bluuebunny/crossref_metadata_2025 huggingface dataset:
Abstract 18367: High Density Lipoprotein Independently Modulates Insulin Sensitivity and Secretion During Acute Phase of Myocardial Infarction
Authors: Carvalho Luiz Sérgio F , Cintra Riobaldo M , Araújo Ana Laura R , Moura Filipe A , Quináglia e Silva José Carlos , Coelho Otávio R , Sposito Andrei C
Published: April 2024

During myocardial infarction (MI), a transient decrease of both insulin sensitivity and secretion triggers stress hyperglycemia which is followed by a substantial increase in mortality. Recent data indicate that HDL modulates insulin sensitivity and secretion. To date, however the role of HDL on stress hyperglycemia remains unknown. We explored the influence of HDL on stress hyperglycemia during acute phase of MI. Consecutive non-diabetic patients with ST-elevation MI (n=183) were selected from the Brasilia Heart Study for this investigation. Blood glucose and plasma insulin and C-peptide were measured in the first 24 hours and at the fifth day after MI onset. Patients were divided into HDL-C quartiles for the analyses (Q1:<31, Q2:31-38, Q3:38-47 and Q4:>47 mg/dL). On admission, no difference was found between the quartiles in blood glucose (p=0.6), plasma insulin (p=0.6), plasma C-peptide (p=0.5), HOMA2S (p=0.9) and HOMA2B (p=1.0). On the fifth day there was a reduction in blood glucose whose intensity was directly proportional to HDL-C quartile (-1±32, -13±46, -19±25, -27±21; respectively, p<0.001). In parallel, there was a reduction in plasma insulin [-7.1(-25,1), -5.5(-22,-1), -9.9(-26,-1), -17.7(-32,-9); respectively, p<0.001] and C-peptide [0(-3,1), -1.2(-3,1), -1.7(-3,0), -2.4(-4,0); respectively, p<0.001] whose magnitude was inversely proportional to HDL-C quartile. Consistently, the change in HOMA2S [1(-11,15), 7(-15,17), 10(-5,30), 15(-8,28); respectively, p<0.001] and HOMA2B [-11(-43,31), 16(-45,48), 22(-8,44), 24(-23,61); respectively, p=0.01] and disposition index (DI) [159(-1693,1988), 1104(-1561,3329), 2444(1099,3899), 2447(1052,4856); respectively, p<0.001] were also proportional to HDL-C quartiles. Furthermore, in a multivariate analysis model, HDL-C levels were positively and independently associated with a higher change in DI (B=0.068; Exp(B)=1.071; p<0.001). This study provides the first evidence that patients with higher HDL plasma levels may be more protected against stress hyperglycemia during MI via acceleration of the improvement in insulin secretion and sensitivity.
Abstract 18369: Cholesteryl Ester Transfer Protein Activity is Associated with Oxidative Stress Markers During Acute Phase of Myocardial Infarction
Authors: Carvalho Luiz Sérgio F , Panzoldo Natália B , de Faria Eliana C , Sposito Andrei C
Published: April 2024

Cholesteryl ester transfer protein (CETP) action enriches HDL particles with triglycerides, depletes HDL by cholesterol esters, consequently reducing size of HDL and increasing catabolism of apolipoprotein AI (Apo AI). The HDL phenotype induced by enhanced CETP activity is considered pro-atherogenic. But recent findings have linked increased CETP activity in sepsis-related acute stress to reduced inflammatory response and there is no information regarding CETP activity impact in acute coronary syndromes (ACS). We evaluated the association between CETP activity and oxidative stress and inflammatory response in patients with myocardial infaction (MI). Consecutive patients (n=38) with ST-elevation MI (STEMI) were selected from the Brasilia Heart Study for this investigation. Plasma CETP activity, HDL cholesterol, triglycerides, C-reactive protein (CRP), interleukin-2 (IL2), interleukin-10 (IL10), tumor necrosis factor α (TNFα) and isoprostane (iso-PGF
2α
) levels were measured in the first 24 hours and at the fifth day after MI onset. Patients were divided in two groups, according to CETP median (6 nmol/mL/h) at admission: M1 (CETP
activity
≤ median) and M2 (CETP
activity
> median). On admission, no difference was found between the groups in plasma HDLc (p=0.5), triglycerides (p=0.1), CRP (p=0.5), IL2 (p=0.9), IL10 (p=0.6), TNFα (p=0.2) and isoprostane (p=0.7) levels. On fifth day, both groups experienced similar reductions in CETP activity [M1: -38%(-100;30); M2: -43% (-75;8); p=0.303]. On an analysis of the change between admission and fifth day, there was a major increase in triglycerides (p<0.01) in M2 group [11% (-18;32)] against M1 [3.3% (-49;16)], and also a major increase in isoprostane (p<0.01) in M2 [9.1% (-30;74)] versus M1 [5.7% (-20;37)]. However, there was no significant change in HDLc (p=0.2), CRP (p=0.5), TNFα (p=0.2), IL2 (p=0.1), IL10 (p=0.9) levels between M1 and M2 groups. This is the first study that observed a marked reduction in CETP activity following STEMI. And also, the findings indicate that higher CETP activity at admission is associated with increased triglycerides and isoprostane, a marker of oxidative stress. Such information contributes for the understanding of CETP role during acute phase of ACS.
Abstract 188: Arterial Oxygen Saturation May Be the Limiting Factor for O
2
Delivery During Compression-Only CPR
Authors: Li Qian , Chitilian Hovig , Liu Yanhong , Kacmarek Robert M , Jiang Yandong
Published: April 2024

Background
Previous studies show that there is no difference in outcomes between bystander conventional and chest-compression-only (CCO) CPR. However, several points need to be addressed: 1) the equivalent, but low, survival rate indicates that there is much room for improvement. The question is whether effective ventilation can be achieved during CPR regardless of approach. 2) the subgroup of patients whose cardiac arrest was not of cardiac origin did not sustain any benefit from ventilation. This finding would imply that adequate ventilation was not achieved. Because cardiac output (CO) generated by chest-compression is low, O
2
delivery (DO
2
) is mainly dependent on arterial O
2
content. We hypothesize that DO
2
is the rate limiting factor and improvement in DO
2
is mainly determined by O
2
content of arterial blood, since CO is at best only 1/3 of the normal value.

