bluuebunny/crossref_metadata_2025 huggingface dataset:
Abstract 4567: Functional Intraoperative Pulmonary Blood Flow Study is a Sensitive Predictor of Right Ventricular Pressure and Successful VSD Closure for Following Complete Uniforcalization in Patients with Pulmonary Atresia with Ventricular Septal Defect and Major Aortopulmonary Collaterals
Authors: Honjo Osami , Al-Radi Osman O , MacDonald Cathy , Davey Lisa , Caldarone Christopher A , Van Arsdell Glen S
Published: July 2021

OBJECTIVE: We hypothesized mean pulmonary artery (PA) pressure obtained from an intraoperative pulmonary flow study would better predict the ability to close the ventricular septal defect (VSD) and better predict postoperative right ventricular systolic pressure (RSVP) than classic anatomical parameters after complete uniforcalization in patients with pulmonary atresia, VSD, and major aortopulmonary collaterals.

METHODS: Sixteen consecutive patients (median, 11 mo, range 2 mo – 16 yrs) underwent one-stage (75%) or staged (25%) uniforcalization between 1/03 and 8/07. Intraoperative functional pulmonary blood flow study was achieved by inserting an arterial cannula in a reconstructed central PA. Flow was increased to 2.5 L/min/m2 while measuring PA pressure. RVSP and systemic systolic pressure (SBP) were recorded after VSD closure. Total neopulmonary artery index (TNPAI) (MAPCA + native PA index), total incorporated pulmonary vascular segments, and pulmonary segment artery ratio (PSAR) (ratio of incorporated segment to 18) were analyzed. Spearman rank correlation and area under the receiver operator characteristics curve (ROC-AUC) were used.

RESULTS: The mean PA pressure on flow study was 21.8+/−6.2 mmHg (range, 11–31). Three patients had a pressure of > 30 mmHg. The VSD was closed in 14 (87%). One patient with flow study mean PA pressure of 25 mmHg had suprasystemic RVSP and underwent intraoperative VSD fenestration. One with a flow study mean PA pressure of 30 mmHg had a prospective fenestrated VSD patch placed. There is a weak negative correlation between TNPAI and the flow study PA pressure (rho=−0.4, p=0.12). The flow study mean PA pressure was correlated with post-repair RVSP (rho=0.72, p=0.0027), and with RVSP/SBP ratio (rho=0.67, p=0.0063). TNPAI, total incorporated segments, and PSAR were not correlated with the postoperative RVSP or RVSP/SBP ratio. Flow study mean PA pressure had the highest sensitivity in predicting VSD closure: ROC-AUC (0.82) vs. TNPAI (0.46), pulmonary segment (0.64), and PSAR (0.64).

CONCLUSIONS: Intraoperative pulmonary flow study predicted the ability of VSD closure better than total incorporated segments, TNPAI, and PSAR. Flow study mean PA pressure highly correlated with postoperative RVSP and RVSP/SBP ratio.
Abstract 4572: Reduced Cardiac Progenitors in the Right Ventricle of Cyanotic Heart Lesions: Insights into RV Adaptation
Authors: Mahmut Naila , Kinnear Caroline , Thompson Megan , Shannon Patrick , Chitayat David , Jaeggi Edgar , Mital Seema
Published: July 2021

The RV in hypoplastic left heart syndrome (HLHS) and Tetralogy of Fallot (TOF) is exposed to hypoxia and abnormal load which may lead to RV dysfunction despite surgical repair. The ability of hypoxia to upregulate angiogenic signaling in the RV is not known. We measured vascular endothelial growth factor (VEGF) mediated regulation of cardiac progenitors in the RV of patients with HLHS and TOF.

Methods: RV myocardial samples were obtained from 6 pts with HLHS (age 0.96±1.5 yrs), 6 pts with TOF (age 3.5±6.3 yrs) and 9 age-matched controls with structurally normal hearts (age 0.16±0.3 yrs) at surgery/transplant/autopsy. The following were measured: VEGF, thymosin β-4 (recruits progenitors), Nkx2.5 (myocyte precursor), Flk-1 (smooth muscle progenitor), CD34 (endothelial progenitor), and von willebrand factor (vWf) (endothelial marker).

Results: (i) VEGF and thymosin β-4 expression was lower in HLHS vs controls. This was associated with reduced cardiac progenitors and lower myocardial capillary density vs controls (0.14±0.01 vs 0.55±0.16, p<0.05). (ii) VEGF expression was preserved but thymosin β-4 was reduced in RV in TOF. This was associated with preserved myocyte progenitors but reduction in endothelial and smooth muscle lineages and reduced capillary density vs controls (0.13±0.03 vs 0.55±0.16, p<0.05) (Figure 1

).

Conclusion: Hypoxia fails to induce an angiogenic response in the RV in cyanotic heart lesions. This may be due to reduced VEGF (HLHS) or impaired coupling of VEGF to thymosin β-4 (TOF). This maladaptation may contribute to post-operative RV dysfunction and lower RV regenerative capacity in later life.

Figure 1:

Reduced capillary density (red) in HLHS and TOF
Abstract 4629: Long-Term Open Label Extension of the Prevention of Embolic and Thrombotic Events on Dabigatran in Atrial Fibrillation (PETRO- Ex study)
Authors: Nagarakanti Rangadham , Ezekowitz Michael D , Parcham-Azad Kambiz , Reilly Paul A , Nehmiz Gerhard , Lionetti Dominick A , Wallentin Lars
Published: July 2021

Dabigatran is an oral direct thrombin inhibitor (DTI), which has a rapid onset of action and can be given twice daily (b-i-d) without anticoagulation monitoring. To determine the long term safety and efficacy of dabigatran in patients with atrial fibrillation (AF). AF patients (n=502) from 53 centers in Denmark, the Netherlands, Sweden and the United States were enrolled in the PETRO study, a 12 week comparison between dabigatran (50, 150, and 300 mg b-i-d) and warfarin (INR 2–3). 361 dabigatran patients were rolled over into a long term extension trial (PETRO-Ex). The warfarin patient arm (n=70) was discontinued. All patients were initially maintained on the same dabigatran doses as in PETRO except the 50 mg b-i-d dose group who were switched to 150 mg once daily (qd). At entry, patients were 70 years old (mean age), 19% female, median AF duration of 4.2 years, and had a median of 3 stroke risk factors. Maximum and mean follow-up times were 51 and 29 months respectively. Due to higher frequency of major bleeding events in 300 mg b-i-d group and thromboembolic events in 150 mg qd group, they were switched to dabigatran 300 mg qd or 150 mg b-i-d groups.

