bluuebunny/crossref_metadata_2025 huggingface dataset:
Abstract 238: Substantial Incomplete Chest Recoil Occurs During CPR in a Pig Model
Authors: Aelen Paul , Ordelman Simone , Paulussen Igor , Noordergraaf Gerrit-Jan , Woerlee Pierre
Published: April 2024

INTRODUCTION

The 2010 AHA / ERC Guidelines recommend compression depths of 5-6 cm. However, the neutral sternal position is assumed to remain unchanged. Changes in chest wall or lungs might cause incomplete chest recoil, altering the effect of 5-6 cm as a percentage of chest diameter. This could induce injury and affect the optimal compression depth. We investigated the hypothesis that incomplete chest recoil occurs during CPR in a pig model and that the speed at which this occurs changes with prolonged CPR. The incomplete chest recoil, or chest molding is a process of change, not a limitation to re-expansion caused by “leaning” or partial compression relaxation.

MATERIAL AND METHODS

Fourteen Yorkshire pigs with an average AP diameter of 20 cm were anesthetized, placed in dorsal recumbency, and ventricular fibrillation (VF) induced. After 90 s of VF, a specially made, proprietary servo controlled automated CPR device was used to deliver compressions of 5 cm depth at various frequencies (80-120 cpm) and duty cycles (40-60%). The plunger position (and unstressed sternal position) was determined at the start of each compression by the servo system. The position of the compression plunger (and thorax) was measured at a sample frequency of 250 Hz. An altered position at the start of a new compression is called the molded position.

RESULTS

In the 14 animals, chest molding occurred with an average initial rate of 0.34 ± 0.12 mm per compression. The average chest molding after 100 compressions was 17.4 ± 3.6 mm. After 21 minutes the average molding was 29.2 ± 10.3 mm with an average molding rate of -0.02 ± 0.04 mm/compression. The moulding curve shape was logarithmic. Initial compression depth was approximately 25% of AP diameter, increasing to 30% after 21 minutes CPR due to chest molding.

CONCLUSION

In conclusion, the molding magnitude was substantial. After initiation of CPR, chest molding occurs quickly, the rate slowing but never stopping, until compressions are stopped. The results could be extrapolated to humans but may be less pronounced due to a more vertical rib construction. Implications on CPR quality and injury need further investigation. Nevertheless, chest molding should be considered in the instructions for compression depth.
Abstract 282: Fat Intravasation from Intraosseous Infusions
Authors: Rubal Bernard J , Hanson Margaret A
Published: April 2024

Rapid vascular access is an essential element in advanced resuscitation procedures and intraosseous (IO) cannulation has proven to be both a rapid and effective alternative to intravenous access. Little attention has been given to refinements in IO procedures that may improve efficacy or reduce complications of use. This study was designed to assess fat intravasation with IO infusions. In this study, IO cannulas (15G, EZ IO, Vidacare Corp, San Antonio, TX) were inserted into the proximal tibias (N=14) and distal femurs (N=11) of seven anesthetized swine (
Sus scrofa,
50.1±3.5 Kg). A lipophilic fluorescent probe (Nile red: Excitation 480nm-Emission 535nm) was used to quantify fat intravasation in venous effluents by relative fluorescent (RFU). Blood for analysis was withdrawn from an 8F catheter placed by fluoroscopic guidance in the external iliac vein. The IO infusion regimen consisted of an initial IO saline flush (10cc), infusion with a pressurized bag (300 mmHg), and infusions at 0.3, 0.5, 1.0, 2.0 and 3.0 ml per second using a programmable pump. An ANOVA and
post hoc
tests were employed to assess the significance of treatment effects. Figure illustrates significant (*P<0.05) fat intravasation (mean ± SD) with initial flush and infusion rates ≥ 1ml per second.

The post mortem assessment of lung tissue from these animals (N=79 samples) using formalin fixed H&E stained sections and frozen sections stained with oil-red-O revealed mild to moderate positive staining for lipid in all lung segments and rare bone marrow emboli consisting of mature adipocytes and hematopoietic cells within medium sized pulmonary arteries. In conclusion, this study suggests that both initial flush and high flow rates induce medullary damage and the embolization of bone marrow and fat. Further studies are needed to determine if refinements in IO flush and infusion practices can maintain the benefits of IO infusions and minimize fat embolization.
Abstract 288: Chest Wall Stiffness Varies During Cardiopulmonary Resuscitation
Authors: Tisherman Sara , Callaway Clifton W
Published: April 2024

Introduction
: Displacement of the sternum during cardiopulmonary resuscitation (CPR) is affected by the elastic properties of the chest wall but the dynamic properties of the chest wall have not been described. This study tested whether chest wall stiffness varies with depth of compression, and whether chest wall stiffness changes with repeated compressions.

Methods
: Acceleration and force applied to the chest wall during CPR were measured using an accelerometer and a force meter “puck” placed between the rescuer hand and the patient sternum (Philips MRX). Displacement of the sternum (double integrated acceleration) was used to calculate chest wall stiffness (force/displacement) using MATLAB and STATA. Changes in stiffness with compression depth and with compression number were analyzed using linear regression.

Results
: CPR data from 10 subjects with out-of-hospital cardiac arrest provided about 50 measurements per compression and 100-4739 compressions per subject. Chest wall stiffness decreased as depth of compression increased (p<0.001), requiring varying force for any given displacement. Chest wall stiffness at a given depth (25 mm) decreased over consecutive compressions (p<0.001) (Figure 1).

