Quasifree Neutron Knockout Reaction Reveals a Small s-Orbital Component in the Borromean Nucleus ^{17}B

A kinematically complete quasifree (p,pn) experiment in inverse kinematics was performed to study the structure of the Borromean nucleus ^{17}B, which had long been considered to have a neutron halo. By analyzing the momentum distributions and exclusive cross sections, we obtained the spectroscopic factors for 1s_{1/2} and 0d_{5/2} orbitals, and a surprisingly small percentage of 9(2)% was determined for 1s_{1/2}. Our finding of such a small 1s_{1/2} component and the halo features reported in prior experiments can be explained by the deformed relativistic Hartree-Bogoliubov theory in continuum, revealing a definite but not dominant neutron halo in ^{17}B. The present work gives the smallest s- or p-orbital component among known nuclei exhibiting halo features and implies that the dominant occupation of s or p orbitals is not a prerequisite for the occurrence of a neutron halo.

Possible involvement of regulatory T cell abnormalities and variational usage of TCR repertoire in children with autoimmune neutropenia

Autoimmune neutropenia (AIN) in childhood is characterized by chronic neutropenia and positivity for anti-neutrophil antibodies, resulting in the excessive destruction of neutrophils. In this study, we investigated the involvement of regulatory T cells (T_regs ) in the pathogenesis of AIN in childhood. T_regs have been classified into three subpopulations based on the expressions of CD45RA and forkhead box protein 3 (FoxP3): resting T_regs , activated T_regs and non-suppressive T_regs . The frequency of activated T_regs (CD4⁺ CD25⁺ FoxP3^high CD45RA^- T cells) as well as that of total T_regs (CD4⁺ CD25⁺ FoxP3⁺ T cells) in peripheral blood was significantly decreased in patients with AIN. Analysis of the T cell receptor (TCR)-Vβ repertoire of CD4⁺ T cells revealed skewed usages in patients with AIN compared with that observed in age-matched control subjects. Regarding T cell subsets, the use of four of 24 TCR-Vβ families in T_regs and one in conventional T cells were increased in patients with AIN. The number of patients with AIN who showed skewed usages of TCR-Vβ family in conventional and T_regs was significantly higher than that reported in control subjects. When the preference between T_regs and conventional T cells in each TCR-Vβ family was individually compared, different use was prominently observed in the TCR-Vβ 9 family in patients with AIN. These results suggest that the quantitative abnormalities of T_regs and the skew of the TCR-Vβ repertoire in CD4⁺ T cells, including T_regs and conventional T cells, may be related to autoantibody production through a human neutrophil antigen-reactive T cell clone.

Surface Localization of the Dineutron in ^{11}Li

The formation of a dineutron in the ^{11}Li nucleus is found to be localized to the surface region. The experiment measured the intrinsic momentum of the struck neutron in ^{11}Li via the (p,pn) knockout reaction at 246  MeV/nucleon. The correlation angle between the two neutrons is, for the first time, measured as a function of the intrinsic neutron momentum. A comparison with reaction calculations reveals the localization of the dineutron at r∼3.6  fm. The results also support the density dependence of dineutron formation as deduced from Hartree-Fock-Bogoliubov calculations for nuclear matter.

