bluuebunny/crossref_metadata_2025 huggingface dataset:
Abstract P27: Microglial Activity and Therapeutic Hypothermia Post Cardiac Arrest Resuscitation in Rats
Authors: Jia Xiaofeng , Tsai Shinyi , Zhen Gehua , Velasquez Adrian , Koenig Matthew A , Pardo Carlos A , Thakor Nitish V , Geocadin Romergryko G
Published: July 2021

Background

Therapeutic hypothermia after cardiac arrest (CA) improves survival and functional outcomes, but its neuroprotective mechanism remains unclear. We previously showed that immediate initiation of hypothermia post-CA led to better neuro-electrical and behavioral recovery. In this study, we quantified the impact of immediate versus conventional hypothermia with stereological technique on microglia (using expression of ionized calcium binding adaptor molecule 1 - Iba1), astrocytes (using expression of glial fibrillary astrocyte protein - GFAP), and neurons (by Cresyl-violet staining with histopathological damage scoring - HDS).

Methods

Forty-eight rats were randomly divided into 3 groups (n=16 per group), based on normothermia (NT, T=37°C), 6 hours of immediate hypothermia (IH, T=33°C, initiated immediately after CA), or 12 hours of conventional hypothermia (CH, T=33°C, initiated one hour after CA) after CA. Each group was then evenly divided to 2 subgroups (n=8 based on 7 or 9 min asphyxial time). Hypothermia was maintained using surface cooling. Neurological recovery was evaluated using serial Neurological Deficit Score (NDS) calculation.

Results

Better recovery by NDS 72 hours post-CA was noted in rats treated with IH (median, interquartile range: 72, 63–74), compared to CH (66, 43–70), and NT (51, 0 – 65) (p=0.005). There was a significantly different proportion of ischemic neurons by HDS in cortex (IH: 18.9±2.5%, CH: 33.2±4.4%, NT: 36.2±4.7%, p=0.002) and CA1 (IH: 14.4±2.9%, CH: 24.6±5.4%, NT: 49.2±5.3%, p<0.001). There was significant less Iba-1 expression in CH compared to IH (p=0.042) and NT (p=0.012) in cortex and CA1. There was no difference for GFAP expression in cortex or CA1.

Conclusions

Immediate hypothermia leads to better functional outcome and lower ischemic neuronal injury in rats after CA. Temperature manipulation seems to affect the immune response to CA, with increased microglial activity in the IH and NT groups compared to CH group in this injury model. The longer hypothermia duration may decrease the microglia activation in response of central nervous system to CA than short duration in this injury model. No difference was noted in the astrocytic activity in the different groups.
Abstract P28: Early Antioxidant Treatment Does Not Provide Additive Neuroprotection with Delayed Hypothermia after Asphyxic Cardiac Arrest in Newborn Pigs
Authors: Yang Zengjin , Ni Xinli , Carter Erin L , Martin Lee J , Koehler Raymond C
Published: July 2021

Clinical efficacy of hypothermia in neonatal hypoxic-ischemic (HI) encephalopathy is limited, in part, by the delay in instituting hypothermia. In a piglet model of HI, half of the neurons in putamen already show ischemic cytopathology by 6 h of recovery. We tested the hypothesis that treatment with the SOD-catalase mimetic EUK-134 at 30 min of recovery provides additive neuronal protection with a clinically relevant delay of 4 h in the onset of whole body hypothermia. Anesthetized piglets were subjected to 40 min of hypoxia (10% inspired O
2
) followed by 7 min of airway occlusion and resuscitation with epinephrine and chest compressions. Body temperature was maintained at 38.5 °C in normothermic groups and at 34 °C in hypothermic groups from 4 h through 24 h of recovery. All groups were mechanically ventilated and sedated with continuous fentanyl and pancuronium infusion during the 4 –24 h period to reduce the stress of hypothermia and shivering. At 10 days of recovery, viable neurons remaining in putamen in a normothermic control group was reduced to 20±13% (±SD; n=8) of the value in a sham-operated control group (100±19%; n=8). Infusion of EUK-134 (2.5 mg/kg at 30 min recovery + 1.25 mg/kg/h until 4 h recovery) with normothermic recovery resulted in 36±18% (n=8) viable neurons in putamen. Treatment with saline vehicle followed by delayed hypothermia resulted in partial protection (58±25%; n=8). Combining early treatment with EUK-134 and delayed hypothermia did not produce additional protection in putamen (47±29%; n=8). We conclude that early treatment with this antioxidant does not extend the therapeutic window of hypothermia in protecting highly vulnerable neurons of putamen in newborn brain subjected to HI, possibly because a subpopulation of neurons are already undergoing irreversible cell death signaling by the 30 min treatment time with EUK-134.
Abstract P34: Nitrite Therapy upon Resuscitation from Cardiac Arrest Reversibly Inhibits Mitochondrial Complex I Reducing ROS Burst and Improving Cardiac Function and Survival
Authors: Dezfulian Cameron , Shiva Sruti , Pendyal Akshay , Alekseyenko Aleksey , Anderson Stasia A , Gladwin Mark T
Published: July 2021

Nitrite reversibly S-nitrosates mitochondrial electron transport chain complex I (cxI) resulting in transient inhibition and reduction of pathological ROS burst after ischemia. We hypothesized that nitrite therapy at CPR initiation could thus improve cardiac contractility and mortality. Anesthetized C57BL/6 mice underwent hyperkalemic cardiac arrest maintained for 12min at 36.5C prior to randomly receiving blinded IV nitrite or saline placebo, epinephrine, chest compressions and ventilation for up to 150 sec. ROSC was obtained in excess of 90% in both groups. Hearts were excised just prior to asystole, 5 or 60 minutes after the initiation of CPR and mitochondria isolated. Respiration was assessed by oxygen consumption after providing the cxI substrate pyruvate or the complex II (cxII) substrate succinate. CxI activity was directly assayed by NADH oxidation, peroxide generation measured by Amplex Red peroxidation and ATP production quantified by luciferin luminescence. Nitrite therapy was associated with improved hemodynamics and significantly improved LVEF and RVEF (Table 1

) and better 22h survival (HR 2.72 [95% CI:1.1– 6.7]). Nitrite significantly reduced cxI mediated respiration 5 min post-CPR with loss of inhibition by 60min based on respiration and ATP production (Table II

). Respiration efficiency (respiratory control ratio) did not change, nor was there significant cxII inhibition. Early cxI inhibition was associated with significantly less ROS. Nitrite therapy transiently and reversibly inhibits cxI reducing reperfusion ROS-mediated injury and resulting in less myocardial dysfunction and death after cardiac arrest.