PETRO and PETRO-Ex results:
Events reported as absolute number of patients (per 100 patient-years) Thromboembolic event rates were lowest in the dabigatran 150 and 300 mg b-i-d groups. Major bleeding was most frequent in the 300 mg b-i-d group. No significant liver function abnormalities were noted in any of the dabigatran groups. The balance between stroke and bleeding risk supported dabigatran doses between 100 and 150 mg b-i-d for the ongoing phase 3 Randomized Evaluation of Longterm anticoagulation therapY (RELY) trial.
Abstract 4649: A Radiofrequency HOT Balloon Catheter for Isolating the Posterior Left Atrium Including All the Pulmonary Veins in the Treatment of Atrial Fibrillation: Feasibility and Safety of a New Approach
Authors: Sohara Hiroshi , Satake Shutaro , Takeda Hiroshi , Ueno Hideki , Oda Toshimichi
Published: July 2021

Atrial fibrillation (AF) is originated from mostly from pulmonary vein (PV) foci or non-PV foci in the posterior left atrium (PLA). The present study was designed to evaluate the usefulness of a radiofrequency HOT balloon catheter (RBC) for isolation of the PLA including all PVs en masse in the patients with AF. In a total of 96 patients (75 men and 21 women; mean age 64±8 years old) with drug-resistant paroxysmal (n=63) and persistent AF(n=33), PLA including all PVs were ablated and isolated using RBC. Dragging the balloon, contiguous lesions at the roof between the superior PVs were first created, then each antrum of all PVs were ablated, and finally, contiguous lesions at the PLA between the both inferior PVs were made, while we performed monitoring esophagus temperature and phrenic nerve pacing. Electro-anatomical bipolar voltage amplitude mapping (CARTO) of the LA-PVs was performed to determine the extent of this electrical isolation after all procedure. Successful isolation of the PLA including all PVs was achieved in all of 96 cases with elimination of all the PLA and PV potentials. The mean total procedure time 133 ± 31 minutes including 32±9 minutes fluoroscopy time. Recurrences of AF were diagnosed by Holter monitoring, mobile electrocardiogram. After first session, eighty- seven (59 paroxysmal, 28 persistent) of 96 patients were free from AF without anti-arrhythmic drugs and the remaining patients could maintain sinus rhythm with anti-arrhythmic drugs except two cases with LA flutter during 11.0±4.1 months follow-up. No major complications such as cerebral embolism, PV stenosis, or phrenic nerve palsy, and LA-esophageal fistula were observed. Complete isolation of the PLA including all PVs using a RBC, is useful for the treatment of both paroxysmal and persistent AF without severe complication.
Abstract 4655: Retrograde Ethanol Infusion in the Vein of Marshall for Ablation of Atrial Fibrillation: Tissue Ablation, Effects on Regional Vagal Innervation and First Human Experience
Authors: Valderrábano Miguel , Chen Harvey R , Sidhu Jasvinder S , Rao Liyun , Ling Yuesheng , Khoury Dirar S
Published: July 2021

The vein of Marshall (VOM) is an attractive target during ablation of atrial fibrillation due to its autonomic innervation and its location anterior to the left pulmonary veins and drainage in the coronary sinus. We studied 14 dogs. A coronary sinus venogram showed a VOM in 10, which was successfully cannulated with an angioplasty wire and a 2 mm balloon. In 5 dogs, electroanatomical (Carto) maps of the left atrium were performed at baseline and after ethanol (100%, 4 – 8 cc) was infused in the VOM, which demonstrated the creation of a new crescent-shaped scar in the left atrium, extending from the annular left atrium towards the posterior wall and left pulmonary veins. In 4 dogs, both cervical vagal trunks were isolated in the carotid sheath and cuff stimulation electrodes were attached to them. Effective refractory periods (ERP) were measured in 3 sites of the left atrium, before and after high-frequency bilateral vagal stimulation. The baseline ERP was 113.6±35.0 ms, and decreased to 82.2±25.4 ms (p<0.05) after vagal stimulation. After alcohol infusion in VOM, vagally-mediated ERP decrease was eliminated (from 108±27.2 ms to 95.6 ±16.7ms, p=NS). This elimination of vagal effects was not uniform and was limited in sites in proximity with the VOM (baseline ERP 105±18.7ms vs post vagal 98.±37.6ms, p=NS, as opposed to 106.7±27.1ms vs post vagal 73.3±19.7ms, p<0.05, in sites remote to VOM). We also tested feasibility of VOM alcohol infusion in humans: 2 patients undergoing pulmonary vein antral isolation had successful VOM cannulation: left atrial voltage maps demonstrated new scar involving the infero-posterior left atrial wall extending towards the left pulmonary veins. Retrograde alcohol infusion in the VOM achieves significant left atrial tissue ablation, abolishes local vagal responses and is feasible in humans.
Abstract 4687: Prospective Comparison of Intracardiac Versus Transoesophageal Echocardiography Guided Closure of Patent Foramen Ovale and Atrial Septal Defects in Adults - Five Year Single Centre Experience
Authors: Asrress Kaleab N , Schrale Ryan G , Mankia Kulveer S , Raza Sayed A , Puli Chandra , Wilson Neil , Ormerod Oliver J , Mitchell Andrew R
Published: July 2021

