bluuebunny/crossref_metadata_2025 huggingface dataset:
Abstract 19090: Assessing the Contribution of Dietary Factors to the Increased Prevalence of Insulin Resistance Amongst Uk Indian Asians Compared to Europeans
Authors: Tan Sian-Tsung , Rai Baldeesh , Boustead Louise , Badii Farah , Howell Nazlin , Frost Gary , Scott James , Elliott Paul , Chambers John C , Koner Jaspal S
Published: April 2024

Background:
Indian Asians comprise a quarter of the world’s population. Insulin resistance (IR) is highly prevalent amongst Indian Asians, contributing to their 4-fold higher risk of type-2 diabetes (T2D) compared to Europeans.

Unfavourable diet (high intake of total and saturated fat, and high glycaemic index foods) is an important determinant of IR. We carried out chemical analysis of duplicate diet samples to investigate whether unfavourable diet contributes to higher risk of IR and T2D in Indian Asians compared to Europeans.

Methods:
We recruited 92 Indian Asian and 94 European men from the lists of primary care physicians in West London (UK). Clinical characterisation included clinical questionnaire, anthropometric measurements and fasting blood samples (including lipid profile, glucose and insulin). Two 24-hour duplicate diets (comprising duplicate portions of all food and drink consumed) were collected, weighed, and homogenised. 30 ml aliquots were sent for chemical analysis (lipids - gas chromatography; carbohydrate - spectrophotometer quantification; protein - Kjeldahl method).

Results:
UK Indian Asians had higher body mass index, waist hip ratio, fasting insulin and were more insulin resistant [homeostatic model assessment-IR (HOMA[[Unable to Display Character: –]]IR)] than Europeans. Intakes of total protein, total fat and monounsaturated fat were lower, carbohydrate higher, and saturated, polyunsaturated and trans fat similar among Indian Asians compared to Europeans. HOMA[[Unable to Display Character: –]]IR was 32% (95% CI, 17[[Unable to Display Character: –]]46%) higher in Indian Asians (p<0.001). In multivariate regression, differences in macronutrients (including fatty acids, p<0.001) did not account for higher HOMA[[Unable to Display Character: –]]IR in Indian Asians.

Conclusion:
Unfavourable diet does not account for the differences in prevalence of IR amongst Indian Asians compared to Europeans. Metabolic profiling of diet samples and plasma may help identify the role of fatty acids and micronutrients with increasing susceptibility to IR in Indian Asians.
Abstract 19111: Multipotent Mesp1 Progenitors Contribute to a Population of Cardiac Fibroblasts During Development and After Injury
Authors: Ranjbarvaziri Sara , Ali Shah R , Talkhabi Mahmood , Subat Ali , Zhao Peng , Ardehali Reza
Published: April 2024

Mesp1 is considered as a master regulator for cardiovascular development. It has previously been shown that progenitor cells expressing Mesp1 contribute to the cardiovascular lineage, including cardiomyocytes, endothelial and vascular smooth muscle cells. To date, no direct link between progenitor cells expressing Mesp1 and cardiac fibroblasts has been reported. We hypothesized that cardiovascular progenitors expressing Mesp1 during early development also give rise to the cardiac mesenchyme. We performed lineage tracing experiments to identify the precursors of cardiac fibroblasts. We generated Mesp1Cre mT/mG mice, in which Mesp1-derived progenies are indelibly labeled GFP. We used fluorescent activated cell sorting (FACS) to isolate fibroblasts using Thy1 as an inclusive surface marker for fibroblasts and excluding hematopoietic markers (CD45, Ter119), macrophages (Cd11b) and endothelial cells (CD31). Our results showed that the majority of cardiac fibroblasts (> 75%) are derived from Mesp1-expressing cells. Cardiac fibroblasts (derived from Mesp1-expressing and Mesp1-nonexpressing cells) were cultured in vitro and positive for fibroblast markers after 3 passages with a dose dependent response to TGFβ treatment. Immunostaining of the adult heart tissue sections also showed presence of fibroblasts derived from both Mesp1 and non-Mesp1 progenitors. In order to determine whether these cells respond differentially to cardiac fibrosis, we performed transaortic constriction and sham surgery on the transgenic mice. Our data shows that the relative proportion of Mesp1-derived fibroblasts remains the same despite proliferation after pressure overload, suggesting that fibroblast division upon injury is not restricted to certain developmentally restricted fibroblast populations. In summary, we provide evidence that cardiac fibroblasts may share a common embryonic origin with the cardiovascular lineages.
Abstract 19145: The Effect of Atrial Fibrillation on In-Hospital Mortality in Patients With Acute Myocardial Infarction
Authors: Smith Triston B , Hajjali Raef
Published: April 2024

Background:
Atrial fibrillation (AF) has been shown in multiple observational studies to be associated with increased long-term mortality. The effect of AF on short-term outcomes in patients with acute myocardial infarction (AMI) is not clearly defined. We sought to investigate the in-hospital mortality among patient with and without AF presenting with acute myocardial infarction.

Methods:
We queried the Nationwide Inpatient Sample (NIS) database from 2008 to 2010. Using the SPSS data analysis package, we identified 374148 adult patients presenting with AMI, both ST elevation myocardial infarction (STEMI) and non-ST elevation myocardial infarction (NSTEMI). Among those, 58031 had a diagnosis of AF. Fisher exact test was used to compare mortality amongst patients with and without AF. Logistic regression analysis was performed to adjust for pertinent clinical variables.

