First observation of 28O

Subjecting a physical system to extreme conditions is one of the means often used to obtain a better understanding and deeper insight into its organization and structure. In the case of the atomic nucleus, one such approach is to investigate isotopes that have very different neutron-to-proton (N/Z) ratios than in stable nuclei. Light, neutron-rich isotopes exhibit the most asymmetric N/Z ratios and those lying beyond the limits of binding, which undergo spontaneous neutron emission and exist only as very short-lived resonances (about 10-21 s), provide the most stringent tests of modern nuclear-structure theories. Here we report on the first observation of 28O and 27O through their decay into 24O and four and three neutrons, respectively. The 28O nucleus is of particular interest as, with the Z = 8 and N = 20 magic numbers1,2, it is expected in the standard shell-model picture of nuclear structure to be one of a relatively small number of so-called 'doubly magic' nuclei. Both 27O and 28O were found to exist as narrow, low-lying resonances and their decay energies are compared here to the results of sophisticated theoretical modelling, including a large-scale shell-model calculation and a newly developed statistical approach. In both cases, the underlying nuclear interactions were derived from effective field theories of quantum chromodynamics. Finally, it is shown that the cross-section for the production of 28O from a 29F beam is consistent with it not exhibiting a closed N = 20 shell structure.

Expanded quantum vortex liquid regimes in the electron nematic superconductors FeSe1-xSx and FeSe1-xTex

The quantum vortex liquid (QVL) is an intriguing state of type-II superconductors in which intense quantum fluctuations of the superconducting (SC) order parameter destroy the Abrikosov lattice even at very low temperatures. Such a state has only rarely been observed, however, and remains poorly understood. One of the key questions is the precise origin of such intense quantum fluctuations and the role of nearby non-SC phases or quantum critical points in amplifying these effects. Here we report a high-field magnetotransport study of FeSe_1-xS_x and FeSe_1-xTe_x which show a broad QVL regime both within and beyond their respective electron nematic phases. A clear correlation is found between the extent of the QVL and the strength of the superconductivity. This comparative study enables us to identify the essential elements that promote the QVL regime in unconventional superconductors and to demonstrate that the QVL regime itself is most extended wherever superconductivity is weakest.

Differences in gaze behaviors between trainees and experts during endovascular therapy for cerebral aneurysms: a preliminary study using a cerebral aneurysm model

In the neuroendovascular field, the training of operators has become an important issue. Recently, eye-tracking technology has been introduced into various fields of medical education. This study aimed to apply eye-tracking technology to the training of neuroendovascular therapy. Six neurosurgeons, including three neuroendovascular specialists and three trainees, at our institution and related facilities participated in the study. Eye movement was recorded by the eye-tracking device during the microcatheter navigation and coil placement into the silastic aneurysm model under biplane X-ray fluoroscopy. Eye-tracking analysis during neuroendovascular therapy was feasible in all six subjects. In microcatheter navigation, specialists tended to more frequently switch their attention between frontal and lateral images than trainees. In coil embolization, the overall gaze frequency tended to increase, and the average fixation duration tended to decrease as the number of experienced cases increased. Inexperienced operators tend to fix their gaze when they are operators than when they are assistants. More experienced operators tended to look at the microcatheter longer in the coil insertion task. The eye-tracking analysis may be useful for operator training in neuroendovascular therapy. Experts may have moved their eyes more frequently than trainees to gaze at the right place. In the future, it will be necessary to collect gaze data for more operators in various tasks.

Study of the N=32 and N=34 Shell Gap for Ti and V by the First High-Precision Multireflection Time-of-Flight Mass Measurements at BigRIPS-SLOWRI

The atomic masses of ^{55}Sc, ^{56,58}Ti, and ^{56-59}V have been determined using the high-precision multireflection time-of-flight technique. The radioisotopes have been produced at RIKEN's Radioactive Isotope Beam Factory (RIBF) and delivered to the novel designed gas cell and multireflection system, which has been recently commissioned downstream of the ZeroDegree spectrometer following the BigRIPS separator. For ^{56,58}Ti and ^{56-59}V, the mass uncertainties have been reduced down to the order of 10 keV, shedding new light on the N=34 shell effect in Ti and V isotopes by the first high-precision mass measurements of the critical species ^{58}Ti and ^{59}V. With the new precision achieved, we reveal the nonexistence of the N=34 empirical two-neutron shell gaps for Ti and V, and the enhanced energy gap above the occupied νp_{3/2} orbit is identified as a feature unique to Ca. We perform new Monte Carlo shell model calculations including the νd_{5/2} and νg_{9/2} orbits and compare the results with conventional shell model calculations, which exclude the νg_{9/2} and the νd_{5/2} orbits. The comparison indicates that the shell gap reduction in Ti is related to a partial occupation of the higher orbitals for the outer two valence neutrons at N=34.

Abnormal foreshortening of a Flow Re-Direction Endoluminal Device caused by in-stent thrombosis immediately after deployment

Thromboembolic complications are a concern in the treatment of cerebral aneurysms using a flow diverter. In this study, we report a case of abnormal foreshortening of a Flow Re-Direction Endoluminal Device (FRED) caused by in-stent thrombosis immediately after its deployment. A 72-year-old woman had a large cavernous carotid aneurysm, which caused ptosis and diplopia. FRED deployment was planned, and dual antiplatelet therapy was initiated 2 weeks before the procedure. Under systemic heparinization, FRED was deployed with local compaction over the aneurysm orifice. Cone-beam computed tomography subsequently revealed slightly poor wall apposition at the proximal side. While the balloon catheter was prepared for angioplasty, the stent became abnormally foreshortened, the proximal side slipped into the aneurysm, and the internal carotid artery became occluded. FRED was removed using a snare wire, and recanalization was obtained. The lumen of the removed FRED was filled with thrombus. The antiplatelet therapy was changed to triple regimen, and a Pipeline Flex embolization device was placed 1 month later. At that time, no thromboembolic complications were noted. It was considered that thrombotic occlusion was followed by foreshortening of FRED on the distal side because of antegrade blood flow. Multiple factors, such as increased mesh density by locally compacted stent deployment, slightly poor wall apposition, clopidogrel resistance, and the dual-layer structure of FRED, may have been involved in thrombus formation.

Prediction of recurrence after catheter ablation for atrial fibrillation using left atrial morphology on preprocedural computed tomography: application of radiomics

Background

Radiomics is a comprehensive analysis methodology of medical image and involves the extraction of numerous features from standard imaging. Its usefulness has been reported mainly in the field of cancer for diagnosis and prediction of prognosis. In the territory of cardiac imaging, several reports have investigated the utility of radiomics for classifying the risk of prognosis in coronary artery disease, and few practical applications have been reported for patients with atrial fibrillation (AF) who underwent pulmonary vein isolation (PVI). Although the left atrial morphology can affect the clinical course after the PVI procedure, it is unclear whether the radiomics feature values of the left atrial morphology on cardiac computed tomography (CT) is useful for predicting the AF recurrence after PVI.

Purpose

To predict the recurrence of AF after PVI using the radiomics feature values of the left atrial morphology on cardiac computed tomography (CT).