Imaging to guide percutaneous closure of patent foramen ovale (PFO) and atrial septal defect (ASD) has traditionally required transoesophageal echocardiography (TOE) with general anaesthesia. The development of intracardiac echocardiography (ICE) allows these procedures to be performed under local anaesthesia, obviating the need for endotracheal intubation and general anaesthesia. We set out to prospectively evaluate the effect of ICE on the success and efficiency of PFO and ASD closure. Data on all adult patients undergoing percutaneous PFO and ASD closure were collected prospectively between 2003 and 2008. Allocation to echocardiographic technique was non-random and determined by availability of anaesthetic and cardiology staff, initial ICE probe availability and relative contraindication to general anaesthesia. Procedure time, fluoroscopy time, radiation dose, device deployment success rate, procedural complications, hospital stay length, and interatrial communication closure at 3 months were compared between the two imaging modalities. 210 consecutive patients underwent percutaneous interatrial defect closure over the study period, 55 (26%) with TOE and 155 (74%) using ICE. Baseline characteristics of the TOE and ICE groups were similar (age 45.3±15.5 vs 47.9±13.6 years,
p
=0.415; male 36% vs 42%,
p
=0.524; body surface area 1.81±0.27 vs 1.90±0.26 m
2
,
p
=0.110; interatrial defect size (for ASD) 19.8±8.9 vs 18.2±7.9 mm,
p
=0.458). Procedural time (not including induction and recovery from general anaesthesia; 50±21 vs 42±18 minutes,
p
=0.007), fluoroscopy time (8.0±6.0 vs 5.4±4.0 minutes,
p
<0.0001), radiation dose (1350±1626 vs 714±1017 cGy/cm
2
,
p
<0.0001), and inpatient stay 1.8±0.9 vs 1.0±3.3 days,
p
<0.0001) were significantly reduced using ICE. There were no differences in the device deployment success rate (94% vs 95%,
p
<0.724) and interatrial communication closure at 3 months (96% vs 93%,
p
=0.722). During percutaneous closure of interatrial defects, ICE avoids the risks and inconvenience of general anaesthesia and is associated with significantly reduced procedure times, radiation doses, and inpatient stay compared to TOE, without compromising procedure success.
Abstract 4696: Myocardial Velocities and Longitudinal Strain Assessed by Speckle Tracking can Predict Optimal Timing of Surgery in Asymptomatic Patients with Severe Primary Mitral Regurgitation
Authors: Florescu Maria , Benea Diana C , Cerin Gheorghe , Diena Marco , Cinteza Mircea , Vinereanu Dragos
Published: July 2021

Optimal timing of mitral valve repair in asymptomatic patients with primary mitral regurgitation (PMR) is still controversial. LV ejection fraction (EF) and end-systolic diameter (ESD) represent the most widely used indices to demonstrate LV dysfunction, however, in many cases, a normal EF can mask significant LV impairment. Therefore, new methods might be better to detect subclinical LV dysfunction, and thereby, to improve timing of mitral valve surgery. To assess accuracy and predictive value of indices of tissue Doppler and speckle tracking to detect subclinical LV dysfunction with further impaired postoperative LV function, in asymptomatic patients with severe PMR. 23 asymptomatic patients (59±13 years, 14 male) with severe PMR (regurgitant volume > 65 ml), and LVEF > 60% and ESD < 45 mm, were evaluated preoperatively and at 14 days after successful MVR. 11 patients had a postoperative EF reduction >10% (group A), and 12 patients an EF reduction <10% (group B). Conventional and tissue Doppler echo were used to assess LV diameters and volumes, LV mass index, EF, and long-axis systolic function (from mean 6 basal segments velocities - STDE, and mean time-to-peak systolic contraction - TTP-S); and 2D speckle tracking was used to assess mean negative longitudinal strain of 6 segments in the apical 4-chamber view (LS). Although both groups had similar preoperative LV mass index, LV diameters and volumes, and EF, group A had significantly lower STDE and LS (7.58±0.9 vs. 10.7±1.3 m/s; and −16.29±4.6% vs. −20.57±2.1%, both p<0.01), and a significant higher TTP-S (207.3±73.6 vs. 147.3 ±24 ms, p=0.01) than group B. Multiple regression analysis showed that STDE, and the combination of STDE and LS, represent the main independent predictors for postoperative EF reduction >10% (R
2
= 0.66, p<0.001; and R
2
= 0.80, p<0.05, respectively). A cutoff limit of STDE of 9.2 cm/s had a 100% sensitivity and 100% specificity to predict a postoperative EF reduction >10%. Tissue Doppler systolic indices and longitudinal strain assessed by speckle tracking can detect subclinical LV dysfunction and predict impaired postoperative LV dysfunction, in asymptomatic patients with severe PMR.
Abstract 4730: Restoring Forces and Lengthening Load are Independent and Important Determinants of Peak Early-Diastolic Mitral Annulus Velocity
Authors: Opdahl Anders , Remme Espen W , Helle-Valle Thomas , Lyseggen Erik , Vartdal Trond , Pettersen Eirik , Edvardsen Thor , Smiseth Otto A
Published: July 2021

Background:
Mechanisms of early-diastolic mitral annulus velocity (E′) are poorly understood. We investigated if restoring forces, generated by contraction below unstressed length, and
lengthening load
, the expanding effect of LV pressure during early filling, may be determinants of E′ in addition to LV relaxation (
tau
).

Methods:
In 15 anesthetized dogs we evaluated LV transmural pressure-diameter loops to define unstressed LV long-axis diameter (L
0
). As a reflection of restoring forces we used the difference between minimum LV long-axis diameter and L
0
(L
min
−L
0
). As a measure of LV
lengthening load
we used LV pressure at the time of mitral valve opening (LVP
MVO
). E′ was measured by sonomicrometry and tissue Doppler imaging (TDI) at baseline, during volume loading, dobutamine infusion (n=9), and after 15 minutes and 3 hours (n=8) of LAD-occlusion.

Results:
Changes in E′ during dobutamine and ischemia correlated inversely with changes in
tau
(R=−0.58), confirming a relationship between E′ and relaxation. Furthermore, E′ showed an even stronger correlation with L
min
−L
0
(R=−0.79, Fig 1

), suggesting a close relationship between E′ and restoring forces. During increased LVP
MVO
, however, there was a marked increase in E′ which could not be attributed to changes in tau or in L
min
−L
0
, but E′ correlated well with LVPMVO (R =0.78, Fig 2

).