Myocardial dysfunction occurs after cardiac arrest and is reduced with nitrite therapy

Nitrite therapy specifically and reversibly inhibits complex I and reduces ROS generation
Abstract P76: Assessment of Resuscitation Skills in Foundation Year 1 Hospital Doctors in Northern Ireland
Authors: Connoly Michael , Toner Philip , Sayee Nicole , McCluskey David , Stevenson Mike
Published: July 2021

Aims: To assess Foundation Year 1 (F1) doctors’ ability to perform effective cardiopulmonary resuscitation (CPR) using different chest compression:ventilation ratios.

Methods: All forty F1 doctors working in a major teaching hospital were asked to participate in the study. Thirty four doctors participated, eighteen male and sixteen female. BMI was recorded in each case. They were asked to perform two, three minute sessions of CPR on a skills reporter manikin separated by a five minute rest period. Half of the doctors started using a ratio of 15:2 and half used 30:2. After a five minute rest the alternate ratio was performed. Their performance was assessed both objectively, by measuring the rate and depth of chest compressions, and subjectively by a panel of five advanced life support (ALS) instructors who reviewed tracings of each CPR session.

Results: Mean compression rate per minute was sixty five while performing 15:2 and ninety one at 30:2. Chest compressions were effective if >38mm. Twenty three doctors (67.7%) achieved >80% effective chest compressions at a ratio of 15:2, compared with nineteen doctors (55.9%) at 30:2. At 15:2, males were 89% effective compared to 44% of females. At 30:2 males were 83 % effective compared to 25% of females. At 15:2 82% of compressions were effective in BMI>24 group compared with 50% of BMI<24. At 30:2 BMI>24 achieved 76% effective compared with 35% in BMI<24 group. Outcome measures shown in table 1

show no statistical difference between 15:2 and 30:2. Subjectively, 41% of doctors were deemed effective at 15:2 compared with 35% at 30:2.

Conclusions:
A
significant number of F1 doctors are unable to perform effective CPR. Objectively, F1 doctors performed better at 15:2 than 30:2 but no statistical significance was noted. Subjectively, ALS instructors favoured the 15:2 regieme. CPR was performed better by males and doctors with BMI>24. F1 doctors’ should be carefully assessed before they act as first responders at in-hospital cardiac arrests.

Mean difference between 15:2 and 30:2
Abstract P80: Short-term Outcomes of Vasopressin Administerd with Epinephrine versus Epinephrine Alone in ED for Out-of-hospital Cardiac Arrest
Authors: Kim Tae Yun , Lee Sun Woo , Kim Kyuseok , Rhee Joong Eui , Jung Sung Koo
Published: July 2021

Introduction: Out-of-hospital cardiac arrest (OOHCA) victims are increasing, but emergency medical service system (EMSS) is not ready for them in Korea. A previous randomized, controlled clinical trial has suggested that vasopressin followed epinephrine was superior to epinephrine in patients with asystole. According to the Korean national registry of OOHCA, patients with asystole were more than two thirds of them. In Korean EMSS, no drugs are permitted to administer in the prehospital phase by law. Thereafter epinephrine or vasopressin cannot be administered until patients are transported to emergency departments (EDs). This study was to evaluate whether the combined administration of vasopressin and epinephrine in ED for OOHCA patients would increase the return of spontaneous circulation (ROSC) and survival discharge.

Methods: From October 2007 to May 2008, we changed the CPR protocol in adult, nontraumatic OOHCA that 40 U of vasopressin was administered as soon as possible after the first dose of epinephrine (the after group). Cardiac arrest data were collected using the Utstein template. Data from January to September 2007, when vasopressin has not been used, were also collected for comparative analysis (the before group). These two groups were compared in terms of ROSC, and survival discharge

Results: There were 45 and 50 patients in the before and after groups, respectively. There was no significant differences in the initial ECG rhythm of asystole (67% vs 78%), witnessed arrest (73% vs 72%), bystander CPR (16% vs 10%), time from collapse to BLS time (6 min vs 8.5 min), and time from collapse to study drugs (23 min vs 26.5 min). The rate of sustained ROSC was similar between the before and after groups (53% vs 48%, P=0.604) as was the survival discharge (27% vs 14%, P=0.123).

Conclusions: Vasopressin with administerd with epinephrine does not increase the rate of ROSC nor the survival discharge.
Abstract P86: The Aed Enlightenment Animation Dvd Motivates Schoolchildren to Learn about Cardiopulmonary Resuscitation and Aed
Authors: Nagatani Atsuko , Yamashita Kazunori , Sakamoto Tetsuya , Shimizu Naoki , Hatanaka Tetsuo , Marukawa Seishiro
Published: July 2021

We developed the AED enlightenment animation DVD (the AED Animation) as a readable and friendly educational material for learning cardiopulmonary resuscitation (CPR) and AED by citizens. The aim of the present study was to investigate how well did schoolchildren understand the contents of the AED Animation, and how the AED Animation has educational and ripple effects to schoolchildren.

[Methods]
Prior to the investigation of schoolchildren, 28 elementary school teachers watched the AED Animation and answered a questionnaire to see if the AED animation arouse schoolchildren, and to evaluate its psychological and educational impacts. Then in fourth, fifthand sixth grades elementary school students (total of 1189) watched the AED Animation and answered questionnaire-based survey.

