IDO-/- mice compared with wild-type ones. Increased release of neurofilament light chain was observed in wild-type mice compared to IDO-/- (median concentrations [interquartile range], pg/mL: wild-type 1,138 [678 to 1,384]; IDO-/- 267 [157 to 550]; P < 0.001, n = 3 to 4). Brain magnetic resonance imaging with diffusion-weighted imaging revealed restriction of water diffusivity 24 h after cardiac arrest in wild-type mice; indoleamine 2,3-dioxygenase deletion prevented water diffusion abnormalities, which was reverted in IDO-/- mice receiving l-kynurenine (apparent diffusion coefficient, μm2/ms: wild-type, 0.48 ± 0.07; IDO-/-, 0.59 ± 0.02; IDO-/- and l-kynurenine, 0.47 ± 0.08; P = 0.007, n = 6). The kynurenine pathway represents a novel target to prevent post-cardiac arrest brain injury. The neuroprotective effects of indoleamine 2,3-dioxygenase deletion were associated with preservation of brain white matter microintegrity and with reduction of cerebral cytotoxic edema.

Acute Obstructive Hydrocephalus: An Unexpected Cause of Cardiac Arrest

BackgroundEmergency physicians are well-versed in managing cardiac arrests, including the diagnostic and therapeutic steps after return of spontaneous circulation. Neurologic emergencies are a common cause of out-of-hospital cardiac arrest and must remain high in the differential diagnosis, as such cases often require specific interventions that may deviate from more common care pathways. Performing a noncontrast head computed tomography (NCHCT) scan after cardiac arrest has been found to change management, although the optimal timing of this imaging is unclear. Case ReportThis is the case of a young, pregnant woman who presented to the emergency department after cardiac arrest with return of spontaneous circulation in the prehospital setting. She was found to have acute obstructive hydrocephalus on NCHCT, which was later confirmed to be due to a previously undiagnosed colloid cyst of the third ventricle. This acute obstruction resulted in myocardial stunning and, ultimately, cardiac arrest. Although outcomes are often dismal when the cause of arrest is secondary to neurologic catastrophe, this patient survived with completely intact neurologic function. Why Should an Emergency Physician Be Aware of This?Although acute obstructive hydrocephalus due to a colloid cyst adjacent to the third ventricle is a rare condition, it is a potentially reversible neurologic cause of out-of-hospital cardiac arrest. However, positive outcomes depend on obtaining the diagnosis rapidly with neurologic imaging and advocating for neurosurgical intervention. This case supports the recommendation that emergency physicians should strongly consider post–cardiac arrest neurologic imaging when another cause is not immediately obvious.

Hemodynamic, Oxygenation, and Ventilation Targets after Cardiac Arrest: the current ABC of post cardiac arrest intensive care.

Post cardiac arrest care has been significantly improved over the past two decades following the publication of the two trials in therapeutic hypothermia, later renamed to targeted temperature management (TTM). While the initial research and treatment guidelines focussed in lowering core temperature, guidelines recommend more treatment goals, some of which are based in very limited evidence. The review seeks to describe the current evidence levels in the guidelines recommended targets for post resuscitation care, and to suggest treatment targets that includes the newest and best available evidence.

Knowledge, attitude, and proficiency of healthcare providers in cardiopulmonary resuscitation in a public primary healthcare setting in Qatar.

Early and effective cardiopulmonary resuscitation (CPR) increases both survival rate and post-cardiac arrest quality of life. This study aims to assess the current knowledge and ability of physicians and nurses in health centers (HCs) operated by the Primary Health Care Corporation (PHCC) in Doha, Qatar, to perform CPR. This study consists of two parts. The first part is a descriptive cross-sectional survey using an online form targeting physicians and nurses working in all HCs to assess their CPR knowledge and attitude. The second part is a direct observation of CPR drills to evaluate the skills and competencies of code blue team members in a convenient sample of 14 HCs. A multivariate model was employed to test the independent effect of explanatory variables on the total knowledge score. A total of 569 physicians and nurses responded to the survey. Only one-half (48.7%) formally received training on basic life support within the last year. Furthermore, 62.7% have tried to revive a dying person with no pulse. All the participants recognize the importance of knowing how to revive a dying adult or child as part of their job. The study showed that being a nurse was the most important predictor of a higher knowledge score in both components. Attending more resuscitation courses (3-6 courses in the last 3 years) ranked second in importance, and a longer experience in clinical practice (5-10 and >10 years) ranked third in predictive power. In addition, the direct observation of CPR drill performance revealed a satisfactory outcome. The level of CPR knowledge and skills practice among healthcare providers in PHCC is deemed satisfactory as most providers reported having performed CPR in the past. Considering that PHCC is the first step to people's healthcare in Qatar, clinical staff should be certified and assessed regularly to ensure retention of resuscitation knowledge and skills.