Conclusions
: Stiffness of the chest wall changes as the depth of compression increases. Over multiple compressions, the stiffness of the chest wall declines, perhaps reflecting loss of rib integrity. Future work should explore whether stiffness is related to optimal chest compression depth.
Abstract 290: Endothelial Dysfunction in a Rat Model of Asphyxia-Induced Cardiac Arrest
Authors: Troelsen Thomas T , Granfeldt Asger , Tønnesen Else , Simonsen Ulf
Published: April 2024

Background: Altered vasoreactivity and elevated markers of endothelial activation are found following cardiac arrest (CA) and resuscitation. However, it is unknown whether the described altered vasoreactivity reflects influence from humoral factors, affection of the underlying smooth muscle or a change in the endothelium itself. Furthermore, it is unknown how the inflammatory markers correlate to endothelial function.

The aim of the present study was to assess endothelial function and the relation to plasma markers of inflammation and adhesion, CA and resuscitation.

Methods: Male Sprague Dawley rats underwent 5 min. of asphyxia-induced CA and subsequent resuscitation. After return of spontaneous circulation (ROSC) animals were euthanized after 30 min. or 2 hrs. Sham operated animals were used as controls. At the end of the experiment blood was drawn and analyzed for IL-1β, IL-6, IL-10, TNF-α, ICAM-1, VCAM-1, VEGF-α, vWF and sP-Selectin. Segments of the Left coronary artery (LCA) and mesenteric resistance arteries were mounted in microvascular myographs. Concentration-response curves for acetylcholine (ACH), NS309, and sodium nitroprusside where obtained.

Results: LCA-segments exhibited an impaired vasodilation to ACH after 30 min. of ROSC as CA animals dilated to a max of 66 ± 2 vs. 94 ± 8% in the sham group (Mean ± SE; P=0.0014). After 2 hrs. of ROSC vasoreactivity was comparable to sham groups for all drugs tested. The mesenteric arteries exhibited a larger response to NS309 after 2 hrs. of ROSC compared to 2 hr. sham (logEC50 ± SE: 0.43 ± 0.05 vs. 1.85 ± 0.23 µM; P<0,001). Levels of sP-selectin, vWF and sVCAM-1 were elevated in both CA groups vs. sham groups, with no correlation to vasoreactivity.

Conclusion: Endothelium-dependent ACH-induced nitric oxide (NO)-mediated vasodilation was blunted in LCA segments in the early post-resuscitation phase, NS309-induced endothelium-derived hyperpolarizing factor (EDHF)-mediated vasodilation was enhanced in mesenteric resistance arteries in the intermediate post-resuscitation phase. There was no relation of vasoreactivity to plasma markers of adhesion and inflammation. The altered vascular reactivity may explain impaired coronary flow and hypotension in the restitution phase after cardiac arrest.
Abstract 312: Outcomes After Therapeutic Hypothermia During Extracorporeal Membrane Oxygenation Following Out-of-Hospital Refractory Cardiac Arrest
Authors: Choi Wook Jin , Hong Jung Seok , Kim Sun Hyu , Ahn Ryeok , Hong Eun Seog , Kim Jeong Won , Jung Jong Pil , Shin Eun Seok , Lee Sang Gon , Ahn Jong Joon
Published: April 2024

Background and Objective:
For cardiac arrest patients who do not respond to conventional cardiopulmonary resuscitation, extracorporeal life-support (ELS) may represent an alternative therapeutic approach allowing significant survival rates. Following cardiac arrest, mild therapeutic hypothermia for 12-24 h is recommended. However, there is little clinical experience with good outcome in out-of-hospital refractory cardiac arrest. We present 5 cases of refractory cardiac arrest, who were treated with therapeutic hypothermia during extracorporeal membrane-oxygenation in the emergency department.

Results:
A retrospective review of 5 out-of-hospital cardiac arrest patients (4 male and 1 female; median age, 43), who were placed on therapeutic hypothermia during ELS, was performed. All patients were unresponsive to conventional CPR and advanced cardiac life support without return of spontaneous circulation beyond 30 min. ELS was initiated under continuous cardiac massage in the emergency department. Mild therapeutic hypothermia was induced and maintained successfully for 24 h via surface cooling methods. Three patients were fully recovered consciousness from being comatose after rewarming and cessation of sedatives. Two patients were discharged with no neurological sequelae (CPC 1).

Conclusion:
Mild therapeutic hypothermia during ELS in the ED can be beneficial in out-of-hospital cardiac arrest patients who are unresponsive to prolonged cardiac pulmonary resuscitation.
Abstract 318: Potential Primary Prevention Implantable Cardioverter-Defibrillator Patients Lack Understanding, Want More Information and Are Willing to Reconsider Implant Refusal
Authors: Singh Narendra , Hall Erin , Lucas Essy , Chandra Sandeep , Song David , Yan Linda , Suh David , Dorsey Anthony , Ramamurthy Suresh
Published: April 2024

Background:
Underutilization of ICD’s for primary prevention of sudden cardiac death has been previously reported in our practice. Factors leading to acceptance or refusal of device implant have not been well studied.

Method:
Prospective standardized interview and use of a 1-10 rating scale of randomly selected heart failure (HF) pts in a suburban outpatient cardiology practice.

Results:
Of the 533 HF pts identified with an ejection fraction of <35%, we randomly interviewed 50. Of these 54% were Caucasian (C), 36% African American (AA), 10% Asian (A). 29 pts (58%) accepted an ICD and 21 pts (42%) refused, the “no ICD” group. The mean age was 62+11 yrs, The mean EF was 24+7%. No significant differences in patient demographics, cardiac risk factors, HF medications or baseline labwork was seen.