Conclusion:
The present study indicates that in the non-failing ventricle restoring forces and lengthening load are important determinants of E′. Furthermore, the apparent preload-dependency of E′ is explained by the effect of lengthening load.

Fig 1

Fig 2
Abstract 4732: Determinants of Left Ventricular Early Diastolic Lengthening Velocities
Authors: Remme Espen W , Opdahl Anders , Smiseth Otto A
Published: July 2021

The proposed determinants of the LV wall early diastolic lengthening velocity (E′) are: relaxation rate of active fiber stress (
tau
), LV pressure during early filling, restoring forces, and passive elastic wall stiffness. In experimental and clinical studies the individual determinants are difficult to alter and investigate separately due to their inter-dependency. The purpose of this study was to develop a mathematical model that provided a physical basis for the determinants and to validate their individual effect on E′. The LV wall was represented by a lumped parameter model consisting of two elements in parallel (Fig. a

): one representing the active fiber stress (Sa) and the other the passive elastic stress (Sp) represented by an elastic spring with stiffness K and resting length L
0
. The sum of active and passive wall stresses was set to equal LV pressure (LVP). Active stress was prescribed to decay exponentially. E′ was assessed during a simulation with baseline model parameter values and a higher value of each parameter in turn. At baseline E′ was 6.2 cm/s. E′ was decreased to 4.1 cm/s and delayed by prolonging relaxation from
tau
= 40 to 60 ms (Fig. b

). Increasing LVP during early filling by 5 mmHg increased E′ to 10.6 cm/s (Fig. c

). Decreasing restoring forces by increasing end systolic length from 57 to 60 mm decreased E′ to 2.6 cm/s (Fig. d

). Increasing passive stiffness from K=1500 to 3000 mmHg/m decreased E′ to 5.1 cm/s (Fig. e

). The mathematical model validated former experimental results and confirmed that E′ increases with shortening of
tau
, increase of diastolic LVP, decreased end systolic length, and decreased passive stiffness.
Abstract 4835: Angiotensin-Converting-Enzyme 2 (rhACE2) Potently Attenuates the Negative Hemodynamic Effects of Angiotensin II (ATII) and Improves Post-Myocardial Infarction (MI) Remodeling
Authors: Unsoeld Bernhard , Schuster Manfred , Loibner Hans , Becker Alexander , Seidler Tim , Jacobshagen Claudius , Kuba Keiji , Imai Yumiko , Penninger Josef , Hasenfuss Gerd
Published: July 2021

ATII is a potent vasoconstrictor involved in the pathophysiology of several diseases. Antagonizing the Renin-Angiotensin-Aldosterone-System (RAAS) is one of the key principles in the treatment of heart failure. ACE2, a recently discovered homologue of the Angiotensin-Converting-Enzyme (ACE), catalyzes the cleavage of ATII to Angiotensin (1–7) as well as other reactions. rhACE2 has proven to be therapeutic in a model of the Adult Respiratory Distress Syndrome (ARDS). This study has been planned to study the in-vivo hemodynamic effects of rhACE2 as well as its effects on post-MI remodeling. rhACE2 was produced in a mammalian expression system. Pressure-volume catheter measurements were carried out in male C57/Bl6N mice. Post-MI remodeling was studied by echocardiography in female C57/Bl6N mice after LAD-ligation. Bolus infusion of 2mg/kg rhACE2 (n=7) lead to a significant reduction of arterial elastance by 13.2±1.1% (p<0.01) paralleled by a modest drop in maximal systolic blood pressure from 93.4±4.2mmHg to 86.3±5.1mmHg (p<0.01). Stroke volume and cardiac output showed a strong trend (p=0.06 and 0.08 respectively) to increase after rhACE2-treatment. Following ACE2 (n=5) or vehicle infusion (n=8) ATII was infused at constant infusion rates from 0.2μg/kg/min to 40μg/kg/min. ACE2 pretreatment shifted the EC50 for the ATII induced increase in systolic blood pressure by almost one order of magnitude from 1.11μg/kg/min (CI 0.42 to 2.9) to 10.9μg/kg/min (CI 7.2 to 16.7) (p=0.014). Similarly the EC50 values for the ATII mediated decrease in ejection fraction and preload adjusted maximal power as well as the increase of end systolic volume were significantly shifted to higher ATII doses. To study post-MI remodeling mice were treated twice daily with intraperitoneal injections of 1mg/kg rhACE2. Echocardiography was performed 2 weeks following LAD. Mice treated with rhACE2 (n=15) showed a significantly improved fractional shortening (14.3±1.6%) compared to vehicle treated mice (10.3±1.1%, n=12, p=0.049). These data show that rhACE2 is highly potent in reducing the negative effects of ATII in vivo which might translate in improved post-MI remodeling. rhACE2 could become an alternative treatment option for several diseases related to an activated RAAS.
Abstract 4858: Patterns in Beta Blockerw use ith Cardiac Resynchronization Therapy: Insights from the COMPANION Study
Authors: McGrew Frank , Boehmer John , Bank Alan , Galle Elizabeth , Yong Patrick , Leigh Jill , Bristow Michael R
Published: July 2021

