bluuebunny/crossref_metadata_2025 huggingface dataset:
Abstract Sa1002: Vasopressor or Advanced Airway First in Cardiac Arrest?
Authors: Wang Henry , Daya Mohamud , Schmicker Robert , Nassal Michelle , Okubo Masashi , ARAMENDI ELISABETE , Alonso Erik , Idris Ahamed , Panchal Ashish , Jaureguibeitia Xabier , Carlson Jestin , Nichol Graham
Published: November 2024

Background:
While early vasopressor administration (epinephrine, vasopressin) and early advanced airway management (laryngeal tube [LT], endotracheal intubation [ETI]) have been associated with improved outcomes after out-of-hospital cardiac arrest (OHCA), their optimal sequence during resuscitation remains unclear.

Aims:
To determine the associations between vasopressor-airway resuscitation sequence and OHCA outcomes and quality of cardiopulmonary resuscitation (CPR) in the Pragmatic Airway Resuscitation Trial (PART).

Methods:
Secondary analysis of the PART trial, which compared initial airway strategies of LT vs. ETI in adults with OHCA. For each patient we determined times of advanced life support (ALS) rescuer arrival, first vasopressor administration, and first successful airway insertion. We defined resuscitation sequence as: 1) vasopressor-first or 2) airway-first. We excluded cases with either vasopressor or airway given before ALS arrival and those that received neither. We used Generalized Estimating Equations to determine associations between resuscitation sequence and outcomes (72-hour survival, ROSC, survival to hospital discharge, survival with favorable neurologic status) and CPR quality (chest compression rate 100-120 per min, chest compression fraction (CCF) ≥0.8, ventilation rate 8-12 per min), adjusting for known confounders. Secondary analyses stratified by initial rhythm (shockable vs. non-shockable) and time to first intervention (vasopressor or airway, ≤10 vs. >10 mins).

Results:
Of 3,004 patients in the parent trial, we included 2,404, including 1,821 vasopressor-first and 583 airway-first. Median intervention times were: ALS arrival-to-vasopressor 8 mins (IQR 6-11) and ALS arrival-to-airway 11 mins (8-15). Compared with airway-first, vasopressor-first sequence was not associated with 72-hour survival (aOR 0.89; 95% CI: 0.66-1.20), ROSC (0.79; 0.62-1.001), hospital survival (0.98; 0.63-1.53), or hospital survival with favorable neurologic status (0.84; 0.47-1.51). Associations were similar when stratified by initial rhythm or time to first intervention. In those with available chest compression (n=1,699) and ventilation (n=892) data, vasopressor-first sequence was not associated with chest compression rate (aOR 0.90; 95% CI: 0.73-1.11), CCF ≥0.8 (0.94; 0.72-1.21) or ventilation rate 8-12 per min (0.79; 0.57-1.08).

Conclusions:
Vasopressor-airway resuscitation sequence is not associated with OHCA outcomes or CPR quality.
Abstract Sa1005: Differences in ETCO
2
Measurement between Sidestream and Mainstream Capnography during CPR.
Authors: Leturiondo Mikel , Uriguen Jose Antonio , Daya Mohamud , Johnson Nicholas , Blackwood Jennifer , Ruiz de Gauna Sofia
Published: November 2024

Introduction:
End-tidal CO
2
(ETCO
2
) has long been proposed as a trustworthy non-invasive indicator of the effectiveness of cardiopulmonary resuscitation (CPR). In fact, ETCO
2
values and trends have been associated to return of spontaneous circulation (ROSC), likelihood of survival or possibility of death. Two different technologies are available to measure ETCO
2
, mainstream and sidestream. In mainstream, the sensor is directly placed on the patient’s airway and samples CO
2
tensions within the airway. Conversely, in sidestream, gas travels through a tubing connected to the patient’s airway, with the CO
2
values being measured from a sampling port on this circuit distant from the airway.

Aim:
Quantitatively analyze the differences in ETCO
2
values between mainstream and sidestream technologies measured concurrently in patients undergoing out-of-hospital CPR.

Methods:
Manual CPR out-of-hospital cardiac arrest cases with defibrillator, spirometry-based tidal volume and inspiratory flow, and concurrent capnography data recorded by both mainstream and sidestream approaches after intubation. For each episode, ventilations were automatically detected in the volume signal and characterized by the ETCO
2
values measured using the mainstream and sidestream waveform capnography tracings. Differences in the measurements obtained by both technologies were quantified in absolute (mmHg) and relative values (%).

Results:
A total of 25 cases were analyzed, comprising 3,275 ventilations with concurrent mainstream and sidestream waveform capnography. Median (IQR) ventilation rate was 12.4 (9.6, 15.6) per minute. Median (IQR) tidal volumes were 380 (318, 478) mL. ETCO
2
values for mainstream presented a median (IQR) of 45.7 (37.6, 62.2) mmHg, while for sidestream were 43.0 (35.0, 59.0) mmHg (p < 0.001). The distribution of absolute differences was 2.6 (1.4, 4.3) mmHg, and of relative differences 6.0% (3.3%, 9.8%).