[Results]
94 percent of the students answered “ the AED Animation is good for me”, 80 percent of them wanted to be able to do CPR and use AED as the characters of the AED Animation did, and 67 percent of them wanted there parents to watch the AED Animation.

[Conclusions]
The AED Animation is a good educational material for schoolchildren that raises interest in AED/CPR, and its educational effects was more than elementary school teachers expected.
Abstract P89: Take Heart America
™
: A Community-based Sudden Cardiac Arrest Survival Initiative is Saving Lives by Implementing the Most Highly Recommended 2005 American Heart Association Resuscitation Guidelines
Authors: Lurie Keith , Steinkamp Janet , Lick Charles , Aufderheide Tom , Sayre Michael , White Lynn , Racht Edward , Gonzales Louis , Nygaard Susan , Niskanen Robert
Published: July 2021

Introduction:
Take Heart America (THA) is a community-based initiative intended to improve survival from sudden, out-of-hospital cardiac arrest (OHCA) in four US communities: St. Cloud (MN), Anoka County (MN), Columbus (OH) and Austin (TX).

Hypothesis:
Implementing a continuum of resuscitation care that includes the most highly recommended 2005 AHA resuscitation guidelines will improve survival from OHCA.

Methods:
In Phase I, the two MN sites (population: greater St. Cloud: ~160K; Anoka Co: ~320K) implemented: a) widespread CPR training in schools and businesses; b) retraining of all EMS personnel in methods to enhance circulation including minimizing CPR interruptions, performing CPR prior to and after single shock defibrillation, and use of an impedance threshold device; c) more widespread deployment of AEDs in schools and public places; and d) transport to and treatment by Level One Cardiac Arrest Centers that provide: therapeutic hypothermia (applied to all comatose patients regardless of initial arrest rhythm), coronary artery evaluation and treatment, and widespread electrophysiological evaluation. During Phase II, Austin and Columbus will implement these same steps. A Standard Chi-Square analysis was performed.

Results:
From 2006 –2007 in the two MN sites, >12,000 people were trained in CPR, bystander CPR rates increased by ~5%, three Level One Cardiac Arrest Centers were established, and interventions a–d above were fully implemented. Survival in all patients following OCHA improved from 9.3% (14/151) in 2005 (historical control) to 17% (31/181) (P=0.0373) in 2007 in these two sites.

Conclusions:
In conclusion, when OHCA patients were treated with a continuum of prehospital and inhospital interventions intended to optimize defibrillation and circulation during CPR, and preserve heart and brain function following cardiac arrest, survival rates nearly doubled when compared to historical controls. The THA initiative is effective in mid-size communities, but regular retraining of EMS personnel is needed to assure full implementation of the key aspects of the program. Phase II is underway to determine if the program can be successfully implemented with similar positive results in communities with populations of 500 –1000K.
Abstract P110: Exploratory Study on Mechanism by Which Hypothermia Improves Outcomes of Cardiopulmonary Resuscitation
Authors: Yu Tao , Ritagno Giuseppe , Cho Jun H , Sun Shijie , Weil Max H , Tang Wanchun
Published: July 2021

Introduction
: In an earlier report, our group demonstrated that when head cooling was started during CPR, outcomes were improved. We had also reported in a series of studies the adverse effects on ultimate outcomes of adrenergic amines, both á
1
and âadrenergic agonists and improved outcomes withá
1
and âadrenergic blockades. We therefore hypothesized that the benefits of rapid head cooling may at least in part relate to reduced adrenergic stimulation. In a small exploratory study, we therefore measured endogenous plasma concentration of norepinephrine.

Methods:
Pilot studies were conducted in 7 domestic male pigs weighing 40±5 kg. After 15 minutes of untreated ventricular fibrillation, in 4 animals head cooling was induced with a Rhino Chill device coincident with start of CPR. An additional 3 animals served as identically treated controls without hypothermia. CPR was continued for 5 minutes in both group prior to defibrillation. Endogenous plasma norepinephrine levels were measured at baseline and 5 minutes after start of CPR.

Results:
None of the control animals were successfully resuscitated, in contrast to 3 of 4 brain cooled animals. Jugular vein temperature was reduced from 38.0°C to 37.0°C in brain cooled animals (
P
<0.001). Endogenous norepinephrine levels were greatly increased in comparing to baseline levels and was significantly less in brain cooled animals (153 vs 381 μg/L,
P
<0.05)

Conclusions:
The mechanism by which rapid head cooling improves outcome of resuscitation may, at least in part, relate to inhibition of the adverse effects of endogenous adrenergic stimulation.
Abstract P124: CGEN-855A, a Small Peptide Agonist of the Formyl Peptide Receptor-Like 1 Reduces Myocardial Reperfusion Injury
Authors: Jiang Rong , Hecht Iris , Rutledge Caleb , Zhao Zhiqing , Rotman Galit , Cohen Yossi , Vinten-Johansen Jakob
Published: July 2021

Background: Neutrophils (PMNs) mediate reperfusion injury in part. Reperfusion (R) accelerates the accumulation of PMNs into ischemic myocardium. Postconditioning (PC) inhibits PMN activation and accumulation in area at risk (AAR) myocardium. Formyl-peptide receptor-like1 (FPRL1) agonists directly inhibit PMN transmigration. Accordingly, this study tests the hypotheses that

the FPRL1 agonist CGEN-855A applied at R reduces infarct size by inhibition of PMN infiltration;

the infarct reduction by CGEN-855A is comparable to that of the mechanical intervention Postconditioning; and

since both CGEN-855A and PC share a common property of PMN inhibition, the combination of CGEN-855A and Postconditioning (PC) will not have an additive effect on infarct size reduction.