Methods

We analyzed 525 consecutive three-dimensional cardiac CT in patients with atrial fibrillation who underwent PVI from 2018 to 2019 in our institute. After marking the region of interest on left atrium (including the root of pulmonary veins) semiautomatically, 107 radiomics feature values were obtained by Python program. After excluding the parameters having collinearity or with low predictive capability for the recurrence of AF after PVI, 42 parameters were applied to the final prediction model. Two prediction models were constructed by multivariate Cox regression analysis and machine learning model by support vector machine algorithm.

Results

The area under the curve (AUC) for predicting the recurrence of AF was 0.815 for the multivariate Cox regression model and 0.826 for the machine learning model by support vector machine.

Conclusion

The radiomics feature values on preprocedural cardiac CT could be helpful for predicting the recurrence of AF after PVI. Since radiomics feature analysis yields a huge number of numerical values representing the left atrial morphology in a reproducible manner, it would provide a new direction to construct a good prediction model using machine learning including artificial intelligence out of a routine cardiac CT scan.

Funding Acknowledgement

Type of funding sources: None.

Interrelation between baseline plaque characteristics and changes in coronary atherosclerosis with the PCSK9-inhibitor alirocumab: insights from the PACMAN-AMI randomized trial

Background

Patients with acute myocardial infarction (AMI) frequently experience recurrent atherothrombotic events, largely attributable to non-culprit lesions with high-risk characteristics. Statins can halt the progression of coronary atherosclerosis, and addition of protein convertase subtilisin/kexin type 9-inhibitors (PCSK9i) results in incremental low-density lipoprotein cholesterol (LDL-C) lowering and atheroma regression.

Purpose

We sought to examine the interrelation between baseline imaging characteristics, on-treatment LDL-C levels, and changes in coronary atherosclerosis as assessed by serial, multi-modality intracoronary imaging in patients with AMI.

Methods

This is a post hoc analysis from the PACMAN-AMI randomized trial. Patients were randomly allocated to biweekly alirocumab 150 mg vs. placebo on top of high-intensity statin initiated within 24h of presentation with AMI, and underwent serial imaging of the two non-infarct-related arteries at baseline and after 52 weeks. The primary endpoint was percent atheroma volume (PAV) by intravascular ultrasound (IVUS). Powered secondary endpoints were maximal lipid core burden index (maxLCBI4mm) by near-infrared spectroscopy (NIRS) and minimum fibrous cap thickness (FCTmin) by optical coherence tomography (OCT).

Results

Of 300 randomized patients (mean age 58.5±9.8 years, 18.7% women, baseline LDL-C 3.94±0.87 mmol/L), IVUS was serially performed in 265 patients (537 arteries). LDL-C levels decreased to 1.92±0.79 mmol/L with placebo and 0.61±0.61 mmol/L with alirocumab (p<0.001). Compared with placebo (statin alone), alirocumab added to statin resulted in greater PAV reduction (−2.13% vs. −0.92%; p<0.001), greater maxLCBI4mm reduction (−79.42 vs. −37.60; p=0.006), and greater increase in FCTmin (62.67 vs. 33.19 μm; p=0.001). Changes in PAV and maxLCBI4mm were inversely related to on-treatment LDL-C levels, and change in FCTmin was positively related to on-treatment LDL-C levels (Figure 1). Across all patients, we found significant, inverse relationships between change in PAV and baseline PAV [slope: −0.072 (95% CI −0.101 to −0.042); p<0.001], between change in maxLCBI4mm and baseline maxLCBI4mm [slope: −0.437 (95% CI −0.505 to −0.369); p<0.001], and between change in FCTmin and baseline FCTmin [slope: −0.436 (95% CI −0.541 to −0.332); p<0.001]; these findings indicate greater PAV and maxLCBI4mm regression in lesions with greater PAV and LCBI4mm at baseline, and greater fibrous cap thickening in lesions with thinner fibrous caps at baseline.

Conclusion

In this study of intensive LDL-C lowering treatment initiated in the acute AMI setting, more favorable plaque changes were observed in patients with lower on-treatment LDL-C levels and in lesions with more adverse baseline plaque characteristics. Whether AMI patients with high-risk plaque features might derive greater clinical benefit from early initiation of intensive LDL-C-lowering therapies requires further investigation.

Funding Acknowledgement

Type of funding sources: Private company. Main funding source(s): Sanofi, Regeneron

Impact of alirocumab added to high-intensity statin therapy on platelet function in AMI patients: a pre-specified substudy of the randomized, placebo-controlled PACMAN-AMI trial

Background

Previous small observational studies have suggested a potential association of proprotein convertase subtilisin kexin type 9 (PCSK9) and platelet reactivity. However, the role of the PCSK9 inhibitor alirocumab on platelet aggregation among patients with acute myocardial infarction (AMI) remains unknown.

Purpose

We investigated the effect of alirocumab on P2Y12 reaction unit (PRU) on top of high-intensity statin therapy among AMI patients receiving dual antiplatelet therapy (DAPT) with a potent P2Y12 inhibitor (ticagrelor or prasugrel).

Methods

This was a pre-specified, powered, pharmacodynamic substudy nested within the PACMAN (effects of the PSCK9 antibody AliroCuMab on coronary Atherosclerosis in patieNts with Acute Myocardial Infarction) trial, a randomized, double-blind trial comparing biweekly alirocumab (150mg) versus placebo in AMI patients undergoing percutaneous coronary intervention (PCI). Patients recruited at Bern University Hospital, receiving DAPT with either ticagrelor or prasugrel at 4 weeks and adherent to the study drug (alirocumab or placebo) were analyzed for the current study. The VerifyNow P2Y12 point-of-care assays were used to measure PRU at baseline (i.e. before first study drug administration), 4 weeks, and 52 weeks after study drug administration (higher PRU levels indicating greater platelet aggregation). The primary endpoint was PRU at 4 weeks.

Results

Among 139 randomized patients (mean age 58.2 years [SD, 9.5], 21 [15.0%] women, mean LDL-C level 150.6mg/dL [SD, 30.9]), baseline characteristics were well balanced between groups including baseline PRU (50.0 [IQR, 120.0] in the alirocumab group vs. 62.0 [IQR, 122.0] in the placebo group, P=0.75). At 4 weeks, mean LDL-C was significantly lower in the alirocumab group (23.5 [SD, 23.7] mg/dL vs. 74.4 [SD, 30.5] mg/dL, P<0.001). The majority of patients received ticagrelor DAPT at 4 weeks (57 [86.4%] vs. 69 [94.5%], P=0.14). There were no significant differences in PRU at 4 weeks (12.5 [IQR, 27.0] vs. 19.0 [IQR, 30.0], P=0.26) and at 52 weeks (25.0 [IQR, 37.0] vs. 34.0 [IQR, 59.0], P=0.07) (Figure). Consistent results were observed in 126 patients treated with ticagrelor (i.e. after excluding 13 patients treated with prasugrel) at 4 weeks (13.0 [IQR, 20.0] vs. 18.0 [IQR, 27.0], P=0.28).