Conclusion:
Sidestream yielded ETCO
2
measurements that were almost always lower than those recorded by mainstream, with median differences close to 3mmHg, or more than 6%. Even if registered values are similar, precise measurements are vital in the context of monitoring the quality of CPR. Because both technologies are widely used, sensors may need to be calibrated to account for technical differences in order to yield accurate measurements.
Abstract Sa1006: Association between Increment of Near-Infrared Spectroscopy-Derived Cerebral Perfusion Index and Return of Spontaneous Circulation in Out-of-Hospital Cardiac Arrest Patients: A Prospective Observational Study
Authors: NISHIOKA NORIHIRO , Kiguchi Takeyuki , Makino Yuto , Ninomiya Kouhei , Kamo Wataru , Kamada tsuyoshi , Maeda Hideki , Iwami Taku
Published: November 2024

Introduction:
Maintaining cerebral blood flow during cardiopulmonary resuscitation (CPR) is vital, yet establishing a dynamic indicator of cerebral blood flow during CPR remains challenging. Near-infrared spectroscopy (NIRS) is a non-invasive technique capable of continuously detecting changes in cerebral blood volume and has the potential to assess cerebral blood flow in real-time during cardiac arrest. Despite its potential, limited research exists on cerebral perfusion indexes measured by NIRS during CPR and their clinical outcomes.

Research Questions:
Can assessing cerebral perfusion indices (CPI) using NIRS during CPR in out-of-hospital cardiac arrest patients serve as a prognostic indicator?

Aims:
To evaluate the association between increased CPI measured by NIRS during CPR by EMS personnel on-scene and return of spontaneous circulation (ROSC) after adult out-of-hospital cardiac arrest (OHCA).

Methods:
Between January 2021 and March 2023, we included consecutive out-of-hospital cardiac arrest patients due to internal causes who were attempted resuscitation by emergency medical services (EMS) in Sapporo city, Japan. EMS placed a NIRS monitor probe (NIRO 200-NX; Hamamatsu Photonics, Japan) on the patient's forehead and began measurements simultaneously upon contact with the patient. Patients treated with a mechanical chest compression device were excluded. We focused on the change of NIRS pulse waves during CPR at the scene and analyzed the values of NIRS pulse waves at two points: patient contact and scene departure by EMS. NIRS technology measures changes in total hemoglobin (ΔcHb) and oxygenated hemoglobin (ΔO2Hb) concentrations. Patients were divided into groups based on whether their ΔcHb and ΔO2Hb levels increased or decreased between patient contact and scene departure. The primary outcome was prehospital ROSC, and no cases of ROSC were observed at the scene.

Results:
During the study period, 91 patients were included. The prehospital ROSC rate was 16.4% (11/67) in the group with an increasing ΔcHb trend, compared to 0% (0/24) in the group with no increasing trend (p = 0.034). Regarding ΔO2Hb, the rate was 14.7% (10/68) in the group with an increasing trend and 4.3% (1/23) in the group with no increasing trend (p = 0.279).

Conclusion:
The increase in CPI measured by NIRS during CPR on-scene was associated with ROSC. Further research is warranted to determine whether CPI can aid in predicting the prognosis of cardiac arrest patients.
Abstract Sa1205: Understanding Barriers to Bystander Use of Automated External Defibrillators (AEDs) in Cardiac Arrest: A Cross-Sectional Survey in North Carolina
Authors: Yonis Harman Gailan Hassan , Kaltenbach Lisa , Nouhravesh Nina , Mark Daniel , Blewer Audrey , Malta Hansen Carolina , Kragholm Kristian , Torp-Pedersen Christian , Starks Monique , Al-Khatib Sana , Monk Lisa , Jollis James , Sasson Comilla , Krychtiuk Konstantin , Granger Christopher
Published: November 2024

Introduction:
Early defibrillation is a critical link in the chain of survival after out-of-hospital cardiac arrest. However, bystander defibrillation rates are extremely low (<2% in North Carolina). Barriers to increasing bystander defibrillation rates and the reasons why bystanders rarely perform early defibrillation are not well-defined in North Carolina.

Objectives:
To assess public awareness of AEDs in areas with an accessible AED. Specifically, we investigated whether the public knew the locations of nearby AEDs, how to use them, and whether they were willing to use an AED in the event of cardiac arrest.

Methods:
We conducted a cross-sectional face-to-face survey study in two large cities in North Carolina (NC): Winston-Salem and Charlotte. The survey instrument consisted of a 14-item questionnaire, which was pre-tested before the study started. Survey locations were chosen based on the availability of a public AED within a radius of 900 feet or less, equivalent to less than a 3-minute round-trip run from the site. Only responders aged 18 years or older who regularly visited or worked in the area were included.

Results:
In total, 94 surveys were completed, with 52 in Charlotte and 42 in Winston-Salem. The survey population consisted of 57.4% males (n=54), 42.6% Black individuals (n=40), with the most frequently reported age category being 25- to 34-year-olds (n=21). In total, 69.1% (95% CI 59.2% to 77.6%) of responders knew what an AED was, and 83.0% (95% CI 74.1% to 89.2%) were willing to use an AED in the event of cardiac arrest. However, only 23.4% (95% CI 16.0% to 32.9%) knew how to use an AED and 19.2% (95% CI 12.5% to 28.3%) knew where the nearest AED was (Table). Previous CPR training was common but did not identify subjects with greater awareness or understanding about the use of AEDs.

Conclusion:
While a majority of respondents in our survey in urban NC were aware of what an AED was and were willing to use one, a concerning number lacked knowledge of how to use an AED and were unaware of an AED available within 900 feet of the assessment site. These results suggest areas in need for improvement in the current approach to public AED placement and signage.
Abstract Sa206: Characterization of TAT-PHLPP9c Pharmacokinetics and Stability
Authors: Li Jing , Zhu Xiangdong , Lin Shaoxia , Vanden Hoek Terry
Published: November 2024

Introduction:
Cardiac arrest (CA) affects about 650,000 people annually. The overall survival rate for OHCA is less than 10% and 25% for IHCA. Early intervention after CA during CPR is essential to the likelihood of survival. We have demonstrated that a novel peptide TAT-PHLPP9c, when administered during CPR, improves survival following asystole, ventricular fibrillation, and pulseless electrical activity arrest in mouse and swine models. To further optimize the use of this peptide for resuscitation, we investigated two clinically relevant factors that could affect TAT-PHLPP9c effectiveness, degradation and storage stability.