Methods
We modeled DO
2
in a range of 0 to critical DO
2
(8.2 ml/kg/min) at variable CO and O
2
contents of arterial blood. We assumed a 70kg patient with a hemoglobin level (Hb) of 15g/dl. Arterial O
2
Content (ml/L) = Hb × Arterial O
2
Saturation × 1.34 ×10. DO
2
(ml/min) = Arterial O
2
Content (ml/L) × CO (L/min).

Result
The half-critical DO
2
at arterial blood O
2
saturation of 80% can be achieved with CO of 1.8L/min. While to achieve the same level of DO
2
at O
2
saturation 40%, require CO of 3.6 L/min. Critical O
2
delivery and half-critical DO
2
are represented with horizontal yellow and red lines respectively. The vertical mahogany and blue lines represent the CO where half-critical delivery at O
2
saturations of 80% and 40%, respectively.

Conclusion
Since the CO obtained with chest compression is at best 1/3 of the normal value; to reach half-critical O
2
delivery requires an O
2
saturation of 80%. CCO seems unlikely to produce O
2
saturation greater than 80%. Therefore, effective ventilation during CPR is essential. Further study is needed to demonstrate whether confirmed adequate ventilation improves outcome during CPR.
Abstract 201: Specific Metabolic Pathways Involved in Outcome of Cardiopulmonary Resuscitation: A Pilot Plasma Metabolomic Study in a Rat Model of Cardiac Arrest and CPR
Authors: Brunelli Laura , Fumagalli Francesca , Bagnati Renzo , Pastorelli Roberta , Latini Roberto , Ristagno Giuseppe
Published: April 2024

Introduction.
The mechanisms responsible for postresuscitation myocardial and cerebral dysfunction are not well understood. We hypothesized that untargeted plasma metabolomic analyses would be a feasible approach to identify perturbations in circulating metabolites and thus potential mechanisms accounting for outcome of cardiac arrest (CA).

Methods.
Six male rats, 440 ± 50 g, were used. Ventricular fibrillation was induced in 3 rats and was untreated for 6 mins. CPR, including mechanical chest compressions, ventilations and epinephrine, was then initiated and continued for additional 6 mins prior to defibrillation. Two hrs following resuscitation, animals were sacrificed and plasma collected. The other 3 rats were not subjected to cardiac arrest and served as controls. Plasma metabolome was examined by liquid chromatography-tandem mass spectrometry. Differences in chromatogram profiles were then analyzed using SIEVE v1.3 analysis software. Chromatographic peaks, with accurate masses, retention time and tandem mass fragmentation patterns were then identified using mass-spectral libraries of metabolites.

Results.
A total of 523 chromatographic peaks showed significant differences after CA. Changes in metabolites participating in purine/pyrimidine metabolism, glycolisis, TCA cycle, pentose phosphate pathways, cholesterols and derivatives, lipids, and fatty acid oxidation, were observed. Changes in long-chain acylcarnitine and corticosterone/cortisol levels were also found, suggesting oxidative damages and deregulation of hypothalamic-pituitary-adrenal axis, respectively. More importantly, numerous metabolites along the kynurenine pathway from tryptophan oxidation, typically related to neurological degeneration, were identified (Figure).

Conclusions.
In this pilot study, plasma metabolomics allowed for identification of specific metabolic pathways, i.e. tryptophan pathway, that ultimately may contribute to CA outcome.
Abstract 208: Achieving the 2010 AHA Guideline Metrics for CPR Quality Is Associated with Improved Survival from Out-of-Hospital Cardiac Arrest
Authors: Bobrow Bentley J , Spaite Daniel W , Stolz Uwe , Panchal Ashish R , Vadeboncoeur Tyler F , Silver Annemarie , Pyers Keith , Venuti Mark , Smith Gary , Ewy Gordon A ,   SHARE Rsch Group
Published: April 2024

Objective:
The 2010 AHA Guidelines stress the need for minimally interrupted, high quality CPR. We performed a prospective, before/after trial to determine if real-time audiovisual feedback (RTAVF) along with scenario-based training (SBT) would 1) achieve the 2010 CPR targets and 2) improve survival from OHCA.

Methods:
Data obtained from EMS care forms and defibrillators (E Series, ZOLL) from 2 EMS agencies (population base-500,000). Phase 1 (P1, before): 18 months of baseline data with the RTAVF mode disabled (9/08-3/10).

Interventions:
1) Guideline-based SBT of ~450 EMTs, 2) RTAVF enabled, 3) EMT post-code debriefings. Phase 2 (P2, after): 8 months following implementation of interventions (5/10-12/10). For univariate analyses we used Fisher's exact test (proportions), t-test (means) or Kruskal-Wallis test (medians). To estimate odds ratios for survival to hospital discharge we used multivariable logistic regression and assessed final model diagnostics, fit, and discrimination.

