bluuebunny/crossref_metadata_2025 huggingface dataset:
Abstract 18023: In vivo Validation of Area Change Ratio to Estimate Myofiber Strain in the Heart
Authors: Ashikaga Hiroshi , Omens Jeffrey H
Published: April 2024

Background:
Area change ratio (AC) using the 3-D speckle tracking echocardiography is emerging as a mechanical index that approximates myofiber shortening by incorporating both circumferential and longitudinal shortening. However, AC has not been validated against myofiber strain in the heart
in vivo
, and its physiological significance remains unclear.

Methods and Results:
We studied the time course of AC in the anterior mid-left ventricular wall of normal canine heart
in vivo
(n=14) during atrial pacing over the entire cardiac cycle using transmurally implanted markers and biplane cineradiography (8 msec/frame). AC was calculated as the myocardial area change relative to the elemental material area on the circumferential- longitudinal plane at the reference configuration (= end diastole). AC was compared with myofiber strain that was determined from transmural fiber orientations directly measured in the heart tissue. The time course of both AC and myofiber strain was determined in the subepicardial, midwall, and subendocardial layers. The time course of AC and myofiber strain was significantly different (P<0.05), and the difference was more pronounced towards the endocardium (Figure). AC consistently overestimated myofiber shortening. The timing of the peak AC was significantly delayed compared to that of the peak myofiber shortening (P<0.05).

Conclusions:
AC is significantly different from myofiber strain both in magnitude and timing
in vivo.
AC overestimates myofiber shortening, and the overestimation is worse towards the endocardial layers, likely resulting from crossfiber deformation that is inherently included in AC. The significant delay in estimating the peak myofiber shortening may hinder accurate optimization and/or responder identification for cardiac resynchronization therapy.
Abstract 18025: Cryomaze for Sole-Therapy Atrial Fibrillation
Authors: Murtaza Ghulam , Wyler von Ballmoos Moritz , Masroor Saqib
Published: April 2024

Objectives:
Surgical AF treatment program was started at our institution in August 2008. We report our initial results using minithoracotomy approach for endocardial cryomaze.

Methods:
All 30 patients undergoing Cryomaze between 8/08 and 12/10 are included. 1 patient underwent MVR while two others needed sternotomy for incidental aortic aneurysm and coronary artery disease diagnosed during preoperative workup. Surgical technique consisted of femoral cannulation for cardiopulmonary bypass and right mini-thoracotomy with video-assistance. Aortic root vent used in all cases and Chitwood clamp was used in arrested heart cases. On the left side, all pulmonary veins were isolated as an island and another line was made to the mitral annulus (LA isthmus line). On the right side, SVC was connected to IVC and this line was connected to tricuspid annulus (RA isthumus line). Left atrial appendage was oversewn in two layers, except during sternotomy, where it was stapled off with endo-GIA stapler. Beta blockers were used as tolerated and amiodarone was only used if patient developed AF. Postprocedure follow-up included spot EKG at 1, 3, 6 and 12 months and yearly thereafter. Symptomatic patients underwent three week continuous rhythm monitoring.

Results:
Outcomes are given in table below. 4(13%) patients required permanent pacemakers. There were 6 (20%) complications including catheter ablation for atrial tachycardia, pericardial effusion (no intervention needed), subcutaneous emphysema, lung hernia, femoral lymph leak and reopening of one LAA. There were no mortalities or strokes.

Conclusions:
Minimally invasive Cryomaze has acceptable morbidity and excellent short-term results in treating AF. Freedom from AF in this series was not influenced by left atrial vs biatrial ablation, beating heart vs arrested heart ablation, primary vs prior failed catheter ablation, or Paroxysmal vs Persistent AF.
Abstract 18029: Left Ventricular Systolic Strain in Older Subjects with No Known Cardiac Disease
Authors: Purushottam Bhaskar , Kotler Morris N , Figueredo Vincent M
Published: April 2024

Introduction:
It is known that with increasing age impaired myocardial relaxation increases, while systolic function is preserved. We hypothesize that there is, in fact, subclinical left ventricular (LV) systolic dysfunction in older subjects. We test this hypothesis by assessing LV systolic strain using velocity vector imaging in older subjects with no known cardiac disease.

Methods:
One-hundred and ninety consecutive subjects with no known cardiac disease had their echocardiograms analyzed by VVI after excluding patients with a left ventricular ejection fraction(LVEF) <55%, grade 2 and above diastolic dysfunction and QRS duration > 120ms. Subjects were divided into 2 groups based on age; older (> 60 years) and younger (< 60 years). Demographic, clinical and echocardiographic data were collected. Time to peak longitudinal and circumferential strain were calculated from apical 4-chamber, 2-chamber and short axis views. The above collected data were compared between groups.

Results:
The final cohort consisted of 136 subjects (46 were older). Mean age was 55 + 16 years, 32% were female and mean LVEF was 60 + 8%. The older group had a higher LVEF (63 + 9% vs. 59 + 6%; p=0.03), smaller LV diastolic dimension (4.4 + 0.5cm vs. 4.7 + 0.5cm; p<0.01) and higher occurrences of diastolic dysfunction (84% vs. 59%; p<0.01) and hypertension (85% vs. 63%; p=0.02), when compared to the younger group. There were no significant differences in the longitudinal and circumferential strain (even with cut-off ages of 50 or 75 years).