Hypothesis:
TAT-PHLPP9c plasma concentrations could be affected by proteases and its activity by changes in storage temperature.

Methods:
TAT-PHLPP9c (7.5 mg/kg) was administered to mice via retro-orbital injection. Plasma concentrations were measured at 5, 10 min, up to 1 h by ELISA assay. An
in vitro
study was also performed by adding 100 nM of TAT-PHLPP9c to the plasma of mice, pigs and humans. The concentrations at baseline, 30, 60, and 120 min were measured. To study the stability, the lyophilized powder of TAT-PHLPP9c was stored at -80, -20, 4, and 20 °C for 6 months. The peptide bioactivity was Akt activation measured by Western blot. In C57BL/6 retired female mice (n=20), a 12-min asystolic arrest was induced with KCl followed by CPR and blinded randomized administration of TAT-PHLPP9c or saline control during CPR. Survival (4h) was assessed.

Results:
The baseline concentration of TAT-PHLPP9c was about 94 µg/ml. Its concentration was 3 µg/ml at 5 min, 0.5 µg/ml at 10 min, and disappeared by 30 min post-injection.
In vitro
studies demonstrated that its plasma concentration at baseline was 25 nM in mice, 50 nM in pigs, and 60 nM in humans, respectively. The concentration was decreased by 50% in mice and about 20% in pigs and humans, which was abrogated by the protease inhibitor complex III. Despite its rapid degradation by proteases, TAT-PHLPP9c administered during CPR in the mouse CA model improved CA outcomes after 12 min arrest. For the stability study, Akt phosphorylation was significantly reduced after 3 months for all the storage temperatures except for -80 °C.

Conclusions:
TAT-PHLPP9c degradation in plasma is primarily mediated by proteases, but despite degradation can retain significant activity. Formulation modifications will be needed to improve stability during storage conditions common to the ambulance environment.
Abstract Sa302: Protective effects of hemodilution in emergency cardiopulmonary bypass resuscitation after cardiac arrest
Authors: Sui Xin , Xu Wenjia , Yin Chengke , Cui Baobin , Wu Tong , Liu Chang , Han Fei
Published: November 2024

Introduction:
The no-reflow phenomenon is considered to be one of the important mechanisms of ischemia-reperfusion injury. Low hematocrit (Hct) after hemodilution can increase microcirculation flow by reducing blood viscosity and improve the non-reflow phenomenon after cardiac arrest. However, the effect of hemodilution remains controversial.

Hypothesis:
To investigate the protective effect of hemodilution and the optimal Hct in emergency cardiopulmonary bypass (ECPB) resuscitation after cardiac arrest.

Methods:
Male SD rats, 400-450 g were subjected to 8 min asphyxial CA and followed by ECPB resuscitation. Sham, Hct 30%-35%, Hct 25%-30% and Hct 20%-25% groups were included. Survival and Neurologic Deficit Score (NDS) were assessed at 24 h, 48 h and 72 h after return of spontaneous circulation (ROSC). Immunohistochemical staining for NeuN, IBA1, GFAP and Tunel staining were performed to assess neurological outcomes. HE staining and Tunel staining were performed to assess the outcomes of heart and kidney.

Results:
There was no significant difference in survival among all groups. NDS in Hct 20%-25% group was significantly better than that in the Hct 30%-35% and Hct 25%-30% groups at 24 h after ROSC (
P
<0.05). Hippocampus was less injured in the Hct 20%-25% than in the Hct 30%-35% and Hct 25%-30% groups (Figure). Hct 20%-25% significantly attenuated damage to heart and kidney.

Conclusions:
Hemodilution to Hct 20%-25% has a protective effect on the hippocampus, heart and kidney in ECPB resuscitation after cardiac arrest.
Abstract Sa304: Breaking New Ground in Prehospital Medicine: The Impact of Prehospital ECPR in Japan - A 14-Patient Case Study
Authors: FUJITA KENSUKE , Hagiwara Yoshihiro , Ogura Takayuki
Published: November 2024

Background:
Since January 2022, our emergency medical center has operated a prehospital extracorporeal cardiopulmonary resuscitation (ECPR) system. The ECPR team is dispatched for suspected CPA cases. Criteria for ECPR on the scene include patients aged 65 or younger with an initial rhythm of shockable or PEA. Additionally, witness presence, bystander CPR, and blood gas analysis are considered. Due to the difficulty in obtaining accurate on-scene information, the Sign of Life (SOL) is crucial. Cannulation is performed in a mobile ICU under mechanical CPR, with ultrasound-guided cannulation as the first choice. Once ECMO is established, systemic O2/CO2 optimization using a gas blender and rapid initiation of targeted temperature management (TTM) at 34°C are performed. This is the only system in Japan systematically performing prehospital ECPR for all OHCA cases, known as the "Utsunomiya model."

Objective:
To evaluate the outcomes and feasibility of prehospital ECPR at our facility in Japan.

Methods:
This retrospective case series included patients who underwent prehospital ECPR between January 2022 and May 2024. The primary outcome was favorable neurological outcome, and secondary outcomes included 28-day survival and complications.