Results:
The final analysis included 284 adult OHCAs (P1-176, P2-108). Mean age 65.4 years (SD ± 15.3) with 66.6% males. Quality measures improved significantly from P1 to P2: Median (Interquartile range) chest compression (CC) rate-121 CC/min (109-135) to 101 CC/min (100-106), p <0.001; CC depth-1.73 in. (1.42-1.97) to 2.09 in. (1.92-2.3), p <0.001; CC fraction-66.5% (59.3-75.9%) to 84.0% (77.8-88.7%), p <0.001. All-rhythms survival increased significantly (p=0.034) from P1 to P2 (18/176, 10.2% vs. 23/108, 19.4%), an absolute survival increase of 9.2% (95% CI: 0.5%-17.9%). Crude odds ratio for survival for P2 vs. P1 was 2.1 (95% CI: 1.1-4.2) and adjusted odds ratio was 5.8 (95% CI: 1.8-18.9), after controlling for confounders including age, sex, location, witnessed arrest, initial rhythm, and therapeutic hypothermia. Survival for arrests with a shockable rhythm was 27.7% (18/65) for P1 and 53.9% (14/26) for P2 (p=0.028).

Conclusion:
RTAVF combined with SBT was associated with a significant improvement in the proportion of compressions meeting the 2010 AHA Guidelines. This intervention was associated with a 90% relative increase in overall survival. We believe this is the first report to show an improvement in OHCA survival by achieving the 2010 AHA CPR Guidelines.
Abstract 215: Does the Relation of CPR Performer to Victim Affect Survival of Out-of-Hospital Cardiac Arrest?
Authors: Inaba Hideo , Tanaka Yoshio , Nishi Daiki , Takei Yutaka , Enami Miki , Goto Yoshikazu
Published: April 2024

Backgrounds and Aim
Early cardiopulmonary resuscitation (CPR) with a considerable quality is essential for survival of out-of-hospital cardiac arrests (OHCAs). The present study was conducted to test our hypothesis that relation of CPR performer to cardiac arrest victim may affect the survival of out-of-hospital cardiac arrests (OHCAs).

Methods
Data from
2068
OHCAs with CPR before emergency medical technician arrival, that occurred at other locations than care facilities from April, 2003 to March, 2010 in Ishikawa prefecture, were prospectively collected and analyzed. The performers of CPR were categorized into 4 groups; family and relatives, friends, strangers and healthcare providers. The backgrounds, characteristics and outcomes of OHCAs were compared among the 4 groups and between family and other 3 or 2 groups.

Results
(see Table) Family and relatives were less frequently the CPR performers in witnessed OHCAs, and were more frequently the CPR performers in OHCAs that occurred at home. They more frequently initiate the CPR following telephone-CPR and perform chest compression-only CPR. When analyzed collectively for all OHCAs, family member or relative as a CPR performer was associated with poor outcomes. When analyzed for subgroups of OHCAs, the effects of relations to victim were significant only for unwitnessed OHCAs and the OHCAs that occurred at other locations than home. Critical time factors related to survival did not significantly differ among or between the groups. Multiple logistic regression analysis for OHCAs that occurred at other locations than home, but not for all OHCAs, disclosed that family member or relative as a CPR performer is an independent factor associated with 1-Y survival.

Conclusions
The relations to victims dependently affect the outcomes of OHCAs. Although the quality of CPR was not determined in this study, this observation should be considered to plan a better strategy for improving the quality of CPR and outcomes of OHCAs.
Abstract 217: Quality of CPR Performed on a Mattress Can Be Improved with a Novel CPR Feedback Device
Authors: Banville Isabelle , Rose Lizabeth , O'Hearn Patty , Campbell Timothy , Nova Richard , Chapman Fred
Published: April 2024

Accelerometer-based CPR feedback devices estimate sensor movement, but cannot distinguish between compression of the chest and deflection of the underlying surface (e.g. mattress). This study aims to compare CPR quality improvement provided by feedback from an accelerometer-based device and a novel device. The novel device provides visual feedback on compression depth, based on measured changes in magnetic field strength between a backpad and a chestpad, and gives audible and visual rate guidance.

Methods:
Critical care nurses performed 2 sets of continuous chest compressions on a weighted manikin placed on a backboard on a common foam mattress and hospital bed. For “baseline”, participants did 120s of CPR with no training or feedback. After 10 minutes for rest and training on use of device feedback to do Guidelines 2010 CPR, they did 120s of compressions with feedback from the novel (MAG) or the accelerometer-based (ACC) device, as randomized. Manikin data on chest compressions were captured and analyzed (PC Skillreporting System, Laerdal).

Results:
Weight and height (73 ± 1 kg, 164 ± 6 cm, mean ± SD) of the 22 nurses (1 male) did not differ significantly between groups. For all nurses, baseline chest compression depth was 37.3 ± 9 mm and rate was 101 ± 17 min
-1
. Manikin-recorded compression depth was significantly higher in the MAG (n=11, 49.0 ± 9 mm) than the ACC group (n=11, 39.3 ± 7 mm), p=0.009. The ACC device-estimated depth (52.9 ± 8 mm) guided the feedback resulting in actual depth of 39.3 ± 7 mm. Compared to baseline, the depth was significantly higher with MAG (95% CI: [2.5, 17.3]) but not with ACC feedback (95% CI: [-3.9, 11.3]). There was a difference in compression rate (94 ± 9 vs 107 ± 10 min
-1
, p=0.005), but not duty cycle (42 ± 4 vs 44 ± 4 %, p=0.3) for MAG vs ACC.

Conclusion:
In a realistic simulation on a hospital bed, use of a novel CPR feedback technology (MAG) by nurses significantly improved their chest compression depth compared to no feedback or to accelerometer-based feedback.
Abstract 231: Blended Advanced Life Support Training: A Randomized Controlled Noninferiority Trial
Authors: Davies Robin P , Lam Jenny , Bullock Ian , Clutton-Broch Tom , Gales Mike , Lockey Andrew , Kimani Peter , Stallard Nigel , Perkins Gavin D
Published: April 2024

Introduction:
Competency in advanced life support (ALS) is a core component of health care curricula. We explored a blended solution which combines e-learning and face to face instructor training.
ISRCTN86380392

Hypothesis:
In participants seeking ALS training is a blended solution to training which uses e-learning and face to face training non-inferior to traditional (face to face) ALS training?