Conclusion

Among AMI patients receiving DAPT with potent P2Y12 inhibitors, alirocumab had no significant effect on platelet function as assessed by PRU.

Funding Acknowledgement

Type of funding sources: Public Institution(s). Main funding source(s): Bern University Hospital

Proton Distribution Radii of ^{16-24}O: Signatures of New Shell Closures and Neutron Skin

The root mean square radii of the proton density distribution in ^{16-24}O derived from measurements of charge changing cross sections with a carbon target at ∼900A  MeV together with the matter radii portray thick neutron skin for ^{22-24}O despite ^{22,24}O being doubly magic. Imprints of the shell closures at N=14 and 16 are reflected in local minima of their proton radii that provide evidence for the tensor interaction causing them. The radii agree with ab initio calculations employing the chiral NNLO_{sat} interaction, though skin thickness predictions are challenged. Shell model predictions agree well with the data.

Genetic Background of Mesalamine-induced Fever and Diarrhea in Japanese Patients with Inflammatory Bowel Disease

BACKGROUND

Some patients with inflammatory bowel disease (IBD) who were under mesalamine treatment develop adverse reactions called "mesalamine allergy," which includes high fever and worsening diarrhea. Currently, there is no method to predict mesalamine allergy. Pharmacogenomic approaches may help identify these patients. Here we analyzed the genetic background of mesalamine intolerance in the first genome-wide association study of Japanese patients with IBD.

METHODS

Two independent pharmacogenetic IBD cohorts were analyzed: the MENDEL (n = 1523; as a discovery set) and the Tohoku (n = 788; as a replication set) cohorts. Genome-wide association studies were performed in each population, followed by a meta-analysis. In addition, we constructed a polygenic risk score model and combined genetic and clinical factors to model mesalamine intolerance.

RESULTS

In the combined cohort, mesalamine-induced fever and/or diarrhea was significantly more frequent in ulcerative colitis vs Crohn's disease. The genome-wide association studies and meta-analysis identified one significant association between rs144384547 (upstream of RGS17) and mesalamine-induced fever and diarrhea (P = 7.21e-09; odds ratio = 11.2). The estimated heritability of mesalamine allergy was 25.4%, suggesting a significant correlation with the genetic background. Furthermore, a polygenic risk score model was built to predict mesalamine allergy (P = 2.95e-2). The combined genetic/clinical prediction model yielded a higher area under the curve than did the polygenic risk score or clinical model alone (area under the curve, 0.89; sensitivity, 71.4%; specificity, 90.8%).

CONCLUSIONS

Mesalamine allergy was more common in ulcerative colitis than in Crohn's disease. We identified a novel genetic association with and developed a combined clinical/genetic model for this adverse event.

Frequency and prognostic impact of periprocedural myocardial infarction determined by various MI definitions in patients with chronic coronary syndromes undergoing percutaneous coronary intervention

Background

Several definitions of peri-procedural myocardial infarction (MI) requiring different biomarker thresholds with or without ancillary criteria for myocardial ischemia are currently recommended without being fully validated in real-world patients with chronic coronary syndrome (CCS) undergoing percutaneous coronary intervention (PCI).

Objectives

We aimed to evaluate the prevalence and prognostic value of high-sensitivity cardiac troponin-based peri-procedural MI according to contemporary MI definitions using a large real-world PCI cohort.

Methods

In CCS patients undergoing elective PCI enrolled to the Bern PCI registry (NCT02241291) between 2010 and 2018, peri-procedural myocardial injury and infarction were assessed according to the 4th and 3rd universal definition of MI (UDMI), academic research consortium (ARC)-2, and Society for Cardiovascular Angiography and Interventions (SCAI) criteria. The primary endpoint was cardiac death at 1 year.

Results

Among 4404 CCS patients, peri-procedural MI defined by the 4th UDMI, 3rd UDMI, ARC-2, and SCAI were observed in 14.9%, 18.0%, 2.0%, and 2.0% of patients, respectively. Cardiac mortality at 1 year in patients with peri-procedural MI defined by 4th UDMI, 3rd UDMI, ARC-2, and SCAI were 3.0%, 2.9%, 5.8%, and 10.0%, respectively. After multivariate adjustments, peri-procedural MI defined by the ARC-2 and SCAI were independently associated with cardiac death at 1 year, while those defined by the 4th and 3rd UDMI were not.

Conclusion

Among CCS patients undergoing PCI, periprocedural MIs defined by theARC-2 and SCAI occurred 7 to 9 times less frequently as compared with the 4th and 3rd UDMI, and were the only definitions significantly associated with cardiac mortality.

Funding Acknowledgement

Type of funding sources: None. Cardiac death at 1 year

Comprehensive non-invasive and invasive functional assessment of anomalous coronary arteries with anatomical high-risk features

Background

Anomalous aortic origin of a coronary artery (AAOCA) is a rare congenital disease associated with an increased risk of myocardial ischemia. In AAOCA, the occurrence of ischemia is based on the extent of a fixed and a dynamic component, each attributed to different anatomical high-risk features (i.e., acute take-off angle, slit-like ostium, proximal narrowing, elliptic vessel shape and intramural course). Coronary computed tomography angiography (CCTA) is the primary non-invasive imaging method to depict the presence and quantitatively assess anatomical high-risk features while invasive physiologic evaluation under maximal dobutamine-volume challenge is the gold standard to unravel the hemodynamic relevance of AAOCA.

Methods

We included all consecutive AAOCA patients with anatomical high-risk features from our prospective, open-label registry. The objective is to quantify anatomical high-risk features in the CCTA and to measure hemodynamic relevance using invasive fractional flow reserve with maximal dobutamine-volume challenge (gradually increasing dose of dobutamine max. 40 μg/kg per body weight/min, max. 3000 mL ringer lactate and max. 1mg atropine). Pathological invasive FFR was defined as FFR Dobutamine<0.80. Additionally, CCTA-data were processed to assess computational fluid dynamics (CT FFR) and intravascular ultrasound (IVUS) was used to determine minimal lumen area (MLA) during baseline and maximal stress conditions.

Results

A total of 11 patients were included between 05/19 and 11/2020. Mean age was 59±13 years (range: 40–79), 10 patients showed a right-AAOCA and one patient showed a single right coronary artery. All patients had either one (i.e., in 1 patient) or more than one anatomical-high risk features (i.e., in 10 patients). Mean invasive FFR Dobutamine was 0.88±0.07 with n=2 (18%) being pathological. Mean non-invasive CT FFR was 0.89±0.04 (FFR<0.80; n=0), mean invasive FFR Adenosine was 0.92±0.06 (FFR<0.80; n=1; 9%). There was a significant decrease in IVUS MLA between rest (7.93±2.79mm2) and under dobutamine-volume challenge (6.57±3.20mm2, p=0.008). Mean percentage of MLA reduction was 19±18%.

Conclusion

Our preliminary results provide evidence that relevant myocardial ischemia seems to be often absent in a middle-aged population with AAOCA and anatomical high-risk features. However, in a minority of cases hemodynamic relevance could be depicted, especially when stressing with dobutamine-volume challenge. The presence of a dynamic component in AAOCA is represented by the reduced minimal lumen area under stress conditions. Comprehensive diagnostic evaluation should be performed to prevent unnecessary guideline recommended open-heart surgery in a middle-aged population with AAOCA.