Results:
Patients with AF were older ((x )
-
76.1 yrs. σ 11.8,) compared to those without AF ((x )
-
68.4 yrs. σ 14.5) p<0.001. The proportion of male was higher in the AF group (55.7% vs. 44.3%, p<0.001), as well as the frequency of shock (7.2% vs. 4.9%, p<0.001), CKD (20.3% vs. 12.6%, p<0.001), ESRD (3.8% vs 3.1% p<0.001), Diabetes Mellitus (33.9% vs 33.4% p<0.016), and need for transfusion (11.3% vs 6.9% p<0.001). Patients with AF were less obese (8.7% vs 11.3% p<0.001) and were more likely to be admitted with NSTEMI (74% vs 64.6% p<0.001) and undergo CABG (13.7% vs 7.9% p<0.001). They were less likely to undergo LHC (51.8% vs 67.7%) or be revascularized with PCI (26.7% vs 47% p<0.001) compared to those without AF. Patients with AF and AMI had a longer length of stay (x
-
6.4 vs x
-
4.6 days). The in-hospital mortality rate for patients with AF and AMI was 8.5%, compared to 4.3% in patients without AF (p<0.001). After adjusting for pertinent clinical and procedural variables using logistic regression analysis, AF remained an independent predictor of higher in-hospital mortality (p<0.001, OR 1.09[1.05-1.13]).

Conclusions:
In patients presenting with AMI, AF is associated with a higher incidence of NSTEMI, lower rates of revascularization via PCI, longer hospital LOS and higher in-hospital mortality rates than non AF patients.
Abstract 19185: Remodeling of Mitral Annulus and Left Atrium in Permanent Atrial Fibrillation: Relationship to Severity of Mitral Regurgitation
Authors: Tsang Michael Y , Luong Christina , Jue John , Gin Kenneth G , Nair Parvathy , Lee Pui-Kee , Barnes Marion E , Tsang Teresa S
Published: April 2024

Background:
Left atrial (LA) size increases in atrial fibrillation (AF). How changes in mitral annulus and atrial volume over time relate to severity of mitral regurgitation (MR) is unknown.

Methods:
This cohort study included 160 patients with a history of permanent AF who had at least 2 transthoracic echocardiograms (TTE) performed between 2005 and 2010 at Vancouver General Hospital (British Columbia, Canada). Patients with structural mitral valve disease, congenital heart disease, more than mild-moderate mitral/tricuspid regurgitation on their first TTE were excluded from analyses. LA volume was determined using biplane area-length method, averaged over 3 cardiac cycles. The mitral annulus diameter (MAD), defined as the distance between the hinge points of the anterior and posterior mitral leaflets from the apical 4-chamber view, was measured during end-systole and end-diastole. Linear mixed effects modeling was used in analyzing the above measurements for change over time. Mitral regurgitation was classified into 3 grades (mild, moderate, or severe) using standard color Doppler and PISA easurements where available.

Results:
Of the 160 subjects included in this analysis, 100 were men (62.5%). The mean age at study entry was 74±10 years. The median number of TTE performed was 3 (range 2 - 6). All 160 patients showed a progressive increase in MAD over time. There was a significant increase in MAD at end-systole and end-diastole over a mean follow-up of 3.2 ± 2.8 years; the increases were 0.48 mm/year (95% CI 0.124 -0.75, P=0.0037) and 0.45 mm/year (95% CI 0.102-0.716, P=0.0029) respectively. LA volume increased from a mean of 43 mL/m2 to 75 mL/m2 for the cohort, or 10 mL/m2 per year. Adjusting for age, sex, and left ventricular ejection fraction, an increase in MR severity by at least 1 grade was strongly and independently associated with an increase in MAD. A 15% increment in MAD was associated with an increase in MR severity by 1 grade.

Conclusion:
Permanent AF was associated with significant increases in MAD and LA volume over time. Severity of MR also significantly increased over time, and was independently related to the change in MAD. Further investigations as to whether this represents a mechanism for left heart failure in patients with permanent AF are warranted.
Abstract 19207: Outcomes in Patients With Atrial Fibrillation Undergoing Coronary Artery Stenting With a Low-moderate Cha2ds2vasc Score. Do They Need Anticoagulation?
Authors: Alonso Albert , Sambola Antonia , Mutuberria Maria , Garcia Bruno , Barrabes Jose A. , Garcia Dorado David
Published: April 2024

Background:
European Society of Cardiology guidelines for the management of atrial fibrillation (AF) recommend oral anticoagulation (OAC) in patients with CHA2DS2VASc score ≥1. When in these patients a coronary stent (CS) is implanted, indication to dual antiplatelet therapy (DAPT) is added, so these patients may be receiving triple therapy (TT). Objective: We assessed the impact of TT in patients with non-valvular AF and a low-moderate thromboembolic risk (CHA2DS2VASc < 2) submitted to coronary stenting (CS).

Methods:
a retrospective multicenter study was conducted from 2007 to 2011 to identify patients with nonvalvular AF who undergoing PCI with stenting. Patients clinical and demographic characteristics,CHADS2VASC2 score, PCI details, antithrombotic therapy at discharge and its duration. Follow-up was 1 year. Clinical outcomes were obtained from hospital readmissions and/or outpatients clinic interview were also reviewed. All bleeding events, stroke, thromboemobolism, death, acute myocardial infarction or target revascularization were recorded.

Results:
We identified 640 consecutive patients with nonv-valvular AF (75.2% male, 73.2±8.2 years). Of them 170 (27%) had a CHA2DS2VASc 3 (7.6% vs 4.2%; p=0.29). At follow-up, patients on TT showed a higher mortality (1.3% vs 8.4%, p=0.03) due an excess of cardiovascular death (0% vs 8.4%, p=0.008), and a higher rate of major bleeding (0% vs 5.3%, p=0.05). However, they showed a similar rates of thromboembolic events (1.3% vs 1.1%, p=0.68), MACE (9.3% vs 13.7%, p=0.26) and MAE (18.7% versus 26.3%, p=0.16) compared to patients on DAPT. A total of 9 patients (5.3%) died during follow-up; 8 (88.9%) of them were on TT, 4 patients had a bleeding event, and 3 of them had a CHA2DS2VASc=1. In a multivariate analysis, in patients with CHA2DS2VASc < 2, the use of TT showed a trend towards increased mortality (OR 8.4; 95% CI: 0.91 to 77.6, p=0.05), and was a predictor of major bleeding (OR 2.9: 1.04-8.25, p=0.042).