Conclusions:
Contrary to our hypothesis, older subjects with no known cardiac disease had a better LVEF than their younger counterparts. There were no significant differences in the longitudinal and circumferential myocardial strain between the older and younger groups. Therefore, impaired myocardial relaxation does not appear to have a direct influence on the myocardial contractility or systolic function in older subjects.
Abstract 18053: Use of Cardiocerebral Resuscitation or AHA 2005 Guidelines by EMS Improves Survival from Out-of-Hospital Cardiac Arrest: A Systematic Review and Meta-Analysis
Authors: Salmen Marcus , Ewy Gordon , Sasson Comilla
Published: April 2024

Background:
The 2005 American Heart Association (AHA) Guidelines on CPR advise minimal interruptions in chest compressions during out-of-hospital cardiac arrest (OHCA). Growing evidence suggests that use of Cardiocerebral Resuscitation (CCR) - compressions without ventilations - may increase survival. To date, no systematic review has been conducted to assess the impact of implementing CCR or AHA 2005 guidelines.

Objective:
To determine if Emergency Medical Services (EMS) implementation of CCR or AHA 2005 protocols improved patient outcomes from OHCA.

Methods:
We conducted a systematic search of electronic databases (MEDLINE, EMBASE, CENTRAL) and consulted experts to identify all potential studies.
A priori
study inclusion criteria were: 1) used human OHCA subjects, 2) compared CCR or AHA 2005 guidelines to AHA 2000 guidelines, and 3) met AHA criteria for “Good” quality.

Results:
We identified 681 potentially relevant articles. The 12 studies meeting inclusion criteria are shown with their data in Table 1. All 3 studies using CCR demonstrated improved survival compared to use of AHA 2000 guidelines, as did 5 out of the 9 studies using AHA 2005 guidelines. Pooled data demonstrates that use of a CCR protocol has an Odds Ratio of 2.25 (95% Confidence Interval [CI]: 1.81-2.79) for survival to hospital discharge among all cardiac arrest patients. Use of AHA 2005 Guidelines increases all patient survival by an OR of 1.39 (95% CI: 1.10-1.75).

Conclusion:
Our systematic review and meta-analysis demonstrated improved survival from OHCA when EMS use CCR or AHA 2005 guidelines. Additional research is needed to further define the difference in outcomes between these two protocols.
Abstract 18075: Resource Utilization in Patients with Mitral Regurgitation Before and After Surgical Intervention: An Analysis of the Centers for Medicare and Medicaid Services Database
Authors: Hong Kimberly N , Iribarne Alexander , Ascheim Deborah , Moskowitz Alan , Gelijns Annetine , Russo Mark J
Published: April 2024

PURPOSE:
The purpose of this study is to characterize resource utilization in Medicare beneficiaries with mitral regurgitation by comparing hospitalization rates and costs before and after surgical intervention.

METHODS:
De-identified inpatient claims data were obtained from the Centers for Medicare and Medicaid services for 1/1/2001 to 12/31/2005. Medicare beneficiaries with functional mitral regurgitation (ICD9: 424.0) who received mitral valve surgery (ICD9 codes: 35.12, 35.23, 35.24, 35.33) during this time period were included in analysis (N=68,344). Only claims data 1 year before (N=44,190) and 1 year after surgical intervention (N=78,600) was analyzed. Costs from surgical intervention hospitalization was excluded from analysis. Outcome measures included median inpatient costs, hospitalization rates and length of stay. Costs were estimated using ratio-of-costs-to-charges, and age-adjusted hospital costs were compared using quantile regression. Primary ICD9 diagnosis code was used to categorize type of hospitalization.

RESULTS (TABLE):
Median hospitalization costs for patients prior to surgical intervention were higher than after (p<0.05). Mean hospitalization rate in the year prior to surgical intervention was lower than in the year immediately following (p<0.001). Mean LOS was also longer after surgical intervention compared to before (p<0.001). A greater proportion of hospitalizations before surgery were associated with Congestive Heart Failure (ICD9: 428.0) compared to after (p<0.001).

CONCLUSIONS:
Even though LOS and readmission rates are higher in Medicare beneficiaries in the year following surgical intervention, hospitalization costs are significantly lower. This may be secondary to fewer Congestive Heart Failure hospitalizations after surgical intervention.
Abstract 18088: The Geriatric Assessment Score is a Proper Clinical Tool to Stratify Older Old Patients Admitted with Heart Failure for In-Hospital and Two-Year Survival
Authors: Rodriguez-Pascual Carlos , Paredes-Galan Emilio , Perez-Soto Daniel , Vilches-Moraga Arturo , Ferrero-Martinez Ana I , Torrente-Carballido Marta , Lazarini Jose Antonio , Rodriguez-Artalejo Fernando
Published: April 2024

OBJECTIVES.
- To determine the influence of physical, cognitive function and other comprehensive geriatric assessment (CGA) components on in-hospital and two-year mortality of older adults admitted with acute heart failure (HF).

METHODS
- Prospective study of 581 individuals aged >75 years admitted due to HF. Demographic, clinical, echocardiographic and analytical data were recorded. CGA included dependence in activities of daily living (ADL), mobility, cognitive status, screening for depression, comorbidity and pharmachological prescriptions. A Geriatric Assessment Score (range 0-10 p) was constructed. Mean follow-up of 533 hospitalization survivors was 77+52 weeks. A logistic regression model to determine factors independently related with in-hospital mortality and a Cox regression model to identify those related with two years mortality were constructed.

RESULTS
- Mean age 85.8±5.8 y., 67% women, 75% preserved ejection fraction, mean comorbidity index 3.97±3.01. Cognitive impairment was present in 45%, depression in 49%, 66% had mobility problems and 50% dependence in >1 ADL. In-hospital fatality was 8.2%. Variables associated with in-hospital mortality included NYHA class III (OR 4.1, 95% CI 1.5-10.8) or IV (OR 19.6, 95% CI 6.3-60.9), pulmonary oedema (OR 3, 95% CI 1.3-6.6), renal failure (OR 2.8, 95% CI 1.2-6.2) and the Geriatric Assessment Score (OR per point of increment 1.2, 95% CI 1-1.4). Two-year mortality related factors included age (OR 1.06, 95% CI 1.03-1.09), Geriatric Assessment Score (OR 1.17, 95% CI 1.09-1.27), NYHA functional class III (OR 1.62, 95% CI 1.18-2.23) or IV (OR 3.02, 95% CI 1.49-6.10), left ventricle systolic dysfunction (OR 1.67, 95% CI 1.20-2.31), comnorbidity index (OR 1.07, 95% CI 1.02-1.12), AF (OR 1.57, 95% CI 1.15-2.15), ACEI or ARB treatment (OR 0.66, 95% CI 0.49-0.90) and renal failure (OR 1.01, 95% CI 1.00-1.01).