Methods:
We conducted an open-label, non-inferiority, randomised controlled trial. Participants seeking ALS training at 30 centres in England, Wales, Scotland and Australia were randomised to the 2 day standard ALS course or a hybrid e-learning course with 1 day face to face training (e-ALS). The primary outcome was success rate in the end of course cardiac arrest simulation test. Secondary outcomes were overall course pass rate and performance in knowledge / skill based tests. The primary analysis was intention to treat.

Results:
1033 (74%) of participants passed the cardiac arrest simulation assessment in the e-learning arm compared to 1146 (80%) in the traditional arm (adjusted odds ratio is 0.698 (95% CI is (0.559, 0.872). Within the performance criteria scores for the peri-arrest management domain the e-ALS group score was higher than c-ALS group (P < 0.0001). By contrast the management of non-shockable rhythms was less than the score of the c-ALS group (P = 0.0495). There was no significant difference in the cardiac arrest management score for shockable rhythms (P= 0.13). Performance in the pre-course MCQ (taken immediately prior to the face to face course) was marginally better in the e-ALS group (mean (SE) % score 92.44 (6.58) vs 88.27 (6.76), P<001). There was no significant difference in the end of course multiple choice knowledge or skill tests. After remedial teaching the final overall course pass rate was 94% in the e-ALS arm had passed and 96% in the conventional arm (P=0.0018). Participants' preferences marginally favoured traditional training.

Conclusion:
A blended approach to ALS training which includes e-learning reduced the duration of face to face training by half at the costs of one additional participant failing to successfully complete the course per 50 course participants.
Abstract 233: Duration of Ventilations During CPR by Lay Rescuers Does Not Interfere with Delivering Chest Compressions
Authors: Beesems Stefanie G , Wijmans Lizzy , Koster Rudolph W
Published: April 2024

Objective:
In the AHA and ERC Guidelines 2005 (G2005) and 2010 for cardiopulmonary resuscitation the importance of minimally interrupted chest compressions (cc) is emphasized. The time taken to give two breaths should not be more than 5 s to allow for a sufficient number of cc delivered. The feasibility of this recommendation for lay rescuers was questioned after manikin studies. This study aims to determine if the expected short interruption for ventilations by trained lay rescuers can be achieved in reality.

Methods:
The Arrest study is a prospective database of all out-of-hospital cardiac arrest in the province North-Holland, in the Netherlands. We used Automatic External Defibrillator (AED) recordings where the chest impedance or sternal displacement was recorded during lay rescuer CPR. We excluded ECGs with a c:v ratio of 15:2, incomplete or technical deficient ECGs. Lay rescuers had received a standard ERC BLS and AED course in the past. A ventilation period was defined as a regular interruption of cc during the CPR cycle for more then 3 s where impedance changes suggest ventilations or during ventilation prompts. The chest compression fraction (ccf) was the time of the cycle that was used for cc. We analyzed the duration of each ventilation- and cc period, as well as the number of cc and ventilations during each 2 minutes CPR cycle.

Results:
We included all 222 AED recordings from lay rescuer CPR from September 2010 until March 2011, trained according to the G2005. The median (IQR) interruption time for two ventilations was 7.4 s (5.8-9.3 s). Of all, 19.4% of rescuers took >10 seconds for a ventilation period. Of the lay rescuers 97% was able to give ≥60 cc min
-1
and 66% to give ≥80 cc min
-1
. The median ccf (IQR) was 76.7% (71.4-83.4%).

Conclusion:
For the great majority of lay rescuers it is feasible to give two rescue breaths in less than 7 s and to give at least 60 compressions per minute. Trained lay rescuers can deliver compressions and ventilate as recommended by the Guidelines.
Abstract 234: Assessment of a Newly Designed Resuscitation Trolley in a Simulated Environment
Authors: Walker Susanna , McKay Anthony , Deelchand Vashist , Gautama Sanjay , Sevdalis Nick , Vincent Charles
Published: April 2024

Introduction
In 2006, data from the UK National Reporting and Learning System (NRLS) database highlighted the fact that ill-stocked resuscitation trolleys directly led to a number of preventable deaths. Of 86 reported incidents involving resuscitation trolleys, 10 contributed to the deaths of patients. In light of this data the National Patient Safety Agency (NPSA) sponsored a redesign of the resuscitation trolley. Over the past 2 years a complex design process culminated in a new ergonomically designed “Resus:Station” prototype.

Objectives
To assess the usability and impact on teamwork of “Resus:Station” when compared with the standard resuscitation trolley in a series of simulated cardiac arrest scenarios.

Methods
15 expert Cardiac Arrest Teams comprising an Anesthesiologist, a Physician, and a Nurse were recruited (45 participants in total). Teams performed resuscitation simulations using both trolleys, with order of use randomised. All research sessions were recorded to facilitate structured debriefing. Following each simulation participants completed questionnaires scoring trolley usability, safety, effects on Resuscitation, and design on 7-point Likert scales. They also indicated their preference for trolley (Resus:Station or old trolley). Team performance was assessed from the video recordings by two trained blinded raters using a validated tool to assess quality of teamworking with each trolley, and to determine differences in efficiency of resuscitation.

Results
Strongly significant (p<0.001) differences favouring the Resus:Station over the old trolley were obtained on all user-rated aspects (usability, safety, effects on Resuscitation, and design). Quality of teamworking in the observed teams did not differ significantly between trolleys, however efficiency of the team was seen to improve when using the new Resus:Station.