In Vivo Ca2+ Imaging of the Insular Cortex during Experimental Tooth Movement

Pain and discomfort are common problems for patients undergoing orthodontic treatment. We have demonstrated that cortical excitation propagation in the somatosensory and insular cortices (IC) induced by electrical stimulation of the periodontal ligament (PDL) is facilitated 1 d after experimental tooth movement (ETM). However, it is necessary to examine ETM-induced changes in neural responses at a single-cell level to understand the mechanisms of cortical plastic changes, in which excitatory glutamatergic and inhibitory GABAergic neurons are intermingled to form cortical local circuits. We performed in vivo 2-photon Ca²⁺ imaging by loading the Ca²⁺ indicator Oregon Green BAPTA with the astrocyte marker sulforhodamine. We focused on the IC region that exhibited the largest neural response to maxillary PDL (mxPDL) stimulation using a VGAT-Venus transgenic rat that expresses venus fluorescent protein in GABAergic neurons and discerned changes in the neural activities of each cortical neuronal subtype before and during ETM treatment of the maxillary incisor and first molar. Notably, 1 d after ETM treatment (1d-ETM), the number of neurons responding to mxPDL stimulation increased from 47.6% to 64.2% in excitatory neurons and from 44.5% to 66.2% in inhibitory neurons. On the other hand, only 3% to 4% of excitatory and inhibitory neurons responded to mandibular molar PDL (mbPDL) stimulation in control rats, and the 1d-ETM group showed significant increases in excitatory (14.0%) and inhibitory neurons (22.5%) responding to mbPDL stimulation. Interestingly, most mbPDL-responding neurons also responded to mxPDL stimulation. The population of excitatory and inhibitory neurons that responded only to mxPDL stimulation was comparable between the control and 1d-ETM groups. The facilitative responses in the 1d-ETM group had almost recovered 7 d after ETM treatment. These results suggest that ETM induces parallel increases in PDL-responding neurons and changes some insensitive neurons to respond to both mxPDL and mbPDL stimulation.

Mapping of a New Deformation Region around ^{62}Ti

We performed the first direct mass measurements of neutron-rich scandium, titanium, and vanadium isotopes around the neutron number 40 at the RIKEN RI Beam Factory using the time-of-flight magnetic-rigidity technique. The atomic mass excesses of ^{58-60}Sc, ^{60-62}Ti, and ^{62-64}V were measured for the first time. The experimental results show that the two-neutron separation energies in the vicinity of ^{62}Ti increase compared to neighboring nuclei. This shows that the masses of Ti isotopes near N=40 are affected by the Jahn-Teller effect. Therefore, a development of Jahn-Teller stabilization appears below the Cr isotopes, and the systematics in Sc, Ti, and V isotopes suggest that ^{62}Ti is located close to the peak of the Jahn-Teller effect.

Study of factors related to social and emotional skills in early childhood in Japan

Background

There are numerous reports that social and emotional skills in early childhood have profound influence on lifelong health. The aim of this research is to determine the relation between the lifestyle and the social and emotional skills among children in present day Japan.

Methods

The object of analysis was a total of 110 parents of kindergarten students (56 boys, 48 girls,6 gender unknown) from 3 kindergartens in central Okinawa Island. The survey was conducted in mid-December 2019. Regarding the content of the survey, parents were asked to answer on a five-point scale, based on their subjective opinion, how good is their child, as compared to other children, in each of the 9 sub-scales of the social and emotional skills proposed in the 2015 OECD report, namely “perseverance,” “self-control,” “passion for goals,” “sociability,” “respect,” “caring,” “self-esteem,” “optimism,” “confidence.” Additionally, other question items were set, mainly to ask about the child's own lifestyle.

Results

The results of multivariate logistic regression analysis are following. As for “achieving goals:” 3 items for perseverance - “there are few likes and dislikes about food (OR:2.67, 95％CI:1.03～6.94, p=.043),” “Time for playing games on smartphone is determined (OR:3.21, 95％CI:1.19～8.68, p=.021),” “Eat more fruits (OR:3.03, 95％CI:1.24～8.26, p=.016),” are statistically significant. [Other results are omitted in this abstract]

Conclusions

It became clear that the acquisition of social and emotional skills during early childhood generally involves regular lifestyle and “discipline” at home as a whole. Besides, it is important for parent and child to do various activities together, including those aiming to increase cognitive skills. This study is considered to be a powerful evidence for the development of future intervention programme, aimed at acquiring social and emotional skills in early childhood.

Key messages

In early childhood family and kindergarten have to cooperate to foster social and emotional skills, important for lifelong health. This study is considered to be a powerful evidence for the development of future intervention programme, aimed at acquiring social and emotional skills in early childhood.