Results:
The prehospital ECPR system responded to 113 calls, resulting in 14 cases where ECPR was performed (11 identified as CPA by dispatchers, and 3 as non-CPA). The average patient age was 59 years, 85.7% were male, 64.3% had witnessed arrests, and bystander CPR was performed in 71.4% of cases. SOL was present in 57.1%, with initial rhythms: shockable in 28.6%, PEA in 50%, and asystole in 21.4%. ECMO-related metrics included a no-flow time of 2.5 minutes and a low-flow time of 33 minutes. Cannulation was performed percutaneously under ultrasound guidance, with an average cannulation time of 9.5 minutes. Favorable neurological outcomes were achieved in 28.6% of cases, with a 28-day survival rate of 64.3% and a complication rate of 0%. Among cases with SOL, the 28-day survival rate was 87.5%, and favorable neurological outcomes were 50%. Of the four cases with favorable outcomes, one had a shockable rhythm, two had PEA, and one had asystole, all with SOL.

Conclusion:
Prehospital ECPR is a feasible intervention within the Japanese emergency medical system, demonstrating promising outcomes. Further studies are required to optimize patient selection and procedural protocols to improve results.
Abstract Sa310: Temporal Dynamics of Perfusion Pressures After Changing Methods of Cardiopulmonary Resuscitation
Authors: Paradis Aidan , Paradis Norman
Published: November 2024

Introduction:
Developing multi-modal cardiopulmonary resuscitation (CPR) in animal models of cardiac arrest is challenging because of the exponential increase in the number of possible combinations of n modalities. As the number of modalities under investigation increases the number of studies necessary become unwieldy. To mitigate this issue, we have considered two methodologic approaches: 1) a variant of the n-of-1 design in which we divide experiments into time-limited epochs with alternating treatment pairs, and 2) using the changes (delta) in perfusion pressures across epochs as the hemodynamic variable. However, the temporal dynamics of perfusion pressures during the alternation of CPR modes remains poorly investigated so the optimal epoch length remains unknown.

Hypothesis:
After changes in CPR efficacy, changes in perfusion pressures reach their new plateau rapidly, allowing for relatively short experimental epochs.

Methods:
In a porcine model of VF (n=6), we compared standard circumferential constriction CPR (
CC-CPR
) with and without interposed abdominal counterpulsation
(IAC-CPR)
. Both treatments were administered by a custom circumferential pneumatic system. Alternating 30-second epochs of each treatment were performed. Aortic (
Ao
) and Right Atrial (
RA
) pressures were measured via micromanometer catheters, and coronary perfusion pressures (
CPP
) were calculated.

Results:
IAC-CPR Ao trended upwards after each change from standard CC-CPR to IAC-CPR. (See Fig.) However, it didn’t reach a clear plateau in 30 sec.

Conclusions:
Relatively short experimental epochs, with changes in hemodynamic indicators as the basis for study, appear to be a promising approach to limited experimental populations. After changing to a CPR therapy of different effectiveness, Ao begins to increase relatively rapidly but does not reach its new equilibrium within 30 sec. So longer experimental epochs may be needed. Additionally, these observations have important implications for the development of new combination CPRs and the application of precision “play the winner” algorithms during actual clinical use.
Abstract Sa601: Relationship between ETCO2 and Hemodynamics in Swine: An Exploratory Secondary Analysis
Authors: Yhdego Haben , Beka Sylvia , Pandit Sandeep , Appleby David , Lampe Joshua
Published: November 2024

Background:
End-tidal carbon dioxide (ETCO2) has been proposed as a surrogate for cardiac output during cardiopulmonary resuscitation (CPR). Chest compressions alter the capnogram waveform, complicating the calculation of ETCO2 values. To explore the utility of ETCO2 as a surrogate marker, we have conducted a retrospective analysis of the relationship between local maxima in the capnogram and hemodynamic metrics in preclinical resuscitation studies.

Methods:
In eight domestic swine (~30 kg), the IVC blood flow, aortic pressure (AOP), right atrial pressure (RAP), and capnogram were measured during resuscitation. Coronary perfusion pressure (CPP) is the difference between the AOP and the RAP during relaxation. ETCO2 is calculated using three methods: averaging the maximum CO2 level reached during each chest compression, selecting the global CO2 maximum measured during each breath, and identifying the maximum CO2 level from the last compression for each breath. The data are modeled using multivariate linear regression as follows:

ETCO2= IVC + CPP + CC Depth + CC rate + Epoch # + Animal #

Results:
Table 1 shows R-squared values relating intra-compression CO2 maxima to hemodynamic measures and compression characteristics. The maximum CO2 value in a breath shows stronger correlations with these parameters than the other CO2 measurements. Table 2 presents regression coefficients for the model using this measure. CC Depth and CPP have coefficients of 3.67 and 2.05 respectively, indicating significant positive influences, while IVC has a coefficient of 0.84, indicating a weaker positive impact compared to CC Depth and CPP.

Table 1. Method for Calculating the ETCO2

Calculating ETCO2

R-Squared

Global CO2 Maximum per breath

0.67

Average of CO2 Maxima

0.64

CO2 Maximum of Last Compression

0.36

Table 2. Variable Coefficients

Outcomes

Regression Coefficients

CPP

2.05

IVC

0.84

CC Depth

3.67

CC Rate

-0.02

Epoch Number

-0.57

Conclusions:
The experimental results show that the global CO2 maximum per breath has the closest relationship to the hemodynamics in this experiment. The analysis suggests that increasing CC Depth, CPP, and IVC flow also increases the calculated ETCO2.
Abstract Sa607: Automated Analysis of Arterial Waveforms and Diastolic Blood Pressure During Cardiopulmonary Resuscitation in a Swine Cardiac Arrest Model
Authors: Sharpe Zachary , Greer Nicholas , Hsu Cindy , Tiba Mohamad
Published: November 2024

Introduction:
Invasive arterial blood pressure can help optimize cardiopulmonary resuscitation due to the relationship of diastolic blood pressure with coronary perfusion pressure. The expulsion of blood from the thoracic cavity during chest compressions can result in retrograde blood flow during decompression causing incorrect extraction of diastolic pressure by monitors. To address this challenge, we evaluated several neural networks for automated extraction of diastolic blood pressure in swine cardiac arrest models.