Conclusions:
In patients with non-valvular AF and CHA2DS2VASc <2 submitted to CS, the addition of OAC to DAPT shows a trends to increases mortality as well as the rate of major bleeding, and does not provide any apparent benefit preventing thromboembolic events.
Abstract 19218: Are the Guidelines Recommendations Followed in the Clinical Practice in Patients With Atrial Fibrillation Undergoing Coronary Stenting?
Authors: Alonso Albert , Sambola Antonia , Mutuberria Maria , Garcia Bruno , Barrabes Jose A. , Garcia Dorado David
Published: April 2024

Background:
Patients with atrial fibrillation (AF) undergoing coronary stenting (CS) have an increased risk of bleeding due to the combination of dual antiplatelet therapy (DAPT: aspirin and clopidogrel) with anticoagulation (TT:triple therapy). The use of TT is a class IIb recommendation of the ACC/AHA/ESC guidelines. Other recommendations such as the use of drug eluting stent(DES), radial approach and closure devices in femoral access are preferred. Objective:to assess adherence in clinical practice to triple therapy, vascular access, the use of closure devices and the type of stent implanted.

Methods:
a multicenter study from 2007 to 2011 identified patients with non-valvular AF submitted to CS. In the included patients the risk associated to TT in terms of use and duration of TT, vascular access, and DES were assessed.

Results:
We identified 640 consecutive patients with AF, 320 (50%) of them were ≥75 years. Among them, 224 (35.2%) had CHADS2 score > 2, 46(73%) CHA2DS2VASc>2, and 164 (25.6%) had a high bleeding risk (HASBLED>3). In 328 (51.3%) a radial approach was chosen.At discharge, 321 (50.2%) patients received TT, 44(6.9%) warfarin plus clopidogrel and 275(41.3%) DAPT. During follow-up, 63 patients(9.8%) died for any cause, and 46(7.2%) because of a cardiovascular cause. 116(18.1%) had a bleeding event, and 37(5.8%) of them were major bleedings. A major adverse cardiac event(MACE: death, acute myocardial infarction and/or target vessel failure) occurred in 111(17.3%) patients and major adverse event (MAE: MACE and/or major bleeding) in 190(29.7%). A multivariate analysis identified as predictors of cardiovascular mortality the age(OR: 1.05; 95%CI 1.00 to 1.11, p=0.043), renal failure(OR 6.24; 95% CI 2.77 to 14.06, p=0.01), and the use of warfarin plus clopidogrel(OR 4.62; 95%CI 1.68 to 12.7, p=0.03).The use of DES, used arterial approach or the use of closure device were not predictors.

Conclusions:
In patients with non-valvular AF submitted to CS guidelines recommendations are not always followed in clinical practice. In these patients, the use of warfarin plus clopidogrel is associated to a higher cardiovascular mortality, while other recommendations such as the use of DES, arterial access approach or closure devices did not seem have effect.
Abstract 19443: Predictors of Wound Healing in Patients With Critical Limb Ischemia With Tissue Loss following Successful Endovascular Therapy
Authors: Kobayashi Norihiro , Muramatsu Toshiya , Tsukahara Reiko , Ito Yoshiaki , Ishimori Hiroshi , Hirano Keisuke , Nakano Masatsugu
Published: April 2024

Background:
Sometimes we can’t achieve wound healing in patients with critical limb ischemia (CLI) with tissue loss even after successful endovascular therapy (EVT). Multiple factors including patient background, intervention outcomes, and also wound characteristics are associated with wound healing. Therefore we evaluated predictors of wound healing in CLI after successful EVT.

Methods:
Between April 2007 and April 2012, 179 patients (217 limbs) with CLI classified to Rutherford 5 or 6 were treated with EVT in our institute. Of these, 128 patients (146 limbs) were successfully treated. Successful EVT was defined as revascularization of achievement of direct blood flow to the wounds evaluated by digital subtraction angiography just after EVT. Each variables were analyzed using the univariate Cox proportional hazards model for wound healing. All variables tested in univariate analysis with p < 0.25 were included in multivariate Cox hazards model.

Results:
The mean follow-up period was 21±17 months. Wound healing rates were 41%, 58%, 71%, and 72%, at 3, 6, 12, and 18 months, respectively. Multivariate Cox proportional hazard analysis revealed that insulin use (HR 0.47, 95%CI 0.30-0.73, p=0.001), dependence on hemodialysis (HR 0.35, 95%CI 0.23-0.53, p<0.001), wounds located only at toes (HR 2.79, 95%CI 1.78-4.38, p<0.001), gangrene (HR 0.66, 95%CI 0.44-0.97, p=0.037), and revascularization basing on angiosome concept (HR 1.53, 95%CI 1.16-2.02, p=0.002) were independent predictors of wound healing following successful EVT.

Conclusions:
Achievement of direct blood flow to the wounds is important factor for wound healing, but that is not enough. Insulin use, dependence on hemodialysis, and gangrene can be predictors of wound healing failure. Furthermore, wounds located only at toes and revascularization basing on angiosome concept can be predictors of wound healing.
Abstract 207: Comparison of Noninvasive pHm and Blood pH in a Swine Model of Resuscitation of Uncontrolled Hemorrhage
Authors: Soller Babs , Smith Charles , Zou Fengmei , Sondeen Jill
Published: April 2024

Near infrared spectroscopy can be used noninvasively and continuously to assess deep muscle pH (pHm) as an indicator of acidosis and adequacy of resuscitation. Since pHm is a new parameter, it was compared to blood measurements of arterial and venous pH (pHa, pHv) during shock in swine to provide data to aid in interpretation during clinical use.