A penalized spline fitting method to optimize geometric parameters of arterial centerlines extracted from medical images

In order to grasp the spatial and temporal evolution of vascular geometry, three-dimensional (3D) arterial bending structure and geometrical changes of arteries and stent grafts (SG) must be quantified using geometrical parameters such as curvature and torsion along the vasculature centerlines extracted from medical images. Here, we develop a robust method for constructing smooth centerlines based on a spline fitting method (SFM) such that the optimized geometric parameters of curvature and torsion can be obtained independently of digitization noise in the images. Conventional SFM consists of the 3rd degree spline basis function and 2nd derivative penalty term. In contrast, the present SFM uses the 5th degree spline basis function and 3rd and 4th derivative penalty terms, the coefficients of which are derived by the Akaike information criterion. The results show that the developed SFM can reduce the errors of curvature and torsion compared to conventional SFM. We then apply the present SFM to the centerline of the SG in an abdominal aortic aneurysm (AAA), and those of bilateral internal carotid arteries (ICA) in 6 cases: 3 cases with aneurysms and 3 cases without any aneurysm. The SG centerlines were obtained from temporal medical images at three scan times. The strong peak of the curvature could be clearly observed in the distal area of the SG, the inversion of the torsion at 0 months in the middle area of SG disappeared over time, and the torsions around the SG bifurcation at the three time periods were inverted. The curvature-torsion graphs along the ICA centerlines superimposing five aneurysmal positions were useful for investigating the relationship between arterial bending structure and aneurysmal positions. Both ICAs had curvature peak values higher than 0.4 within the ICA syphons. The ICA torsion graphs indicated that left and right ICA tended to be a right- and left-handed helix, respectively. In the left ICA syphon, the biggest aneurysm could be observed downstream of the salient torsion inversion. All aneurysms for 3 cases were positioned at the downstream of the inverted torsion.

AB0196 THE ASSOCIATION BETWEEN OSTEOPOROSIS AND FUNCTIONAL IMPAIRMENT EVALUATED BY THE LOCOMO25 IN RHEUMATOID ARTHRITIS

Background:

Locomotive syndrome is a condition in which activities of daily living are affected by impairment of the motor organs, most often due to rheumatoid arthritis (RA). Locomo25 is a new index developed for the early detection of locomotive syndrome. It consists of 25 items associated with pain, physical activity, and subjective state of health, with a score of 7 points or higher classed as Grade 1 locomotive syndrome and a score of 16 points or higher as Grade 2. In RA, joint impairment causes the appearance of problems affecting motor organs as a whole, as well as progressive functional impairment. As functional impairment progresses, it causes increasing immobility, which raises the risk of osteoporosis.

Objectives:

Locomo25 was used to investigate functional impairment and its association with RA disease activity and osteoporosis indicators.

Methods:

The subjects were 105 patients with RA (24 men and 81 women) with a mean age of 68.7 (28–91) years. In terms of staging, 25 were Stage I, 22 Stage II, 17 Stage III, and 41 Stage IV, and their motor disability was Steinbrocker Class 1 in 68 cases, Class 2 in 27, Class 3 in 9, and Class 4 in 1. Disease activity according to the Disease Activity Score 28 with erythrocyte sedimentation rate (DAS28 ESR) was assessed as remission in 44 cases, low disease activity in 24, moderate in 33, and high in 4. The associations between the Locomo25 score and disease activity indices, bone mineral density (BMD), and bone turnover markers (TRACP-5b, NTX, urinary DPD, BAP, total P1NP, and 25(OH)D) were investigated.

Results:

Locomo25 grade was 0 in 37 cases (35.2%), 1 in 24 (22.9%), and 2 in 44 (41.9%). Locomo25 grade was significantly associated with Steinbrocker class (r= 0.4299, Spearman’s rank correlation coefficient,p< 0.0001). DAS28 ESR and Health Assessment Questionnaire scores increased as locomotive syndrome progressed. There was no significant difference in eGFR between groups, but bone resorption markers (TRACP-5b, NTX, and urinary DPD) and a bone quality marker (pentosidine) decreased significantly as locomotive syndrome progressed. There were no significant differences in BMD or other bone turnover markers.

Conclusion:

The Locomo25 score was useful for evaluating functional impairment in RA. The prevalence of Grade 2 locomotive syndrome in the general population is reported to be around 25%, and many patients with RA had advanced locomotive syndrome. Although there was no significant difference in BMD, elevated bone resorption and deteriorating bone quality were associated with progressive functional impairment, suggesting that RA patients with advanced locomotive syndrome may be at risk of increasingly severe osteoporosis as a result of immobility.