Methods:
Fifty-two Yorkshire swine were anesthetized, instrumented, and subjected to 5 or 10 minutes of ventricular fibrillation or sham intervention. Cardiac arrest animals were resuscitated with mechanical chest compression and defibrillations, then monitored for 24 hours after return of spontaneous circulation. Systolic and diastolic locations were labeled for twenty seconds of data at each minute of resuscitation and each hour of monitoring. Several neural networks used in similar applications including ECG peak detection were built with Python’s TensorFlow library. A 70% train-test split was performed, and 5-fold cross validation was used to determine optimal hyperparameters. Models were evaluated on the final test set using F1 score.

Results:
The four models had similar performance on systolic peak detection with mean (SD) F1 scores of 0.99 (0.002) and 0.98 (0.002) for compression and non-compression waveforms respectively. The diastolic detection task was more difficult, with non-compression diastolic detection F1 score at 0.96 (0.006) and compression detection F1 score of 0.91 (0.01). Model size had a negligible relationship with F1 score. Compatible models were converted to the smaller TensorFlow Lite format and showed no drop in effectiveness despite a large reduction in memory requirement.

Conclusion:
Small models performed similarly to larger ones while requiring less memory. These models will allow easy analysis of compression effectiveness in cardiac arrest and are small enough to be integrated into a microcomputer onboard a portable monitor, enabling real-time resuscitation feedback. Additional data will be integrated into models, along with evaluation on human-derived waveform data.
Abstract Sa701: Sex disparities in receipt of bystander-initiated cardiopulmonary resuscitation and associated time measures
Authors: Blewer Audrey , Krychtiuk Konstantin , Yonis Harman , Starks Monique , B. Bosworth Hayden , Malta Hansen Carolina , Powell Stephen , Monk Lisa , Kaltenbach Lisa , Al-Khalidi Hussein , Vandeventer Steve , McNally Bryan , Al-Khatib Sana M. , Mark Daniel , Granger Christopher
Published: November 2024

Introduction:
Female sex is associated with lower rates of bystander cardiopulmonary resuscitation (B-CPR) in public. Telecommunicator CPR (T-CPR), or provision of CPR instructions when individuals call 9-1-1, is essential to improving B-CPR. Few investigations have examined how T-CPR impacts this known sex difference in receipt of B-CPR.

Objectives:
We sought to examine sex disparities in receipt of B-CPR and time measures with provision of T-CPR. We hypothesized that with provision of T-CPR instruction, there would be no sex disparity in the receipt of B-CPR.

Methods:
We conducted a retrospective cohort study of adult, non-traumatic out-of-hospital cardiac arrests (OHCA) from the North Carolina (NC) RACE-CARS trial (
NCT04660526)
dispatch module. We examined differences between males and females in receipt of B-CPR (primary outcome) and time measures (secondary outcomes), including time to recognition and time to first compression (secs). Between-group comparisons were assessed using the Pearson’s Chi-square or Fisher’s exact test for categorical variables and the Wilcoxon rank-sum test for continuous variables.

Results:
From 7/2022-12/2023, RACE-CARS collected data on 8,839 OHCAs covering 52 counties in NC. After excluding pediatric, traumatic, EMS-witnessed, and healthcare facility arrests there were 2,398 OHCAs. Median (25
th
, 75
th
percentiles) age was 63 (49-74), 67% were White, and 37% were female. B-CPR was administered in 52% of the OHCAs (81% with telecommunicator assistance vs. 19% without). When the telecommunicator provided assistance vs when they did not, B-CPR was 44% vs. 9% for female patients and 40% vs. 11% for male patients; these sex differences were not statistically significant (p=ns). Median time to CPR recognition from call received (secs) was 87 (50-149) for females vs. 87 (53-160) for males. Median time to first compression from telecommunicator call to call received (secs) was 204 (147-275) for females vs. 207 (145-281) for males (p=ns).

Conclusion:
Telecommunicator CPR may potentially attenuate the known sex disparity in receipt of B-CPR. Understanding this may help inform future health policy and advocacy for prehospital systems of care. Future work may examine how T-CPR decreases sex variation and increases B-CPR especially in women.
Abstract Sa805: Diastolic Blood Pressure Response to Sodium Bicarbonate Administration in Pediatric In-Hospital Cardiac Arrest
Authors: Sorcher Jill , Duster Nicole , Kleinman Monica , Ross Catherine
Published: November 2024

Background:
Despite national guidelines recommending against its routine use, sodium bicarbonate (SB) is administered in approximately 50% of pediatric in-hospital cardiac arrests (p-IHCA). This may partially be explained by the commonly held belief that SB administration increases extracellular pH and mitigates myocardial depression associated with intra-arrest acidosis. However, physiologic response to SB during p-IHCA has not been previously described and may provide insight for its use during cardiopulmonary resuscitation (CPR).

Aim:
To explore diastolic blood pressure (DBP) response to SB administration during p-IHCA.

Hypothesis:
We hypothesized that SB administration would be associated with increased DBP.