Funding Acknowledgement

Type of funding sources: None.

Identifying patients with atrial fibrillation during sinus rhythm on ECG: confirming the utility of artificial intelligence algorithm in a small-scale cohort without structural heart diseases

Background

Detection of atrial fibrillation (AF) out of electrocardiograph (ECG) on sinus rhythm (SR) using artificial intelligence (AI) algorithm has been widely studied within recent couple of years. Generally, it is believed that a huge number of ECGs are necessary for developing an AI-enabled ECG to be adequate to correspond to a lot of minor variations of ECGs. For example, structural heart diseases have typical ECG characteristics, but they could be a noise for the purpose of detecting the small signs of electrocardiographic signature of AF. We hypothesized that when patients with structural heart diseases are excluded, AI-enabled ECG for identifying patients with AF can be developed with a small number of ECGs.

Methods

We developed an AI-enabled ECG using a convolutional neural network to detect the electrocardiographic signature of AF present during normal sinus rhythm (NSR) using a digital, standard 10-second, 12-lead ECGs. We included all patients who newly visited the Cardiovascular Institute with at least one NSR ECG between Feb 1, 2010, and March 31, 2018. We classified patients with at least one ECG with a rhythm of AF as positive for AF (AF label) and others as negative for AF (SR label). We allocated ECGs to the training, internal validation, and testing datasets in a 7:1:2 ratio. We calculated the area under the curve (AUC) of the receiver operating characteristic curve for the internal validation dataset to select a probability threshold, which we applied to the testing dataset. We evaluated model performance on the testing dataset by calculating the AUC and the sensitivity, specificity, F1 score, and accuracy with two-sided 95% confidence intervals (CIs).

Results

We totally included 19170 patients with 12-lead ECG. After excluding patients with structural heart diseases, 12825 patients with NSR ECGs at the initial visit were identified (1262 were clinically diagnosed as AF anytime during the time course and 11563 were never diagnosed as AF). Of 11563 non-AF patients, 1818 patients who were followed over 1095 days were selected for the analysis with the SR label, to secure the robustness for maintaining SR. Of 1262 AF patients, 251 patients were selected for the analysis with the AF label, of whom a NSR ECG within 31 days before or after the index AF ECG (the first AF ECG during the time course) could be obtained. In the patients with AF label, the NSR ECG of which the date was the nearest to the index AF ECG was selected for the analysis. The AI-enabled ECG showed an AUC of 0.88 (0.84–0.92) with sensitivity 81% (72–88), specificity 80% (77–83), F1 score 50% (43–57), and overall accuracy 80% (78–83).

Conclusion

An AI-enabled ECG acquired during NSR allowed identification of patients with AF in a small population without structural heart diseases.

Funding Acknowledgement

Type of funding sources: None.

Derivation and validation of myocardial bridge characteristics by optical coherence tomography: a prospective multimodality imaging study

Background

Optical coherence tomography (OCT) findings of myocardial bridge (MB) have not been established.

Purpose

We aimed to establish the OCT appearance of MB compared with the half-moon sign derived by intravascular ultrasound (IVUS) and to assess the prevalence among patients undergoing coronary angiography and OCT in clinical practice.

Methods

For derivation of the OCT appearance of MB, imaging data obtained from 122 patients undergoing OCT and IVUS for the left anterior descending artery (LAD) enrolled in two prospective imaging studies were analyzed. To assess the prevalence of OCT-derived MB, 470 patients undergoing OCT for LAD in clinical routine were analyzed.

Results

We found a homogeneous band with intermediate light intensity surrounding the vessel wall as assessed by OCT corresponding to half-moon sign derived by IVUS. Mean length, angle, and thickness of OCT-MB were 21.2±10.8mm, 205.7±56.5°, and 0.39±0.06mm, respectively. Mean length of IVUS-MB was significantly longer as compared with OCT-MB (23.7±11.9, P=0.010), while there were no significant differences in angle and thickness. MB angle was >180° in approximately 50% of frames with MB. There was a strong/moderate correlation between OCT-MB and half-moon sign (MB length: r=0.81, P=0.001, MB angle: r=0.58, P=0.001). In the derivation cohort, sensitivity, specificity, positive predictive value, negative predictive value, and accuracy of OCT-MB for the milking effect by angiography were 96.3%, 62.1%, 41.9%, 98.3%, and 69.7%, respectively, and much comparable with the IVUS half-moon sign. In the validation cohort, OCT-detected MB was observed in 139 (29.6%) patients, of whom 57.6% (n=80) did not have angiographic evidence of milking effect.

Conclusion

OCT is able to identify IVUS-defined MB as homogenous band with intermediate light intensity surrounding the vessel wall. There was a high concordance in terms of MB angle and thickness between OCT and IVUS. In clinically-indicated OCT cases of the LAD, more than half of OCT-MBs were angiographically silent. OCT assessment of MB may facilitate the accurate diagnosis of MB and thus provide useful information in determining the subsequent treatment strategy for the patients with MB.

Funding Acknowledgement

Type of funding sources: None. Representative imaging of MBCase of OCT-MB without milking effect

Evaluation of the differences in pressure applied to the vessel wall by different types of balloon remodeling microcatheters in an experimental model

BACKGROUND

We examined compliance differences among balloon remodeling microcatheters, which have not been established previously.

METHODS

Straight and 120° angulated vascular models were created in a 3 mm diameter tube with 3 mm hole (vascular model A), a tube with a 4 mm hole (vascular model B), and a 4 mm diameter tube (vascular model C). We compared the pressure exerted when each balloon was herniated 1 or 2 mm between three compliant balloons (SHOURYU SR, TransForm C, and Scepter C) and four super-compliant balloons (HyperForm, SHOURYU HR, TransForm SC, and Scepter XC).

RESULTS

In vascular model A, there was a significant difference in the pressure exerted by compliant balloons and super-compliant balloons in both the straight and angulated models. In the straight model (1 and 2 mm), the lowest pressure was exerted by HyperForm (super-compliant balloons group) and SHOURYU SR (compliant balloons group). The lowest pressure was exerted in the angulated model by HyperForm (super-compliant balloons group) and Scepter C (compliant balloons group). The Scepter balloon exerted higher pressure in the straight model than other balloon remodeling microcatheters but less in the angulated model. In vascular model B, the pressure decreased in all balloons compared with model A. In vascular model C, the pressure increased in all balloons compared with model A.

CONCLUSIONS

Pressure differed across balloon remodeling microcatheters. In addition, vessel shape and diameter, and hole size, affected the results. Our findings can help select balloon remodeling microcatheters.

Material survey for a millimeter-wave absorber using a 3D-printed mold

Radio absorptive materials (RAMs) are key elements for receivers in the millimeter-wave range. We previously established a method for production of RAM by using a 3D-printed mold. An advantage of this method is a wide range of choices for absorptive materials to be used. To take advantage of this flexibility, we added a range of absorptive materials to a base epoxy resin, STYCAST-2850FT, and examined the optical performance of the resultant RAM across a wide frequency range under cryogenic conditions. We found that adding a particular type of carbon fiber produced the best performance with a reflectance at 77 K estimated as 0.01%-3% over a frequency range of 20-300 GHz.