Conclusions
The Resus:Station is safe to use in a simulated environment, there is no detrimental effect on team performance, some improvement in efficiency, and it is strongly preferred by clinical staff. In view of these strongly positive results, the “Resus:Station is being assessed further in a real clinical environment.
Abstract 239: Does the Performance of Emergency Medical Dispatch (EMD) Affect Survival from Out-of-Hospital Cardiac Arrests (OHCAs)? An Analysis of the Taipei Utstein Arrest Registry
Authors: Chiang Wen-Chu , Liu Yueh-Ping , Liu Shih-Hung , Ko Patrick Chow-In , Yang Chi-Wei , Wang Hui-Chih , Lee Bing-Chow , Hsiung Kuang-Hua , Hsiao Ying-Wen , Lai Mei-Shu , Ma Matthew Huei-Ming
Published: April 2024

Introduction
Dispatch-instructed bystander cardiopulmonary resuscitation (DI-CPR) was recommended by current resuscitation guidelines. The pivotal step of DI-CPR was the accurate recognition of OHCAs by interview of caller. However, previous studies showed the compliance of dispatchers in posing priority questions to identification of OHCAs is unsatisfactory. This study aimed to estimate the incremental effect on recovery of spontaneous circulation (ROSC) of OHCAs if the dispatcher could have more OHCAs recognized through a better adhesion to dispatch protocol.

Methods
Emergency medical service system of Taipei City is the first one in Taiwan to implement service of prehospital advanced life support (ALS) and to develop the database of Utstein registry to track the OHCAs. We analyzed the Taipei Utstein database to evaluate the association between bystander CPR and ROSC of OHCAs stratified by EMD performance including recognition of OHCA and instruction of CPR. Because the recognition of OHCAs was not requested in registry, we used the results of dispatched tier as surrogates. The dispatcher would send an ALS team to the scene if they succeed to alert the OHCAs by call, while only a BLS team would be dispatched if they failed to.

Results
From 2008 to 2009, there were total 3573 adult non-traumatic OHCAs registered with attempted resuscitation. Among them, bystander CPR rate and overall ROSC rate were 15.4% and 22.2% respectively. Bystander CPR was significantly associated with better ROSC even after adjustment for other variables. The bystander CPR rate was up to 25.5% in OHCAs recognized by EMD but was only 10.0% in those who did not. The association between ROSC and the performance of dispatchers were tabulated beneath.

Conclusion
Bystander CPR was one of the most important factors to survival of OHCAs in Taipei. Performance of EMD had the potential to benefit the ROSC rate of OHCA patients as long as the dispatcher could recognize more OHCAs cases.
Abstract 241: Pre- and Postshock Electrogram Features in Human VF and the Occurrence of Refibrillation
Authors: Afatmirni Elnaz , Khusa Marjan , Umapathy Karthikeyan , Masse Stephane , Nair Krishnakumar , Farid Talha , Krishnan Sridhar , Dorian Paul , Nanthakumar Kumaraswamy
Published: April 2024

Background:
During cardiac resuscitation, recurrence of VF (or refibrillation) is a common problem that could affect the survival rates. Predicting the occurrence of refibrillation by analyzing the pre-shock/post-shock waveform would enable the EMS personnel to administer anti-arrhythmic drugs that could prevent refibrillation and could help in optimizing resuscitation outcomes.

Objective:
To evaluate wavelet based features extracted from pre-shock waveform and QT interval measurements from post-shock waveform in predicting refibrillation.

Method:
The human VF database used in this study consisted of 14 successful, 7 refibrillation, and 13 unsuccessful out-of-the-hospital VF tracings extracted from the Zoll defibrillators recorded by the Toronto area EMS personnel. For the wavelet analysis (continuous wavelet transform) we used the 10s pre-shock waveforms from all the 34 cases that were not corrupted by the CPR artifacts. Wavelet features that indirectly measure signal (i.e., electrogram) complexity were extracted as features. A two stage classification was performed, in the first stage the 34 cases were classified into two classes i.e., CLASS I: 14 succ. + 7 refib. cases and CLASS II: 13 unsuccessful cases, and in the second stage the correctly classified CLASS I was further classified into succ. and refib. categories. The QT interval analysis used the first 3 beats of the post-shock waveforms of the 7 refib. cases and verified if a decrease in QT interval was observed.

Results:
For the first stage CLASS I and CLASS II categories, we obtained a classification accuracy of 76.5 % and for the second stage succ. and refib. categories, we obtained a classification accuracy of 75%. However considering only the prediction of refib., we could correctly classify 4 out of the 7 refib. cases. An automated pattern classifier was used for the pattern classification. The QT interval analysis did not yield conclusive results for this study.

Conclusions:
The pre-shock electrogram features demonstrate potential in predicting refibrillation while the post-shock electrogram features were inconclusive.
Abstract 243: Time-Dependent Benefit of Biphasic Defibrillators in Patients with Witnessed Out-of-Hospital Cardiac Arrest from VF/Pulseless VT
Authors: Nakashiro Soichi , Matoba Tetsuya , Yonemoto Naohiro , Nonogi Hiroshi , Seo Hiromi , Yokoyama Hiroyuki , Nagao Ken , Kimura Takeshi
Published: April 2024

Background:
Biphasic defibrillator is shown to be superior to monophasic one to terminate VF; however, it remains unclear whether biphasic defibrillator improves neurological outcome in patients of witnessed out-of-hospital cardiac arrest (OHCA) from shockable ventricular arrhythmia. Hence we examined that the superiority of biphasic defibrillator in association with the time from the onset to first shock in patients of witnessed OHCA.