Comparing ICD pts to no ICD pts - in both groups understanding of HF was poor, 4.5 on a scale of 1-10. The no ICD pts had less understanding of ICD purpose p<0.0003 , were less likely to have been given written ICD information (71 vs 38%, p=0.02) and were less likely to recall a recent discussion on the topic of ICD’s (52%). In both groups quality of life was more important than quantity 7.7+3 out of 10. Although 93% were Christian, religious belief (3.3+3 out of 10) and cultural values (3.2+3 out of 10) did not play a major role in decision making. Both group felt they had great access to health care resources and physicians (8.5+2 out of 10). Only 2 (7%) of ICD pts would not accept an ICD again, while 18 no ICD (86%) pts would now reconsider implant, p<0.001

Women were less likely to be married 26 vs 63%, p=0.02. A pts were younger than C, 56 vs 66 yrs, p=0.04. AA pts had less understanding of low EF vs C, p=0.02 and trended towards having less access to best medications p=0.1.

Conclusions:
Our qualitative study suggest that underutilization of ICD’s for primary prevention of SCD may in part be related to limited communication and poor understanding of HF, sudden death, and the devices. Furthermore the majority of pts initially refusing a device are willing to reconsider implant. These findings, with further validation, offers a potential approach to improving ICD underutilization in these high risk patients.
Abstract 13444: Mechanism of Extravasation of Infused Regenerative Cells from Microvessels into Tissue Parenchyma
Authors: Cheng Ke , Shen Deliang , Sun Baiming , Xie Yucai , Cingolani Eugenio , Malliaras Konstantinos , Duong Doan Tran , Chowdhury Supurna , Marban Eduardo
Published: April 2024

Ke Cheng, 2012 Finalist and Presenting Author
Abstract 18716: Survival for Infants with Critical Congenital Heart Defects in Atlanta, Georgia, 1979-2005: Temporal Trends and Prognostic Factors
Authors: Oster Matthew E , Lee Kyung A , Honein Margaret A , Colarusso Tiffany , Shin Mikyong , Correa Adolfo
Published: April 2024

Matthew E Oster, 2012 Finalist and Presenting Author
Abstract 58: Locating AEDs in an Urban City: A Geospatial View
Authors: Merchant Raina , Griffis Heather M , Leung Alison C , Lozada Kirkland N , Saynisch Olivia B , Asch Jeremy M , Shofer Frances S , Starr Larry M , Hershey John C , Hill Shawndra , Nichol Graham , Asch David A , Becker Lance B
Published: April 2024

Background:
Survival from out-of-hospital cardiac arrest (OHCA) is poor and varies by geography. Variability in AED locations may be a contributing factor, but this is understudied. As publically accessible AEDs are more likely to be in commercial rather than residential areas, we sought to determine AED density in a large urban city relative to population and employment demographics.

Methods:
This was a retrospective analysis of MyHeartMap, a prospective cohort of AEDs in Philadelphia County. Geographic and population characteristics were obtained from US census and Local Employment Dynamics (LED) data by zipcode. Census characteristics included number of residents, percent of residents with a high school degree or above, median household income, and percent of African Americans. LED characteristics included total number of jobs reported, percent of jobs requiring a high school degree or above, percent of jobs with an annual income above $40,000, and percent of African Americans in jobs. Multivariate regression models using a Poisson distribution related the distribution of AEDs to population and employment characteristics using commercially available geographical information systems (GIS) software (ArcGIS Redlands CA)

Results:
AED locations (n=1295) and density per zip code (range 2-179) varied across the city. Population and employment characteristics were significantly related to the number of AEDs per zipcode (p<0.001) [R-square=0.38 and 0.74, respectively]. The incident rate ratio (IRR) for AED density was higher in zipcodes with higher-education (1.10, p<.01) and lower in zipcodes with more African American residents (0.99, p<.01). Regarding employment characteristics, the IRR for AEDs was higher in zipcodes with jobs requiring a higher education (1.03, p<.01) and jobs with higher income (1.04, p<.01) and lower in zipcodes with more African American employees (0.99, p<.01).

Conclusions:
Significantly fewer AEDs were located in areas with lower socioeconomic status. Employment characteristics better explained this variation across zipcodes. A more thorough study of this variability is important as optimizing the placement of AEDs in public areas may help to increase OHCA survival.
Abstract 80: Infliximab Is Superior to Etanercept for the Treatment of Postresuscitation Myocardial Dysfunction in a Swine Model of Ventricular Fibrillation
Authors: Youngquist Scott T , Niemann James T , Shah Atman P , Thomas Joseph L , Rosborough John P
Published: April 2024

Introduction: Infliximab, a monoclonal antibody directed against the inflammatory cytokine TNF-α, has been shown to attenuate the myocardial dysfunction and hemodynamic decompensation associated with post-cardiac arrest syndrome. The aim of this study was to compare the effects of etanercept, a TNF-α receptor antagonist, to infliximab in a swine model of ventricular fibrillation (VF).

Methods: Under general anesthesia, VF was induced electrically in domestic swine (n=30). After 7 minutes of VF, standard ACLS resuscitation was performed. Animals achieving return of spontaneous circulation (ROSC) were randomized to immediately receive infliximab (5 mg/kg, n=10) or etanercept (0.3 mg/kg [4 mg/m2], n=10) or vehicle (250 mL normal saline [NS], n=10) and LV function and hemodynamics were monitored for 3 hours.

Results: Following ROSC, mean arterial pressure (MAP), stroke work (SW), and LV dP/dt fell from prearrest values in all groups. However, at the 30 minute nadir, infliximab-treated animals had higher MAP than either the NS group (difference 14.4 mm Hg, 95% confidence interval [CI] 4.2-24.7) or the etanercept group (19.2 mm Hg, 95% CI 9.0-29.5), higher SW than the NS group (10.3 gm-m, 95% CI 5.1-15.5, Figure) or the etanercept group (8.9 gm-m, 95% CI 4.0-14.4) and greater LV dP/dt than the NS group (282.9 mm Hg/sec, 95% CI 169.6-386.1) or the etanercep group (228.9 mm Hg/sec, 95% CI 115.6-342.2).