Streak Metal Artifact Reduction Technique in Cone Beam Computed Tomography Images after Endovascular Neurosurgery

Cone beam computed tomography (CBCT) images are degraded by artifacts due to endovascular implants. We evaluated the use of streak metal artifact reduction technique (SMART) in non-contrast CBCT images after endovascular neurosurgery obtained from 148 patients (125 with aneurysm and 23 with dural arteriovenous fistula [dAVF]). Three neurosurgeons evaluated the cistern and brain surface visibility in CBCT images with and without SMART correction based on a 4-point scale (1, excellent; 2, good; 3, limited; and 4, insufficient). Significant improvement in visibility was achieved when the median scores improved from 4 or 3 to 2 or 1 or from 2 to 1. Metal artifact reduction in adjacent slices without metal and new artifacts after SMART correction was also examined. A significant improvement was achieved regarding the visibility of the cistern in 90 (60.8%) images and of the brain surface in 108 (73.0%) images. Metal size (cistern: odds ratio [OR], 0.91 per 1 mm increase; 95% confidence interval [CI], 0.83–0.99), irregular metal shape (cistern: OR, 0.18; 95% CI, 0.05–0.60 and brain surface: OR, 0.15; 95% CI, 0.05–0.45), and infratentorial lesions (cistern: OR, 0.37; 95% CI, 0.14–0.96 and brain surface: OR, 0.30; 95% CI, 0.11–0.80) were negatively correlated with improved visibility. Metal artifact reduction in adjacent slices without metal was obtained in 25.6% and 34.8% of images with aneurysm and dAVF, respectively. New artifacts after SMART correction were found in 4.8% and 13.0% of images with aneurysm and dAVF, respectively. SMART is especially effective for supratentorial small aneurysms.

Direct Vertebral Artery Puncture During Open Surgery for the Endovascular Treatment of a Recurrent Vertebro-Vertebral Arteriovenous Fistula

BACKGROUND

Vertebro-vertebral arteriovenous fistula (VVAVF) is a condition in which there is an arteriovenous shunt directly connecting the extracranial vertebral artery to the vertebral venous plexus. Many reports have described fistula occlusion or vertebral artery trapping as treatments for VVAVF. Here, we describe a case in which endovascular treatment for recurrent VVAVF using a transfemoral approach was unsuccessful; thus, the vertebral artery (VA) was directly punctured during open surgery and the treatment was successful.

CASE DESCRIPTION

The patient was a 47-year-old female who had undergone endovascular treatment for VVAVF. The patient developed subarachnoid hemorrhage. Digital subtraction angiography revealed a left VVAVF. The left VA was trapped with coils at the C2 and C3 levels and an arteriovenous shunt formed from the VA between the 2-coil mass to the vertebral venous plexus. In addition, reflux was observed in the spinal vein. Endovascular treatment was attempted with a transfemoral approach, but we could not reach the shunt. Five days post-treatment, the patient had a second subarachnoid hemorrhage and surgery was performed to occlude the radiculomedullary vein; however, residual reflux went into the spinal vein from another spinal level. Later, the VA was directly punctured and treated with N-butyl cyanoacrylate, and the shunt disappeared.

CONCLUSIONS

Direct puncture of the vertebral artery was useful in this case, where it was difficult to reach the lesion. Although direct VA puncture is associated with more complications than the transfemoral or transbrachial approach, it may be an option when other methods are difficult.

Prediction of atrial fibrillation by 12-lead electrocardiogram parameters in patients without structural heart disease

Background

Recently, the analysis of electrocardiogram (ECG) waveform by artificial intelligence has been reported to pick out those who have atrial fibrillation (AF) or have a high potential of developing AF, which, however, cannot explain the mechanisms or algorisms for the prediction from its nature.

Purpose

The purpose of this study is to conduct a comprehensive analysis to investigate the difference of weighting in predicting capability for AF among hundreds of automatically-measured ECG parameters using a single ECG at sinus rhythm.

Methods and results

Out of Shinken Database 2010–2017 (n=19170), 12825 patients were extracted, where those with ECG showing AF rhythm at the initial visit (including all persistent/permanent AF and a part of paroxysmal AF) and those with structural heart diseases were excluded. Out of 639 automatically-measured ECG parameters in MUSE data management system (GE Healthcare, USA), 438 were used. [Analysis 1] A predicting model for paroxysmal AF were determined by logistic regression analysis (Total, n=12825; paroxysmal AF, n=1138), showing a high predictive capability (AUC = 0.780, p<0.001). In this model, the relative contribution of ECG parameters (by coefficient of determination) according to the time phase were P:72.4%, QRS:32.7%, and ST-T:13.7%, respectively (Figure A). [Analysis 2] Excluding AF at baseline, a predicting model for new-developed AF were determined by Cox regression analysis (Total, n=11687; new-developed AF, n=87), showing a high predictive capability (AUC = 0.887, p<0.001). In this model, the relative contribution of parameters (by log likelihood) according to the time phase were P:40.8%, QRS:42.5%, and ST-T:24.9%, respectively (Figure B).

Conclusions

We determined ECG parameters that potentially contribute to picking up existing AF or predicting future development of AF, where the measurement of P wave strongly contributed in the former whereas all time phases were similarly important in the latter.

Weighting of parameters to predict AF

Funding Acknowledgement

Type of funding source: Private hospital(s). Main funding source(s): Self funding of the institute

Heart rate recovery after exercise as a prognostic predictor in patients with atrial fibrillation

Background

A delayed heart rate recovery (HRR) after exercise is related to mortality in sinus rhythm. This study aimed to investigate this concept can be applied to patients with atrial fibrillation (AF).

Methods

We analyzed 483 patients with AF (mean 65 years, male 74%). HRR integral was calculated by integrating the difference in HR in every 3 second between the end of exercise and the specified time after the exercise (30, 60, 120 and 180 seconds). After evaluating the prognostic power of each HRR integral, we selected HRR integral of 180 seconds (180HRR-integral).

Results

We divided the patients into two groups using median value of 180HRR-integral. All-cause mortality, the incidence of cardiovascular events and heart failure events were higher in the poor 180HRR-integral. After adjustment for covariates, the impact of the high 180HRR-integral for all-cause mortality was 3.15 (p=0.057), 1.77 for cardiovascular events (p=0.067) and 1.28 for heart failure events (p=0.519).

Conclusion

Poor HRR was associated with worse prognosis in patients with AF.

Funding Acknowledgement

Type of funding source: None

Quantitative flow ratio to predict non-target-vessel-related events at 5 years in STEMI patients undergoing angiography-guided revascularization

Background

In patients with ST-segment-elevation myocardial infarction (STEMI), angiography-based complete revascularization is associated with superior outcomes compared with culprit-lesion-only percutaneous coronary intervention (PCI). Quantitative Flow Ratio (QFR) is a novel, non-invasive, vasodilator-free method to assess the hemodynamic significance of coronary stenoses.