Methods and Results:
We prospectively analyzed the data collected by Japanese official EMS at Ministry of Internal Affairs and Communications in Japan from April 1, 2006 to December 31, 2009. There were 15,040 patients of witnessed OHCA with VF or pulseless VT aged ≥18, and for whom shock was delivered within 30 minutes from the onset. We performed multivariate analysis and found that age, use of biphasic defibrillator, chest compression by bystander, and some other factors predicted better 1-month survival with Glasgow-Pittsburgh cerebral performance category 1 or 2. Shock was delivered using monophasic defibrillator in 3,242 patients (21.6%, monophasic group) and biphasic defibrillator in 11,798 patients (78.4%, biphasic group). The probability of 1-month survival with CPC 1 or 2 was higher in biphasic group than monophasic group when first shock was delivered 6 to 11 minutes after the onset (Figure, *P<0.05 by Fisher's exact test). Odds ratio (OR) for the outcome was time-dependent, and biphasic defibrillator was better when first shock was delivered at 6-10 min (OR 0.64, 95% CI 0.54-0.75) or 11-15 min (OR 0.68, 95% CI 0.56-0.82) after the onset (Figure). No significant benefit of the use of biphasic defibrillator was observed during earlier or later period.

Conclusions:
Biphasic defibrillator improved 1-month survival with favorable neurological outcome in witnessed OHCA from VF/pulseless VT. The beneficial effect was time-dependent and significant when the first shock is delivered 6 to 15 minutes after the witness.
Abstract 245: Economic Evaluation of the Wearable Cardioverter-Defibrillator in Patients After ICD Explantation
Authors: Wan Chingping , Glad Jo Ann , Bianco Nicole , Szymkiewicz Steven
Published: April 2024

Introduction
Device infection and lead failure are severe complications in implantable cardioverter defibrillator (ICD) recipients. The standard of care includes aggressive antibiotic therapy and in many cases ICD system removal, leaving patients unprotected from sudden cardiac death (SCD). Studies have demonstrated that the wearable cardioverter defibrillator (WCD) is effective in bridging patients while infections are resolved and they can have their devices re-implanted.

Hypothesis
We sought to evaluate whether WCD is cost-effective in ICD explantation patients.

Methods
We included all WCD patients whose medical orders indicated an ICD removal. Patients' compliance, shock events, outcomes, and end of use reasons were retrieved from the manufacturer database (ZOLL). Direct and indirect costs other than WCD itself, probabilities of ventricular arrhythmia and mortality were estimated from published articles. The WCD survival rate was calculated as number of saves (remain at home or conscious arrival at the ER) out of the total true shock events. Patients who finished a WCD therapy course were most often re-implanted, with some relying on standard medical therapy only. We used non-WCD patients who utilized the regular emergency medical service (EMS) as the baseline; and computed the incremental cost-effectiveness ratio (ICER) as the difference in costs divided by the difference in lives saved and life-year gained, respectively, within 5 years. Sensitivity analyses were performed to assess how the two ICERs responded as the values of variables changed. All monetary cost was converted to 2010 dollars at a 3% discount rate.

Results
A total of 3,021 patients used a WCD after an ICD explantation. The mean length of use was 45.4±58.3 days, with an average daily use of 20.35±5.8 hours (85% of the day, median=21 hours). Among those who had ended use, 56.1% got re-implanted. We estimated the first-month mortality was 2.5 times higher than the subsequent months. The calculated ICERs for WCD were $105,869 per life saved and $27,493 per life-year gained. Sensitivity analysis revealed that the ratios were not sensitive to the percentage of re-implantation.

Conclusions
The use of WCD is highly cost-effective in protecting ICD explantation patients against SCD.
Abstract 249: Primary Ventricular Fibrillation in ST-Elevation Myocardial Infarction Remains the Major Early Complication
Authors: Rosell-Ortiz Fernando , Mellado-Vergel Francisco J , Ruiz-bailén Manuel ,   EPES Working Group on Out-of-Hosp Cardiac Emergencies
Published: April 2024

Some data from in-hospital cohorts show that Primary Ventricular Fibrillation (pVF) is declining in patients with ST-Elevation Myocardial Infarction (STEMI). Our objective is to assess the current incidence, associated factors and early mortality of pVF in a pre-hospital cohort of STEMI patients.

Methods
Prospective cohort of unselected STEMI patients cared for by pre-hospital emergency teams in Andalusia. We analyzed the documented pVF episodes either as initial rhythm or as a complication before in-hospital admission. Univariate and multivariate analysis.

Results
Of 5529 patients included, 412(7.45%) had at least one pVF episode. All patients were treated, 383(92.9%) were admitted and 288(69.9%) were discharged alive. Univariate analysis: pVF patients are: younger (56.7vs64.1,p<0.0001), male (8.2% vs 5.%,p=0.001), no diabetes (4.8% vs 8.5%,p< 0.0001), no hypertension (6.2% vs 8.9%, p<0.0001), no dyslipidemia (5.7% vs 8.5%,p<0.0001), no prior myocardial infarction (5.6% vs 7.7%,p=0.04), shorter interval from onset-symptoms to call-EMS (63.6 vs 169.8,p<0.0001, median in minutes, p<0.0001), larger infarctions (≥5 leads, 7.9% vs 6.3%,p=0.03), hypotension (95.4 vs 125 mmHG,p<0.0001), higher early mortality: on scene (36,3% vs 7%,p<0.0001) and in-hospital(13.5% vs 6.6%,p<0.0001). 1-month and 1-year mortality were not associated to pVF. pVF patients received more rescue PCI (12.6% vs 7.2%,p<0.0001) but no other reperfusion treatments.

Multivariate analysis:
pVF was associated to younger patients (OR:0.978;CI 0969-0.987,p<0.0001), neither diabetes (OR:1.063;CI 1.150-2.234,p=0.005) nor dyslipidemia (OR:1.429;CI:1.091-1.872,p=0.01), hypotension (OR:0.986;CI 0983-0.989,p<0.0001), shorter interval symptoms (OR:0.998;CI:0997-0.999,p<0.0001) and early mortality (OR:2.390;CI 1.673-3.415,p<0.0001). They receive more rescue-PCI (OR:1.938;CI 1.362-2.759,p<0.0001).