Methods:
Anesthetized 40 kg female swine (n=26) underwent hemorrhage until 24 mL/kg of blood was removed (Shock); followed by transection of the spleen causing uncontrolled hemorrhage throughout the remainder of the protocol. After 15min, 15.25mg/kg of resuscitation fluid (hextend, fresh frozen plasma or platelets) was given over 30min. Arterial and venous blood gases were measured at baseline, shock, end resuscitation and end of the study. Spectra were collected continuously from the posterior thigh muscle using a prototype CareGuide 1100 Oximeter. pHm was calculated from the spectra using the equation contained in the CareGuide 3100 product. Differences between survivors and non-survivors were assessed with two-way repeated measured ANOVA followed by a Tukey test.

RESULTS:
Thirteen of the 26 swine did not survive for the full 5 hrs. pHv and pHm discriminated survivors and non-survivors at the end of resuscitation (p < 0.05) with lower pH for the non-survivors. pHa did not discriminate between survivors and non-survivors at any time point.

Conclusions:
Noninvasive pHm is a surrogate for peripheral venous pH during swine hemorrhage and resuscitation.
Abstract 209: Focused Training Results in a Decrease in Inpatient Respiratory Arrests
Authors: Minokadeh Anushirvan , Sell Rebecca E , Aguilar Steve A , Viillanueva-Reiakvam Sheri J , Chappel Ruth W , McNulty Wayne J , Barlow Halsey T , Davis Daniel P
Published: April 2024

Background:
The leading cause of inpatient arrests are due to respiratory causes and in our hospital, due to apneic/hypopneic events.

Objective:
To characterize patterns of apneic and hypopneic events in at risk population.

Methods:
This study was performed in one urban, academic inpatient facility. Eighteen at risk postoperative patients were identified in the post-anesthesia care unit (PACU) and admitted to the intermediate care unit (IMU) with continuous pulse oximetry and capnometry. Criteria included apnea, hypopnea, bradypnea (less than 8 breaths per minute), and inability to wean of nasal cannula oxygen. Major and minor events were identified (Fig. 1).

Results:
Patients who exhibited major apneic events had a significantly greater number of minor apneic events per shift relative to those who only had minor events (8.3 vs 2.5, Fig. 2). The day shift (8am-8pm) had more major apneic events (83.4% vs 16.6, Fig. 3) than the evening shift (8pm-8am). Incidentally, the training for this trial effectively reduced the number of total respiratory arrests in the hospital (Fig. 4).
Abstract 217: Effect of Amiodarone with Therapeutic Hypothermia on Arrhythmia Substrates During Global Myocardial Ischemia
Authors: Kouk Shalen , Wilson Lance D , Piktel Joseph S
Published: April 2024

Background:
The effect of therapeutic hypothermia (TH) after cardiac arrest on susceptibility to arrhythmias is not well understood. We have shown that TH has a beneficial effect on reentrant substrates for ischemia-induced arrhythmias by limiting decreases in conduction velocity (CV) and attenuating increases in transmural dispersion of repolarization (DOR). As amiodarone is utilized during TH, it is important to understand the effect of TH and amiodarone on arrhythmia substrates during ischemia. Our hypothesis is that amiodarone worsens the antiarrhythmic effect of TH during global ischemia. To test this hypothesis, a model of no flow global ischemia in the canine wedge preparation was used to study the effects of ischemia on all cell types spanning the transmural wall.

Methods:
Optical action potentials were recorded transmurally with high spatial (1 mm), temporal (.5 ms) and voltage (.5mv) resolution. Amiodarone (5microM) was used at both 36oC (control, CTAmio n=4) and 32oC (THAmio, n=4) during 15 min of no flow global ischemia and compared to controls (CT=7, TH=6). Action potential duration (APD), DOR, and CV were measured for all conditions. Programmed electrical stimulation (PES) was performed to assess for ischemia-induced arrhythmias and compared to prior controls (CT, n=5, TH, n=4).

Results:
At baseline, TH prolonged APD in both THAmio and TH, but there was no difference between DOR and CV. At 15 minutes of ischemia, DOR increased in the THAmio group compared to TH (34±3 ms to 79±9 ms vs. 25±3 to 37±7 ms, p=.04). There was a trend towards worsening ischemia-induced conduction slowing in the THAmio group vs TH, but not significant (39±4 to 24±3 cm/s vs 44±2 to 35±3 cm/s, p=.06). There was no difference under control temperature of CTAmio vs CT for CV, DOR, or APD. PES induced arrhythmias in 2/4 in the CTAmio group vs. 0/4 in THAmio group (compared to 3/5 in CT group, 1/4 in TH group).

Conclusions:
Amiodarone worsens the beneficial effect of TH on ischemia-induced DOR, but does not worsen susceptibility to arrhythmias. Further study in translatable models of ischemia-induced cardiac arrest is warranted to assess the effect of ACLS pharmacology on arrhythmias with the increased use of TH.
Abstract 220: Development of a Supraglottic Airway Device with the Function of Pharyngeal Cooling
Authors: Takeda Yoshimasa , Hashimoto Hiroshi , Mizoue Ryoichi , Sato Sachiko , Morimatsu Hiroshi
Published: April 2024

Introduction:
Intra-ischemic brain hypothermia has shown better neuroprotective effects when it is initiated earlier after the onset of resuscitation. To initiate brain hypothermia simultaneously with airway management at the beginning of resuscitation, we developed a supraglottic airway device that enables initiation of pharyngeal cooling. The effects of the airway device on brain temperature were evaluated.