Conclusions: In conclusion, only infliximab demonstrated a beneficial effect on post cardiac arrest hemodynamics and LV function in this swine model. Etanercept was no better in this regard than saline.
Abstract 8950: Simple and Accurate Electrocardiographic Criteria for Differentiation Among Acute Coronary Syndrome, Acute Pulmonary Embolism, and Takotsubo Cardiomyopathy
Authors: Kosuge Masami , Ebina Toshiaki , Hibi Kiyoshi , Tsukahara Kengo , Iwahashi Noriaki , Maejima Nobuhiko , Endo Mitsuaki , Morita Satoshi , Umemura Satoshi , Kimura Kazuo
Published: April 2024

Background:
Negative T waves (Neg T) in precordial leads are often seen in acute coronary syndrome (ACS), but also occur in acute pulmonary embolism (APE) and takotsubo cardiomyopathy (TC). Differentiating these 3 diseases is important with regard to selecting the appropriate treatment strategy.

Methods:
We studied 278 patients (178 patients with ACS, 80 with APE, and 20 with TC) who were admitted within 48 h from symptom onset and had Neg T ≥1.0 mm in ≥2 contiguous precordial leads (V1-4) without ST-segment elevation on admission ECG. In all patients with ACS, the culprit lesion was confirmed to be located in the left anterior descending coronary artery by angiography during hospitalization. Baseline characteristics and ECG findings on admission were analyzed.

Results:
In patients with ACS, APE, and TC, age was 67±10, 64±14, and 69±12 years (p=0.10); the rates of women were 38%, 69%, and 75% (p<0.01); positive troponin T was 46%, 49%, and 85% (p<0.01); S1Q3T3 pattern was 0%, 25%, 0% (p<0.01); right axis deviation was 0%, 8%, and 0% (p<0.01); ST-segment depression ≥0.5 mm was 40%, 18%, and 25% (p<0.01), and the amplitude of maximal Neg T was 5±3, 3±2, and 7±3 mm (p<0.01). The prevalence of Neg T is shown in Figure, in which the anatomically contiguous Cabrera sequence was used to display limb leads, and it significantly differed in all 12 leads among the 3 groups (p<0.001, respectively). Neg T in both leads III and V1 identified APE with 86% sensitivity, 98% specificity, and 95% predictive accuracy, and Neg T in lead -aVR (ie, positive T wave in lead aVR) combined with no Neg T in lead V1 identified TC with 95% sensitivity, 99% specificity, and 99% predictive accuracy, representing the highest diagnostic accuracies.

Conclusions:
The distribution of Neg T obviously differed among ACS, APE, and TC, suggesting the differences in underlying electrophysiologic mechanisms. These differences were useful for differential diagnosis of these 3 diseases.
Abstract 8994: Elevated C-Reactive Protein Levels Predict Prognosis and Interact With Diabetes and Hypertension in the Development of Coronary Spasm
Authors: Hung Ming Yow , Hsu Kuang-Hung , Hu Wei-Syun , Chang Nen-Chung , Hung Ming Hui
Published: April 2024

Introduction:

The prognostic significance of high-sensitivity C-reactive protein (hs-CRP) in patients with coronary spasm and its association with diabetes and hypertension on the risk of coronary spasm remain unexplored.

Hypothesis:

We assessed the hypothesis that elevated hs-CRP level predicts outcomes in patients with coronary spasm and interacts with diabetes and hypertension in coronary spasm development.

Methods:

Patients undergoing coronary angiography with proven coronary spasm but without coronary stenosis >50% were evaluated. A total of 897 subjects, including 350 women and 547 men, were analyzed and followed up for a median of 5.8 years. The levels of hs-CRP measured before coronary angiography were examined in a subset of 555 patients.

Results:

In women, only the highest hs-CRP tertile (>3 mg/L) was independently associated with coronary spasm. In men, age, smoking and the highest hs-CRP tertile were independently associated with coronary spasm. Patients with the highest hs-CRP tertile had more coronary events compared with those without (p = 0.021, log-rank test). The highest hs-CRP tertile was a significant independent predictor of poor prognosis. The odds ratios of coronary spasm in both women and men with hs-CRP in the highest tertile reduced from 4.41 (95% confidence interval [CI]=1.77-10.97, p=0.001) to 1.45 and 2.86 (CI=1.47-5.57, p=0.002) to 1.59, respectively, if they had diabetes, and from 9.68 (CI=2.63-35.68, p=0.001) to 2.43 and 2.67 (CI=1.17-6.08, p=0.019) to 1.68, respectively, if they had hypertension.

Conclusions:

Elevated hs-CRP level predicts adverse outcome in coronary spasm patients. The negative effects of diabetes and hypertension on coronary spasm suggest that the pathogenesis of coronary spasm differs from that of coronary atherosclerosis.
Abstract 9002: Off-pump Rather than On-pump Coronary Artery Bypass Grafting Increases Late Mortality: A Meta-analysis of Randomized controlled Trials
Authors: Goto Shin-nosuke , Takagi Hisato , Iwata Kotaro , Yamamoto Hirotaka , Umemoto Takuya
Published: April 2024

Background:
A recent meta-analysis incorporating 59 randomized controlled trials (RCTs) of off-pump versus on-pump (conventional) coronary artery bypass grafting (CABG) suggests that there appears to be a beneficial effect of off-pump CABG on post-operative (30-day or in-hospital) stroke but neither all-cause mortality nor myocardial infarction. To determine whether off-pump CABG reduces late all-cause mortality, we performed a meta-analysis of RCTs of off-pump versus on-pump CABG.

Methods:
MEDLINE, EMBASE, and the Cochrane Central Register of Controlled Trials were searched through January 2012. Eligible studies were RCTs of off-pump versus on-pump CABG and reporting late (≥1-year) all-cause mortality as an outcome. For each RCT, data regarding mortality in both the off-pump and on-pump CABG groups were used to generate odds ratios (ORs) and 95% confidence intervals (CIs).