Methods:
Retrospective single center study of patients ≤ 18 years old who experienced pulseless IHCA and received intra-arrest SB with an arterial line present from 2013 to 2023. Events in which epinephrine was given in the same minute as the first dose of SB were excluded. Events were divided into 30-second epochs for which the average DBP was calculated using stored monitor data. The 30-second epoch prior to the minute of SB administration was used as the baseline. The primary outcome was the change in DBP one minute post-SB administration, defined as the average of the 2 epochs
after
the full minute of SB administration. We also performed a sensitivity analysis, expanding the post-SB period as the 4 epochs (2 minutes) after SB administration for patients with ongoing CPR and without epinephrine administration in the interim period. Change in DBP was compared using a paired t-test.

Results:
In the 32 events included, the mean DBP 1minute post-SB administration significantly increased from 39.2 mmHg to 42.7 mmHg (mean difference 3.5, 95% CI: 0.4, 6.6,
p
= 0.03). Sensitivity analysis (n=24) at 2 minutes post-SB administration showed a change in mean DBP from 41.2 mmHg to 43.5 mmHg (mean difference 2.3 mmHg, 95% CI: -0.8, 5.05
p
= 0.13).

Conclusions:
SB administration during p-IHCA was associated with a significant increase in DBP 1 minute post-SB, but the increase in DBP did not reach statistical significance when averaged over 2 minutes post-SB. Given known associations between DBP and outcomes in p-IHCA, these results support the need for further investigation of physiologic response and clinical outcomes associated with intra-arrest SB administration.
Abstract Sa904: Relationship between time of occurrence and survival of in-hospital cardiac arrests triggered by medical adverse events(Nationwide medical adverse events database in Japan)
Authors: Kanayama Yu , Kiguchi Takeyuki , Nakai Chinatsu , Hamai Yasutaka , Nishiyama Chika , Nitta Masahiko , Norii Tatsuya , Iwami Taku
Published: November 2024

Background:
The outcome of in-hospital cardiac arrest (IHCA) has improved over the past decade, although the survival rate is still approximately 25%. Some cases of IHCA are triggered by medical adverse events, and their outcomes might be different by time when how many staffs is available. But the relationship between the time of occurrence and outcome remains unclear. The aim of this study is to compare the survival outcomes of IHCA at night with those during the daytime using the nationwide medical adverse events database in Japan.

Methods:
We searched the Japan Council for Quality Health Care nationwide in-hospital adverse events database, which registered 1 million cases per year, from 2010 to 2023. We extracted cases of IHCA and analyzed the cases by time of occurrence, grouping them into day time shift (8am-4pm), midnight shift (4pm-0am), and late night shift (0am-8am). The primary outcome was survival to discharge, and we performed multivariate logistic regression to adjust for age, sex, holiday, cause of medical adverse events, event location, occupation of the involved party, occupational history of the involved party and assignment period of the involved party as potential confounders.

Result:
A total of 4,252 cases were included during the study period. The most common age group was over 70years old (54.2%, n = 2,303 /4,252). 2,627 patients (61.8%) were male. The number of IHCA per time period was 1949 (45.8%) in the day time shift, 1,349 (31.7%) in the midnight shift and 954 (22.4%) in the late night shift. The most common cause of medical adverse events in all time periods was treatment or procedures. However, the rate of medical care was higher in the late night shift. Regarding the location of the event, the general ward was the most common location at all times. Multivariate logistic regression for survival on discharge yielded an adjusted odds ratio of 1.56 (95% confidence interval [CI]: 1.30–1.86) ,1.33 (95% CI: 1.11–1.59) for the day time shift and midnight shift compared to the late night shift.

Conclusion:
Approximately 20% of in-hospital cardiac arrests due to medical adverse events occurred on the late night shift, with poor outcomes. Time of occurrence was associated with survival to discharge among IHCA cases that were identified in the nation-wide adverse events database.
Abstract Su1003: Prospective Assessment of Myocardial Function&Systemic Inflammation after Pediatric Cardiac Arrest: Results from a Pilot Study Utilizing Echocardiogram&Circulating Plasma Biomarkers
Authors: Gardner Monique , McKelvey Alanah , Wang Yan , Chen Fang , Morgan Ryan , Graham Kathryn , Berg Robert , Mercer-Rosa Laura , Yehya Nadir , Topjian Alexis
Published: November 2024

Background:
Myocardial function and systemic inflammation and their impact on outcomes after pediatric cardiac arrest is understudied. We aimed to prospectively evaluate the association of early myocardial dysfunction and systemic inflammation with hospital mortality. We also sought to identify correlations between arrest characteristics and outcomes with echocardiographic myocardial function and circulating inflammatory biomarkers to inform future study design. We hypothesized that worse myocardial function and higher levels of inflammation would be associated with hospital mortality.

Methods:
We prospectively enrolled children <18 who received CPR
>
1 minute after in- or out-of-hospital cardiac arrest and were admitted to an intensive care unit. We excluded subjects on extracorporeal life support, or within 7 days of bypass. We obtained echocardiograms for global longitudinal and circumferential strain (GLS, GCS) and blood samples for measure of 15 biomarkers within 36 hours of arrest. Clinical data, GLS and GCS, and log-transformed biomarker levels were compared between non-survivors and survivors. Correlations between variables was made with Spearman rho coefficients (ρ). Univariate logistic regression tested the associations between exposures and hospital mortality. In this pilot, p<0.1 was deemed significant for future study.