Methods:
A Japanese monkey (10 kg) was anesthetized with isoflurane. The airway was maintained with our newly developed supraglottic airway device. Artificial ventilation was performed with tidal volume = 100 ml, respiratory rate = 20±5 times /min and peak airway pressure < 20 cmH2O. PaCO2 was maintained at 40±5 mmHg. Right epidural temperature (parietal cortex), right sub-cortical temperature (3 cm below the cortical surface) and rectal temperature were monitored. A pharyngeal cooling cuff attached under the supraglottic airway device was perfused with physiological saline (5 °C) at the rate of 500 ml/min for 60 min. Intracuff pressure was maintained < 50 cmH2O.

Result:
Initiation of pharyngeal cooling did not affect respiratory conditions, including peak airway pressure and PaCO2. Epidural temperature had decreased by 3.1 °C and 4.7°C at 30 min and 60 min after the onset of cooling, respectively. Sub-cortical temperature had decreased by 2.7°C and 4.2 °C at 30 min and 60 min after the onset of cooling, respectively. Rectal temperature had decreased by 1.9 °C and 3.2 °C at 30 min and 60 min after the onset of cooling, respectively.

Conclusion:
The supraglottic airway device with the function of pharyngeal cooling can reduce the onset time for initiation of brain cooling.
Abstract 265: Analyzing Resuscitation Quality by Reviewing Automatic External Defibrillator Data Using Empirical Mode Decomposition Based Algorithm
Authors: Chang Eric Chun-Yi , Ko Patrick Chow-In , Lo Men-Tzung , Lin Lian-Yu , Chiang Wen-Chu , Lin Chen , Hsieh Wan-Hsin , Chang Yi-Chung , Chen Wei-Ting , Ma Matthew Huei-Ming
Published: April 2024

Background:
High quality cardiopulmonary resuscitation (CPR) improves survival of out-of-hospital cardiac arrests (OHCAs). Our team has developed an empirical mode decomposition (EMD) based algorithm to identify chest compression fluctuations from ECG signals retrieved from automatic external defibrillators (AEDs) in OHCAs presenting with asystole. In this study, we further applied this method on pulseless electric activities (PEAs).

Methods:
ECGs of AED from 30 randomly selected OHCAs in Taipei EMS presented with PEA were retrieved. Initial 5 minutes of each ECG strips were divided into 5 one-min segments. EMD decomposed the ECG segments into several intrinsic mode fluctuations (IMFs). The dominant IMFs attributed to chest compressions are identified before fed back to the original corrupted signals as a reference to pursuit optimal compression signal by least linear square method. Each compression can be identified by checking local periodicity of the optimized compression signal. CPR quality indicators, including compression number, no flow time and compression rate, were calculated min-by-min by the algorithm, and compared with those derived from manual reviews of ECG and audio by experienced physicians.

Result:
Thirty OHCAs were enrolled and 106 segments, excluding 44 segments with transport movement artifacts, underwent both algorithm and manual review. The results derived from two methods were highly correlated (compression number, r=0.86; no flow time, r=0.81) with good agreements shown in Bland-Altman plot. (Fig.)

Conclusion:
The EMD algorithm is capable of extracting CPR signals during PEA and enables potential monitoring for CPR quality.
Abstract 271: Predicting Defibrillation Success Without Interrupting Chest Compression in Cardiac Arrest Patients
Authors: Firoozabadi Reza , Helfenbein Eric , Babaeizadeh Saeed
Published: April 2024

Background:
In performing CPR on sudden cardiac arrest patients, a balance between chest compressions (CC) and defibrillation is needed. Optimizing the timing of defibrillation shocks may improve outcomes compared to time-based protocols. There exist numerous predictive features computed from the ECG signal before shock delivery to distinguish between rhythms which convert to spontaneous circulation and those which do not. Unfortunately, since CC induce significant artifact on the ECG signal, all these features assume a pause in CC before delivering the shock, so that there is no CC artifact on the ECG signal to be analyzed. However, in the 2010 guidelines, the AHA challenges manufacturers to “seek innovative methods to decrease the amount of time chest compressions are interrupted for AED operation.” It would be beneficial if the predictive features could be calculated while CC are performed and CC artifact is present.

Objective:
Examine the effects of CC artifact on shock success predictive features and how such effects can be minimized.

Methods:
A total of 111 short waveform segments from cardiac arrest patients with VF rhythm and transition from CC to hands-off were used. Thirteen temporal and spectral predictive features were calculated on a 4-sec “noisy” interval containing CC artifact preceding the transition at the end of CC, and on the adjacent 4-sec “clean” interval with no CC artifact following the transition. We presumed the underlying VF remained constant during both intervals. Predictive features were then calculated on a “filtered” version of the noisy segments with CC artifact removed using a newly developed method.

Results:
The Wilcoxon signed-rank paired test showed CC artifact had a significant impact on all predictive features. However, after removal of CC artifact using our filter, the test showed all but one feature gave similar values to those from the “clean” segments.

Conclusion:
The results demonstrate that CC artifact has a significant impact on shock success predictive features, but that the effect can be minimized using our CC artifact filtering method. Large prospective studies are needed to show if a combination of our filtering method and predictive features can help minimize CC interruptions and improve resuscitation outcomes.
Abstract 279: Real-time Cerebral Hemoglobin Concentration Changes From NIRS; a Valid Evaluation Method for Quality CPR Chest Compression in Out-of-Hospital Cardiac Arrest
Authors: Koyama Yasuaki , Wada Takafumi , Takamatsu Yuka , Takita Mumon , Lohman Brandon D , Matsumoto Junichi , Fujitani Shigeki , Taira Yasuhiko
Published: April 2024

Background:
Near-Infrared Spectroscopy (NIRS) is a non-invasive real-time measurement device capable of monitoring the cerebral perfusion volume and may potentially represent the efficacy of chest compression.