Results:
Eighteen RCTs enrolling 5358 patients were identified. Pooled analysis suggested a significant increase in late total mortality among patients randomized to off-pump versus on-pump CABG in the fixed-effects model (OR, 1.35; 95% CI, 1.07-1.70;
P
=0.01; Figure). There was minimal trial heterogeneity (
P
=0.87) and accordingly little difference in the pooled result from the random-effects modeling. Mortality increase remained significant even after elimination of the largest and highest-weight RCT (Randomized On/Off Bypass [ROOBY] study) (OR, 1.32; 95% CI, 1.01-1.72;
P
=0.04). In general, exclusion of any single RCT from the analysis did not substantively alter the overall result of our analysis. There was no evidence of significant publication bias.

Conclusions:
Off-pump rather than on-pump CABG appears to significantly increase late (≥1-year) mortality
Abstract 9003: Evolution of the Arterial Structure and Function from Infancy to Adolescence is related to Anthropometric and Blood Pressure Changes
Authors: Sarkola Taisto , Manlhiot Cedric , Slorach Cameron , Bradley Timothy J. , Hui Wei , Mertens Luc , Redington Andrew , Jaeggi Edgar
Published: April 2024

Objective:
To develop a normative dataset and to study the relationship between arterial structure, different anthropometric measures, blood pressure and arterial function during healthy childhood using very-high resolution ultrasound (25-55 MHz).

Methods and Results:
In 135 healthy children between 0 and 18 years we assessed the structure of the carotid arteries, larger peripheral arteries, aorta and left ventricle with ultrasound. Arterial stiffness was assessed by pulse wave velocity (PWV) and endothelial function by brachial flow-mediated dilatation (FMD). Reference curves adjusted for age and body surface area of arterial lumen diameters (LD), intima-media (IMT) and adventitia (AT) thickness were developed. Arterial walls thicken during childhood predominantly due to a progressive increase in IMT. There were significant associations between LD (R
2
range: 0.20-0.88 for different arteries; p<0.001), IMT (R
2
range: 0.47-0.85; p<0.001), left ventricular mass (LV mass; R
2
= 0.90; p<0.001) and AT (R
2
range: 0.15-0.22; p<0.001) with gender, age, body surface and systolic blood pressure. Arterial wall stress was associated with LD (R
2
range 0.52-0.83; p<0.001) and IMT (R
2
range 0.53-0.88; p<0.001). Limited relations were found between arterial wall layer thickness, stiffness and endothelial function.

Conclusion:
In healthy children the evolution of the arterial structure is mainly related to anthropometrics and blood pressure.
Abstract 9039: Predictors of High Defibrillation Energy Requirements: Results From the NCDR ICD Registry
Authors: Russo Andrea M , Al-Khatib Sana M , Wang Yongfei , Curtis Jeptha , Marcus Greg M , Hsu Jonathan C , Sood Nitesh , Parker Matthew W , Kluger Jeffrey , Lampert Rachel
Published: April 2024

Background:
Defibrillation testing is typically performed at the time of ICD implantation to establish effective arrhythmia termination. Despite technological advancements, including biphasic waveforms and higher output devices, an inadequate safety margin for defibrillation may still occur. The NCDR ICD Registry was examined to evaluate predictors of a high defibrillation requirement (DER) using modern day devices.

Methods:
Patients who underwent defibrillation testing in the NCDR ICD Registry were examined to determine characteristics associated with a high DER. This included 45,686 initial ICD implantation procedures from April 2010 to December 2010 performed at 1261 facilities. Patient characteristics were compared using chi-square tests for categorical variables and unbalanced t-tests for continuous variables. Multivariable logistic regression was used to assess independent predictors of a "high" DER, which was defined as >25 joules.

Results:
A high DER was noted in 4.1% of patients undergoing testing. Patients with a high DER were more often younger, male, on dialysis, and were more likely to have a higher NYHA functional class, lower LVEF, higher creatinine, and wider QRS. Patients on antiarrhythmic drugs and those with nonischemic heart disease were more likely to have a high DER. Independent predictors of a high DER included younger age, higher NYHA class, and increased QRS duration. A high DER was associated with longer post-procedure length of stay (1.6 ± 2.9 vs. 2.1 ± 3.8 days, p<0.001) as well as any complication or death prior to hospital discharge (2.6% vs. 4.0%, p<0.001).

Conclusions:
A high DER was observed in 4.1% of patients and was associated with more complications and mortality. Several clinical predictors of a high DER were identified, potentially enabling the identification of patients most likely to benefit from testing. Additional study is needed to determine if testing predicts long-term outcome of patients with modern day devices.
Abstract 9042: Left Ventricular End Systolic Cross-Sectional Area Shows Strong Correlation with Short Axis Untwisting Rate
Authors: Tee Michael , Ashraf Muhammad , Sahn David J
Published: April 2024

Background:
The untwisting rate of the left ventricle (LV) has been related to early diastolic filling and is proposed as a sensitive index of diastolic function of the heart. In this investigation, we examined the LV segmental untwisting rate (specifically at the lateral and septal walls) with relation to the efficiency of systolic contraction computed as end-systolic short axis area.

Methods:
We analyzed high-resolution image data acquired from the LV of 15 open chest pigs using a 10MHz probe on a GE Vivid 7 Dimension ultrasound system. Apical short axis views were exported to EchoPac PC. With this software, end systolic area was measured by tracing the endocardium at maximum contraction. Using 2D speckle tracking, untwisting rate was recorded at the septal wall and the opposing lateral wall of the heart at the mid cavity level just above the papillary muscles.