Conclusions.
The incidence of pVF in STEMI remains high when testing a pre-hospital cohort. It's an early complication, in younger patients without traditional risk factors, with hypotension during the episode and with high early mortality. Nevertheless, after discharge, the prognosis is as good as in no pVF patients.
Abstract 25: Site of Cardiac Arrest: At Home and in Public Places, 2 Different Realities
Authors: Rosell-Ortiz Fernando , Mellado-Vergel Francisco J , Ruiz-Bailén Manuel ,   EPES Working Group on Out-of-Hosp Cardiac Emergencies
Published: April 2024

One of the current debates on strategies to improve survival in cardiac arrest (CA) is whether the approach must be different as it occurs at home or in a public place. Our objective was to compare survival at hospital discharge of patients resuscitated from CA according to the place of the event.

Methods:
prospective cohort study from the Andalusian Registry of Out-of-hospital CA (Spain). Consecutive patients with CA of cardiac aetiology cared for by out-of-hospital emergency teams from Jan-2008 to Dec-2010. Dependent variable: place of CA (CA at home vs CA at public place). Multivariate analysis.

Results:
Advance life support maneuvers were performed in 2960 patients. Cardiac aetiology was diagnosed in 2331(78.75%) cases. Of these, 1328(57%) cases occurred at home. Distribution by gender and age was male 69% vs 76.6% (p<0.0001), age 63.53 vs 61.47 years (p=0.002) at home vs public place respectively. The event was not witnessed in 52.1% vs 68.8% (home/public, p<0.0001) and there was basic life support by witness in 35.2% vs 56.7% (home/public, p<0.001) cases. Initial rhythm was shockable in 13.26% vs 26.79% (home/public, p<0.0001). The median interval between collapse and emergency team on scene was 11 vs 12 minutes (home/public, p=0.04). Return of spontaneous circulation and hospital admission were achieved in 22.8% vs 33.4%(p<0.0001) patients and survival at hospital discharge with good neurological function (CPC
1-2
) in 5.72% vs 13.35% (p=0.006) home/public patients respectively. In the multivariate analysis, variables associated with the site of event: witness (OR 0.412;CI 0.245-0.692, p=0.001) survival with CPC
1-2
(OR 2.294;CI 1.338-3-931.692, p=0.003).

Conclusions:
Cardiac arrest at home is less witnessed and shows a survival rate lower than that occurring in public places and may require a specific strategy to improve outcomes.
Abstract 252: Negative D-dimer Test for Acute Aortic Dissection
Authors: Satoh Yukio , Suzuki Masaru , Shiroshita-Takeshita Akiko , Tamura Tomonori , Kurihara Tomohiro , Shimizu Hideyuki , Hori Shingo
Published: April 2024

OBJECTIVE:
Recent studies have indicated the effectiveness of D-dimer values as a negative predictor to rule out a diagnosis of acute aortic dissection (AAD) in patients with chest pain. In contrast, there are several other studies suggesting D-dimer levels are not always elevated in dissecting patients in emergency settings. The aim of the present study is to identify the independent predictors relating to negative results of D-dimer testing for AAD.

METHODS:
Single center prospective observational study was performed for 5 years in an emergency department of a university hospital in Tokyo. Consecutive 49 patients with AAD (32 males, median age: 63 y/o) were enrolled in this study. Diagnosis of AAD was confirmed by enhanced computed tomography (CT) in all patients. Of those, 18 patients presented Stanford type A and 22 patients had thrombosed false lumen. Venous blood was drawn soon after patients' arrival (all performed within 24 hrs from symptom onset, median time: 50 min), and WBC, CRP, and D-dimer levels were obtained. Dissection lengths were measured using CT by another physician in a blinded fashion. Univariate anlyses were performed by t-test or chi-square test where appropriate, and a Logistic regression analysis was used as a multivariate analysis.

RESULTS:
Medain (IQR) of plasma D-dimer levels of a consecutive series of 49 patients were 7.8 (0.3 to 113.8) μg/ml. Of the 49 patients, 5 (10.2%) showed negative D-dimer test results (< 0.5μg/ml). Although age, sex, Stanford types, false lumen conditions, WBC, and CRP levels in these 5 patients were similar to those in other 44 patients with positive results, dissection length was significantly shorter in 5 negative results patients (132±119 vs 314±147 mm in positive results patients, P=0.01). The Logistic regression analysis using a backward elimination model revealed age and dissection length were identified as independent predictors for a negative D-dimer test result (Odds ratio and [95% CI]: 0.89 [0.79 to 0.99], 0.98 [0.96 to 0.99], respectively).

CONCLUSION:
In the present patient registry, 10% of patients with acute aortic dissection in emergency settings showed negative D-dimer test results. The negative D-dimer results were related to younger age and shorter dissection length.
Abstract 259: Lipid-Based Oxygen Microparticles Do Not Change in Size Following Intravenous or Intraosseous Injection
Authors: Kheir John , Black Katie , Reese James , McGowan Francis
Published: April 2024

Background.
Lipid-based oxygen microparticles (LOMs) have been developed for intravascular oxygen delivery. The size of these particles is important to the safety and efficacy of the suspension following injection, and the particles may change in size following the trauma of injection into an intravenous (IV) or intraosseous (IO) line.

Hypothesis.
The size distribution of gas filled particles will not change following injection through an IV or an IO line.