Introduction:
NIRS assesses cerebral hemoglobin concentration changes ([[Unable to Display Character: ⊿]]cHb) independently of pulse by utilizing adhesive sensors that are placed on the forehead where [[Unable to Display Character: ⊿]]cHb measurements are evaluated within the segment of cerebral tissue analyzed. [[Unable to Display Character: ⊿]]cHb waveforms are displayed real-time and reflect chest compression quality which we defined as compressions of adequate depth capable to increase cerebral perfusion manifesting as waveforms on monitor. We set out to identify whether a relationship between [[Unable to Display Character: ⊿]]cHb and quality chest compressions could be determined with NIRS.

Method:
We prospectively enrolled eight out-of-hospital cardiac arrest (OHCA) patients admitted to our ED. The exclusion criteria included trauma and age < 15. Seven (87.5%) underwent both [[Unable to Display Character: ⊿]]cHb evaluation with the NIRO200NX (Hamamatsu Photonics) using NIRS and compression depth evaluation with the MRx-QCPR (Philips Healthcare). Each 2-minute CPR session is administered by one same operator and may be relegated in-between CPR sessions. From the whole resuscitation process, we randomly selected from 3 CPR sessions over 100 [[Unable to Display Character: ⊿]]cHb waveforms for every subject (~30 waveforms per session) and investigated correlations between the selected [[Unable to Display Character: ⊿]]cHb waveforms amplitudes and the depth of their respective chest compression.

Results:
2 (29%) were strongly correlated. Within each single 2-minute CPR session, significant correlation was observed, whereas the totality of three CPR sessions demonstrated poor correlations attributable to several CPR manipulators.

Conclusion:
Strong correlation appears to exist between [[Unable to Display Character: ⊿]]cHb waveforms and chest compression depth. NIRS can evaluate in real-time[[Unable to Display Character: ⊿]]cHb waveform and may potentially serve as an index to evaluate quality CPR chest compression.
Abstract 285: Does the Real-Time Audio Feedback From an Automated External Defibrillator Enhance Cardiopulmonary Resuscitation Quality During Emergency Resuscitation?
Authors: O’Hare Peter , Di Maio Rebecca , Torney Hannah , McIntyre Colette , McCanny Paul , Adgey Jennifer
Published: April 2024

Objective:
The 2010 AHA guidelines have outlined the importance of providing early high-quality CPR in conjunction with an AED to enhance survial outcomes post sudden cardiac arrest. However, there is little information available as to how real-time feedback may positively enhance the quality of compression rates. The purpose of this study was to evaluate the impact of CPR feedback given by out-of-hospital (OOH) responders following SCA. Response to feedback was gauged by analysing changes in the impedance cardiogram (ICG) and ECG waveforms recorded by the AED during OOH resuscitation in an attempt to establish if the rescuer responded to audible instruction.

Methods:
Data was collected from events recorded by HeartSine Samaritan AEDs over a five month period. A total of nine events were received and assessed. Event files that included the ECG and ICG recordings were downloaded using SaverEvo® Software and analysed. Data also included the time of each instruction, the nature of the instruction (e.g. push harder, push faster, push slower, good compressions) and the associated changes in the ECG and ICG waveforms were interpreted to assess reaction times where appropriate.

Findings:
A total of 177 instructional CPR prompts were given to the rescuers over nine events, 70 (39.5%) of which resulted in a positive modification of CPR rate or force. On average there was a 1.44 second delay in reaction time to each prompt. Of the 70 positive changes in the ICG, 30 of the cases showed a corresponding change in the ECG indicating that the ICG is a better indicator of CPR efficacy.

Conclusions:
This study demonstrates that real-time feedback during CPR is beneficial in enhancing the quality of CPR in emergency resuscitation. Even where there was no response to the prompt, CPR at least continued at the same rate suggesting that there was no detrimental affect on the quality of CPR. Furthermore, the results indicate that ICG is an effective way to monitor the quality of rescuer CPR.
Abstract 293: More Nursing Care Increases In-Hospital Cardiac Arrest Survival
Authors: Rochman Monica F , Kalisch Beatrice J
Published: April 2024

The objective of this study was to investigate the association between shift level nurse staffing, and survival to discharge for patients sustaining an in-hospital cardiac arrest (IHCA). In many instances, the most likely first responder to witness IHCA and provide needed treatment is the registered nurse. Delays in treatment are associated with decreased survival; every minute is important during cardiac arrest. Little if any comprehensive research has been undertaken to determine the features of nursing that are important in the outcomes of cardiac arrest, however. Thus, there is a critical need to thoroughly examine if and how nursing affects survival patients experiencing in-hospital cardiac arrest. This study was a cross sectional secondary analysis of an in-hospital cardiac arrest registry and staffing data obtained from hospital productivity reports.

Registered nurse hours per patient day were analyzed during the nursing shift that the cardiac arrest occurred. Generalized estimating equation models were used account for the clustering of patients within units.

The sample consisted of adult patients aged 18 and older who sustained an in hospital cardiac arrest between May 2004 and December 2009 in one Mid-western academic hospital. The final analytic sample consisted of 299 patients in 22 medical surgical, rehabilitation and intensive care units.

One additional hour per patient day of RN care results in 19% greater odds of surviving to discharge while controlling for patient and unit characteristics in the model.