Results:
The septal untwisting rate (102.9 ± 23.5 deg/s) was significantly greater than the lateral untwisting rate (25.0 ± 13.9 deg/s). Although both showed a strong negative correlation with end systolic area, our results indicate that the septal wall untwisting rate showed a stronger correlation (R = -0.85, p < 0.05) with end systolic area than lateral wall untwisting rate (R = -0.79, p < 0.05).

Conclusions:
Septal untwisting rate showed a stronger negative correlation with the end systolic LV cavity area at the mid level than the lateral wall untwisting rate.
Abstract 9139: Inspiratory and Expiratory Main Pulmonary Artery Dimensions on Chest CT Exclude Pulmonary Hypertension in Chronic Obstructive Pulmonary Disease
Authors: Fenster Brett , Gethin-Jones Thomas , Lee Samuel , Honeyman Alex , Bowler Russell , Make Barry , Buckner J. Kern , Schroeder Joyce
Published: April 2024

Background:
Pulmonary hypertension (PH) is present in 30-70% of chronic obstructive pulmonary disease (COPD) and is a strong predictor of morbidity and mortality. Although previous studies have demonstrated that a chest CT-determined main pulmonary artery diameter (MPAD) of ≥ 29 mm during inspiration is associated with PH, these have utilized small groups of heterogenous pulmonary disease. Consequently, the predictive value of MPAD in a pure COPD population remains unknown. In addition, previous studies have not evaluated the diagnostic utility of expiratory phase MPAD. Since variable inspiratory effort and loading of the pulmonary vasculature may confound efforts to predict PH, expiratory phase MPAD measurement may be a reliable indicator of PH. COPDGene is multicenter prospective study that correlates genotype with chest CT COPD phenotype. Using a large subgroup of the COPDGene cohort, we hypothesized that inspiratory MPAD (iMPAD) and expiratory MPAD (eMPAD) on chest CT accurately predict PH when defined by echocardiographic estimation of RVSP in a cohort of COPD patients.

Methods:
COPDGene subjects who completed both high-resolution chest CT as well as echocardiography were included for analysis. Cross-sectional iMPAD and eMPAD were measured at the widest dimension at the level of the aorta using the VIDA Pulmonary Workstation 2 software by 3 blinded readers. Based upon the previous World Health Organization definition of mild PH as 40-50 mmHg, a right ventricular systolic pressure (RVSP) ≥ 45 mmHg was classified as PH.

Results:
Multivariate regression analysis of 182 COPD subjects revealed significant correlations between RVSP and iMPAD (r .45, p < .0001) as well as eMPAD (r .41, p < .0001). Optimal diagnostic performance of iMPAD occurred at ≥ 28 mm with an AUC of .69 and a NPV of 88% but a PPV of only 38%. In comparison, optimal performance of eMPAD occurred at ≥ 31 mm with an equal AUC (69%) and nearly equivalent NPV (85%) and PPV (42%).

Conclusions:
Both iMPAD and eMPAD perform with excellent NPV but poor PPV for prediction of PH in a COPD cohort. In contrast to previous studies indicating good PPV in heterogenous pulmonary disease populations, the diagnostic utility of pulmonary artery diameter measurement in the COPD population may reside in its NPV for PH.
Abstract 9278: Neutrophil to Lymphocyte Ratio is associated with All-cause, Cardiovascular and Ischemic Heart Disease Mortality: the National Health and Nutrition Examination Survey
Authors: Dabhadkar Kaustubh C , Deshmukh Abhishek J , Mehta Jawahar L , Quyyumi Arshed A , Wilson Peter W
Published: April 2024

Introduction:
The neutrophil to lymphocyte (NTL) ratio has emerged as a predictor of mortality following acute coronary syndrome, but the predictive role of NTL ratio on mortality has not yet been studied in epidemiologic study.

Objective:
We examined association between NTL ratio and risk of all-cause, cardiovascular (CVD) and ischemic heart disease (IHD) mortality in a nationally representative cohort.

Methods:
Participants between ages 30 and 74 enrolled in the National Health and Nutrition Examination Survey (NHANES) III study from 1988 to 1994 had WBC count with differential, and known CVD risk factors (age, sex, race, BMI, diabetes, hypertension, smoking history, total cholesterol, HDL cholesterol, history of CVD, family history of CVD, medication use) measured. All-cause, CVD and IHD mortality through 2006 were obtained via linkage with the National Death Index. Cox proportional hazards model was used to estimate hazards ratio (HR) and 95% confidence interval (CI) for mortality after adjusting for known CVD risk factors and total WBC count.

Results:
10296 participants (mean age 50 ± 13.5 years, 52.8 % females, and 39.3 % ethnic minorities) had complete data. Mean NTL ratio was 2 ± 1. During 140, 958 person-years follow-up (median follow-up: 14.4 years), there were 2188 deaths including 674 CVD deaths and 502 IHD deaths. In multivariate analysis, comparing participants in NTL ratio quartile 4 to quartile 1, the adjusted HR was 1.37 (95% CI, 1.21-1.56) for all-cause mortality, 1.58 (95% CI, 1.25-1.99) for CVD mortality, and 1.75 (95% CI, 1.33-2.3) for IHD mortality. Increasing quartiles of NTL ratio were a strong marker of risk for future all-cause, CVD and IHD mortality (p for trend < 0.001 for each outcome).