COCNLUSIONS
- In very elderly heart failure patients, an index incorporating comorbidities, total number of prescription drugs, cognitive, functional and mobility status predicts in-hospital and two-year survival. In addition to other variables previously known, these should be considered for a better stratification of elderly patients admitted with HF.
Abstract 18097: Diagnostic and Prognostic Value of Serum Concentration of High-Sensitivity Cardiac Troponin T Relative to Heart-Type Fatty Acid-Binding Protein in the Early Hours of Suspected Acute Coronary Syndrome
Authors: Matsui Shigeru , Ishii Junnichi , Kawai Tomoko , Hattori Tousei , Hattori Kousuke , Okumura Masanori , Naruse Hiroyuki , Motoyama Sadako , Izawa Hideo , Nomura Masanori , Ozaki Yukio
Published: April 2024

Background:
Heart-type fatty acid-binding protein (H-FABP), a low-molecular-mass cytoplasmic protein, has been proposed as an early biomarker for acute myocardial infarction (AMI). Thus, we prospectively investigated the diagnostic and prognostic value of serum level of high-sensitivity troponin T (hsTnT) relative to H-FABP in the early hours of acute coronary syndrome (ACS).

Methods:
Serum samples for measurements of hsTnT and H-FABP were drawn on admission in 460 consecutive patients (median age, 67.5 yrs) hospitalized to the cardiac emergency department for suspected ACS within 6 hrs (3.5 hrs) after the onset of chest symptom. Cardiac events, which were defined as cardiac death or rehospitalization for ACS or heart failure, were monitored for 12 months after admission. The final diagnosis was adjudicated by two independent cardiologists.

Results:
224 (48.7%) patients were diagnosed as AMI [ST-segment elevation myocardial infarction in 154 (33.4%) patients; and emergent coronary angiography within 24 hrs after admission in 195 (42.4%) patients]. The area under the ROC curve was higher for hsTnT than for H-FABP
(Table).
The sensitivity and predictive accuracy of increased hsTnT (> 0.014 ng/ml of 99th percentile) were higher than those of increased H-FABP (≥ 6.2 ng/ml of upper reference limit). Also, there was no significant difference in specificity between hsTnT and H-FABP. During 12-month follow-up period, there were 38 (8.3%) cardiac events including 11 cardiac deaths. In a stepwise Cox regression analysis, increased hsTnT (relative risk 14.5, P = 0.009), but not H-FABP, was independently associated with cardiac events. Patients with increased hsTnT had a higher risk of cardiac events within 12 months compared with those without (14.1% vs. 0.5%, P < 0.0001).

Conclusion:
An hsTnT assay may provide diagnostic and prognostic information superior to H-FABP assay in the early hours of suspected ACS.
Abstract 18122: The Severity and Extent of Coronary Artery Stenosis Predicts Long-Term Mortality Even in Patients with Non-Obstructive Disease
Authors: Mudrick Daniel W , Horton John R , Shaw Linda K , Douglas Pamela S
Published: April 2024

Introduction:
The influence of non-obstructive coronary artery disease (CAD) on long-term mortality, and therefore optimal intensity of treatment, has not been well defined.

Hypothesis:
Increasing grades of coronary stenosis at invasive angiography will predict long-term all-cause mortality, even among patients with non-obstructive disease.

Methods:
We identified 31,121 consecutive adult patients without acute coronary syndrome or prior revascularization undergoing first invasive coronary angiography at Duke Hospital to evaluate CAD between 1986 and 2007. We evaluated all-cause death using Cox proportional hazards models including CAD severity (as defined by a Modified Duke CAD Index - see figure legend), baseline characteristics, and risk factors. Complete follow-up was obtained in 99% of patients by survey, Social Security Master Death File search and National Death Index search.

Results:
Median follow-up time was 9.3 years (IQR 5.0-15.5 years) with 14,588 deaths. Unadjusted hazard ratio of death increased with CAD grade, even with non-obstructive CAD (Figure). In multivariable analysis, Modified Duke CAD Index remained the strongest predictor of mortality after age, CHF class, and ejection fraction (Wald X
2
= 411.0, HR 1.10 per grade, p<0.0001). Adjusted mortality increased with increasing CAD grade at 5 years (10%, 15%, 18%, 19%, 22%, 27%, 31%) and 10 years (19%, 29%, 34%, 36%, 41%, 48%, 53%).

Conclusions:
The relationship between CAD severity and mortality is continuous, including non-obstructive CAD. Studies to determine optimal treatment strategies for patients with non-obstructive CAD may be indicated.
Abstract 18178: Role of Mesenchymal Stem Cell SDF-1 Release and Myocardial CXCR4 Expression in Post -MI Cardiac Repair
Authors: DONG Feng , Finan Amanda , Weber Kristal , Penn Marc
Published: April 2024

Introduction:
Adult stem cell based repair of the heart is due to paracrine factor release. SDF-1 has been shown to affect multiple pathways involved in tissue repair and is secreted by mesenchymal stem cells (MSC). In this study we directly tested the importance of MSC SDF-1 release on myocardial response to MSC engraftment after myocardial infarction (MI).