Association between post-cardiac arrest treatments and clinical outcomes according to scene time interval in out-of-hospital cardiac arrest: Retrospective cross-sectional study

BackgroundPrevious studies have reported that Post-Cardiac arrest (PCA) treatments including targeted temperature management (TTM), coronary reperfusion therapy (CRT), and extracorporeal membrane oxygenation (ECMO) are time-sensitive; however, there are no reports of the clinical outcomes of PCA treatment according to the scene time interval (STI). Our study aimed to investigated the clinical outcomes of PCA treatment according to the STI. MethodsWe used a Korean nationwide OHCA cohort database from January 2017 to December 2020. The inclusion criteria were all adult OHCA patients with a presumed cardiac etiology, bystander-witnessed arrest, and prehospital return of spontaneous circulation (ROSC). The outcomes were survival to discharge and good neurological recovery. The main exposure of interest was PCA treatment. We compared the outcomes using multivariable logistic regression, and interaction terms were included in the final model to assess whether the STI modified the effect of PCA treatment on clinical outcomes of OHCA. ResultsTTM and CRT were associated with high survival to discharge and good neurological recovery. In the interaction analysis, ECMO had an interaction effect with the STI on a good CPC among patients with OHCA [short STI (0 to 11 min) (1.16 (0.77—1.75)), middle STI (12 to 15 min) (0.66 (0.41—1.06)), and long STI (16 to 30 min) (0.59 (0.40—0.88)) (p for interaction <0.05)]. ConclusionIn adult bystander-witnessed patients with OHCA with prehospital ROSC, an STI of >16 min was a risk factor for poor neurological outcome in those patients who underwent ECMO.

Comparison of Prognostic Performance between Procalcitonin and Procalcitonin-to-Albumin Ratio in Post Cardiac Arrest Syndrome.

(1) Background: Post-cardiac arrest syndrome (PCAS) is a type of global ischemic reperfusion injury that occurs after the return of spontaneous circulation (ROSC). The procalcitonin to albumin ratio (PAR) has been studied as an independent prognostic factor of various diseases. There are no previous studies of PAR in patients with PCAS. We assessed if PAR is more effective than procalcitonin (PCT) in predicting prognosis for patients with PCAS. (2) Methods: This retrospective cohort study included a total of 187 patients with PCAS after non-traumatic out-of-hospital cardiac arrest (OHCA) between January 2016 and December 2020. Multivariate logistic regression analysis was conducted to assess the association between PAR and PCAS prognosis. The predictive performance of PAR was compared with PCT via the receiver-operating characteristic (ROC) analysis and DeLong test.; (3) Results: PAR at 24 and 48 h after hospital admission were independently associated with one-month neurological outcome (OR: 1.167, 95% CI: 1.023-1.330; OR: 1.077, 95% CI: 1.012-1.146, p < 0.05). By ROC analysis, PAR showed better performance over PCT at 48 h after admission in predicting one-month CPC (0.763 vs. 0.772, p = 0.010). (4) Conclusions: Our findings suggest that PAR at 48 h after admission is more effective in predicting a one-month neurological outcome than PCT at 48 h after admission in patients with PCAS after OHCA.