Conclusion:
In a nationally representative sample of US adults, higher NTL ratio conveyed greater hazard for all-cause, CVD and IHD mortality. NTL ratio may reflect a simple, yet effective marker of cardiovascular risk and merits further study.
Abstract 9387: Painless Acute Aortic Dissection is Associated with Poor Functional Outcome: Relationship to Clinical Characteristics and Diagnostic Procedure
Authors: Imamura Hiroshi , Mochizuki Katsunori , Nitta Ken-ichi , Takayama Hiroshi , Iwashita Tomomi , Dohgomori Hiroshi , Okamoto Kazufumi
Published: April 2024

Background:
Prompt diagnosis of acute aortic dissection (AAD) is essential for successful management. AAD classically presents with severe chest, back, or abdominal pain. However, there have been several documented cases presenting with atypical features. Making diagnosis is difficult when the classic pattern of pain is absent. Hypothesis: The purpose of this study was to investigate the clinical characteristics of patients with painless AAD and to assess the hypothesis that the diagnostic delay in painless AAD might cause poor prognosis.

Methods:
One hundred and twenty-four patients with AAD were admitted our hospital from 2002 to 2007. After excluding patients with an out-of-hospital cardiac arrest, 98 patients (53 males, 45 females; 66±12 years) were studied. Sixteen patients (17%) had no pain (Painless group) and 82 patients had pain (Painful group). Eighty-one per cent and 70% of patients had a type A dissection, respectively.

Results:
The time from admission to a definite diagnosis was longer in the Painless group (P=0.004). The diagnosis was made within 1 hour of admission in 40% of patients in the Painless group and in 76% in the Painful group. The Painless group more frequently had a persistent disturbance of consciousness (44% vs 6%, P<0.001); syncope (25% vs 1%, P<0.001); and a focal neurologic deficit (19% vs 2%, P=0.006) as presenting symptoms. Cerebral ischemia (50% vs 1%, P<0.001) and cardiac tamponade (38% vs 13%, P=0.01) were more frequent complications in the Painless group. In-hospital mortality was not significantly different (19% vs 15%). However, the Painless group had a more unfavorable functional outcome on Overall Performance Category (P<0.001). Characteristics associated with unfavorable functional outcome were cerebral ischemia and cardiac tamponade on admission. The time from admission to a definite diagnosis was not significantly related with unfavorable functional outcome.

Conclusions:
Painless AAD patients often present with a disturbance of consciousness or a neurologic deficit and have higher morbidity. Although it takes more time for definite diagnosis of painless AAD than painful AAD, the major causes for increased morbidity are complications of AAD on admission rather than the diagnostic delay.
Abstract 9461: Circulating CD14
+
CD16
+
Monocyte Subsets as Biomarkers for Severity of Coronary Artery Disease in Patients With Stable Angina Pectoris
Authors: Ozaki Yuichi , Imanishi Toshio , Aoki Hirishi , Orii Makoto , Shiono Yasutsugu , Shimamura Kunihiro , Ishibashi Kohei , Tanimoto Takashi , Yamano Takashi , Ino Yasushi , Yamaguchi Tomoyuki , Kubo Takashi , Akasaka Takashi
Published: April 2024

Background:
Circulating monocytes can be divided into two subsets typically identified by the expression of CD14 and CD16. Although previous studies have shown that circulating monocytes contribute to the progression of coronary atherosclerotic lesions, the relationship between the severity of coronary artery disease (CAD) and the two distinct monocyte subsets has not previously been evaluated. We investigated the relationship between monocyte subsets and severity of CAD assessed by coronary angiography (CAG) in patients with stable angina pectoris (SAP).

Methods:
We enrolled 125 patients who underwent diagnostic CAG. Patients were divided into three groups; those without CAD, those with single-vessel disease (SVD), and those with multiple-vessel disease (MVD), according to diagnostic CAG findings. In addition, severity of CAD was evaluated by Gensini score. Two monocyte subsets (CD14
+
CD16
-
and CD14
+
CD16
+
) were measured by flow cytometry.

Results:
Circulating CD14
+
CD16
+
monocytes were more frequently observed in patients with MVD (24.4 [18.5 to 29.8] %) than in those with SVD (vs. 12.8 [10.0 to 16.2] %, p<0.001) or without CAD (vs. 8.9 [7.6 to 10.2] %, p<0.001). High-sensitivity C-reactive protein and soluble CD40 ligand were not significantly different among the three groups. The proportion of CD14
+
CD16
+
monocytes was positively correlated with Gensini score (r=0.618, p<0.001). Multivariate logistic regression analysis revealed that the preferential increase of CD14
+
CD16
+
monocytes was an independent predictor of MVD ((odds ratio: 1.475; 95% confidence interval: 1.273 to 1.708, p<0.001).

Conclusions:
Our results revealed that the increased proportion of CD14
+
CD16
+
monocytes associated with severity of CAD in patients with SAP. Preferential increase in peripheral CD14
+
CD16
+
monocytes might closely relate to the pathophysiology of CAD progression.
Abstract 9479: Comparison of European Society of Cardiology and Circulation Criteria for Interpretation of the electrocardiogram in Young Athletes
Authors: Menafoglio Andrea , Di Valentino Marcello , Limoni Costanzo , Siragusa Patrick , Moschovitis Giorgio , Gallino Augusto
Published: April 2024

Background:
adding ECG to cardiovascular screening of young athletes remains controversial. One of the reasons refers to the false positive rate of ECG requiring subsequent examinations and raising costs. In an attempt to increase specificity, the European Society of Cardiology (ESC) in 2010 and a group of experts in 2011 (Circulation - CIRC) have proposed recommendations for interpretation of ECG in athletes. The purpose of this study is to compare the ESC and the CIRC criteria for interpreting ECG in young athletes.

Methods:
ECG was analysed as part of a prospective study about the impact of cardiovascular screening with ECG in young (14-35 years) competitive athletes. ECG was interpreted applying strictly the ESC criteria and the CIRC criteria. The rate of pathologic ECG following both criteria were compared.