Shift- level staffing measured at the time of the event was found to positively predict in-hospital cardiac arrest survival. The findings from this study will serve to inform nursing practice with regard to the importance of staffing levels which can impact survival. Response times to cardiac arrests depend on recognizing the arrest and the ability to respond and provide treatment in a timely manner. This is directly the result of the availability of staff to react to such a situation. Moreover, a closer perspective in examination of a specific event and shift-level staffing, the more likely important process improvement initiatives will be appropriate and successful.
Abstract 298: End-Tidal Carbon Dioxide Values as an Indicator of Arrest Etiology and Prognosis
Authors: Pearce Alex K , Sell Rebecca E , Chappell Ruth W , Minokadeh Anushirvan , Davis Daniel P
Published: April 2024

Background:
During cardiopulmonary resuscitation (CPR), end tidal carbon dioxide (PetCO2) is used to assess the quality of compressions, return of spontaneous circulation (ROSC), and the futility of continued resuscitative efforts. In out-of-hospital cardiac arrest, the first measured PetCO2 correlates with the etiology of arrest, distinguishing between asphyxial and ventricular fibrillation/ventricular tachycardia (VF). This has not been analyzed in the inpatient setting.

Objective:
To compare the initial PetCO2 during CPR for inpatients with cardiopulmonary arrest (CPA) from VF versus asphyxia.

Methods:
This study was performed in two urban, academic inpatient facilities. Patients were enrolled from July 2006-May 2013. A comprehensive database of all inpatient resuscitative events is maintained at these institutions, including demographic, clinical, and outcomes data. Arrests are stratified by primary etiology of arrest using a priori criteria. Patients with CPA from asphyxia versus VF and in whom PetCO2 data were available were included in the analysis. Patients in whom capnography was placed after ROSC or more than ten minutes following initiation of CPR were excluded. Patients with VF versus asphyxia were compared with regard to initial PetCO2 values. In addition, initial PetCO2 values for asphyxial arrest victims with and without ROSC were compared.

Results:
A total of 63 patients with pre-ROSC capnography data were identified; 16 of these had asphyxial arrest and 3 had VF. Initial PetCO2 values were higher in asphyxial arrest victims (25.4 mmHg versus 9 mmHg, p=0.005). In addition, patients with ROSC had higher initial PetCO2 values among all patients (p=0.011) and in the subgroup with asphyxial arrest (30 mmHg versus 15 mmHg).

Conclusions:
Initial PetCO2 values are higher in inpatients with asphyxial versus VF etiology of arrest. This is consistent with published data on initial etCO2 during OHCA. In addition, initial PetCO2 values are higher in patients with eventual ROSC. This analysis is limited by relatively small sample sizes.
Abstract 331: The Effects of the Rate of Post-resuscitation Rewarming following Hypothermia on Outcomes of CPR in a Rat Model
Authors: Lu Xiaoye , Ma Linhao , Sun Shijie , Tang Wanchun , Xu Jeifeng
Published: April 2024

Background:
Both clinical and laboratory studies have demonstrated that mild therapeutic hypothermia(TH) following CPR improves myocardial and neurologic outcomes of cardiac arrest. However, the optimal rewarming strategy following TH remains to be explored. The present study investigated the optimal rewarming rate following TH in a rat model of CPR.

Methods and Results:
Four groups of SD rats were randomized: 1) Control; 2) rewarming rate at 2°C/h; 3) rewarming rate at 1°C/h ; 4) rewarming rate at 0.5°C/h. VF was induced and untreated for 8 mins; defibrillation was attempted after 8 mins of CPR. The body temperature of the controls were maintained at 37±0.2°C throughout the experiment; For 2°C/h, 1°C/h and 0.5°C/h groups, rapid cooling was started with the aid of ice packs at the beginning of CPR. Upon reaching the target temperature of 33±0.2°C, the temperature was maintained with the aid of a cooling blanket until 4hrs after resuscitation. The rewarming was then initiated at the rate of 2.0°C, 1.0 °C or 0.5 °C per hour respectively until the body temperature reached 37±0.2 °C,which maintained at 37±0.2 °C for 6 hrs in 2 °C/h group, 4 hrs in 1 °C/h group, and 0 hours in 0.5 °C/h group. Blood samples were drawn at baseline, PR4, 6, 8, 10 and 12hrs for the measurements . Blood temperature was significantly decreased in the TH groups from CPR to PR 4hrs. Significantly better CO, EF, MPI and reduced neurological scores, longer duration of survival were observed in 1°C/hr and 0.5°C/hr groups. The increased serum levels of TnI, IL-6 and TNF-α was partly attenuated in 1°C/hr and 0.5°C/hr groups when compared with control and 2°C/hr groups.

Conclusions:
The present study demonstrated that the severity of myocardial, cerebral injuries and inflammatory reaction after CPR were reduced when mild TH was applied. A rewarming rate at 0.5-1°C/h did not alter the beneficial effects of TH. However, a rapid rewarming rate at 2°C/h abolished the beneficial effects of TH.
Abstract 332: Simulation to Derive the Operating Characteristics of a Bayesian Adaptive Clinical Trial Design to Determine Optimal Duration of Hypothermia Following Out-of-Hosptial Cardiac Arrest
Authors: Meurer William J , Berry Scott , Ramakrishnan Viswanathan , Silbergleit Robert
Published: April 2024

Introduction:
Therapeutic hypothermia (TH) improves outcomes in comatose survivors of cardiac arrest, but optimal duration of cooling is unknown. An innovative adaptive trial may address this question efficiently and with fewer prior assumptions, but its complexity requires simulation to characterize the trial’s power and accuracy.

Objective:
To evaluate the operating characteristics (OC) of an adaptive clinical trial designed to characterize the TH duration response relationships for patients with shockable and non-shockable rhythms.

Methods:
The proposed ICECAP trial design uses a flexible, Bayesian normal dynamic linear model to estimate the relationship between duration of TH and 90 day modified Rankin Scale. The trial initially allocates 150 patients equally to 12, 24, or 48 hrs of cooling and models duration-response. The model then iteratively refines itself using response adaptive randomization ratios updated every 100 subsequent enrollments to time windows from 6 to 72 hours as needed to identify transitions in duration-response. Shockable and non-shockable rhythms are fitted separately. Sample sizes from 1600-2300 were simulated. The design was tested under hypothetical scenarios of no treatment effect, small, medium and large effects, and harm (outcomes worsen with duration). Each combination of sample size and scenario was simulated 1000 times.