Purpose

To investigate the incremental value of QFR over angiography alone in the assessment of non-culprit lesions (NCL) in STEMI patients undergoing primary PCI.

Methods

In the randomized, multicenter COMFORTABLE AMI trial, STEMI patients underwent angiography-guided complete revascularization. QFR was determined in untreated non-target vessels by assessors blinded for clinical outcomes.

Results

Out of 1161 STEMI patients, 946 vessels in 617 patients could be analyzed by QFR. At 5-year follow-up, the rate of the primary endpoint cardiac death, non-target vessel myocardial infarction (non-TV-MI) and clinically indicated, non-target vessel revascularization (non-TVR) was significantly higher in patients with QFR ≤0.80 compared with QFR >0.80 (62.9% vs. 12.7%, HR 7.20, 95% CI 4.46–11.62, p<0.001), driven by higher rates of non-TV-MI (15.4% vs. 3.6%, HR 4.59, 95% CI 1.72–12.23, p=0.002) and non-TVR (58.6% vs. 7.7%, HR 10.99, 95% CI 6.39–18.91, p<0.001). No significant differences for cardiac death were observed. Multivariate analysis identified QFR ≤0.80, MI SYNTAX score and left ventricular function as independent predictors of the primary endpoint. QFR ≤0.80 showed an accuracy of 86.1%, sensitivity of 23.2%, specificity of 97.5%, positive predictive value of 62.9% and negative predictive value of 87.5% for the prediction of the primary endpoint.

Conclusions

Our study results suggest incremental value of QFR over angiography-guided PCI for NCL among STEMI patients undergoing primary PCI.

Kaplan-Meier curves of primary endpoint

Funding Acknowledgement

Type of funding source: None

Shape Coexistence at Zero Spin in ^{64}Ni Driven by the Monopole Tensor Interaction

The low-spin structure of the semimagic ^{64}Ni nucleus has been considerably expanded: combining four experiments, several 0^{+} and 2^{+} excited states were identified below 4.5 MeV, and their properties established. The Monte Carlo shell model accounts for the results and unveils an unexpectedly complex landscape of coexisting shapes: a prolate 0^{+} excitation is located at a surprisingly high energy (3463 keV), with a collective 2^{+} state 286 keV above it, the first such observation in Ni isotopes. The evolution in excitation energy of the prolate minimum across the neutron N=40 subshell gap highlights the impact of the monopole interaction and its variation in strength with N.

Electromagnetic character of the competitive γγ/γ-decay from 137mBa

Second-order processes in physics is a research topic focusing attention from several fields worldwide including, for example, non-linear quantum electrodynamics with high-power lasers, neutrinoless double-β decay, and stimulated atomic two-photon transitions. For the electromagnetic nuclear interaction, the observation of the competitive double-γ decay from ^137mBa has opened up the nuclear structure field for detailed investigation of second-order processes through the manifestation of off-diagonal nuclear polarisability. Here, we confirm this observation with an 8.7σ significance, and an improved value on the double-photon versus single-photon branching ratio as 2.62 × 10^-6(30). Our results, however, contradict the conclusions from the original experiment, where the decay was interpreted to be dominated by a quadrupole-quadrupole component. Here, we find a substantial enhancement in the energy distribution consistent with a dominating octupole-dipole character and a rather small quadrupole-quadrupole component in the decay, hindered due to an evolution of the internal nuclear structure. The implied strongly hindered double-photon branching in ^137mBa opens up the possibility of the double-photon branching as a feasible tool for nuclear-structure studies on off-diagonal polarisability in nuclei where this hindrance is not present.

Two-Neutron Halo is Unveiled in ^{29}F

We report the measurement of reaction cross sections (σ_{R}^{ex}) of ^{27,29}F with a carbon target at RIKEN. The unexpectedly large σ_{R}^{ex} and derived matter radius identify ^{29}F as the heaviest two-neutron Borromean halo to date. The halo is attributed to neutrons occupying the 2p_{3/2} orbital, thereby vanishing the shell closure associated with the neutron number N=20. The results are explained by state-of-the-art shell model calculations. Coupled-cluster computations based on effective field theories of the strong nuclear force describe the matter radius of ^{27}F but are challenged for ^{29}F.

Comparison of cerebral cortex activation induced by tactile stimulation between natural teeth and implants

Background

The purpose of this study was to assess the cortical-level sensory differences between natural teeth with a periodontal membrane and dental implants.

Material and Methods

We used functional near-infrared spectroscopy (fNIRS) to measure brain activity in the cerebral cortex of 12 patients who had both natural teeth and dental implants in the lower molar region. Painless vibratory tactile stimulation was performed on both the natural teeth and the dental implants.

Results

Activation was seen in the somatosensory cortex during stimulation of both natural teeth and dental implants. A comparison of cortical activation showed no significant differences between natural teeth and dental implants.

Conclusions

These results indicate the possible existence of sensory input to the cerebral cortex via dental implants as well as natural teeth, and thus suggest that may not only the periodontal membrane be involved in the signaling pathway. The data from this experiment may help us for understanding the neural mechanisms underlying natural teeth and dental implants.

Key words:fNIRS, natural teeth, implants, brain activity, somatosensory cortex.

P1480 A case of triple left ventricular aneurysms diagnosed by CT and echocardiography

【Background】

Left ventricular aneurysms is complication of myocardial infarction (MI) that can lead to death or serious morbidity. False aneurysm is rare complications of myocardial infarction or iatrogenic perforation and represent a contained myocardial rupture. False aneurysm does not contain all the three layers of the myocardium and is frequently lined by pericardium and mural thrombus. Definitive diagnosis is achieved by echocardiography, computed tomography (CT), angiography, or magnetic resonance imaging. Coexistence of true and false aneurysms is rare.

【Case】 A 58 years old man with a history of hypertension and MI was referred to our hospital for aneurysmectomy. During the course of prior MI, he got fever and pericardial effusion.

CT revealed that three left ventricular aneurysms were present. Also, three aneurysms were connected by narrow ducts each other. Transthoracic echocardiography (TTE) revealed that three ventricular aneurysms were connected via acceleration blood flow which swirling in the spherical aneurysm. We determined that this triple ventricular aneurysms were at high risk for rupture, so we performed surgery.

The postoperative course was good and he was discharged without any complications.

【Discussion】

False aneurysms occur after hemorrhagic dissection into an area of transmural infarction and most commonly result in free intrapericardial rupture of the heart, cardiac tamponade, and death. Rarely, if the overlying pericardium becomes adherent to the epicardium along the surface of the infarct, it can contain the rupture.

We were able to evaluate the mechanism of development with triple left ventricular aneurysms using CT and TTE. We could know about spatial comprehension of triple aneurysms using CT. False aneurysms were restricted enlargement due to stiff pericardium because of complicating Dressler syndrome. We hypothesis that aneurysms were enlarging in the direction of the base of heart in the adhered pericardium space.

We were able to evaluate the thickness of aneurysms and blood flow condition using TTE. TTE revealed that the wall of aneurysm was fragile. Multimodality imaging like TTE or cardiac CT are useful diagnostic methods in this case.