Methods: In anesthetized open-chest rats, the left coronary artery (LCA) was occluded for 30 min and reperfused for 3 hours. Rats (n=10) were randomly assigned to:

Control- equal volume vehicle 5 min before R;

PC: three cycles of 10-s R followed by 10-s re-occlusion during the first minute of R;

2 mg/kg CGEN-855A administered 5 min before R;

2 mg/kg CGEN-855A + PC at R. Separate experiments were performed to assess PMN accumulation in AAR tissue by immunohistochemistry in control, CGEN-855A and PC groups.

Results: The AAR (% left ventricular mass, AAR/LV) was comparable among groups. Infarct size (necrosis as % AAR, AN/AAR), was significantly less in the PC (41.2 ± 2.7*) and CGEN-855A (43.6 ± 2.9*) groups vs Control (57.0 ± 2.3). There was no additive effect of the combination of CGEN-855A and PC at R (44.6 ± 1.3). Both CGEN-855A (30.1 ± 0.6/HPF) and PC (34.8 ± 1.5/HPF) significantly reduced PMN accumulation in AAR tissue vs control (43.2 ± 0.7/HPF).

Conclusions:

stimulation of the FPRL1 with agonist CGEN-855A exerts cardioprotection at R by reducing infarct size;

CGEN-855A peptide inhibits PMN accumulation;

the extent of cardioprotection and PMN inhibition by CGEN-855A is similar to that of PC;

there is no additive effect of their combination, consistent with a similar physiological pathway of PMN inhibition. *P<0.05 vs Control
Abstract P139: A Paradoxical Increase in Brain Temperature Occurs Early During Cardiopulmonary Arrest.
Authors: Boller Manuel C , Katz Joseph M , Becker Lance B
Published: July 2021

Introduction
: In patients with cardiac arrest, brain cooling is a powerful intervention to improve neurological outcome. However, brain temperature variation during the initial phase of untreated cardiac arrest has not been well characterized.

Objective
: To describe passive changes in brain temperature in early untreated cardiac arrest.

Methods
: Eleven domestic swine (35 kg) were anesthetized and routine respiratory and cardiovascular parameters were monitored and recorded. Temperature was recorded from various sites including the forebrain. External heat support was adjusted to maintain rectal temperature at 37±0.5 °C at baseline, but was discontinued thereafter. Ventricular fibrillation was then induced and cardiac arrest remained untreated for 15 minutes. During this phase, forebrain temperature was recorded every 60 seconds.

Results
: The brain temperature increased in all animals after induction of cardiac arrest and remained above baseline for the duration of the study period. Peak mean (±SEM) increase above baseline was 0.26 (±0.03) °C and was reached after 9 minutes. Brain temperature slowly declined thereafter. The maximum and minimum temperature increase in individual animals was 0.42 °C and 0.13 °C, respectively.

Conclusions
: Brain temperature consistently and rapidly increases in the early phase of untreated cardiac arrest in anesthetized swine. This may parallel ongoing, yet diminishing, heat production from cerebral metabolic activity in the face of cessation of convective heat removal via cerebral blood flow.
Abstract P142: Erythropoietin Administered after Resuscitation from Cardiac Arrest Improves Myocardial Function in a Rat Model of CPR
Authors: Pytte Morten , Sun Shijie , Tang Wanchun , Weil Max H
Published: July 2021

Introduction
: Erythropoietin (EPO) administered prior to or following either myocardial or cerebral infarction minimizes the severity of ischemic injury. We hypothesized that when EPO is administered after resuscitation from cardiac arrest, post resuscitation myocardial function and survival would improve.

Methods
: In an established model of cardiac arrest, ventricular fibrillation (VF) was electrically induced in 32 male SD rats weighing 520±20 g and left untreated for 8 minutes, followed by 6 minutes of pre-cordial compressions and attempted defibrillation. Resuscitated animals were randomized to receive either EPO 5000 units/kg, which was injected into the right atrium, or saline as a control. The primary investigator was blinded to the randomization. Dp/dt
40
and −dp/dt were calculated based on continuously measured left ventricular pressure. Ejection fraction (EF) measured echocardiographically and blood gases were both measured hourly for four hours. Survival was observed at 72 hours.

Results
: Twenty animals were successfully resuscitated and randomized. EPO significantly improved both EF and contractility as measured by dp/dt
40
. It also reduced the severity of post resuscitation hypo-perfusion based on arterial blood lactate measurements (Figure

). However, no statistically significant differences in survival were observed. Figure

. Box plot of dp/dt
40,
EF and arterial lactic acid.

Conclusion
: EPO improved myocardial function and minimized the severity of post-resuscitation perfusion failure. However, no persuasive survival benefit was demonstrated.
Abstract P153: The Cumulative Dose of Epinephrine During Cardiopulmonary Resuscitation Increases Mortality and Functional Outcome after Non-Ventricular Fibrillation Cardiac Arrest
Authors: Arrich Jasmin , Sterz Fritz , Herkner Harald , Behringer Wilhelm
Published: July 2021

Background -

Epinephrine is the drug of choice during advanced cardiac life support. The cumulative dose of epinephrine applied during resuscitation was shown to be independently associated with unfavorable outcome after ventricular fibrillation cardiac arrest in humans. We investigated the association between the cumulative dose of epinephrine applied during resuscitation and outcome after non-ventricular fibrillation cardiac arrest.

Methods -

Adults admitted to the University Hospital Emergency Department with witnessed, non-traumatic, normothermic, non-ventricular fibrillation cardiac arrest of cardiac or pulmonary origin were included. The primary endpoint was in-hospital mortality, the secondary endpoint was unfavorable functional outcome (best cerebral performance category within 6 months; CPC 1, normal, CPC 2, moderate disability; CPC 3, severe disability and not able to live independently; CPC 4, coma; CPC 5, dead or brain dead; CPC 3–5 considered as unfavorable).