Methods:
Cardiac myocyte (CM)-CXCR4 null mice were generated using tamoxifen inducible cardiac specific cre by crossing the CXCR4 floxed with the MCM-cre mouse. Studies were performed in littermates who did (CM-CXCR4 null) or did not (control) receive tamoxifen at least 3 weeks before MI. Mice were randomly selected to receive either 100,000 GFP positive MSC or saline 1 d after MI. Cardiac stem cells (CSC) population in the heart 7 days post MI were investigated by flow cytometry. Serial echocardiography was used to assess cardiac function. The number of TUNEL positive cardiac myocytes in the infarct border zone was quantified 4 days after AMI. Vascular density and infarct size were measured 21 d after AMI.

Results:
The αMHC-MerCreMer promoter is activated in both endogenous CSC and cardiac myocytes. There was a similar level of MSC engraftment in wild-type (WT) and CM-CXCR4 null mice 7 days following MSC infusion. MSC engraftment led to a significant increase of CSC recruitment (100.9%, p<0.01) in the heart of WT mice 7 days after MI that was decreased to 55.4% in CM-CXCR4 null mice. MSC treatment decreased CM apoptosis by 44% in WT mice but only 23% in CM-CXCR4 null mice (p<0.01). Consistent with improved CM survival, MSC infusion led to an 80% (p<0.05) increase in ejection fraction in WT mice compared to a 40% (p=NS) increase in CM-CXCR4 null mice despite similar levels of an increase (16%) in vascular density in the presence or absence of CM-CXCR4.

Conclusion:
Our results demonstrate a specific paracrine mechanism of MSC engraftment and support an important role for SDF-1/CXCR4 in CSC recruitment and cardiac myocyte survival after AMI. Furthermore, our data demonstrate that in the absence of SDF-1 mediated increases in cardiac myocyte survival and CSC recruitment, the increase in vascular density induced by MSC engraftment is unchanged but insufficient to induce significant improvements in cardiac function after AMI.
Abstract 18196: Aldehyde Oxidase is a Potent Source of Superoxide Generation and Can Modulate Cardiac Contractile Function
Authors: Kundu Tapan K , Reyes Levy , Varadharaj Saradhadevi , Zweier Jay L
Published: April 2024

Aldehyde oxidase (AO) is a cytosolic enzyme belonging to the xanthine oxidoreductase (XOR) family. A variety of aldehyde substrates are known to be formed in cardiovascular disease secondary to inflammation and oxidative stress that are efficient AO substrates. While XOR has been reported to influence heart function in heart failure and is well known to be an important source of superoxide (O
2

•
-

), little is known regarding the role of AO in cardiac oxidant signaling. In order to assess the presence of AO in the heart and its potential role in cardiovascular pathophysiology, we studied the distribution of AO in rat myocardium and isolated cardiac myocytes as well as its levels and activities in heart tissue. Furthermore, in isolated perfused rat hearts we measured the functional effect of AO activation or inhibition. Immunohistochemistry, using an AO specific antibody, showed a myofibrillar / sarcomere distribution for AO. In control rat myocardium, the activity of AO was found to be 1.5-fold higher than that of total XOR (0.21±0.02
vs
. 0.14±0.01 nmol min
-1
mg
-1
of protein), and the levels of protein 2.5-fold higher than that of XOR (30.26±2.42
vs
. 11.86±1.07 nM), while O
2

•
-

production (measured by cytochrome c assay) in the presence of optimal substrate levels was estimated to be >10-fold higher for AO than XOR. In isolated perfused rat hearts, infusion with the AO substrate 4-(dimethylamino)cinnamaldehyde (
p
-DMAC) (10 μM) resulted in a significant increase in left ventricular developed pressure (LVDP) of 14±3% (p<0.05), while treatment with the potent inhibitor amadone (10 μM) completely inhibited this increase. Thus, AO is present in cardiac myocytes adjacent to the contractile proteins and in the presence of aldehyde substrates it can function as an important source of O
2

•
-

modulating contractile function. Further studies will be needed to assess the potential role of AO in modulating cardiac function in ischemic syndromes and heart failure.
Abstract 18212: Relationship Between Aortic Distensibility and Coronary Blood Flow in Patients with Ascending Thoracic Aortic Aneurysm
Authors: Bavishi Chirag , Siddiqi Faisal , Alkhateeb Haider , LeMaire Scott , Coselli Joseph , Diez Jose G
Published: April 2024

Introduction:
We have observed coronary slow flow in patients with aortic aneurysms in the absence of coronary artery disease (CAD). Other observations have identified that aortic wall distensibility influences coronary blood flow. In order to further evaluate this phenomenon, we sought to study the relationship between aortic distensibility and coronary blood flow among the patients with ascending thoracic aortic aneurysms (ATAA).

Methods:
Evaluation of consecutive patients referred for surgical repair of ATAA who had non- obstructive CAD (<40% stenosis) as evaluated by coronary angiography. Aortic distensibility was calculated from aortograms using the formula D = 2 x (change in aortic diameter) / (diastolic aortic diameter) x (change in aortic pressure). Coronary blood flow was measured in all major coronary arteries by calculating TIMI frame count. Spearman rank correlation test was performed to evaluate the correlation between aortic distensibility and TIMI frame counts for the three major coronary arteries.

Results:
Out of 96 patients with angiographic slow flow, 89 (92.7%) patients had involvement of the ascending aorta with or without arch and/or descending aorta and non-obstructive CAD. Analysis of the 89 ATAA patients showed a significant correlation between decreased ascending aortic distensibility and prolonged TIMI frame count in all the three coronary arteries. Correlation coefficient between ascending aortic distensibility and LAD flow is r = -0.23, p = 0.03, LCX is r = -0.28, p = 0.007, RCA is r = -0.30, p = 0.005. A significant inverse correlation, r = -0.23, p = 0.04 is also observed between aortic arch distensibility and LAD flow.