Abstract P1480 Figure. Triple aneurysms

1638 A case of capturing changes in interatrial blood flow and anatomical structure during percutaneous PFO closure with platypnea orthodeoxia syndrome using intra-cardiac echocardiography

Background

Platypnea–orthodeoxia syndrome (POS) is an uncommon condition characterized by positional dyspnea and hypoxemia due to intracardiac right-to-left shunting through a patent foramen ovale (PFO). The most commonly associated conditions included pneumonectomy, ascending aortic dilation, and arch surgery, as previously reported. Percutaneous closure of PFO is useful treatment for POS.

Case

A 76 year old man used home oxygen therapy because of unexplained hypoxemia. A decrease in blood oxygen saturation was observed in sitting and standing positions. The patient was diagnosed as "POS" because a shunt blood flow with PFO and atrial septal aneurysm (ASA) and eustachian valve was observed at transesophageal echocardiography. He was admitted for the purpose of percutaneous PFO closure.

He was treated with intra-cardiac echocardiography (ICE) guidance under local anesthesia because of poor lung function.

PFO closure was performed successfully with 30mm AMPLATZER Cribriform. The ICE findings prior to PFO closure showed a right-to-left shunt blood flow through the PFO in the sitting position but almost disappeared after closure. Furthermore, it was observed that the aortic artery compression was stronger in the sitting position than in the supine position with right-to-left shunt blood flow. After PFO closure, hypoxia associated with postural change improved and patient’s symptom as shortness of breath also significantly improved.

Discussion

POS is a position-dependent condition of dyspnea and hypoxemia due to right-to-left shunting. It often remains unrecognized in clinical practice, possibly because of its complex underlying pathophysiology. It is considered that the cause of POS in this patient was multiple factors such as ASA, aortic displacement, and venous valve remnant. In addition, being able to observe the change of the atrium due to compression from the aortic artery using ICE during the operation was very significant to explain the mechanism of POS.

Abstract 1638 Figure. Intra-cardiac echocardiography

P1713 A case of quadricuspid aortic valve complicated with infective endocarditis diagnosed by 3D transesophageal echocardiography

Background

Quadricuspid aortic valve (QAV) is a rare congenital heart disease with an estimated incidence of 0.008% to 1.46%. The functional status of QAV is predominantly a pure aortic regurgitation. The extensive use of echocardiography has allowed an early and accurate diagnosis of this malformation. In many cases, the transthoracic echocardiography (TTE) is suitable for the diagnosis but, transesophageal echocardiography (TEE), especially 3-dimensional (3D) TEE, is a tool for the accurate definition of the valve anatomy.

Clinical case

A 60-year-old female underwent a head CT for intermittent headaches for one month ago. She was admitted to neurosurgery in our hospital diagnosed of subarachnoid hemorrhage. Four mm aneurysm was found on the periphery of the right middle cerebral artery on CT examination, and a cerebral aneurysm coil embolization was performed with a catheter in emergency. The possibility of infectious cerebral aneurysm was pointed out, and we examined in cardiovascular internal medicine. TTE revealed moderate aortic regurgitation. The ventricular septum exhibits sigmoid septum. A mobile mass was found near the left ventricular outflow tract in the sigmoid septum. TEE revealed a hypoplasia cusp (accessory cusp) is found between non coronary cusp and right coronary cusp. Aortic valve leaflets have become thickened and regurgitation from the central part of the cusps. 3DTEE was able to more accurately visualize that only the accessory cusp was hypoplastic, and the size of the other three leaflets appears almost the same. Similarly, vegetation on the left ventricular outflow tract were clearly revealed by 3DTEE.

Based on the above, it was diagnosed that quadricuspid aortic valve complicated with infective endocarditis (IE) with aortic valve regurgitation. After treatment with antibiotics according to IE, surgical treatment was scheduled.

Discussion

QAV is a rare congenital heart disease, and TTE is an important imaging tool for accurate diagnosis. Furthermore, TEE, especially 3DTEE, was a more appropriate diagnostic method in QAV and IE.

Abstract P1713 Figure. 3DTEE

Underlying Structure of Collective Bands and Self-Organization in Quantum Systems

The underlying structure of low-lying collective bands of atomic nuclei is discussed from a novel perspective on the interplay between single-particle and collective degrees of freedom, by utilizing state-of-the-art configuration interaction calculations on heavy nuclei. Besides the multipole components of the nucleon-nucleon interaction that drive collective modes forming those bands, the monopole component is shown to control the resistance against such modes. The calculated structure of ^{154}Sm corresponds to the coexistence between prolate and triaxial shapes, while that of ^{166}Er exhibits a deformed shape with a strong triaxial instability. Both findings differ from traditional views based on β/γ vibrations. The formation of collective bands is shown to be facilitated from a self-organization mechanism.

Quasifree Neutron Knockout from ^{54}Ca Corroborates Arising N=34 Neutron Magic Number

Exclusive cross sections and momentum distributions have been measured for quasifree one-neutron knockout reactions from a ^{54}Ca beam striking on a liquid hydrogen target at ∼200  MeV/u. A significantly larger cross section to the p_{3/2} state compared to the f_{5/2} state observed in the excitation of ^{53}Ca provides direct evidence for the nature of the N=34 shell closure. This finding corroborates the arising of a new shell closure in neutron-rich calcium isotopes. The distorted-wave impulse approximation reaction formalism with shell model calculations using the effective GXPF1Bs interaction and ab initio calculations concur our experimental findings. Obtained transverse and parallel momentum distributions demonstrate the sensitivity of quasifree one-neutron knockout in inverse kinematics on a thick liquid hydrogen target with the reaction vertex reconstructed to final state spin-parity assignments.

P5500Acute coronary syndrome in young patients: frequency, mechanisms and clinical outcomes following percutaneous coronary intervention

Introduction

Acute coronary syndromes (ACS) mainly affect older patients and little is known on the frequency, the underlying causes and outcomes following ACS in young.

Purpose

To investigate the frequency, mechanisms and clinical outcomes of young patients suffering from ACS and undergoing percutaneous coronary intervention (PCI).

Methods

Between February 2009 and December 2016, 6720 consecutive patients undergoing PCI for an ACS were prospectively enrolled. We defined young patients as male <45 years or female <50 years. The primary endpoint was the patient-oriented composite endpoint (POCE) defined as the composite of all-cause death, myocardial infarction or any revascularization at 12 months. The mechanisms of ACS in young patients (atherosclerotic vs. embolic vs. spontaneous coronary artery dissection) were retrospectively assessed by an adjudication committee based on clinical and angiographic criteria.