References:

[1]Yoshimura Y, Ishijima M, Ishibashi M, Liu L, Arikawa-Hirasawa E, Machida S, Naito H, Hamada C, Kominami E. J Orthop Sci. 2019 Nov;24(6):1094-1104. doi: 10.1016/j.jos.2019.08.009. Epub 2019 Sep 3.

[2]Siu PPY, Cheung PWH, Cheung JPY. J Orthop Sci. 2019 Nov;24(6):1110-1117. doi: 10.1016/j.jos.2019.07.012. Epub 2019 Aug 14.

Disclosure of Interests:

None declared

AB0964 THE ASSOCIATION BETWEEN RESIDUAL SYMPTOMS AND CERVICAL SPINE LESIONS IN RHEUMATOID ARTHRITIS

Background:

Treatment outcomes in rheumatoid arthritis (RA) have been improved with advances in drug therapy. In daily clinical practice, the outcomes are assessed based on the presence of swollen or tender joints, global assessment using a visual analog scale by a patient (GVAS) and a physician (DrVAS), etc., in addition to inflammatory findings. Although inflammation and joint symptoms are suppressed, many patients show no improvement in GVAS scores. The reported residual RA symptoms include morning stiffness (MS), pain (P), and dullness (D), but their causes are not completely known. Latent cervical spine lesions sometimes exist in RA, but their association with residual RA symptoms is unknown.

Objectives:

We examined cervical spine lesions and residual symptoms in patients with RA who achieved the therapeutic goal.

Methods:

Of 124 patients with RA, 82 (25 men and 57 women) who achieved a low disease activity (LDA) state on the Disease Activity Score for 28 joints with erythrocyte sedimentation rate (DAS28-ESR) were included. The mean age was 65.7 (28- 83) years, and the disease stage was Stage I in 28 patients, Stage II in 14, Stage III in 13, and Stage IV in 27. Dysfunction was graded as Class 1 in 63 patients, Class 2 in 18, and Class 3 in one (Steinbrocker classification). Biopharmaceuticals had been administered in 27 patients. As for disease activity, the DAS28-ESR scores indicated complete remission in 54 patients and LDA in 28. The survey form was used to investigate the presence or absence/duration of MS, the presence or absence/severity of P (Pain VAS), and the presence or absence/severity of D (Dullness VAS). On lateral functional radiographs of the cervical spine, patients with spinal lesions were selected and divided into the asymptotic stability (ASS; atlantoaxial dislocation ≥3 mm) + vertical setting (VS; Ranawat value <13 mm) group, the cervical spondylolisthesis group (≥3 mm of slippage on dynamic radiographs), and the spondylolisthesis group (≥3 mm of slippage on dynamic radiographs). They were examined for association with residual symptoms.

Results:

According to cervical spine lesions, the patients who achieved the therapeutic goal were divided into the ASS+VS group comprising 15 patients (18.3%), the spondylolisthesis group comprising 11 (13.4%), and the stenosis group comprising 18 (22.0%). Among them, only the spondylolisthesis group showed significant differences in residual RA symptoms. In the spondylolisthesis group, the disease duration was longer, but there was no difference in age. MS, P, and D were significantly severer. The duration of MS was longer, and both Pain and Dullness VAS scores were higher. The score on each component of the DAS28 showed no difference in inflammatory findings. GVAS and DrVAS scores were higher. No common perceptions of spinal symptoms were shared between any patients with cervical spine lesions and physicians.

Conclusion:

Improved patient-reported outcomes (PROs) are considered to be important to achieve more complete remission. There are various reports on the causes of residual RA symptoms, but many aspects remain unknown. Based on the results of this study, because asymptomatic subaxial subluxation is one of concerns in patients with spondylolisthesis with dynamic instability of the cervical spine, cervical spine diseases should also be considered in patients with severe residual symptoms. Not only radiography but also magnetic resonance imaging needs to be performed.