Results -

Of 2716 enrolled patients 578 patients fulfilled the inclusion criteria. The median cumulative amount of epinephrine administered during resuscitation was 3 mg (IQR 2– 6), ranging from 1 to 50 mg. Of all patients, 390 (67%) died during their hospital stay, 310 (62%) showed an unfavorable functional outcome. Patients, who died during hospital stay, received a statistically higher cumulative dose of epinephrine than patients, who survived, median (IQR) 4 mg (2– 6) vs. 2 mg (2– 4), p<0.01. After controlling for possible confounders (patient characteristics, resuscitation factors, comorbidities), logistic regression analysis showed that higher doses of epinephrine were independently associated with an increased mortality (OR 1.3 per quartile administered epinephrine, 95% CI 1.07–1.65, p=0.01), and unfavorable functional outcome (OR 1.4 per quartile administered epinephrine, 95% CI 1.12–1.81, p=0.004).

Conclusions

-Our results indicate that an increasing cumulative dose of epinephrine during resuscitation independently increases the risk for in-hospital death and unfavorable functional outcome after non-ventricular fibrillation cardiac arrest. Further studies are needed to re-evaluate the use of epinephrine during resuscitation in humans.
Abstract P157: Echogram Finding as a Marker of Resuscitation Outcome in Patients Who Were Treated with Extracorporeal-cpr after Out-of-hospital Cardiac Arrest Failed
Authors: watanabe kazuhiro , kikushima kimio , tominaga yoshiteru , tada katsushige , nishikawa kei , matsuzaki masakazu , tateda yutaka , ikeda harumi , yagi tsukasa , nagao ken
Published: July 2021

BACKGRAUND) Since 1996, we performed E-CPR (PCPS, coronary reperfusion therapy and hypothermia) in patients who arrived at the ER in cardiac arrest and failed to respond to standard CPR. However, few studies of echogram were available for resuscitation outcome.

METHODS) A total of 24 patients treated with E-CPR were enrolled in this prospective study. Using echogram, cardiac function (CI, LVSVI, and aortic valve ejection time (AVET)) for cardiac resuscitation and common carotid artery (CCA) flow for cerebral resuscitation were investigated according to our E-CPR protocol.

RESULTS) Of the 32 patients, 17 (53%) were weaned from PCPS successfully, and 6 (18%) had a favorable neurological outcome at 30 days after out-of-hospital cardiac arrest. At the time of PCPS flow of 2.0 l/min, Succeeded PCPS weaning group was higher levels of AVET than failed PCPS weaning group (AVET 216.9 vs 135.5, p<0.0001). The favorable recovery group was a higher level of CCA flow than the unfavorable group (375.9 vs 168.0 p=0.0002). The CCA flow cut off value of 173ml/min for a favorable neurological outcome.

CONCLUSIONS) In patients who were treated with E-CPR, echogram findings at the time of PCPS flow of 2.0ml/min were a useful marker of resuscitation, especially CCA flow of 173ml/min or more was associated with improvement of a favorable neurological outcome.
Abstract P159: Causes of Late Death in Patients Discharged Alive after In-hospital Cardiac Arrest: Arrhythmic or Not?
Authors: Keuper Wessel , Clappers Nick , Dieker Hendrik-Jan , Brouwer Marc A , Verheugt Freek W
Published: July 2021

Background
Survival to discharge after in-hospital cardiopulmonary resuscitation (CPR) is approximately 17%. Data on longer-term survival is scarce and 1-year survival varies between 50 to 80% for patients who survived to discharge. The cause of late death in this patient population is unknown. However, this is of great importance for therapeutic considerations such as prevention of arrhythmic death with an implantable cardiac defibrillator (ICD). Therefore, we obtained long-term survival and the cause of death of patients surviving to discharge after in-hospital cardiac arrest.

Methods
Single centre study of consecutive in-hospital cardiac arrest patients ≥ 18 years. The cause of late death was based on data obtained from medical records, interviews with general practitioners or if available, autopsy reports. Deaths were classified according to a modified scheme for deaths used in antiarrhythmic trials.

Results
Between 1997 and 2004 a total of 222 in-hospital cardiac arrest patients underwent CPR and 42 (19%) patients survived to discharge. After a median follow-up of 2.9 years (IQR 1.5–7.2) 18 (43%) patients had died. There were 6 cardiac and 12 non-cardiac causes of death (table

). Of the cardiac causes 2 were arrhythmic and 4 non-arrhythmic. Amongst the 18 deceased patients 7 had ventricular fibrillation at the in-hospital cardiac arrest and thus an indication for an ICD. Of these patients one eventually had an arrhythmic cause of death.

Conclusion
In this study of patients discharged alive after in-hospital cardiac arrest 3-year survival was 60%. Surprisingly a late cause of death of cardiac origin was found in only a third of the patients and was mostly non-arrhythmic. Of the 7 patients with a current ICD-indication after the index event only one had a potentially preventable arrhythmic cause of late death. Validation of these findings in larger studies seems warranted.
Abstract P163: Accuracy to Diagnose Cardiac Arrest and Quickness to Start Chest Compression in Different BLS Algorithms; a Comparative Study
Authors: Tamura Tomoko , Tanigawa Koichi , Kusunoki Shinji , Sadamori Takuma , Otani Tadatsugu , Ishida Makoto , Ota Kohei , Yamaga Satoshi , Kida Yoshiko , Tsumura Ryu , Kondo Tomohiro , Takeda Taku , Iwasaki Yasumasa , Hirohashi Nobuyuki
Published: July 2021

Background; BLS algorithms for health care providers or experience personnel recommended by AHA, European Resuscitation Council (ERC), and Japanese Resuscitation Council (JPN) differ with respect to the sequence of assessment and procedures. The differences may affect accuracy to diagnose cardiac arrest and quickness to start chest compression. We compared BLS algorithms recommended by these organizations with respect to accuracy of respiratory/circulatory assessment, and quickness to start chest compression using a computed manikin model.