Results:
We included 38 subjects with echocardiography; 20 of which had blood samples. Median age was 2.5 years (IQR 0.8-7.1); 57% (n=23) had out-of-hospital arrests and median CPR duration was 10 minutes (IQR 3.5-16.1). Ten subjects (26%) died prior to hospital discharge. GLS (OR 0.98, p=0.72) and GCS (OR 0.92, p=0.22) were not associated with mortality, while MMP-1 (OR 1.67, p=0.09) and IL-8 (OR 2.7, p=0.08) suggested association with mortality. CPR duration was not associated with GLS and GCS but was moderately correlated with MMP-1 (ρ=0.41) and ST2 (ρ=0.51). CXCL10 and TNFa (ρ=0.74), IL-10 and TNFa (ρ=0.70), IL-10 and CXCL10 (ρ=0.83), sRAGE and IL-6 (ρ=0.72) were strongly correlated. MMP-1 and IL-8 (ρ=0.75) and MMP-9 and ST2 were strongly inversely correlated (ρ=-0.72).

Conclusion:
This pilot study found preliminary associations between inflammatory biomarkers, including including MMP-1 and IL-18, and hospital mortality, but not between echocardiographic function and morality. Larger studies will further investigate the association of myocardial dysfunction and inflammation with pediatric post-cardiac arrest outcomes.
Abstract Su107: The Role of TRPV2 Ion Channel in NAMPT Secretion During Cardiac Arrest
Authors: Zhu Xiangdong , Li Jing , Lin Shaoxia , Vanden Hoek Terry
Published: November 2024

Introduction:
Extracellular NAMPT functions as a novel damage-associated molecular pattern. It has been shown to be released from many cell types including neutrophils and cardiomyocytes. In a mouse model of cardiac arrest, increased plasma NAMPT correlates with inflammation, cardiovascular dysfunction and poor survival, and neutrophils are the major contributor to plasma NAMPT during cardiac arrest. However, the mechanisms of NAMPT release are currently not well understood.

Hypothesis:
We hypothesize that NAMPT release is regulated by a non-selective cation channel TRPV2.

Methods:
Human blood neutrophils were isolated by Percoll density gradient. TRPV2 channel activity was measured by calcium influx using Furo-4. The effect of TRPV2 agonist and inhibitor on the intracellular free Ca
2+
flux was performed by monitoring fluorometric kinetic readings. Extracellular NAMPT concentration in cell supernatants was measured by ELISA.

Results:
NAMPT release is affected by extracellular pH. The decrease in pHo from 7.4 to 7.0 significantly reduced the amount of eNAMPT from 8.31 ± 0.3 ng/ml to 1.72 ± 0.4 ng/ml. By contrast, the increase of the pHo from 7.4 to 7.8 enhanced NAMPT secretion into supernatant from 8.31 ± 0.3 ng/ml to 12.04 ± 0.3 ng/ml. We therefore reasoned that ion channels sensitive to pH change might play a role in NAMPT secretion. Several transient receptor potential (TRP) channels are exquisitely sensitive to extracellular pH. Calcium chelator EGTA at 1 mM completely blocked NAMPT release, which indicates a calcium channel is involved. 2-aminoethoxydiphenyl borate (2-APB) has been shown to stimulate many TRPV channels. 2-APB increased NAMPT release in a dose-dependent manner, and maximal release was induced by 1 mM 2-APB. Tranilast and piperlongumine, two structurally unrelated TRPV2 antagonists, significantly inhibited NAMPT release from neutrophils. By contrast, neither TRPV1 inhibitor SB366791 nor TRPV4 inhibitor GSK219384 has any effect on NAMPT release. Furthermore, TRPV2 inhibitors tranilast and piperlongumine blocked calcium influx induced by 2-APB.

Conclusion:
NAMPT release from neutrophils is regulated by TRPV2 channel-mediated calcium influx.
A Proteomics-Based Approach for Prediction of Different Cardiovascular Diseases and Dementia
Authors: Ho Frederick K. , Mark Patrick B. , Lees Jennifer S. , Pell Jill P. , Strawbridge Rona J. , Kimenai Dorien M. , Mills Nicholas L. , Woodward Mark , McMurray John J.V. , Sattar Naveed , Welsh Paul
Published: November 2024

BACKGROUND:

Many studies have explored whether individual plasma protein biomarkers improve cardiovascular disease risk prediction. We sought to investigate the use of a plasma proteomics-based approach in predicting different cardiovascular outcomes.

METHODS:

Among 51 859 UK Biobank participants (mean age, 56.7 years; 45.5% male) without cardiovascular disease and with proteomics measurements, we examined the primary composite outcome of fatal and nonfatal coronary heart disease, stroke, or heart failure (major adverse cardiovascular events), as well as additional secondary cardiovascular outcomes. An exposome-wide association study was conducted using relative protein concentrations, adjusted for a range of classic, demographic, and lifestyle risk factors. A prediction model using only age, sex, and protein markers (protein model) was developed using a least absolute shrinkage and selection operator–regularized approach (derivation: 80% of cohort) and validated using split-sample testing (20% of cohort). Their performance was assessed by comparing calibration, net reclassification index, and
c
statistic with the PREVENT (Predicting Risk of CVD Events) risk score.

RESULTS:

Over a median 13.6 years of follow-up, 4857 participants experienced first major adverse cardiovascular events. After adjustment, the proteins most strongly associated with major adverse cardiovascular events included NT-proBNP (N-terminal pro B-type natriuretic peptide; hazard ratio [HR], 1.68 per SD increase), proADM (pro-adrenomedullin; HR, 1.60), GDF-15 (growth differentiation factor-15; HR, 1.47), WFDC2 (WAP four-disulfide core domain protein 2; HR, 1.46), and IGFBP4 (insulin-like growth factor-binding protein 4; HR, 1.41). In total, 222 separate proteins were predictors of all outcomes of interest in the protein model, and 86 were selected for the primary outcome specifically. In the validation cohort, compared with the PREVENT risk factor model, the protein model improved net reclassification (net reclassification index +0.09), and
c
statistic (+0.051) for major adverse cardiovascular events. The protein model also improved the prediction of other outcomes, including ASCVD (
c
statistic +0.035), myocardial infarction (+0.023), stroke (+0.024), aortic stenosis (+0.015), heart failure (+0.060), abdominal aortic aneurysm (+0.024), and dementia (+0.068).