Interpretable machine learning model for imaging-based outcome prediction after cardiac arrest

IntroductionEarly identification of brain injury patterns in computerized tomography (CT) imaging is crucial for post-cardiac arrest prognostication. Lack of interpretability of machine learning prediction reduces trustworthiness by clinicians and prevents translation to clinical practice. We aimed to identify CT imaging patterns associated with prognosis with interpretable machine learning. MethodsIn this IRB-approved retrospective study, we included consecutive comatose adult patients hospitalized at a single academic medical center after resuscitation from in- and out-of-hospital cardiac arrest between August 2011 and August 2019 who underwent unenhanced CT imaging of the brain within 24 hours of their arrest. We decomposed the CT images into subspaces to identify interpretable and informative patterns of injury, and developed machine learning models to predict patient outcomes (i.e., survival and awakening status) using the identified imaging patterns. Practicing physicians visually examined the imaging patterns to assess clinical relevance. We evaluated machine learning models using 80%-20% random data split and reported AUC values to measure the model performance. ResultsWe included 1284 subjects of whom 35% awakened from coma and 34% survived hospital discharge. Our expert physicians were able to visualize decomposed image patterns and identify those believed to be clinically relevant on multiple brain locations. For machine learning models, the AUC was 0.710 ± 0.012 for predicting survival and 0.702 ± 0.053 for predicting awakening, respectively. DiscussionWe developed an interpretable method to identify patterns of early post-cardiac arrest brain injury on CT imaging and showed these imaging patterns are predictive of patient outcomes (i.e., survival and awakening status).

Association between time-dependent changes in cerebrovascular autoregulation after cardiac arrest and outcomes: A prospective cohort study

This prospective observational single-center cohort study aimed to determine an association between cerebrovascular autoregulation (CVAR) and outcomes in hypoxic-ischemic brain injury post-cardiac arrest (CA), and assessed 100 consecutive post-CA patients in Japan between June 2017 and May 2020 who experienced a return of spontaneous circulation. Continuous monitoring was performed for 96 h to determine CVAR presence. A moving Pearson correlation coefficient was calculated from the mean arterial pressure and cerebral regional oxygen saturation. The association between CVAR and outcomes was evaluated using the Cox proportional hazard model; non-CVAR time percent was the time-dependent, age-adjusted covariate. The non-linear effect of target temperature management (TTM) was assessed using a restricted cubic spline. Of the 100 participants, CVAR was detected using the cerebral performance category (CPC) in all patients with a good neurological outcome (CPC 1–2) and in 65 patients (88%) with a poor outcome (CPC 3–5). Survival probability decreased significantly with increasing non-CVAR time percent. The TTM versus the non-TTM group had a significantly lower probability of a poor neurological outcome at 6 months with a non-CVAR time of 18%–37% (p < 0.05). Longer non-CVAR time may be associated with significantly increased mortality in hypoxic-ischemic brain injury post-CA.

Case Reports Study on Methanol Poisoning in King Abdul Aziz Specialist Hospital, Taif, Saudi Arabia

Methanol poisoning is a challenging issue due to its inducing acute multiple organ failures, and especially due to a lack of preparedness, available antidotes, and management protocols. The current study presents six cases of methanol poisoning that attended the emergency department of King Abdul Aziz Specialist Hospital, Taif, Saudi Arabia, between March and November 2022. All of the patients suffered from severe metabolic acidosis and visual impairment following the ingestion of homemade alcoholic beverages and colonia. Three patients were comatose, suffered from post-cardiac pulmonary arrest, and, finally, died, while the other three were non-comatose and discharged from the ICU after improvement. Management was based on clinical symptoms and other laboratory findings due to a shortage of methanol level measurement resources. The antidote, fomepizole, was not given to all of the cases due to its deficiency, and ethanol was given only to one patient due to difficulties in administering it without monitoring its concentration. Methanol poisoning and its outbreak provide insights into the dangers of hazardous homemade alcohol and other pharmaceutical preparations that might be adulterated with methanol, particularly to the shortage of suitable diagnostic testing and antidotes in addition to poor resources for management of intoxicated patients in some regions of Saudi Arabia.