Results:
The proportion of trials correctly identifying the target duration (for both rhythm types) ranged from 72% (N=1600), to 81% (N=2300). A sample size of 1800 had 85% power to select the target (the true or larger adjacent) duration. OC remained robust in specific challenging scenarios including a very early plateau with similar efficacy at 18-72 hours, and an inverted U with efficacy upsloping to 18 hours and diminishing from 30-72 hours. In the null scenario, identical outcomes for all durations from 6-72 hours, the design only incorrectly identifies a winning dose in 4-7% of trials. It was also efficient in this scenario, terminating 35% of trials early for futility. In harm scenarios, trials terminate early 86% of the time.

Conclusions:
The ICECAP trial design performs well under a variety of scenarios. Flexible, adaptive Bayesian trial designs are promising and ready to be implemented.
Abstract 334: Slight Therapeutic Hypothermia (35°C) is Effective and Safe as a Post Cardiac Arrest Care for Low Left Cardiac Function PCAS Patients
Authors: Orita Tomohiko , Toyoda Yukitoshi , Yamazaki Motoyasu , Funabiki Tomohiro , Shimizu Masayuki , Matsumoto Shokei , Sato Tomohiro , Takebe Motojiro , Hiroe Nao , Kazamaki Taku , Nakamichi Yoshimi , Kitano Mitsuhide
Published: April 2024

Background:
Mild therapeutic hypothermia (32-34°C, 24-48 hours: mild TH) for post cardiac arrest syndrome (PCAS) due to ventricular fibrillation (VF) has been recommended in the American Heart Association (AHA) Guidelines 2010 (class I) and the International Liaison Committee on Resuscitation (ILCOR). But it is still unknown what temperature is good for low left cardiac function patients including acute myocardial infarction (AMI) cases. Sometimes executing mild TH for patients with severe left ventricular dysfunction are difficult because of hypotension, arrhythmias, unstable vital signs and so on. So we studied whether slight therapeutic hypothermia (35°C: Slight TH) was effective and safe compare with mild TH for PCAS due to VF.

Methods:
Consecutive PCAS patients who were witnessed, confirmed VF caused by cardiac or coronary events and introduced therapeutic hypothermia for the latest 58 months were sorted into the GroupM (Mild TH, 34°C, 24-48 hours) and the GroupS (Slight TH, 35°C, 24-48 hours).The primary end point was a favorable neurologic outcome (cerebral performance category: CPC 1 or 2) in 90th days after cardiac arrest. Secondary end points were the changes of cardiac index (CI) after introducing therapeutic hypothermia, the time required to reach target temperature and the rate of complications (infections, bleeding, arrhythmias etc.) within fourteen days.

Results:
forty-eight patients (twenty-two AMI cases) were studied (GroupM 24 patients and GroupS 24 patients). The rate of favorable neurologic outcome was available and did not differ significantly between the two groups (13/24 54% vs. 17/24 71%, p=0.34). The time to reach target temperature was significantly shorter in the GroupS (5.4h vs. 1.6h, p<0.01). The decrease of CI was remarkable in the groupM (before TH/during TH, GroupM 2.8/2.1, p<0.01, GroupS 2.2/2.1, p=0.33). The rate of complications did not differ significantly between them and there were no major complications.

Conclusion:
Slight therapeutic hypothermia for PCAS due to VF with low left cardiac function is effective and safe possibility.
Abstract 343: Poloxamer 188 Reduces the Infarct Size in Pigs Undergoing ST Elevation Myocadial infarction
Authors: Sarraf Mohammad , Matsuura Timothy , Caldwell Emily , Bates Frank S , Metzger Joseph M , Yannopoulos Demetris
Published: April 2024

Introduction:
Poloxamer 188 (P188) is a synthetic surfactant known to stabilize the cell membrane integrity and thus minimizes reperfusion injury (RI). RI protection protects the myocardial loss due to reperfusion phase of myocardial infarction. We hypothesized that treatment with P188 at the beginning of reperfusion in acute ST elevation myocardial infarction (STEMI) reduces the infarct size.

Methods:
Ten pigs underwent total occlusion of the middle left anterior descending artery with a 3.0x12mm balloon at 6 atmospheres for 40 minutes. EKG and angiogram confirmed the presence of STEMI. Amiodarone (40mg IV) was given before the STEMI to prevent fatal arrhythmias. We deflated the balloon at 40 min in the control group (n=5) and reperfused for 4 hours. In the P188 group (n=5), we administered a single bolus of 10gm of P188 immediately after balloon deflation, through the guide in the left main and subsequently 250mg/Kg of P188 was systemically infused over 4 hours of reperfusion. The area at risk (AAR), the infarct area (IA) and normal myocardium were stained by triphenyltetrazolium chloride and Evans blue, before euthanizing the animal. We harvested all hearts and weighed the left ventricle mass (LVM). The endpoint of the study was infarct size ratio (ISR); defined as IA/AAR. We cut the hearts in short axis to estimate the ISR by Photoshop®. We used unpaired t-test for statistical analysis.

Results:
All animals survived the STEMI phase without complication. There was no significant difference in LVM between the control and P188 groups (106±9 vs. 102±6gm, P=0.7). AAR was similar in P188 and control groups (43%±6% vs. 47±4%, p=0.5). The ISR (Figure) was significantly reduced in P188 group vs. the control group (13±4% vs. 61±3%, p<0.0001).

Conclusion:
The RI protection is an important step of myocardial protection in STEMI after reperfusion. P188 protects the cell membrane and reduces the infarct size when applied immediately after establishing flow to the coronary artery.