Cardiac resynchronization therapy (CRT) is typically delivered in addition to background heart failure medications that include beta blockers (BB). Since CRT devices also provide rate support, it was hypothesized that CRT may influence BB use post-implant. We sought to compare BB use in the treatment arms of the COMPANION study, which randomized patients (pts) to optimal pharmacological therapy (OPT) alone or in combination with CRT with or without a defibrillator. The database was analyzed retrospectively for a 12-month period post-randomization. BB dosages were evaluated at the 12-month visit with the last follow-up (FU) visit used for those without 12 month FU data. Pts with no FU data were excluded. Dosages are expressed in carvedilol equivalents. The median dose between the two treatment arms were compared as well as up/down titration rates. Of 1520 pts randomized, 1376 (91%) were followed for at least three months and 689 (50%) were followed for at least 12 months. The median dose was 25 mg/day for both groups at baseline (p=0.93) and again at 12 months (p=0.53). BB use between arms is characterized in the tables below: In this retrospective analysis of the COMPANION trial, there was no significant association between treatment arm and BB drug use. Up/down-titration rates and median dosages were virtually identical between the two arms. COMPANION did not require investigators to increase BB dosage; accordingly, a prospective study would be needed to definitively determine if BB dosage can be titrated more aggressively with CRT.
Abstract 4912: Thin Fibrous Caps with Excessive Macrophage Infiltration in Culprit Lesions of Patients with Acute Coronary Syndromes are Associated with Increased Local Temperature
Authors: Riga Maria , Toutouzas Konstantinos , Tsiamis Eleftherios , Karanasos Antonios , Tsioufis Costas , Stefanadi Elli , Karabelas John , Trikas Athanasios , Tousoulis Dimitrios , Stefanadis Christodoulos
Published: July 2021

Background:
Optical coherence tomography (OCT) provides detailed analysis of the morphological characteristics of the culprit lesion (CL) and determines macrophage density within fibrous caps. Intracoronary thermography (ICT) detects the local inflammatory activation of the CL. We investigated the correlation between morphological and functional characteristics of the CL as analysed by OCT and ICT in patients with acute coronary syndromes (ACS).

Methods:
We studied 31 CL of 31 pts (mean age 61±14 years) with ACS. We measured by ICT the temperature difference between the lesion and the healthy proximal vessel wall (ΔT). Thereafter, we measured the minimal thickness of the fibrous cap (mTFC) at CL by OCT. CL with mTFC ≤65 μm were characterized as thin cap plaques and CL with mTFC >65 μm as thick cap plaques. By OCT, macrophage density in the fibrous cap of the CL was also determined from optical signals.

Results:
Nineteen CL (61.29%) had increased plaque temperature (ΔT≥0.05°C) and 12 CP (38.7%) had low ΔT (ΔT<0.05°C). All CL (100%, p<0.01) with low ΔT had thick cap (mTFC=98±22 μm). Three CL (15.78%) with high ΔT had thick cap (mTFC=78±9μm, p=0.02), whereas 16 CL with high ΔT (84.2%) had thin cap plaques (mTFC=49±12μm, p=0.02) (Figure

). Among CL with high ΔT, 18 CL (94.7%) had excessive macrophage infiltration in OCT analysis. Only 1 CL with low ΔT(8.3%) had macrophage infiltration of its fibrous cap (p<0.01).

Conclusions:
CL with thin fibrous cap have increased inflammatory activation. Morphological and functional characteristics of the CL of pts with ACS, evaluated by OCT and ICT, are correlated. Thus, the use of OCT and ICT can provide more information regarding the high-risk plaques.
Abstract 4915: Reduction of X-Ray Exposure by Patient Contouring
Authors: Lefèvre Thierry , Ohanessian Alice , Wimille Benjamin , Robert-Fournier Dominique , Felix Cecilia , Chettibi Mohamed , Louvard Yves , Morice Marie-Claude
Published: July 2021

Purpose of the study
. With increasing case complexity, radiation exposure is becoming a very important issue. One obvious element, which can result in dose reduction, is optimal placement of image receptor as close to the patient as possible. As part of the clinical workflow, even with best of intentions, the detector is often parked at a significant distance away from the patient and this may be improved by an automatic user-gantry interaction which automatically places the detector at an optimal distance from the patient surface.

Methods
. We determine the operator dose reduction impact of a patient contouring system which utilizes active sensors placed around the rim of the detector to optimally position the detector close to the patient surface compared to a conventional approach in the real world. On the cathlab platform Innova 2100
IQ
(GE, Waukesha, WI), capacitive sensor elements are placed around the detector cover, which measures the minimal distance between the cover and the patient. Using a computer algorithm, the detector location is automatically controlled such that it rests at a preprogrammed distance of 7 cm from the patient surface with a fast response time of 20 deg/sec. Dose to the operator was recorded by an electronic dosimeter placed on the external side of the lead apron.

Results
. 250 consecutive patients admitted for coronary angiogram (n=234)or angioplasty (n=16) were randomly assigned for conventional approach (n=117) or patient contouring (n=133). The 2 patients populations were identical for age, indications, approach (radial or femoral), size, weight and body mass index. The operator effective dose was 5.71±6.34 μSv in the conventional group and 3.68±4.09 μSv in the patient contouring group (p = 0.0035), with an operator effective dose reduction of 35.5%.

Conclusions
. A simple technique of patient contouring may reduce operator effective dose by >30%.
Abstract 4951: Serum N-Terminal Pro-Brain Natriuretic Peptide Reflects the Grade of Congestive Heart Failure in Children
Authors: Sugimoto Masaya , Kajino Hiroki , Manabe Hiromi , Goh Kazutomo , Fujieda Kenji
Published: July 2021

Background:
The N-terminal pro-brain natriuretic peptide (NTproBNP) has a longer serum half-life than the brain natriuretic peptide (BNP), and it is reported to be advantageous in the accurate detection of congestive heart failure (CHF) in adults. However, it has not been sufficiently examined in children. Therefore, we investigated which of the 2 peptides is more beneficial and identified their cut-off levels at the CHF grades in children.

Methods:
Plasma BNP and serum NTproBNP levels were determined in 252 healthy children (median age, 3.5 years) and in 142 children with congenital heart disease (median age, 2.6 years). CHF severity was assessed by using the modified Ross score to classify the severity into 4 grades (I–IV). The BNP and NTproBNP levels were analyzed and compared with the CHF grade.

Results:
Both BNP and NTproBNP levels increased significantly with the CHF grades (Fig. 1

). The change in the NTproBNP level was more remarkable in each CHF grade than in BNP. Furthermore, at CHF grades of II or higher, the area under the receiver operating characteristic curve was larger with NTproBNP than with BNP (Fig. 2

). The cut-off levels of BNP and NTproBNP were 47.3 and 333.4 pg/mL, respectively, in CHF grade II and higher; 101.4 and 2415.5 pg/mL, respectively, in CHF grade III and higher; and 320.0 and 3617.0 pg/mL, respectively, in CHF grade IV.