Preliminary Prognostication for Good Neurological Outcomes in the Early Stage of Post-Cardiac Arrest Care

We investigated prognostic strategies for predicting good outcomes in the early stage of post-cardiac-arrest care using multiple prognostic tests that are available until 24 h after the return of spontaneous circulation (ROSC). A retrospective analysis was conducted on 138 out-of-hospital cardiac-arrest patients who underwent prognostic tests, including the gray–white-matter ratio (GWR-BG), the Glasgow Coma Scale motor (GCS-M) score before sedative administration, and the neuron-specific enolase (NSE) level measured at 24 h after the ROSC. We investigated the prognostic performances of the tests as single predictors and in various combination strategies. Classification and regression-tree analysis were used to provide a reliable model for the risk stratification. Out of all the patients, 55 (44.0%) had good outcomes. The NSE level showed the highest prognostic performance as a single prognostic test and provided improved specificities (&gt;70%) and sensitivities (&gt;98%) when used in combination strategies. Low NSE levels (≤32.1 ng/mL) and high GCS-M (≥4) scores identified good outcomes without misclassification. The overall accuracy for good outcomes was 81.8%. In comatose patients with low NSE levels or high GCS-M scores, the premature withdrawal of life-sustaining therapy should be avoided, thereby complying with the formal prognostication-strategy algorithm after at least 72 h from the ROSC.

State of the Art Post-Cardiac Arrest Care: Evolution and future of post cardiac arrest care.

Out-of-hospital cardiac arrest is a leading cause of mortality. In the prehospital setting, bystander response with cardiopulmonary resuscitation and use of publicly available automated external defibrillators have been associated with improved survival. Early in-hospital treatment still focuses on emergency coronary angiography for selected patients. For patients remaining comatose, temperature control to avoid fever is still recommended, but former hypothermic targets have been abandoned. For patients without spontaneous awakening, the use of a multimodal prognostication model is key. After discharge, follow-up with screening for cognitive and emotional disabilities is recommended. There has been an incredible evolution of research within cardiac arrest. Two decades ago, the largest trials include a few hundred patients. Today, undergoing studies are planning to include 10-20 times as many patients, with improved methodology. This article describes the evolution and perspectives for the future in post-cardiac arrest care.

Inflammatory response after out-of-hospital cardiac arrest-Impact on outcome and organ failure development.

Post-cardiac arrest syndrome that occurs in out-of-hospital cardiac arrest (OHCA) patients is characterized by inflammatory response. We conducted a scoping review of current evidence regarding several inflammatory markers' usefulness for assessment of patient outcome and illness severity. We also discuss the proposed underlying mechanisms leading to inflammatory response after OHCA. We searched the MEDLINE, PubMed Central, Cochrane CENTRAL and Web of Science Core Collection databases with the following search terms: ("inflammation" OR "cytokines") AND "out-of-hospital cardiac arrest." Each inflammatory marker found was combined with "out-of-hospital cardiac arrest" using "AND" to find further relevant studies. We included original studies measuring inflammatory markers in adult OHCA patients that assessed their prognostic capabilities for mortality, neurological outcome, or organ failure severity. Fifty-nine studies met the inclusion criteria, covering in total 65 different markers. Interleukin-6 (IL-6), procalcitonin (PCT) and C-reactive protein (CRP) were the most studied markers, and they were associated with poor outcomes in 13/15, 13/14 and 11/17 studies, respectively. Based on area under the receiver operating characteristic curve (AUC) value, the time point of best discriminatory capacity for poor outcome was ICU admission for IL-6 (median AUC 0.78, range 0.71-0.98) and day one after OHCA for PCT (median AUC 0.84, range 0.61-0.98). Seven studies reported AUCs for CRP (range 0.52-0.76) with no measurement time point being superior to others. The association of IL-6 and PCT with outcome appeared stronger in studies with more severely ill patients. Studies reported conflicting results regarding each marker's association with organ failure severity. Inflammatory markers are potentially useful for early risk stratification after OHCA. PCT and IL-6 have moderate prognostic value during the first 24 h of the ICU stay. Predictive accuracy appears to be associated with the study overall event rate.

General Critical Care, Temperature Control, and End-of-Life Decision Making in Patients Resuscitated from Cardiac Arrest.