Acknowledgments:

The authors wish to acknowledge Miss Sasaki

Disclosure of Interests:

None declared

AB0899 TREATMENT STATUS OF PATIENTS WITH GLUCOCORTICOID-INDUCED OSTEOPOROSIS IN THE AKITA ORTHOPEDIC GROUP ON RHEUMATOID ARTHRITIS REGISTRY

Background:

Glucocorticoids (GC) have potent anti-inflammatory and immunosuppressive effects and are used to treat a variety of diseases. However, GC are associated with several adverse effects. Glucocorticoid-induced osteoporosis (GIO), a bone metabolism disorder, accounts for 25% of the side effects associated with GC, and long-term use of these agents leads to fragility fractures in 30 to 50% of patients [1]. GC are frequently used to treat rheumatoid arthritis (RA). No report on the current treatment status for glucocorticoid-induced osteoporosis (GIO) has been published following the publication of the new guidelines for the management and treatment of GIO issued by the Japanese Society for Bone Mineral Research provided in 2014 (Figure 1) [2].

Objectives:

The present study aimed to investigate the current treatment status of GIO patients in the Akita Orthopedic Group on Rheumatoid Arthritis (AORA) registry.

Methods:

This retrospective, multicenter study included 683 patients (138 men, 545 women) with fracture risk factor scores ≥3 based on the new guidelines who were in the AORA registry. We examined patient characteristics, differences in patient backgrounds between treated and non-treated groups.

Results:

There were no significant differences in mean GC dose between men and women (4.0 ± 2.3 mg/day vs 3.6 ± 1.8 mg/day, p = 0.08). The mean disease duration of RA in women was significantly longer than in men (180.2 ± 140.2 months vs 143.8 ± 129.6 months, Untreated GIO patients were significantly more likely to be men and younger. The univariate analysis showed that clinic visits, male sex, younger age, and longer disease duration were significant risk factors for lack of therapeutic intervention for GIO. Multivariate analysis showed that being treated in a clinic, male sex, and younger age were significant risk factors for lack of therapeutic intervention for GIO.

Conclusion:

Our results emphasize the importance of considering the prevention and treatment of GIO in all patients with RA, including younger and male patients, who have lower intervention rates.

References:

[1]Weinstein RS. Clinical practice. Glucocorticoid-induced bone disease. New Engl J Med. 2011; 365(1): 62-70.

[2]Suzuki Y, Nawata H, Soen S, Fujiwara S, Nakayama H, Tanaka I, et al. Guidelines on the management and treatment of glucocorticoid-induced osteoporosis of the Japanese Society for Bone and Mineral Research: 2014 update. J Bone Miner Metab. 2014; 32(4): 337-350.

Disclosure of Interests:

None declared

How Different is the Core of ^{25}F from ^{24}O_{g.s.} ?

The structure of a neutron-rich ^{25}F nucleus is investigated by a quasifree (p,2p) knockout reaction at 270A  MeV in inverse kinematics. The sum of spectroscopic factors of π0d_{5/2} orbital is found to be 1.0±0.3. However, the spectroscopic factor with residual ^{24}O nucleus being in the ground state is found to be only 0.36±0.13, while those in the excited state is 0.65±0.25. The result shows that the ^{24}O core of ^{25}F nucleus significantly differs from a free ^{24}O nucleus, and the core consists of ∼35% ^{24}O_{g.s.}. and ∼65% excited ^{24}O. The result may infer that the addition of the 0d_{5/2} proton considerably changes neutron structure in ^{25}F from that in ^{24}O, which could be a possible mechanism responsible for the oxygen dripline anomaly.

Acetazolamide-Loaded Dynamic 7T MR Quantitative Susceptibility Mapping in Major Cerebral Artery Steno-Occlusive Disease: Comparison with PET

BACKGROUND AND PURPOSE

Dynamic changes in cerebrovascular reactivity after acetazolamide administration vary markedly among patients with major cerebral arterial steno-occlusive disease. MR quantitative susceptibility mapping can dynamically quantify the cerebral magnetic susceptibility. The purpose of this study was to determine whether dynamic changes in susceptibility after administration of acetazolamide on 7T quantitative susceptibility mapping are associated with pre-existing states of CBV and the cerebral metabolic rate of oxygen in the cerebral hemispheres with major cerebral arterial steno-occlusive disease.

MATERIALS AND METHODS

Sixty-five patients underwent 7T MR imaging at baseline and at 5, 10, 15, and 20 minutes after acetazolamide administration. Differences between the susceptibility of venous structures and surrounding brain tissue were calculated in the quantitative susceptibility mapping images. Susceptibility differences at 5, 10, 15, and 20 minutes after acetazolamide administration relative to baseline were calculated in 97 cerebral hemispheres with major cerebral arterial steno-occlusive disease. CBV and the cerebral metabolic rate of oxygen were also calculated using ¹⁵O-gas PET in the resting state.