Conclusions:
Our study clearly demonstrated that blood levels of BNP and NTproBNP reflected the severity of CHF in the children. Of these, NTproBNP showed better specificity and sensitivity for the evaluation of CHF severity in children. Therefore, we concluded that NTproBNP is beneficial as a biomarker for assessing CHF in children.

This research has received full or partial funding support from the American Heart Association, AHA National Center.

Fig. 1

Fig. 2
Abstract 5585: Understanding Physicians’ Risk Stratification of Acute Coronary Syndromes: Insights from the Canadian ACS II Registry
Authors: Yan Andrew T , Yan Raymond T , Huynh Thao , Casanova Amparo , Raimondo F. E , Fitchett David H , Langer Anatoly , Goodman Shaun
Published: July 2021

An important treatment-risk paradox exists in the management of acute coronary syndromes (ACS). However, the process of risk stratification by physicians and its relationship to patient management have not been well studied. Our objective was to examine patient risk assessment by physician in relation to treatment and objective risk score evaluation, and the underlying patient characteristics that physicians consider to indicate high risk. The prospective Canadian ACS II Registry recruited 1956 patients admitted for non-ST elevation ACS in 36 hospitals in Oct 2002-Dec 2003. Patient risk assessment by the treating physician and management were recorded on standardized case report forms. We calculated the TIMI, PURSUIT and GRACE risk scores for each patient. Of the 1956 ACS patients, 347 (17.8%) patients were classified as low risk, 822 (42%) as intermediate risk, and 787 (40.2%) as high risk by their treating physicians. Patients considered as high risk were more likely to receive aggressive medical therapies and to undergo coronary angiography and revascularization. However, there were only weak correlations (Kendall’s tau-b correlation coefficients ranging from 0.08 to 0.14) between risk assessment by physicians and all 3 validated risk scores. Advanced age was an independent
negative
predictor. Furthermore, there was no significant association between the high risk category and several established prognosticators, such as history of heart failure, hemodynamic variables, and creatinine. Contemporary risk stratification of ACS appears suboptimal and may perpetuate the treatment-risk paradox. Physicians may not recognize and incorporate the most powerful adverse prognosticators into overall patient risk assessment. Routine use of validated risk score may enhance risk stratification and facilitate more appropriate tailoring of intensive therapies towards high-risk patients.
Abstract 5592: In Acute Coronary Syndromes Being Totally Revascularized Is As Good As Having A Normal Coronary Angiogram
Authors: Teixeira Rogerio , Lourenco Carolina , Jorge Elisabete , Baptista Rui , Antonio Natalia , Monteiro Silvia , Monteiro Pedro , Freitas Mario , Providencia Luis A
Published: July 2021

Background: Revascularization is a crucial therapy in acute coronary syndromes (ACS). Purpose: to assess ACS patients outcomes, stratified according to the coronary angiography and/or angioplasty.

Population and methods: 786 consecutive ACS patients submitted to an invasive strategy, divided in 3 groups: A (n=111) normal coronary angiogram; B (n=327) fully revascularized; C (n=348) incomplete revascularization. A 1-year follow up targeting major adverse cardiovascular events (MACE) was performed.

Results: Group A had more females (38.7 vs 21.1 vs 24.4% p<0.01), patients were more admitted for unstable angina (37.3 vs 14.9 vs 17.9% p<0.01) and had a higher left ventricular ejection fraction (LVEF). Group B were more on previous statin therapy, had more often an admission for ST elevation acute myocardial infarction (17.3 vs 51.7 vs 42.4% p<0.001) and higher peak levels of cardiac biomarkers. Group C were older and had more frequently a previous history of coronary disease. Group C patients had a worse in-hospital mortality (1.8 vs 1.2 vs 7.5% p<0.01) and morbidity. The MACE free survival rate was significantly lower for group C (92.9% vs. 92.9% vs. 78.2%; log rank p<0.001). In a multivariate Cox regression analysis, incomplete revascularization remained an independent predictor of MACE at 1 year (HR 2.74, CI 1.50 – 4.94), in a model that included, age, gender, LVEF, diabetes, coronary anatomy, and admission diagnosis.

Conclusion: Our data strongly support the use of an aggressive invasive strategy in ACS, aimed at achieving full revascularization, as these patients had the same medium term prognosis as those with normal coronary angiogram.
Abstract 5599: Relationship between Coronary Arterial Remodeling and Fibrous Cap Thickness in Patients with Acute Coronary Syndrome
Authors: Kashiwagi Manabu , Tanaka Atsushi , Kitabata Hironori , Ozaki Yuichi , Shimokado Aiko , Matsumoto Hiroki , Tsujioka Hiroto , Okouchi Keishi , Ikejima Hideyuki , Arita Yu , Kuroi Akio , Komukai Kenichi , Kataiwa Hideaki , Ishibashi Kouhei , Tanimoto Takashi , Takarada Shigeho , Nakamura Nobuo , Hirata Kumiko , Mizukoshi Masato , Imanishi Toshio , Akasaka Takashi
Published: July 2021