Conclusion:
As the distensibility of the aorta decreases in patients with thoracic aortic aneurysm, the coronary blood flow also decreases. Our study for the first time shows that among the patients with thoracic aortic aneurysms, aortic distensibility does impact coronary blood flow in the absence of significant CAD, possibly through alteration in coronary blood flow mechanics and microvascular dysfunction. The clinical impact of this finding warrants further studies.
Abstract 18260: Local Interleukin-6 and Pericardial Drainage Volume are Associated with Atrial Fibrillation After Coronary Artery Bypass Grafting
Authors: Wenyan Tao , Fangqin Wu , Hongyuan Tang , Dongyan Shen , Haibyong Zhang , Haibo Zhao , Ying Wu
Published: April 2024

Objective.
To examine the relationship between IL-6, WBC, CRP levels and volume of pericardial drainage in patients with AF following CABG.

Method.
In 124 patients with sinus rhythm (SR) undergoing elective isolated CABG, IL-6, WBC count and CRP levels were measured in pericardial drainage and peripheral blood at six, 12, and 18 hours (hrs) postoperatively. The volume of pericardial drainage was also recorded at the same time interval. Two-factor ANOVA for repeated measures was used to test the trends of the above parameters and their relationship with postoperative AF (POAF).

Results.
AF occurred in 44 (35.5%) patients and IL-6 levels in pericardial drainage increased over time in this group (from 1353.9 pg/ml at six hours to 2189.2 pg/ml at 18 hrs), while it was peaked at 12 hrs and declined thereafter in the SR group (1541.5 pg/ml at six hours, 1906.3pg/ml at 12 hrs, and 1876.2 pg/ml at 18 hrs). Two-factor ANOVA for repeated measures showed that the change of mean IL-6 levels in drainage over time between the two groups was significantly different (
P
= 0.016). The postoperative levels of IL-6 in peripheral blood declined slowly over 18 hours in both groups (from 71.61 pg/ml to 62.90 pg/ml and 85.56 pg/ml to 75.92 pg/ml, respectively). Interestingly, IL-6 levels in drainage were 28 and 22 times higher in drainage than those in blood in the AF and SR groups, while the difference of IL-6 levels in drainage and blood in the AF group was six times higher than in the SR group (
P
= 0.014). Although the volume of drainage decreased over time in both groups, logistic regression showed that age adjusted total drainage of ≥ 430 ml during the first 18 hours post-op was an independent predictor of POAF (OR 3.91, 95%CI 1.55-10.27). CRP levels in the drainage of the AF and SR groups increased noticeably from 3.74 and 3.08 mg/L at six hours, to 16.76 and 15.45 mg/L at 18 hrs after surgery, and in blood from 9.95 and 9.82 mg/L to 41.70 and 41.36 mg/L, respectively. CRP levels in blood were higher than in drainage for both groups (
P
< 0.001). There was no association between the occurrence of POAF and CRP levels or WBC in either drainage, or blood.

Conclusion.
IL-6 may be produced locally after CABG, and the levels of IL-6 in, as well as the volumes of pericardial drainage were associated with POAF.
Abstract 18299: Perceived Social Support Operates Through Self-Efficacy to Positively Influence Heart Failure Self-Care Management
Authors: Cene Crystal W , Haymore Beth , Dolon-Soto Diane R , Lin Feng-Chang , Pignone Michael , DeWalt Darren , Broucksou Kimberly , Hawk Victoria , DeLong Christine , Wu Jia-Rong , Corbie-Smith Giselle
Published: April 2024

Background:
Studies show a modest positive association between social support and chronic illness self-management. However, the extent to which social support influences Heart Failure (HF) self-care and whether HF self-efficacy mediates this relationship is not well understood.

Methods:
We conducted a cross-sectional survey of community-dwelling patients with systolic or diastolic HF seen in a university internal medicine or cardiology clinic. We separately assessed HF self-care
maintenance
(i.e. engaging in behaviors to help maintain physiologic stability- medication adherence and frequent weighing) and self-care
management
(i.e. decision-making in response to symptoms- recognizing signs of fluid overload and adjusting diuretic dose) using the Self-Care of Heart Failure Index (SCHFI). Emotional/informational support was assessed using the Medical Outcomes Study social support survey. HF self-efficacy was assessed using the SCHFI self-efficacy subscale. We used linear regression to examine differences in self-management behaviors, adjusting for age, race, gender, marital status, education, income, and self-rated health. Mediation analysis was done according to Baron & Kenny method.

Results:
Of the 146 participants (mean age 61yrs; 51% female; 43% African Americans), mean (SD) emotional/information support and self-efficacy were 82.4 (SD 19.8) and 64.5 (SD 17.0), respectively; 33% had “adequate” HF self-efficacy (scores ≥ 70). In multivariable analysis, more emotional/informational support was associated with better self-care
maintenance
(B coefficient 0.14, SE 0.60; p=0.03). More emotional/information support was associated with better self-care
management
(B coefficient 0.23, SE 0.11; p=0.04) in bivariate but not multivariable analysis (B coefficient 0.18, SE 0.12; p=0.12). HF self-efficacy strongly mediates the association between emotional/informational support and self-care
maintenanc
e, but not
management.

Conclusion:
Emotional/informational support is more strongly associated with behaviors to maintain physiologic stability than with decision-making related to symptom management. Greater self-efficacy is a mechanism by which emotional/informational support influences HF self-care
management
.
Abstract 18353: FOXO3a and Cardiac Remodeling - Modulation of MMP13 Expression
Authors: Stehr Jenny , Schmidt Franziska , Holzhauser Luise , Jenke Alexander , Schultheiss Heinz-Peter , Skurk Carsten
Published: April 2024

Objective:
Structural alterations of cardiac extracellular matrix occur as a result of pathological processes in the heart, e.g. dilated cardiomyopathy or myocardial infarction. Matrix metalloproteinases (MMPs) are proteolytic enzymes which play a pivotal role in stress induced matrix remodeling. FOXO transcription factors are important stress-activated regulators of cell cycle and size. Therefore, we hypothesized that FOXO3a, a member of the FOXO family known to be expressed in myocardium, modulates the expression of MMPs.