Methods; Thirty three subjects (16 physicians and 17 medical students) were enrolled. The Sim-Man (Laerdal) was used to develop 2 scenarios (no pulse/no breathing, with pulse 60/min and breathing 10/min). The three algorithms and 2 scenarios were randomly assigned to the subject, and the accuracy to diagnose cardiac arrest and the time from confirmation of loss of consciousness to starting chest compression were evaluated.

Results; The rates of incorrect assessment of respiratory/circulatory status were AHA;9.8% (13 out of 132), ERC;9.1%(12 out of 132) and JPN;6.8%(9 out of 132)(n.s. among algorithms). When the results were analyzed with respect to clinical experiences of the subjects, i.e. physicians vs. medical students, significant differences were found between the groups: AHA;17.2% (11 out of 64), ERC;15.6% (10 out of 64), JPN;12.5% (8 out of 64) in students, whereas AHA;2.9% (2 out of 68), ERC;2.9% (2 out of 68), JPN;1.5% (1 out of 68) in physicians* (* p<0.05 vs. students). The time to starting chest compression were AHA;27.8±5.1 sec, ERC;18.6±3.2** sec, JPN;23.7±4.2 sec (**p<0.05 vs. AHA and JPN), and no significant differences were found between physicians and students.

Conclusions; No differences were found in accuracy of respiratory and circulatory assessment among the algorithms, although it may be influenced by clinical experiences of evaluators. The BLS algorithm starting CPR from chest compression such as ERC guidelines may reduce the time of no-flow status in cardiac arrest.
Abstract P176: Resumption of Cardiopulmonary Resuscitation after Defibrillation Induces Recurrence of Ventricular Fibrillation
Authors: Berdowski Jocelyn , van Zyll de Jong Liesbeth , Koster Rudolph W
Published: July 2021

Introduction- Resuscitation guidelines 2005 advise to resume cardiopulmonary resuscitation (CPR) immediately after defibrillation. We hypothesized that this promotes recurrence of ventricular fibrillation (VF).

Methods- This was a prospective per-patient randomized controlled trial. We randomized Automated External Defibrillators (AEDs) used by first responders to either a) perform post-shock analysis and prompt rescuers to a pulse check - guidelines 2000 - or b) to resume CPR immediately after defibrillation - guidelines 2005. Between June 2006 and April 2008, we collected continuous ECG and impedance signal of all patients with a non-traumatic out-of-hospital cardiac arrest to whom a study AED was applied. We annotated and calculated time intervals between the first effective shock, moment of CPR resumption, moment of refibrillation, and subsequent defibrillation shock. Intervals are expressed as median and inter quartile range.

Results- We collected 120 ECGs of patients with a shockable rhythm: 61 were randomized to guidelines 2000 and 59 patients to guidelines 2005. In respectively 54% (33/61) and 56% (33/59) of the patients VF recurred after the first effective shock. Rescuers resumed CPR after 32 (24–45) and 8 (7–9) seconds (P<0.01), VF recurred at 35 (21–57) and 13 (8–25) seconds after the first effective shock (figure 1

; P=0.02), the time interval between resumption of CPR and refibrillation was 4 (−8–20) and 6 (1–22) seconds (P=0.59), and VF sustained for 98 (63–204) and 150 (98–261) seconds (P=0.15).

Conclusion- CPR induces recurrent VF. Immediate resumption of CPR after effective defibrillation is associated with early and longer lasting recurrence of VF.
Abstract 224: 20-hydroxyeicosatetraenoic Acid Mediated Amp Activated Protein Kinase Suppression Induces Endothelial Nitric Oxide Synthase Uncoupling
Authors: Ward Natalie , Chen Kai , Croft Kevin , Keaney John
Published: July 2021

20-Hydroxyeicosatetraenoic acid (20-HETE), a cytochrome P450 product of arachidonic acid metabolism, is a potent vasoconstrictor thought to be involved in vascular dysfunction and the regulation of blood pressure. 20-HETE has been demonstrated to play an inhibitory role in eNOS activity and both animal and human studies have revealed strong associations between 20-HETE and endothelial dysfunction. However, the signalling mechanisms are largely unknown. Previous studies have shown that AMPK activity is involved in the Hsp90-eNOS association. Therefore we sought to investigate the effect of 20-HETE on eNOS and Hsp90 association, and whether this was mediated by AMPK. Treatment of human umbilical vein endothelial cells (HUVECs) with 10μM 20-HETE for 24h induces an increase in eNOS phosphorylation, which is not observed following acute treatment (30mins). This was accompanied by transient changes in Akt phosphorylation. Conversely, upstream AMPK activity increased rapidly following 20-HETE treatment (<1min) before decreasing by 30mins. Treatment with 20-HETE also resulted in an acute increase in the production of reactive oxygen species (ROS), which returned to control levels at >2hr post-20-HETE treatment. Immunoprecipitation of eNOS in cells treated with 20-HETE revealed a decrease in basal, VEGF and A23187 stimulated Hsp90 association with eNOS, indicating an uncoupling mechanism. Pre-treatment of the cells with AICAR (a chronic activator of AMPK) prevented the loss of Hsp90 association with eNOS following 20-HETE treatment. To further investigate the functional effect of Hsp90 dissociation, we utilised an endothelial-smooth muscle cell system to measure cGMP production. Chronic 20-HETE treatment appeared to reduce both basal and VEGF stimulated cGMP levels. Pre-treatment of the cells with AICAR protected against the 20-HETE induced decrease in cGMP levels, both basally and following VEGF stimulation. In conclusion, 20-HETE suppression of AMPK activity impairs eNOS-Hsp90 association, providing a mechanism for reduced NO bioactivity and endothelial dysfunction in diseases with elevated 20-HETE levels, such as hypertension.
Abstract 227: Activity of Soluble Guanylyl Cyclase, the Nitric Oxide Receptor, is Modulated by Cysteines Redox
Authors: Couloubaly Samba , Sayed Nazish , Hedhli Jamila , Baskaran Padmamalini , Beuve Annie
Published: July 2021