The aim of this study was to evaluate the relationship between coronary arterial remodeling and the thickness of fibrous cap in patients with acute coronary syndrome (ACS). Thin-capped fibroatheroma is recognized as a precursor lesion for ACS. Positive remodeling (PR) is predominant pattern of arterial remodeling in patients with ACS. However, the relationship between PR and the thickness of fibrous cap has not been elucidated in vivo. We enrolled 41 patients with ACS who underwent both intravascular ultrasound (IVUS) and optical coherence tomography (OCT). The arterial remodeling was assessed by IVUS and the thickness of fibrous cap was measured by OCT. The thin fibrous cap was defined as <70μm in the thinnest part. Remodeling index (RI) was calculated as lesion divided by the reference external elastic membrane cross-sectional area and PR was defined as RI > 1.05 (a PR group). Thin-capped fibroatheroma were observed more frequently in the PR group than in the intermediate and negative remodeling (IR/NR) groups (63% versus 16%, p=0.0057). RI was inversely correlated with the thickness of fibrous cap (r=−0.53, p=0.019). High-sensitive C-reactive protein (hs-CRP) levels were higher in the PR group than in the IR/NR groups (0.50±0.63mg/dL versus 0.20±0.15mg/dL, p<0.05). Also, the hs-CRP levels were higher in patients with thin fibrous cap (0.54±0.71mg/dL versus 0.21±0.14mg/dL, p<0.05). The coronary arterial remodeling, the thickness of fibrous cap and CRP level in patients with ACS were associated with each other. These results suggest that inflammatory process contributes to both plaque growth and plaque instability.
Abstract 5602: Initial Angle and Overcorrected Angle at Coronary Lesion Predicts Delayed Drug-Eluting Stent Fracture: Quantitative Angle Analysis in Stent Fracture Patients
Authors: Hwang Kyung-Kuk , Bae Jang-Whan , Lee Won-Yik , Kim Dong-Woon , Cho Myeong-Chan
Published: July 2021

Background
: Stent fracture (SF) is a potential cause of restenosis, pseudoaneurysm or thrombosis, which acquire special significance in the treatment failure with drug-eluting stent (DES). From a point of view that chronic fatigue stress associated with anlge and angular momentum, we quantitatively analyzed the initial native maximum and minimum angles (Ai-max, Ai-min) and the change (ΔAi) in repetitive bending movement of coronary lesion before stenting, angles (Ap-max, Ap-min, ΔAp) after immediate stenting, corrected angle [A corr-max=Δ (Ap−Ai) max] by stent, and angles (Asf-max, Asf-min, ΔAsf) after SF in delayed DES fracture patients.

Methods
: From October 2005 to July 2006, 139 patients underwent follow-up coronary angiography after 258 DES implantations. DES fractures were detected at 13 patients (M:F=12:1, Age: 60.3±9.4 year-old). We quantitatively analyzed the angles (Ai, Ap, ΔA, Asf) at the same plane view by Nexus 1.0 in 13 patients.

Results
: The follow-up duration was 255.7±75.7 days. All 13 DES fractured patients had no clinical symptoms associated with SF, and had a male-predominance. The number of stent implantation at target lesion associated fracture site was 1.9±0.6. Stent diameter and length were 3.00±0.25 and 53.0±17.4 mm. Four of 13 patients had multiple fractures (LAD; 2, RCA: 2 cases). Nine patients had single fracture (LAD; 1, LCX; 3, RCA; 5 cases). All most all fracture sites (92.3%, 12/13cases) were angulated and bending lesion. Only 1 fracture site was not associated with angulated lesion. The mean ΔAi, Ai-max and Ai-min were 18.9°, 145.5° and 125.8°. Mean ΔAp, Ap-max and Ap-min were 4.9°, 158.8° and 154.1°. Mean maximal corrected angle by PCI were 28.3°. In SF, The mean ΔAsf, Asf-max and Asf-min were 13.8°, 149.4° and 133.5°. These Asf values had a strong tendency to recover the initial native physiologic angle (Ai) against corrected angle by stenting. The simulation program for evaluation of angular momentum in DES supports the same results.

Conclusion
: Theses findings suggest that the initial angle and extent of overcorrected angle against physiologic coronary configuration are important at delayed DES fracture. And it has considering potential as a new marker for assessing risk of DES fracture.
Abstract 5605: Real World Comparison of Long Term Mortality after Primary Percutanous Coronary Intervention (PPCI) versus Fibrinolysis for Acute St Elevation Myocardial Infarction: Initial Experience from the 24 Hour PPCI Program in Nova Scotia
Authors: Chan Boniface , Curran Helen , Love Michael P , Fort Stephen
Published: July 2021

Background Randomized controlled trials indicate that acute ST elevation myocardial infarction (STEMI) patients have better clinical outcomes if rapid, complete and stable coronary artery patency can be achieved. The Queen Elizabeth II Health Sciences Center in Halifax, Nova Scotia (QEIIHSC) commenced a 24 hour PPCI program in November 2005. This real world study compares 2 year mortality in STEMI patients treated by PPCI versus patients treated by fibrinolysis with provisional rescue PCI within Nova Scotia, Canada.

Methods This was a single center retrospective cohort study. All consecutive Nova Scotia, fibrinolytic and PPCI eligible STEMI patients presenting within 12 hours of symptom onset between July 1
st
2005 and June 30
th
2006 treated by PPCI at the QEIIHSC or fibrinolyis outside the QEIIHSC were included. The outcome measure was all cause mortality censored on June 30
th
2007. The crude and independent association between PPCI versus fibrinolysis on mortality was estimated using a Cox regression model.

Results Data for 423 eligible patients (100% of cohort) comprised of 359/423 (85%) patients treated with fibrinolytics and 64/359 (18%) treated by PPCI were analyzed. The median follow-up was 1.4 years. The median (Q25 to Q75) door to needle times in the fibrinolytic group and corresponding door to balloon times in the PPCI group were: 0.5 (.3 to .9) and 1.5 (1.1 to 1.9) hours respectively. PPCI was associated with a consistent trend toward lower mortality versus fibrinolysis during hospitalization: 2/64 (3.1%) vs. 29/359 (8.1%), P=0.16 and at 30 days 2/64 (3.1%) vs. 32/359 (15%), P=0.12. This association was significant at 1 and 2 year follow-up: 2/64 (3.1%) vs. 41/359 (11%), P=0.043 and 2/64 (3.1%) vs. 45/359 (12%), P=0.027 respectively. This corresponded with an independent HR for 2 year mortality of: 0.1 (.01 to 0.8), p=0.03.