Cardiac arrest affects millions of people per year worldwide. Although advances in cardiopulmonary resuscitation and intensive care have improved outcomes over time, neurologic impairment and multiple organ dysfunction continue to be associated with a high mortality rate. The pathophysiologic mechanisms underlying the post-resuscitation disease are complex, and a coordinated, evidence-based approach to post-resuscitation care has significant potential to improve survival. Critical care management of patients resuscitated from cardiac arrest focuses on the identification and treatment of the underlying cause(s), hemodynamic and respiratory support, organ protection, and active temperature control. This review provides a state-of-the-art appraisal of critical care management of the post-cardiac arrest patient.

Post-cardiac arrest intensive care in Sweden: A survey of current clinical practice.

European guidelines recommend targeted temperature management (TTM) in post-cardiac arrest care. A large multicentre clinical trial, however, showed no difference in mortality and neurological outcome when comparing hypothermia to normothermia with early treatment of fever. The study results were valid given a strict protocol for the assessment of prognosis using defined neurological examinations. With the current range of recommended TTM temperatures, and applicable neurological examinations, procedures may differ between hospitals and the variation of clinical practice in Sweden is not known. The aim of this study was to investigate current practice in post-resuscitation care after cardiac arrest as to temperature targets and assessment of neurological prognosis in Swedish intensive care units (ICUs). A structured survey was conducted by telephone or e-mail in all Levels 2 and 3 (= 53) Swedish ICUs during the spring of 2022 with a secondary survey in April 2023. Five units were not providing post-cardiac arrest care and were excluded. The response rate was 43/48 (90%) of the eligible units. Among the responding ICUs, normothermia (36-37.7°C) was applied in all centres (2023). There was a detailed routine for the assessment of neurological prognosis in 38/43 (88%) ICUs. Neurological assessment was applied 72-96 h after return of spontaneous circulation in 32/38 (84%) units. Electroencephalogram and computed tomography and/or magnetic resonance imaging were the most common technical methods available. Swedish ICUs use normothermia including early treatment of fever in post-resuscitation care after cardiac arrest and almost all apply a detailed routine for the assessment of neurological prognosis. However, available methods for prognostic evaluation varies between hospitals.

Time-course relationship between cerebrospinal fluid and serum concentrations of midazolam and albumin in patients with cardiac arrest undergoing targeted temperature management

AimTo understand the serum and cerebrospinal fluid (CSF) distribution of midazolam is important for proper timing of neurological prognostication of targeted temperature management(TTM) patients. Midazolam binds extensively to albumin in serum although non protein bound form exist in CSF. We investigated the time-course of CSF, serum concentrations of midazolam and albumin in patients with cardiac arrest who underwent TTM. MethodsThis prospective, single-center, observational study was conducted between May 2020 and April 2022. Midazolam and albumin concentrations in CSF and serum were quantified 0, 24, 48, and 72 h after the return of spontaneous circulation for comparison between the good (Cerebral Performance Category (CPC) 1 and 2) and poor (CPC 3, 4, and 5) neurologic outcome groups. The CSF/serum (C/S) ratios of midazolam and albumin concentrations were determined, along with their correlation coefficients. ResultsOf the 19 enrolled patients, 13 experienced poor outcomes. At 0 h, serum midazolam concentrations were the lowest, whereas serum albumin levels were the highest; in the CSF, the concentrations of both peaked at 24 h. There were no significant inter-group differences in midazolam concentrations in CSF or serum. The C/S ratios of midazolam and albumin significantly differed between the groups. Moderate to strong positive correlations were observed between the midazolam and albumin C/S ratios. ConclusionIn CSF, midazolam and albumin concentrations peaked 24 h post-cardiac arrest. Midazolam and albumin C/S ratios were significantly higher in the poor outcome group and positively correlated with each other, suggesting blood–brain barrier disruption 24 h post-cardiac arrest.

Exploration of Optimal pH in Hypothermic Machine Perfusion for Rat Liver Grafts Retrieved after Circulatory Death.