Methods.
Because LOMs are rapidly consumed in living animals, we utilized an asanguinous, post-mortem model to test the effect of infusion on particle sizes. The circulatory system of a 4.5 kg rabbit was flushed with saline. We placed a 4 French Cordis sheath into the right femoral vein and a 15 gauge Jamshidi intraosseous needle into the left forelimb. The central veins were dissected out for sampling of LOMs following injection. Eight-20 mL aliquots of LOMs were prepared by admixing a lipid-based solution with oxygen gas under high energy conditions. Particle size distribution of each aliquot was characterized by light scatter (Particle Sizing Systems). Each aliquot was hand injected into either an IO (n=4) or a central venous line (n=4) at 60 mL/minute. During each infusion, samples of LOM were visualized flowing within veins (LOMs are bright white), and were withdrawn by direct puncture of the vein. The particle size distribution of post-infusion samples was again determined by light scatter. Size distributions were compared prior to and following each infusion type by a Mann Whitney test.

Results.
Suspensions contained a mean diameter of 6.45±3.08 microns prior to infusion, 7.38±4.84 microns following IV infusion and 6.31±4.28 microns following IO infusion. Compared to pre-infusion sizes, particle size distributions did not differ following either IV (p=0.8399) or IO (p=0.8621) infusions (see Figure).

Conclusions.
In a post-mortem model, LOMs do not change in size following injection through an IV or an IO line.
Abstract 270: A Novel Mechanism of Preconditioning: Attenuating Reperfusion Injury through Enhanced Myocardial Substrate Uptake via Insulin-Stimulated Akt and AMPK Activation
Authors: Ji Lele , Cai Xiaoqing , Liu Wenchong , Fu Feng , Gu Xiaoming , Yang Weidong , Wang Jing , Zhang Haifeng , Wang Haichang , Gao Feng
Published: April 2024

Introduction:
Ischemic preconditioning (IPC) is an intrinsic protective mechanism which markedly enhanced the ability of the heart to withstand a subsequent ischemic injury. We previously found that IPC cardioprotection was markedly attenuated in diabetic rats. Therefore, we hypothesized that insulin-regulated myocardial substrate metabolism may play a key role in IPC-afforded cardioprotection.

Methods:
Adult male rats were subjected to 30 min of myocardial ischemia and 3 h of reperfusion (MI/R). IPC was achieved by two cycles of 5 min ischemia and 5 min reperfusion. Myocardial glucose and fatty acid (FA) uptake were assessed at the end of 1 h reperfusion by determining
18
F-2-deoxy-2-fluoro-D-glucose uptake and fatty acid translocase (FAT)/CD36 translocation, respectively.

Results:
IPC significantly improved cardiac function (n=8,
P
<0.05) with reduced myocardial infarction, apoptotic cell death and blood creatine kinase/lactate dehydrogenase levels following MI/R (all
P
<0.05). Myocardial glucose uptake was markedly elevated after IPC treatment (17.0±1.5 vs. 12.4±1.0 in MI/R, n=10-12,
P
<0.05), as well as translocation of glucose transporter 4 (GLUT4) to plasma membrane (PM) (
P
<0.01). Meanwhile, myocardial PI3K expression and Akt phosphorylation were significantly enhanced in IPC group (
P
<0.05). Interestingly, IPC also increased CD36 translocation to PM and AMPK phosphorylation (
P
<0.05). Wortmannin not only abrogated the cardioprotective effect of IPC, but also inhibited IPC-induced Akt/AMPK phosphorylation and subsequent GLUT4/CD36 translocation. Furthermore, the cardioprotection of IPC was markedly blunted in STZ-induced insulin-deficient diabetic hearts with failure of increase in glucose/FA uptake and impaired IPC-stimulated PI3K-Akt and AMPK signaling (n=6,
P
<0.05).

Conclusions:
These results suggest that IPC increases both glucose and FA uptake during early reperfusion to resist myocardial injury via insulin-stimulated, and PI3K-dependent Akt and AMPK activation. Therefore, augmenting insulin signaling may be a potential therapy to improve myocardial substrate uptake and restore the cardioprotection of IPC in diabetic hearts.
Abstract 276: The Impact of Ventricular Assist Devices on Blood Product Utilization for Cardiac Transplantation
Authors: Stone Matthew L , LaPar Damien J , Benrashid Ehsan , Mulloy Daniel P , Ailawadi Gorav , Kron Irving L , Blank Randal S , Kern John A
Published: April 2024

Purpose:
Ventricular assist device (VAD) support as a bridge to cardiac transplantation has introduced device-related complications to cardiac surgery. Specifically, therapeutic anticoagulation in newer generational devices is a primary challenge. The purpose of this study was to examine whether blood product utilization and mortality significantly differ for VAD patients compared to non-VAD (NVAD) patients following cardiac transplantation.

Methods:
From 2004-2010, 76 patients underwent cardiac transplantation at a single institution. Patients were stratified by VAD presence at transplantation: VAD patients (n=40, age: 50.8±11.0 years) vs. NVAD patients (n=36, age: 48.6±12.3 years). The primary outcomes of interest were blood product transfusion requirements and 30-day mortality.

Results:
Preoperative patient characteristics were similar for VAD and NVAD patients. NVAD patients presented with higher median preoperative creatinine levels compared to VAD patients (1.3 [1.10-1.58] vs. 1.1 [0.93-1.38], P=0.01). In addition, more NVAD patients required preoperative ACE-inhibitor therapy (P<0.001). Preoperative warfarin therapy was expectedly more common among VAD patients (P<0.001). Importantly, VAD patients accrued higher intra-operative transfusion of all blood products (all P<0.001) as well as higher postoperative packed red blood cell transfusions (P=0.04) compared to NVAD patients (Table). 30-day mortality was not significantly different between groups (7.5% vs. 8.3%, P>0.99).

Conclusions:
VAD support and the inherent requirement for anti-coagulation have significantly increased blood product utilization for cardiac transplantation. Despite these requirements, mortality rates remain similar to that of NVAD patients undergoing transplantation. Further study to define an optimal preoperative anticoagulation strategy for VAD patients may help to decrease the future resuscitative burden for cardiac transplantation.