The enzyme soluble guanylyl cyclase (sGC) increases cellular level of the second messenger cGMP upon stimulation by nitric oxide (NO), whose role is exemplified in the cardiovascular system where it governs smooth muscle cell proliferation, vascular relaxation and platelet aggregation. Various pathologies like diabetes, hypertension and hypercholesterolemia are associated with enhanced oxidative stress with increased formation of reactive oxygen (ROS) and nitrogen species (RNS). We recently showed that cysteines beta1C243 and beta1C122 are S-nitrosylated in sGC leading to its desensitization. We have now identified by Mass Spectrometry, two additional cysteines (beta1C571 and alpha1C516) as potentially modified. Our hypothesis is that loss in vascular reactivity in oxidative pathologies is mediated, in part, by desensitization of sGC via thiols oxidation. We studied the effect of oxidative stress on sGC in primary vascular smooth muscle cells (VSMC) by directly exposing them to hydrogen peroxide (H2O2) in the absence or presence of a catalase inhibitor Amino-Triazole (AT). H2O2 induced inhibition of NO-stimulated sGC activity in VSMC and in COS 7 cells transiently transfected with sGC. Desensitization of sGC was further increased in VSMC treated with both H2O2 and AT. Next, we conducted mutational analysis of the 4 cysteines to assess their involvement in redox sensing. Replacement of C571 and C122 eliminated the oxidative-dependent desensitization observed in the wild-type. In addition, peroxynitrite, a strong oxidant, inhibited the NO-stimulated sGC activity in a purified system without oxidation of the heme. In conclusion, our results suggest that sGC activity is directly modulated by the redox state of the cells. Moreover, the identified 4 cysteines can be modified by both ROS and RNS suggesting a complex modulation. Ultimately, our goal is to determine whether loss of vascular reactivity in oxidative pathophysiologies is in part mediated by desensitization of sGC and what are the involved cysteines.

This work was supported by NIH GM067640, HL089771.
Abstract 229: Novel Plasma Membrane Beta Adrenergic Receptor Resensitization By Protein Phosphatase 2a
Authors: Vasudevan Neelakantan T , Shukla Anita , Prasad Sathyamangla V Naga
Published: July 2021

Resensitization of β-adrenergic receptor (βAR) occurs by dephosphorylation of the internalized βAR by protein phosphatase 2A (PP2A) before being recycled back to plasma membrane (PM). Contrary to this classical paradigm, cardiac specific expression of inactive PI3Kγ (PI3Kγ
inact
) leads to receptor resensitization at the plasma membrane as measured by adenylyl cyclase activity in mice chronically treated with the agonist. We hypothesized that PI3K activity inhibits PM receptor resensitization. Using cells stably expressing FLAG-β
1
AR alone (single) or along with PI3Kγ
inact
(double), we show that inhibition of PI3K activity results in novel PM receptor resensitization. Agonist activation of single stables showed significant receptor desensitization as measured by reduced cAMP generation (35.6 ± 4.6 pmol/mg protein). In contrast, double-or wortmannin (Wort, PI3K inhibitor) pre-treated single- stables showed marked generation of cAMP (87.4 ± 3.2 or 83.1 ± 5.7) showing β
1
AR resensitization. Agonist stimulation of metabolically labeled β
1
ARs pre-treated with inhibitors of internalization, sucrose and β-cyclodextrin resulted in accumulation of phosphorylated receptors at the PM, which was abolished with PI3Kγ
inact
suggesting dephosphorylation of β
1
ARs. Inhibition of PP2A by okadaic acid or Fostriecin resulted in complete loss of β
1
AR resensitization despite the presence of PI3Kγ
inact
showing that PI3K regulates PP2A activity at the β
1
AR complex. Pre-treatment of single stable cells with Wort resulted in significant increase in β
1
AR-associated phosphatase activity following dobutamine (Dob) treatment (Veh, 4131 ± 14; Dob, 3180 ± 111; Dob + Wort, 17123 ± 680 pmoles/mg protein). Consistently, similar results were obtained
in vivo
using single transgenic (FLAG-β
1
AR, Veh, 87 ± 12; Dob, 61.7 ± 8.3) and double transgenic (FLAG-β
1
AR and PI3Kγ
inact
, Veh, 93 ± 9; Dob, 118 ± 6) mice.
In vivo
metabolic labeling, co-immunoprecipitation and
in vitro
kinase assays showed that inhibitor of PP2A (I2PP2A) protein as a target of PI3K in regulating PP2A activity at the β
1
AR complex. Indeed, siRNA knock down of I2PP2A results in preservation of β
1
AR function by PM receptor resensitization demonstrating a novel role for PI3K in receptor resensitization.

This research has received full or partial funding support from the American Heart Association, AHA Great Rivers Affiliate (Delaware, Kentucky, Ohio, Pennsylvania & West Virginia).
Abstract 235: Sonic Hedgehog Induces Angiogenesis via Rho Kinase-dependent MMP-9 and Osteopontin Expression
Authors: Renault Marie-Ange , Roncalli Jerome , Tongers Joern , Thorne Tina , Misener Sol , Volpert Olga V , Mehta Shanu , Burg Aaron , Luedemann Corinne , Qin Gangjian , Kishore Raj , Losordo Douglas W
Published: July 2021