Results:
ECG of 1070 athletes (75 % males, age 19.7 ± 6.3 years) was analysed. ECG was considered pathologic in 211 (19.7 %) athletes following the ESC criteria and in 42 (3.9 %) athletes following the CIRC criteria (p < 0.001). In table 1 are reported the ECG changes in whom there were differences in pathologic ECG applying ESC and CIRC criteria.

Conclusions:
strictly applying ESC criteria for interpretation of ECG in young athletes, in respect to CIRC criteria, results in a considerably higher proportion of pathologic ECG thus requiring more subsequent examinations. It appears that ESC criteria should be improved toward the best balance between false positive and negative findings.
Abstract 9502: Is Auscultation the Achilles' Heel of Sports Screening? -Evidence on the Proficiency of Primary Care Physicians
Authors: Martinez Matthew W , Ayub Bilal , Barrett Michael
Published: April 2024

Background
Preparticipation sports screening relies heavily on physical examination. Studies have shown that most sports preparticipation examinations are performed by non-cardiology physicians. The question we sought to examine was whether primary care physicians can reliably recognize heart murmurs and sounds including the murmur of hypertrophic cardiomyopathy.

Methods
Primary care physicians attending a national meeting for internal medicine were examined on their ability to recognize basic murmurs including aortic stenosis, mitral regurgitation, and innocent systolic murmurs. In addition, extra heart sounds and the advanced murmur of hypertrophic cardiomyopathy were also examined. Murmurs and other heart sounds were played in random order on a torso showing the location of the stethoscope. Participants were required to identify the heart sounds on a blank sheet of paper as the pretest. All attended a 90 minute workshop on cardiac auscultation. Murmurs and heart sounds were randomly retested.

Results
1086 physicians participated in the pre and post testing. Average pretest score was 47% (range 36-54%). There was no difference whether testing was tested on basic murmurs, extra heart sounds or hypertrophic cardiomyopathy. Average posttest score was 77% (range 65-86%) (p <0.001 by paired t test).

Conclusions
Primary care physicians perform the majority of sports screening in the US. They primarily utilize physical examination to determine safety for play. These data suggest common murmurs are often unrecognized. Murmur recognition is easily improved after a brief education. Additional studies should be aimed at identifying if this is sustained learning or whether continuous education for murmur recognition should be required for those performing sports screening.
Abstract 9528: Excellent Mid-Term Outcomes in Asymptomatic patients with Mitral Regurgitation: A Case for Early Intervention
Authors: Varghese Robin , Anyanwu Anelechi C , Itagaki Shinobu , Adams David H
Published: April 2024

Objective:
To assess outcomes of mitral valve repair surgery stratified by a patient's ACC/AHA guideline indication for surgery.

Methods:
Between May 2003 and December 2010 data was collected on 645 consecutive elective patients with degenerative severe mitral valve regurgitation who underwent mitral valve repair surgery (MVRr). Study patients were stratified into and subsequently analyzed as three cohorts based on the ACC/AHA guidelines: Group 1: Asymptomatic patients without ACC/AHA echocardiographic or clinical triggers for surgery (133 patients), Group 2: Asymptomatic patients with at least one ACC/AHA echocardiographic or clinical trigger for surgery (135 patients), and Group 3: Symptomatic patients with or without ACC/AHA echocardiographic triggers for surgery (377 patients). Echocardiographic parameters and survival were measured during the follow up period.

Results:
Patient follow up was 100%. Mean age was 54.4 +/- 12.2 years, 56.2 +/- 10.7, and 58.2 +/- 14.2 in groups 1, 2, and 3 respectively (p=0.013). Preoperative comorbidities were similar in the three groups. A 100% repair rate was achieved in the series. 30-day operative mortality was 0% (0/133) in group 1, 0% (0/135) in group 2 and 1.1% (4/377) in group 3 (p=0.24). Mean preoperative ejection fraction was expectantly different between the cohorts: Group 1; 64% +/- 5%, group 2; 58% +/- 7%, and group 3; 60% +/- 8% (p=0.001). Echocardiographic follow-up ranged from 0.07 -100 months with mean follow up of 2.2 years. The overall survival at 8 years was: Group 1; 100%, group 2; 100%, and group 3; 91% +/- 3%. Freedom from moderate MR at 8 years was: Group 1; 93% +/- 4%, group 2; 86% +/- 3%, and group 3; 88% +/- 3%.

Conclusions:
Early mitral valve repair can be offered to patients with near 100% likelihood of repair and low morbidity. Early repair had a trend to a better freedom from moderate MR at 8 years. At expert centers, early mitral valve repair surgery should be offered to asymptomatic patients without echocardiographic or clinical triggers.
Abstract 9546: Oxidized Calcium Calmodulin Dependent Kinase II Causes Increased Mortality after Myocardial Infarction in Diabetic Mice
Authors: Luo Min , Guan Xiaoqun , Anderson Mark
Published: April 2024

Diabetes increases oxidant stress and doubles the risk of dying suddenly after myocardial infarction (MI) but the mechanisms for increased mortality are unknown. Mice with streptozotocin (STZ)-induced diabetes developed profound heart rate slowing and died at twice the rate of controls after MI surgery. Oxidized CaMKII (ox-CaMKII) was significantly increased in pacemaker tissues from diabetic compared to non-diabetic patients after MI and from STZ-treated diabetic mice. STZ-treated mice had increased pacemaker cell ox-CaMKII and apoptosis, which were further enhanced by MI. We developed a knock-in mouse model of oxidation-resistant CaMKIIδ (MM-VV). STZ-treated MM-VV mice and wild type mice infused with MitoTEMPOL, a mitochondrial-targeted antioxidant, showed significantly reduced ox-CaMKII, increased pacemaker cell survival, preserved heart rates and were resistant to diabetes attributable mortality after MI. Our findings suggest activation of a mitochondrial/ox-CaMKII pathway contributes to increased sudden death in diabetic patients after MI.