Methods:
Cardiac myocytes and fibroblasts were transduced with adenoviral vectors encoding either wild-type FOXO3a (WT-FOXO3a), constitutive-active FOXO3a (TM-FOXO3a) or GFP as control. Effects on potential target genes were assessed by QRT-PCR, Western blot/IHC, specific Collagenase assay, CHIP or luciferase promoter assay. Effects of viral myocarditis were studied in WT and FOXO3a-/- mice.

Results:
Cardiac myocytes and fibroblasts transduced with FOXO3a did not show differences in MMP1, -2, -3, -9 as well as TIMP 1,-2,-4 gene or protein expression when compared with control vector. However, WT-FOXO3a or TM-FOXO3a gene transfer dose-dependently upregulated MMP13 mRNA expression (3.5 ± 1.2 and 22.0 ± 11.0 fold; p < 0.001, WT and TM-FOXO3a vs. GFP, respectively). Furthermore, MMP13 protein levels were also significantly upregulated under these conditions (p < 0.01). Moreover, FOXO3a transduction led to significantly increased Collagenase activity (p < 0.01). Accordingly, FOXO3a-/- mice showed diminished MMP13 mRNA and protein expression. CHIP and luciferase promoter assays revealed binding of FOXO3a to the MMP13 promoter and its transcriptional activation. Finally, viral myocarditis led to FOXO3a activation associated with increased MMP13 mRNA expression that was significantly diminished in FOXO3a-/- mice which demonstrated increased Collagen 1 and 3 protein expression in IHC (p < 0.05).

Conclusion:
In conclusion our results implicate FOXO3a directly in the regulation of MMP13 expression. FOXO3a might play an important role in controlling extracellular matrix remodeling processes under cardiovascular stress and injury such as inflammation. Thus, targeting FOXO3a might have therapeutic potential.
Abstract 18358: Active Aging and Self-Management of Cardiovascular Medications
Authors: Swanlund Susan
Published: April 2024

The rising population of community-dwelling older adults in the United States (US) independently administers an average of five to seven different medications per day. Problems associated with cardiovascular medication self-management include increasing adverse effects and failed symptom management, both possibly leading to hospitalization.

Objectives:

The objective of this research was to explore lifestyle patterns and characteristics and their influence upon successful cardiovascular medication management as perceived by adults over age 65.

Methods:

Guided by naturalistic inquiry, two qualitative exploratory studies were conducted in different US geographical locations. Each study's methodology consisted of qualitative interview sessions with 19 older adults living in community-based settings.

Results:

Inductive data analysis from the first group of participants revealed the themes of organization in daily living, being active and perceiving oneself as healthy as important in medication self-management. Data analysis from the second study revealed parallel findings, with the inclusion of some potential barriers to successful medication self-management: unorganized or inactive lifestyles. Results from both of these studies indicate that older adults whose lifestyle patterns reflect activity and organization are more likely to be successful with their medication self-management than those whose lifestyle patterns reflect inactivity or unorganization. Participants from both studies provided examples of methods to maintain order and remain active despite physical limitations. Older adults' descriptions of themselves as healthy equated with mobility and activity and descriptions of themselves as unhealthy centered on immobility and weakness.

Conclusions:

Through their scheduled days, older adults who accomplished the goals of exercise, social interaction, and taking care of self and others to remain independent were more successful in their medication management processes than those who did not exhibit these characteristics. This information is important to cardiovascular health care professionals as they educate and encourage older adults about health promotion activities and self-management of medications.
Abstract 18406: Are Medical Emergency Team Call Event Rates to the Radiology Department Greater Than to the General Hospital Wards?
Authors: Ott Lora , Pinsky Michael , Hoffman Leslie , Ren Dianxu , Clarke Sean , Clark Sunday , Hravnak Marilyn
Published: April 2024

Objective
: To establish if hospital in-patients are at greater risk for requiring Medical Emergency Team (MET) assistance while in the Radiology Department, we determined the event rates of MET calls to the Radiology department (MET-RD) and the general hospital wards (MET-W).

Design/Participants
: Retrospective review of in-patients experiencing a MET call in 2009.

Setting
: Tertiary care hospital with a well-established MET system admitting 32,000 patients and performing 160,000 in-patient Radiology (RD) procedures per year.

Measurements
: The number of MET-RD was adjusted for length of stay (LOS) to determine the number of MET-RD/hour/1000 RD admissions. The number of MET-W was adjusted for LOS to determine the number of MET-W/hour/1000 hospital admissions.

Main Results
: The MET-RD event rate was slightly higher than MET-W (0.42 v. 0.31 events/hour/1000 hospital admissions) but not statistically different (p=0.73). The overall average LOS in the RD (LOS-RD) was 58 min. General x-ray (XR) comprised 63% of RD admissions but only 11% of MET-RD (LOS 40 min, XR event rate 0.09). Event rates and LOS in the radiology specialty modality areas revealed that 38% of MET-RDs occurred in computed tomography (CT) (average CT LOS 47 min) and an event rate (0.94) over twice the RD average. Magnetic resonance imaging (MRI) represented only 5% of the RD admissions but had 27% of MET-RD (average MRI LOS-RD 90 minutes) and an event rate (1.43) that was 3.5 times higher than the RD average. The longest LOS-RD was in Nuclear medicine (NM; 111 minutes) and represented only 1% of RD admissions but 5% of MET-RD, with an NM event rate (1.34) that was 3.2 times higher than the RD average. Analysis of event rates for the combined RD specialty modalities (minus XR) revealed an average RD specialty modality event rate that was significantly higher when compared to MET-W (0.76 v. 0.31, p=.007).