The morphogen Sonic Hedgehog (Shh) is known to promote neovascularization in adults via indirect induction of pro-angiogenic cytokine expression by fibroblasts. Direct effects of Shh on endothelial cell (EC) function and angiogenesis, however, have not been characterized. Accordingly, we performed a series of in vitro and in vivo studies to evaluate the direct effects of Shh on EC and to investigate certain mechanisms by which Shh modulates angiogenesis. Our data disclose that Shh promotes capillary morphogenesis (tube length on Matrigel
™
increased to 271±50% of the length in untreated cells), induces EC migration (191±35%) and increases EC expression of matrix metalloproteinase 9 (MMP-9) and osteopontin (OPN), which are shown to be essential for Shh-induced angiogenesis both
in vitro
and
in vivo
. Shh effects in ECs, however, occur while Gli-dependent transcription is not modulated. Furthemore, our studies show that changes in gene expression and EC migration are mediated by Shh induction of Rho. The Rho dependence of Shh-induced EC angiogenic activity is documented
in vitro
using dominant negative constructs for RhoA and Rho kinase (ROCK), showing that RhoA and ROCK blockade attenuates Shh induced migration and tube formation, as well as the Shh induced expression of MMP-9 and OPN.
In vivo
in the mouse corneal angiogenesis model pharmacologic inhibition of ROCK blocks Shh induced angiogenesis, confirming the ROCK dependence of this process. Furthermore, in MMP-9 and OPN null mice Shh induced angiogenesis also blocked, indicating that Shh induced angiogenesis is also dependent on MMP-9 and OPN expression. These data elucidate an entirely novel, “non-classical” pathway by which Shh
directly
modulates EC phenotype and angiogenic activity
Abstract 300: Pathophysiologically Regulated Gene Expression in Human Stem & Progenitor Cells for Cardiogenic Differentiation and Repair
Authors: Chen Zhilin , Hall Sean R , Brunt Keith R , Liu Zhan , Ademidun David A , Pang Stephen C , Ward Christopher A , Melo Luis G
Published: July 2021

Human stem and progenitor cells have emerged as potentially useful substrates for cardiovascular repair through neovascularization and myocardial regeneration. However, efficacy is limited by impedance to stem cell retention, homing and differentiation in hostile microenvironments, as occur in infarcted myocardium. The objective of the current study was to regulate gene function for tailored therapy in post infarct myocardium. Here we show that hypoxic and inflammatory stimuli of the infarct microenvironment regulate a proportional response in gene expression in human endothelial progenitor (EPC) and mesenchymal stem cells (MSC). Highly efficient lentiviral vectors incorporating hypoxia (HRE) and nuclear factor kappa B (NFkB) responsive elements are used to drive transgenes for survival, autologous stem cell homing and cardiogenic differentiation. Utilizing an internal cytomegalovirus promoter deleted lentiviral transfer vector, an HRE-NFkB bicistronic promoter-reporter vector was constructed with a modified internal ribosome entry sequence between green fluorescent protein and luciferase or therapeutic genes. Either hypoxia or inflammation resulted in a seven to ten-fold response of transgene expression assessed by luciferase activity in EPC (hypoxia, 7608±954; inflammation 11492±1384, P<0.01 and P<0.001 vs control 1049±139 respectively, N=6), while combined hypoxic-inflammatory stimuli resulted in a sixty-fold increase of transgene expression (hypoxic-inflammation, 62364±6609, P<0.001 vs control 1049±139, N=6). These results were recapitulated in MSC and with a series of therapeutic genes as determined by transcript, protein expression and activity. Our results demonstrate that regulated vectors provide a proportional response to hostile post-infarct myocardium. Translating cardiovascular regenerative medicine using stem cells requires managing stem cell survival, function and differentiation. Utilizing site-specific pathophysiological cues to auto-regulate reparative and regenerative gene expression, this study is a starting point for sophisticated platforms for patient tailored cell-based cardiogenic therapy.
Abstract 308: Rgs2 Is An Endogenous Inhibitor Of Insulin Signaling
Authors: Sharma Prem , Bever Jennie , Heximer Scott , Dessauer Carmen , Olefsky Jerrold M
Published: July 2021

Background: Insulin resistance is the hallmark of type 2 diabetes and is a known risk factor for the development of cardiovascular diseases. We have determined that overexpression of a GTPase-activating protein, RGS2 decreases insulin sensitivity. This study describes RGS2 regulation of insulin signaling pathways in order to assess whether this information can be used to reverse insulin insensitivity in diabetes.

Hypothesis, Methods and Results: RGS2 protein levels were elevated 3 to 5-fold in white adipose tissues from ob/ob and high fat diet induced Insulin Resistant mice. Further, RGS2 protein is elevated in insulin resistant 3T3-L1 adipocytes treated chronically with either insulin, ET-1, or TNF-aplha. Further, SiRNA knockdown of endogenous RGS2 protein increases basal, insulin independent and insulin-dependent GLUT4 translocation. We hypothesized that the RGS2 regulatory system is defective/overactive in insulin resistance, and that a modulation of this regulatory system by RGS2 inhibition would improve insulin sensitivity. Thus, we determined the mechanisms whereby RGS2 modulates insulin sensitivity in 3T3-L1 adipocytes; focusing on insulin-regulated G-protein/PI3-K pathways leading to GLUT4 translocation and glucose uptake; utilizing adenoviruses over-expressing wild-type and mutants RGS2, as well as by siRNA-mediated knock down of endogenous RGS2. We overexpressed the Wild-Type (WT), GTPase defective (GD), and plasma membrane translocation defective (TD) RGS2 proteins in 3T3-L1 adipocytes. Overexpression of WT RGS2 leads to ~ 50% inhibition of insulin induced 2-DOG uptake, without affecting IR Tyr phosphorylation. RGS2 constitutively associates with Galpha/q11, and prevent its Tyr phosphorylation and activation by insulin. Interestingly, insulin-stimulated PKClambda phosphorylation was completely blocked by RGS2, whereas, AKT phosphorylation was minimally inhibited. Neither the insulin receptor tyrosine phosphorylation nor insulin-stimulated MAPK phosphorylation was affected by RGS2.

Conclusion: This study identifies a novel role of RGS2 in cellular insulin resistance by negatively regulating signaling through the Galpha/q11 pathway to glucose uptake.

This research has received full or partial funding support from the American Heart Association, AHA Western States Affiliate (California, Nevada & Utah).