Ex vivo hypothermic machine perfusion (HMP) is a strategy for controlling ischemia-reperfusion injury in donation after circulatory death (DCD) liver transplantation. The pH of blood increases with a decrease in temperature and water dissociation, leading to a decrease in [H+]. This study aimed to verify the optimal pH of HMP for DCD livers. Rat livers were retrieved 30 min post-cardiac arrest and subjected to 3-h cold storage (CS) in UW solution (CS group) or HMP with UW-gluconate solution (machine perfusion [MP] group) of pH 7.4 (original), 7.6, 7.8, and 8.0 (MP-pH 7.6, 7.8, 8.0 groups, respectively) at 7-10 °C. The livers were subjected to normothermic perfusion to simulate reperfusion after HMP. All HMP groups showed greater graft protection compared to the CS group due to the lower levels of liver enzymes in the former. The MP-pH 7.8 group showed significant protection, evidenced by bile production, diminished tissue injury, and reduced flavin mononucleotide leakage, and further analysis by scanning electron microscopy revealed a well-preserved structure of the mitochondrial cristae. Therefore, the optimum pH of 7.8 enhanced the protective effect of HMP by preserving the structure and function of the mitochondria, leading to reduced reperfusion injury in the DCD liver.

P105: Pre-Emptive Use of Mechanical Circulatory support in sudden cardiac death- A contrasting case series

Life-threatening ventricular tachycardia(VT) and fibrillation(VF) are the most important causes of sudden cardiac death(SCD). Patients who survive are often predisposed to recurrent VT secondary to scar tissue and require definitive ablation therapies. However given the unpredictable nature of arrhythmias, patients can degenerate into VT storm even as outpatient and become hemodynamically unstable which precludes ablation therapies. Using preemptive mechanical circulatory support in such patients as a bridge to ablation can be a game changer, especially in the event of a fresh VT. We present two contrasting cases, where preemptive use of Impella showed better outcomes in neurological status post cardiac arrest. Our patient is a 16-year-old competitive basketball player who suffered an out-of-hospital VT arrest during match practice requiring bystander CPR and multiple shocks. He was stabilized in an outside hospital and brought to us intubated, paralyzed, on multiple pressors and maintained on IV amiodarone and lidocaine. ECHO demonstrated a very large right ventricle (RV) with severe left ventricle(LV) dysfunction, ejection fraction(EF) 10-15% with basal RV diameter 6.8cm. Cardiac MRI(CMRI) showed an area of late gadolinium enhancement (LGE) of the RV-free wall near the apex. Endomyocardial biopsy, Cardiac catheterization, and CT angiogram were unremarkable. With improvement in volume status, he was weaned off all inotropes and antiarrhythmics, received an AICD, and maintained only on sotalol and lisinopril. On outpatient follow-up, repeat CMRI confirmed Arrhythmogenic RV dysplasia. Unfortunately, four months later, the patient had another episode of cardiac arrest secondary to a VT storm with 20 minutes of downtime. He was deemed too unstable for VT ablation and thus emergently underwent a stellate ganglion block. The patient remained encephalopathic post-cardiac arrest with very slow neurologic recovery. He subsequently underwent cardiac transplantation The second case is that of a 63-year-old male with a past medical history of nonischemic cardiomyopathy with LVEF of 10% status post-ICD placement, and VT on amiodarone who presented with episodes of monomorphic VT followed by ICD shocks and syncope. Heart catheterization showed diffuse three-vessel disease. Due to recurrent VT patients, he received an Impella CP as a bridge to VT ablation. Interestingly during ablation, the patient goes into cardiac arrest requiring CPR for 90 minutes. He had successful VT ablation and with no neurological deficit post-procedure. Multiple trials have shown an improved 30-day survival rate without neurological sequelae with early implantation of Impella during ongoing CPR for cardiac arrest. Impella has several favorable properties by unloading the LV which limits the infarct size and maintains cerebral perfusion during the arrest. Preemptive Impella use is often used as a bridge to transplant, however using it as a bridge to ablation is yet to gain prominence.