Results

Among 6720 ACS patients, 378 (5.6%) patients were young (41±5 years, 73% male). Young patients, as compared to old patients, presented more frequently with STEMI (64% vs. 45%; p<0.001) and single vessel disease (85% vs. 74%; p<0.001). Cardiovascular risk factors were more frequent in young patients including BMI>30 kg/m2 (34% vs. 22%; p<0.001), smoking (68% vs. 31%; p<0.001), positive family history of coronary artery disease (35% vs. 23%; p<0.001) and baseline LDL-C levels (3.3±1.1 mmol/l vs. 2.9±1.1 mmol/l; p<0.001). Diabetes mellitus was less frequent in the young patient group (10% vs. 21%; p<0.001). The mechanisms of ACS in young patients were atherosclerotic in 87%, coronary embolism in 9%, and spontaneous coronary artery dissection in 4%. At 12 months, the primary endpoint POCE occurred less frequently in young patients (9.3% vs. 17%; HR 0.52, 95% CI 0.37–0.73; p<0.001). The rates of the individual components of the primary endpoint were lower in young patients including all-cause death (3.4% vs. 9.4%; HR 0.36, 95% CI 0.21–0.62; p<0.001), myocardial infarction (1.9% vs. 3.7%; HR 0.48, 95% CI 0.22–1.01; p=0.053) and any revascularization (5.6% vs. 7.7%; HR 0.68, 95% CI 0.44–1.05; p=0.083). Young patients with coronary embolism or spontaneous coronary artery dissection had a higher rate of cardiac death at 12 months as compared to young patients with atherosclerotic disease (embolic vs. atherosclerotic: 9.4% vs. 2.2%; HR 4.3, 95% CI 1.11–16.71; p=0.02; spontaneous coronary artery dissection vs. atherosclerotic: 17.6% vs. 2.2%; HR 8.1, 95% CI 2.1–31.1; p<0.001).

Conclusions

Approximately one out of 20 ACS patients undergoing PCI was young and the main presumed mechanism of ACS was atherosclerosis (87%) followed by coronary embolism (9%) and spontaneous coronary artery dissection (4%). While young ACS patients carry a lower risk for future cardiovascular events as compared with older patients, the high cardiac death rates following embolic disease or spontaneous coronary artery dissections deserves particular attention.

P2666Association of out-of-hospital cardiac arrest occurrence time and the survival in all-Japan utstein registry: difference between international resuscitation guidelines 2005 and 2010

Background/Introduction

Previous studies have shown that out-of-hospital cardiac arrest (OHCA) occurring at night have poor outcomes compared with OHCA occurring during daytime. On the other hand, nationwide OHCA outcomes have gradually improved in Japan.

Purpose

We sought to examine whether one-month survival of OHCA differed between daytime and nighttime occurrences, and they differed between the periods of International Resuscitation Guidelines 2005 and 2010.

Methods

Using the All-Japan Utstein Registry between 2005 and 2015, adult OHCA patients whose collapse was witnessed by a bystander and the call-to-hospital admission interval was shorter than 120 min were included in this study. OHCA patients were divided by period of the International Resuscitation Guideline 2005 and 2010. Guideline 2005 included years from 2006 to 2010, while Guideline 2010 included years from 2011 to 2015. The primary outcome was one-month survival with favorable neurological outcome, defined as Cerebral Performance Category scale of 1 or 2. Daytime, evening, and night were defined as 0700 to 1459 h, 1500 to 2259 h, and 2300 to 0659 h, respectively.

Results

Among 479,046 cases, 20.3% revealed OHCA occurring at night. OHCA patients occurring at night had lower rate of bystander cardiopulmonary resuscitation (CPR) and automated external defibrillator use than those occurring at both daytime and evening. In addition, of those who received bystander CPR, higher rate of patients received CPR by family members. OHCA patients occurring at night in both guideline periods had significantly worse one-month survival than those occurring during daytime (reference) (adjusted odds ratio, 0.69, 0.64; 95% confidence interval 0.65–0.72, 0.61–0.67; P<0.001, P<0.001, Guideline 2005 and 2010 respectively). OHCA patients occurring during daytime in Guideline 2010 had better one-month survival than those in Guideline 2005 (adjusted odds ratio, 1.29; 95% confidence interval 1.24–1.34; P<0.001).

Conclusions

One-month survival with favorable neurological outcome in OHCA patients occurring at night remains to be significantly worse than those occurring during daytime, even improved by the periods during daytime. CPR training for the family members should be more expanded and strengthened against the night time imperfection.

122Mechanism and impact of lesion morphology on the late lumen loss of drug-eluting resorbable magnesium scaffolds: a serial optical coherence tomography study

Introduction

Resorbable Magnesium Scaffolds have demonstrated favourable clinical results with acceptable late lumen loss (LLL). However, the pathomechanisms influencing LLL of resorbable sirolimus-eluting metallic scaffold (Magmaris) have not been analyzed.

Purpose

Using serial optical coherence tomography (OCT), we investigated potential factors, i.e. the contribution of recoil versus neointimal hyperplasia (NIH).

Methods

Patients who were enrolled into BIOSOLVE-II, and underwent serial angiography and OCT (baseline and follow-up: 6-month and/or 1-year) were analyzed. Patients were divided into 2 groups based on angiographic in-scaffold LLL <0.5mm or ≥0.5mm. Endpoints were late absolute recoil and NIH area as assessed by OCT.

Results

A total of 70 patients (LLL <0.5mm: n=41, LLL ≥0.5mm: n=29) were serially analyzed. Patient and lesion characteristics were comparable and there was no significant difference in mean and minimal scaffold area between groups at baseline. Late absolute recoil was significantly smaller among patients with LLL <0.5mm (0.53±0.68 mm2) compared with those with LLL ≥0.5mm (1.48±1.20 mm2, P<0.001) (Figure). A small difference in NIH area at follow-up was observed (LLL <0.5mm: 1.47±0.33 mm2 vs. LLL ≥0.5mm: 1.68±0.34 mm2, P=0.013). In a matched-frame analysis (baseline and follow-up), late absolute recoil varied according to the underlying plaque type (lipid: 0.63±1.23 mm2, calcified: 0.81±1.44 mm2, and fibrous: 1.20±1.52 mm2, P<0.001), while there was no difference with regards to NIH area (P=0.132).

Conclusion

The main driver of late lumen loss of sirolimus-eluting absorbable metal scaffold was late scaffold recoil, while the contribution of NIH was modest. The degree of late scaffold recoil depended on the underlying plaque type and was highest among fibrotic lesions. Future studies will address the impact of procedural factors such as adequate lesion preparation and post-dilatation.

Acknowledgement/Funding

Biotronik

REDUCTION IN AMBIENT GAMMA DOSE RATE FROM RADIOCESIUM DUE TO SNOW COVER

In the present study, variations in ambient gamma dose rate associated with snow cover were examined in a radioactive-contaminated site in Fukushima Prefecture, Japan. The ambient gamma dose rates decreased with increasing snow depth. The reduction trends were different between fresh snow (0.1-0.2 g/cm3) and granular snow (0.3-0.4 g/cm3) depending on snow density. Snow cover water content (snow water equivalent) calculated from snow depth and density was a key parameter governing the reduction in the ambient gamma dose rate. The ambient gamma dose rates reduced to 0.6 and 0.5 at 4 g/cm2 and 8 g/cm2 of snow water equivalent, respectively. Based on gamma-ray flux density distributions, the ambient gamma dose rates from the primary gamma rays decreased more compared to those from scattered gamma rays due to snow cover.