Conclusions
: Although overall MET-RD event rates were similar to MET-W, they were unevenly distributed across patients receiving CT, MRI and NM studies. The combined event rate in the RD specialty modalities suggest increased MET risk for patients in these areas, which may have implications for RD surveillance practices.
Abstract 196: Measurement of Depth, Thrust and Thoracic Impedance During Mechanical Cardiopulmonary Resuscitation: Is Thoracic Impedance a Potential Indicator of Effective External Cardiac Massage in a Porcine Model of Cardiac Arrest?
Authors: Di Maio Rebecca , Howe Andrew , Crawford Paul , Brody David , Navarro Cesar , McEneaney David , Clutton Eddie , Anderson John , Adgey Jennifer
Published: April 2024

Purpose of the Study:
The 2010 AHA guidelines currently recommend a depth of at least 2 inches (5cm) during external cardiac massage. The purpose of this study was to determine if the use of an alternative measure to depth could assist in quantifying the effectiveness of CPR in an out-of-hospital setting and to determine how achievable depths of at least 2 inches are in experimental models of cardiac arrest.

Materials and Methods:
A total of 12 porcine models were used each weighing 30.7±4.2kg. Depth (mm), thrust (kg); End-tidal CO
2
, and Cardiac Output (CO) were measured at 2 minute intervals for each model. The Impedance Cardiogram (ICG)/Thoracic Impedance (non-invasive measure of cardiac output) was recorded via 2 standard defibrillation electrodes, as a method of detecting the presence of effective CPR. Ethical approval was granted by the Northern Ireland Home Office. Models were anaesthetised using Isoflurane and connected to a Datex Ohmeda® for anaesthesia monitoring. Depth and rate of CPR were continuously measured using Q-CPR®, Philips. CPR was administered using the HLR-201®, Michigan Instruments. Recordings from each experiment were acquired using the Datex Ohmeda for statistical analysis using Microsoft Access®.

Results:
During CPR, cardiac output was maintained at an average of 21% of normal CO levels. At thrusts of 60kg and a rate 112±2 compressions per minute, the average depth (using Q-CPR®, Philips) achieved using a stabilised mechanical CPR system was 37.12mm±3 (1.46±0.12inches). Using the HLR-201®, Michigan Instruments the average depth achieved was 50mm (1.97inches). A strong linear correlation was achieved when comparing depth (mm) using Q-CPR® and the thrust (kg) using the HLR-201®, Michigan Instruments; r=0.856. In addition a strong linear correlation was attained when the Impedance cardiogram (ICG) (ohms) was compared with depth (mm) using Q-CPR®, Philips of; r=0.86.

Conclusions:
A depth of at least 2 inches was almost unattainable in this porcine model, even at thrusts of 60 kg. An algorithm will incorporate the results from this study, providing feedback to the operator on the quality of CPR by measuring the ICG amplitude which has been strongly correlated with standard measures of depth as well as a number of physiological parameters.
Abstract 216: How Many Shocks Should Be Given to Victims with Out-of-Hospital Cardiac Arrest with Shockable Rhythm On-site Before Transportation?
Authors: Hanada Hiroyuki , Yonemoto Naohiro , Kimura Takeshi , Nonoki Hiroshi , Nagao Ken
Published: April 2024

Early defibrillation and high quality cardio-pulmonary resuscitation (CPR) are the key of survival with minimal neurologic impairment (good neurological survival (GNS)) in out-of-hospital cardiac arrest (OHCA) cases. But it has not been clarified how long emergency medical service (EMS) personnel stay on site of OHCA and give CPR with defibrillation before transportation to the hospital. To clarify this, we examined the relationship between the number of defibrillation and the rate of GNS which was defined as the Glasgow-Pittsburgh cerebral performance category of 1 or 2 after one month of OHCA.

Methods and Results.
From January 1, 2005, through December 31, 2009, we conducted a prospective, population-based, observational study involving the consecutive patients across Japan who had OHCA (n=547,218). Since the defibrillation protocol of one shock followed by immediate chest compression and ventilation for 2 minutes had started from January 1, 2007 in Japan, we analyzed from January 1, 2007 to December 31, 2009. We identified 13,152 EMS-treated, witnessed cardiac arrest cases, with the age >18 years old, with the initial rhythm of ventricular fibrillation or tachycardia (VF/VT). Results were shown in the figure. The intervals from witness to start CPR and the rates of by-stander CPR given by citizen were not different among each group. GNS rate was decreased as the number of defibrillation was increased, but GNS rate was still over 10% in the group of 8 shocks.

Conclusions.
In conclusion, up to two shocks on site before transportation would be acceptable (because GNS was more than 20%), and CPR with defibrillation should not be stopped during transportation as long as VF/VT persists.
Abstract 225: Hands-off Fraction Is Not Negatively Impacted by Deployment of the AutoPulse During Out-of-Hospital Cardiac Arrest
Authors: Wik Lars , Olsen Jan-Aage , Persse David , Sterz Fritz , Lozano Michael , Brouwer Marc A , Westfall Mark , Souders Chris M , Malzer Reinhard , van Grunsven Pierre M , Travis David , Whitehead Anne , Herken Ulrich R , Lerner E Brooke
Published: April 2024

Background:
Deployment of mechanical chest compression devices is suspected to increase hands-off fraction. A potential benefit of mechanical devices is defibrillation during compressions, but it is unknown if this is utilized in the field. Our objectives were to compare hands-off fraction between manual CPR (M-CPR) and integrated AutoPulse CPR (iA-CPR), and to determine if providers will defibrillate during mechanical compressions.