SHOCK3: Comparing Veno-arterial Extracorpeal Membrane Oxygenation (VA-ECMO) vs. VA-ECMO plus Impella (ECPELLA) on Mortality in Patients with Cardiac Arrest After an Acute Myocardial Infarction (AMI)

Background: More than 800,000 people suffer from an AMI in the United States every year. One of the most feared complications of an AMI is cardiac arrest, and even if return of spontaneous circulation is achieved, profound cardiogenic shock (CS) is a common sequalae. VA-ECMO is utilized to support patients with CS, and now more frequently, used in conjunction with an Impella to off-load the left ventricle, though a paucity of evidence supports this practice. The goal of this study was to determine whether a mortality difference was observed in VA-ECMO alone vs ECPELLA in patients with CS after cardiac arrest secondary to an AMI. Methods: A dual-center, retrospective chart review of 52 patients who suffered cardiac arrest from an AMI and were supported with VA-ECMO or ECPELLA was performed. Univariable comparisons consisting of baseline demographics, cardiac arrest data, catheterization laboratory reports and intensive care unit (ICU) data were compared between the two groups using chi-squared analysis, independent t-test, and Wilcoxon Rank Sum Test to determine statistical significance. Cox proportional hazard models were constructed to test the independent association between treatment groups and mortality, controlling for various acute physiology and post-cardiac arrest prognostic scores. Results: Thirty-four patients received VA-ECMO only, and 16 patients were supported with an ECPELLA strategy. Ninety-day mortality was 67.6% in the VA-ECMO group, and 87.5% in the ECPELLA group. There was no statistically significant difference between the groups within regards to mortality (Hazard Ratio (HR): 1.69, 95% confidence interval 0.86-3.30). This remained true even when adjusting for the following validated prognostic scores: Simplified Acute Physiology Score II (SAPS), Survival after veno-arterial ECMO (SAVE), modified SAVE, Cardshock, and Charlson Comorbidity index. There we no differences in baseline demographic data nor ICU complications between the groups. Patients who experienced a ST elevated myocardial infarction (STEMI) were more likely to be in the VA-ECMO group rather than the ECPELLA group (p=0.044). Conclusion: Our results found no significant differences in mortality in patients with CS after cardiac arrest secondary to an AMI when treated with VA-ECMO vs ECPELLA. It should be highlighted that the study population was only 52 patients, thus the power of the study was significantly limited. Therefore, more experience and broader collaboration/data sharing is needed to identify if ECPELLA is a beneficial acute cardiac support strategy in this patient population.Figure 1. VA-ECMO vs ECPELLA Survival Curve

Insufficient oxygen inhalation during cardiopulmonary resuscitation induces early changes in hemodynamics followed by late and unfavorable systemic responses in post-cardiac arrest rats.

Cardiac arrest (CA) and concomitant post-CA syndrome lead to a lethal condition characterized by systemic ischemia-reperfusion injury. Oxygen (O2 ) supply during cardiopulmonary resuscitation (CPR) is the key to success in resuscitation, but sustained hyperoxia can produce toxic effects post CA. However, only few studies have investigated the optimal duration and dosage of O2 administration. Herein, we aimed to determine whether high concentrations of O2 at resuscitation are beneficial or harmful. After rats were resuscitated from the 10-min asphyxia, mechanical ventilation was restarted at an FIO2 of 1.0 or 0.3. From 10 min after initiating CPR, FIO2 of both groups were maintained at 0.3. Bio-physiological parameters including O2 consumption (VO2 ) and mRNA gene expression in multiple organs were evaluated. The FIO2 0.3 group decreased VO2 , delayed the time required to achieve peak MAP, lowered ejection fraction (75.1 ± 3.3% and 59.0 ± 5.7% with FIO2 1.0 and 0.3, respectively; p < .05), and increased blood lactate levels (4.9 ± 0.2 mmol/L and 5.6 ± 0.2 mmol/L, respectively; p < .05) at 10 min after CPR. FIO2 0.3 group had significant increases in hypoxia-inducible factor, inflammatory, and apoptosis-related mRNA gene expression in the brain. Likewise, significant upregulations of hypoxia-inducible factor and apoptosis-related gene expression were observed in the FIO2 0.3 group in the heart and lungs. Insufficient O2 supplementation in the first 10 min of resuscitation could prolong ischemia, and may result in unfavorable biological responses 2 h after CA. Faster recovery from the impairment of O2 metabolism might contribute to the improvement of hemodynamics during the early post-resuscitation phase; therefore, it may be reasonable to provide the maximum feasible O2 concentrations during CPR.