Conclusion Initial data from the PPCI program at the QEIIHSC in Halifax, Nova Scotia indicates that PPCI was associated significant reductions in mortality versus fibrinolysis for real world patients presenting with STEMI. This mortality reduction was achieved in the early pilot phase of a PPCI program with evolving door to balloon timelines versus an established fibrinolytic program with acceptable door to needle timelines.
Abstract 5647: Autonomic Nervous System Dysregulation in Implantable Cardioverter Defibrillator Patients with Depression and Anxiety
Authors: Kop Willem J , Francis Jennifer L , Haigney Mark C , Weinstein Ali A , Stein Phyllis K , Gottdiener John S , Krantz David S
Published: July 2021

Background
: Autonomic nervous system (ANS) dysregulation increases risk of ventricular arrhythmias in patients with implantable cardioverter defibrillators (ICD). ANS dysregulation is common in depression and anxiety, but the relationship between these psychological factors and ANS dysregulation has not been investigated in ICD patients.

Methods
: ANS indices reflecting parasympathetic control of heart rate were obtained using heart rate variability (HRV) analyses in 44 ICD patients with documented coronary artery disease (age 62±9 yrs; ejection fraction 35.9±12.7%). Ambulatory 24-hr ECG recordings were used to calculate HRV (rMSSD and pNN50). Depression was assessed using the Beck Depression Inventory (BDI) and anxiety using the Taylor Manifest Anxiety Scale (TMA). Validated cut-off scores were used (depression: BDI≥10; anxiety: TMa≥9), and data were analyzed using Analysis of Variance.

Results
: ICD patients with depression symptoms (n=12) had significantly lower HRV markers of ANS parasympathetic activity (rMSSD:15.2±5.7 ms vs. 25.0±13.4 ms, p=0.002; pNN50:1.8±2.7% vs. 5.6±5.7%, p=0.006) than patients with low depression symptoms (n=32). High anxiety (n=10) was related to lower rMSSD (p =0.014). Comorbid depression and anxiety was associated with substantial HRV reduction (p<0.001) (Figure

).

Conclusion
: Depression and anxiety in ICD patients are associated with autonomic nervous system dysregulation (reduced HRV markers of parasympathetic control). Reduced parasympathetic activity may therefore contribute to the elevated risk of life-threatening cardiac arrhythmias in ICD patients with depression and anxiety.

Figure 1.

RMSSD among depression/anexity groups
Abstract 5731: An Increase of Intrinsic Endothelial Progenitor Cells after Acute Myocardial Infarction was Associated with Spontaneous Neovascularization but not with Improvement of Left Ventricula Remodeling
Authors: Date Motoo , Ito Hiroshi , Iwakura Katsuomi , Okamura Atsunori , Koyama Yasushi , Higuchi Yoshiharu , Inoue Koichi , Kimura Ryusuke , Nagai Hiroyuki , Toyoshima Yuko , Imai Michio , Ozawa Makito , Ito Norihisa , Okazaki Yukinori , Shibuya Masahiko , Suenaga Hidetaka , Kubota Asuka , Fujii Kenshi
Published: July 2021

Endothelial progenitor cells (EPC) increase after acute myocardial infarction and may contribute to neovascularization in the infarct zone. The aim of this study was to elucidate the relation of EPC release to recovery of microvascualr and myocardial function. Eighteen patients with acute myocardial infarction (AMI) undergoing primary PCI within 12 hours after onset were enrolled. CD34
+
cells were counted at days-1, 7 and 14 as an index of EPC. We performed triggered end-systolic myocardial contrast echocardiography (MCE) at every 6 cardiac cycles with continuous infusion of Levovist at days-2 and 14. We performed left ventriculography 6 months later to calculate left ventricular ejection fraction (LVEF) and end-diastolic volume index (LVEDVI). The number of EPC at day-7 was significantly higher than that at day-1 (1.29+/−0.75 vs. 2.10+/−1.25/micL, p<0.001). It was correlated with myocardial blood volume (MBV), that implies microvascular integrity, at day-14 measured from MCE image (r
2
=0.652, p<0.005) and with an increase in MBV from day-1 to day-7 (r
2
=0.533, p<0.005). To evaluate the correlation between EPC and LV function, we divided patients into two groups according to the number of EPC at day-7. LVEF and LVEDVI were comparable between the higher number of EPC and the lower number of EPC groups (49.3+/−12.2 vs. 52.4+/−8.1%, 65.2+/−13.1 vs. 69.1+/−16.6ml/m
2
). EPC spontaneously released after AMI and number of released EPC is correlated to the amount of neovascularization in the infarct zone. The number of EPC was not necessarily related to the functional improvement or attenuation of LV remodeling.
Abstract 5764: Molecular Imaging Tracking Phagocytosis and Protease Activity Reports on Cardiac Allograft Rejection
Authors: Christen Thomas , Nahrendorf Matthias , Wildgruber Moritz , Swirski Filip K , Aikawa Elena , Waterman Peter , Shimizu Koichi , Weissleder Ralph , Libby Peter
Published: July 2021

Recently developed molecular and cellular imaging techniques that probe macrophage (MΦ) functions might provide an alternative to invasive endomyocardial biopsy. Yet, which aspect of MΦ host response represents a useful marker for detecting parenchymal rejection remains uncertain. We transplanted cardiac isografts from B6 mice and allografts from Balb/c mice heterotopically into B6 recipients. During rejection, crucial Mϕ functions including phagocytosis and release of proteases render these abundant innate immune cells attractive imaging targets. Seven days after transplantation we injected either a fluorescent protease sensor or a magnetofluorescent phagocytosis sensor. Histological and flow cytometric analyses established that Mϕ function as the major cellular signal source. In vivo, we obtained a 3D functional map of Mϕ showing higher uptake of phagocytosis sensor during rejection using MRI (contrast-to-noise ratio (CNR) 51.5±8.5 in allografts (n=4) versus 19.8±8.7 in isografts (n=3), p<0.05) and higher protease activity in allografts than in isografts using fluorescence mediated tomography (FMT, fluorescence 41.2±5.2 pmol in allografts (n=8) versus 23.5±5.7 pmol in isografts (n=6), p<0.05). Finally, detection of significantly attenuated signals in recipients deficient in recombinase-1 demonstrated the sensitivity of Mϕ-targeted imaging. Reporters on either phagocytosis or protease activity can detect cardiac allograft rejection noninvasively, may facilitate the evaluation of novel tolerance-inducing strategies, and have translational potential.