Methods:
An international randomized clinical trial of EMS treated adult cardiac arrests of cardiac origin was conducted at 5 sites from March 2009 to January 2011. All EMS providers received 4 hours of training in providing high quality CPR and AutoPulse deployment. After initial manual compressions, patients were randomized to iA-CPR or M-CPR. ECG and impedance or accelerometer data were analyzed to determine the number of compressions per minute, and hands-off fraction was calculated at 10 and 20 minutes. Descriptive statistics and 95% CI were calculated.

Results:
A total of 4,232 subjects were enrolled. Electronic data were available for 4,135 (98%) cases (2,055 M-CPR, 2,080 iA-CPR). There were 117 (3%) cases with no compression data (69 M-CPR, 48 iA-CPR). There were more compressions per minute in the M-CPR arm (table). The mean hands-off fraction at 10 minutes was 20.4% M-CPR and 21.5% iA-CPR (difference 1.1%; 95% CI 0.5% to 1.7%) and at 20 minutes was 20.2% M-CPR and 19.6% iA-CPR (difference -0.6%; 95% CI -1.2% to 0.1%). Average time to AutoPulse start after defibrillator on was 172 seconds (±183). In 84% of the iA-CPR cases the device was not stopped during the first cycle of resuscitation. 74% of the defibrillated iA-CPR cases were shocked during compressions.

Conclusion:
This is the first study to document operational deployment of the AutoPulse. There was no difference in hands-off fraction between M-CPR and iA-CPR. Providers without prior experience using the AutoPulse shocked through compressions in the majority of cases.
Abstract 228: High Incidence of Hyperventilation Associated with Defibrillation Shock Delivery During Out-of-Hospital Cardiac Arrest Patient Resuscitation
Authors: Daya Mohamud , Firoozabadi Reza , Helfenbein Eric , Edelson Dana , Idris Ahamed , Babaeizadeh Saeed , Zhou Sophia
Published: April 2024

Background
Previous studies have highlighted the importance of avoiding hyperventilation during resuscitation of patients with out-of-hospital cardiac arrest (OHCA). Despite this, hyperventilation is often detectable on recorded capnograms, and the causative factors remain undefined. We studied the relationship between hyperventilation and defibrillation shocks. We hypothesized that immediately before and after shock delivery, a link to hyperventilation may exist due to the extreme high stress levels of the rescuers.

Objective
To evaluate quantitatively the time difference between hyperventilation events and shock delivery.

Methods
CO2 and shock data were collected from 270 OHCA patients from two EMS agencies based in Oregon and Texas between 2008 and 2010. We applied an automated hyperventilation detection algorithm with thresholds of respiratory rate > 12 bpm and EtCO2 < 20 mmHg, and manually reviewed results to obtain a total of 209 hyperventilation events from 83 patients who also had a shock (n=476) delivered within 20 minutes. Each hyperventilation event time was subtracted from the nearest shock time to generate the distribution of this difference. To investigate that this distribution actually shows a relation between hyperventilation and shock time that is not random, we generated a similar distribution of the difference between equally spaced points at 10 second intervals to shock times. The variances of the distributions were compared using a two-sample F-test.

Results
The figure shows the distribution of hyperventilation events in relationship to the closest defibrillation shock, and the distribution of all 10 second intervals to shock times. The variances of the distributions were significantly different (p < 0.0001). A total of 48 (23%) hyperventilation events occurred within 1 minute of a defibrillation shock.

Conclusion
Hyperventilation is particularly common immediately before and after shock delivery during OHCA resuscitation.
Abstract 230: Comparing Manual and Mechanical Chest Compression Quality Parameters in 30:2 Mode with Use of a Novel Approach
Authors: Lindblad Pär , Åström Victorén Annika , Axelsson Christer , Madsen Härdig Bjarne
Published: April 2024

This study aimed at analyzing the possibility of evaluating the logistic differences between manual chest compressions (M-CC) and mechanical chest compressions (LUCAS
TM
2, (L-CC)) performed by 17 paramedics. CPR in 30:2 was performed with both techniques on a modified Leardal manikin. The modification consisted of two cords placed at a depth of 4.5 cm inside the manikin. These cords were connected to the electrodes on the manikin and then connected to the defibrillation leads of a Life-Pack 12 defibrillator enabling registration of impedance measurements in CODE-STAT. Thus only compressions reaching the set depth (4.5 cm) were recorded as a correct compression. Two scenarios were tested with both M-CC and L-CC; the first was a stationary scenario of 10 min CPR on the floor, the second scenario explored CPR during; two min on the floor, 2 min on the stretcher and during 2 min in the ambulance. Parameters compared were number and length of pauses, frequency and chest compression ratio (correct chest compressions alone in % of time). The first scenario revealed, significant differences regarding pauses that occurred significant more often 32 (26-33) compared to 29 (28-29) (Median (Min-Max)) and lasted longer time (s): 129 (105-155) compared to 110 (104-122) for the M-CC group compared to the L-CC group resulting in a chest compressions ratio, lower in the M-CC group: 79 % (65-87%) compared to L-CC group: 84% (33-89%). This result was due to a significant higher frequency of chest compression in the M-CC group 116 (92-133) compared to 99 (98-110). In the two minutes scenario on the floor no significant differences were found, except regarding frequency, but in the M-CC group significantly fewer chest compressions reached 4.5 cm on the stretcher and due to loading in the ambulance. In conclusion: With only small changes done to a manikin we were able to mimic impedance measurements, including depth, using CODE-STAT. An increased frequency during 30:2 CPR also increases the number of pauses and L-CC gives stricter and fewer pauses during CPR in 30:2 resulting better chest compression ratio.