CONCLUSIONS:

Measurement of targeted protein biomarkers produced superior prediction of aggregated and disaggregated cardiovascular events. This study represents proof of concept for the application of targeted proteomics in predicting a range of cardiovascular outcomes.
Unipolar Voltage Mapping to Predict Recovery of Left Ventricular Ejection Fraction in Patients With Recent-Onset Nonischemic Cardiomyopathy
Authors: Chaumont Corentin , Peyster Eliot G. , Siontis Konstantinos C. , Muser Daniele , Kapa Suraj , Markman Timothy M. , Pathak Rajeev K. , Oraii Alireza , Rodriguez-Queralto Oriol , Anselme Frederic , Margulies Kenneth B. , Marchlinski Francis E. , Frankel David S.
Published: November 2024

BACKGROUND:

The ability to predict recovery of left ventricular ejection fraction (LVEF) in response to guideline-directed therapy among patients with nonischemic cardiomyopathy is desired. We sought to determine whether left ventricular endocardial unipolar voltage measured during invasive electroanatomic mapping could be used to predict LVEF recovery among those with recent-onset nonischemic cardiomyopathy.

METHODS:

We analyzed the left ventricular voltage maps of patients included in the eMAP trial (Electrogram-Guided Myocardial Advanced Phenotyping; NCT03293381), a prospective, nonrandomized, interventional trial conducted at 2 institutions between 2017 and 2020. Patients had recent-onset nonischemic cardiomyopathy defined by LVEF ≤45% and development of symptoms or signs of heart failure within the past 6 months. Detailed voltage maps of the left ventricular endocardium were generated using the Carto electroanatomic mapping system. Abnormal unipolar amplitude was defined as <8.27 mV. The primary end point was recovery of LVEF (Recovery) defined by a 1-year LVEF ≥50% or ≥45% with ≥10% increase from baseline.

RESULTS:

Of the 29 enrolled patients (median age, 49 years [25th percentile, 39; 75th percentile, 59], 8 females [27.6%]), LVEF recovered in 13 (44.8%) by 1-year follow-up. The percentage of total endocardial surface area with unipolar voltage abnormality (AUA) was significantly lower among Recovery patients than No Recovery patients (18.2% [25th percentile, 6.4; 75th percentile, 22.4] versus 80.0% [25th percentile, 29.5; 75th percentile, 90.9];
P
=0.004). Percent AUA was associated with lower likelihood of Recovery (odds ratio, 0.64 per 10% increase in AUA; 95% CI, 0.47–0.88;
P
=0.006). A 28% cutoff value for percent AUA was 92% sensitive and 75% specific with an area under the receiver operating characteristic curve of 0.81 (95% CI, 0.63–0.99;
P
=0.001) for predicting recovery versus no recovery. The majority of patients (12 of 13; 92.3%) with a percent AUA >28% did not recover.

CONCLUSIONS:

Left ventricular unipolar voltage abnormality is a potent predictor of LVEF recovery among patients recently diagnosed with nonischemic cardiomyopathy. Detailed left ventricular unipolar voltage mapping could therefore be used as a valuable prognostic tool in guiding treatment decisions.
Left Ventricular Hypertrophy in Women With a History of Preeclampsia
Authors: Hauge Maria G. , Damm Peter , Kofoed Klaus F. , Møller Emma Louise Ries , Lopez Andrea G. , Ersbøll Anne S. , Johansen Marianne , Sigvardsen Per E. , Pham Michael H.C. , Goetze Jens P. , Fuchs Andreas , Kühl Jørgen T. , Nordestgaard Børge G. , Køber Lars V. , Gustafsson Finn , Linde Jesper J.
Published: November 2024

BACKGROUND:

As a hypertensive disorder of pregnancy, preeclampsia is associated with increased cardiovascular morbidity and mortality later in life. Since early signs of myocardial affection could indicate a higher risk of future cardiovascular disease manifestations, we investigated whether women with prior preeclampsia have a higher prevalence of left ventricular hypertrophy compared with women from the general population and to what extent chronic hypertension affects any potential difference.

METHODS:

In a cohort study, women aged 40 to 55 years with prior preeclampsia were compared with age- and parity-matched women from the general population. They underwent a research cardiac computed tomography, and the primary outcome was left ventricular hypertrophy, defined as a left ventricular mass index >30 g/m
2.7
.

RESULTS:

In 679 women with prior preeclampsia and 672 controls (median age, 47 years), we found a higher prevalence of left ventricular hypertrophy (14.0% versus 6.4%) in the preeclampsia group with an odds ratio of 1.62, 95% CI (1.07–2.46),
P
=0.024, median of 15 years (range, 0–28) after pregnancy, after adjustment for cardiovascular risk factors, including chronic hypertension. Left ventricular hypertrophy was more frequent among women with preeclampsia with (26.2% versus 15.6%) and without (5.5% versus 2.4%) chronic hypertension, and a mediation analysis showed that chronic hypertension explained 22% of the association between preeclampsia and left ventricular hypertrophy.

CONCLUSIONS:

Women with prior preeclampsia had a 2-fold higher prevalence of left ventricular hypertrophy compared with women from the general population, and preeclampsia was independently associated with left ventricular hypertrophy, regardless of the presence of cardiovascular risk factors, including chronic hypertension.

REGISTRATION:

URL:
https://www.clinicalTrials.gov
; Unique identifier: NCT03949829.