RESULTS

Dynamic changes of susceptibility after acetazolamide administration were classified into 3 patterns: abnormally increasing 5 or 10 minutes after acetazolamide administration; abnormally decreasing within 20 minutes after acetazolamide administration; and remaining unchanged after acetazolamide administration. CBV was significantly greater in the first pattern than in the latter 2. The cerebral metabolic rate of oxygen differed significantly in descending order from the first to middle to last pattern.

CONCLUSIONS

Dynamic changes of susceptibility after acetazolamide administration on 7T MR quantitative susceptibility mapping are associated with pre-existing states of CBV and the cerebral metabolic rate of oxygen in major cerebral arterial steno-occlusive disease.

Evaluation of a receptor gene responsible for maternal blood IgY transfer into egg yolks using bursectomized IgY-depleted chickens

In avian species, maternal immunoglobulin Y (IgY) is transferred from the blood to the yolks of maturing oocytes; however, the mechanism underlying this transfer is unknown. To gain insight into the mechanisms of maternal IgY transfer into egg yolks, IgY-depleted chickens were generated by removing the bursa of Fabricius (bursectomy) during egg incubation, and their egg production and IgY transport ability into egg yolks were determined. After hatching, blood IgY concentrations of the bursectomized chickens decreased gradually until sexual maturity, whereas those of IgA remained low from an early stage of growth (from at least 2 wk of age). Chickens identified as depleted in IgY through screening of blood IgY and IgA concentrations were raised to sexual maturity. At 20 wk of age, both blood and egg yolk IgY concentrations in the IgY-depleted group were 600-fold lower than those of the control group, whereas egg production did not differ between the groups. Intravenously injected, digoxigenin-labeled IgY uptake into the egg yolk was approximately 2-fold higher in the IgY-depleted chickens than in the controls, suggesting that IgY depletion may enhance IgY uptake in maturing oocytes. DNA microarray analysis of the germinal disc, including the oocyte nucleus, revealed that the expression levels of 73 genes were upregulated more than 1.5-fold in the IgY-depleted group, although we could not identify a convincing candidate gene for the IgY receptor. In conclusion, we successfully raised IgY-depleted chickens presenting a marked reduction in egg yolk IgY. The enhanced uptake of injected IgY into the egg yolks of the IgY-depleted chickens supports the existence of a selective IgY transport mechanism in maturing oocytes and ovarian follicles in avian species.

Light Dark Matter Search with Ionization Signals in XENON1T

We report constraints on light dark matter (DM) models using ionization signals in the XENON1T experiment. We mitigate backgrounds with strong event selections, rather than requiring a scintillation signal, leaving an effective exposure of (22±3) tonne day. Above ∼0.4  keV_{ee}, we observe <1  event/(tonne day keV_{ee}), which is more than 1000 times lower than in similar searches with other detectors. Despite observing a higher rate at lower energies, no DM or CEvNS detection may be claimed because we cannot model all of our backgrounds. We thus exclude new regions in the parameter spaces for DM-nucleus scattering for DM masses m_{χ} within 3-6  GeV/c^{2}, DM-electron scattering for m_{χ}>30  MeV/c^{2}, and absorption of dark photons and axionlike particles for m_{χ} within 0.186-1  keV/c^{2}.

Search for Light Dark Matter Interactions Enhanced by the Migdal Effect or Bremsstrahlung in XENON1T

Direct dark matter detection experiments based on a liquid xenon target are leading the search for dark matter particles with masses above ∼5  GeV/c^{2}, but have limited sensitivity to lighter masses because of the small momentum transfer in dark matter-nucleus elastic scattering. However, there is an irreducible contribution from inelastic processes accompanying the elastic scattering, which leads to the excitation and ionization of the recoiling atom (the Migdal effect) or the emission of a bremsstrahlung photon. In this Letter, we report on a probe of low-mass dark matter with masses down to about 85  MeV/c^{2} by looking for electronic recoils induced by the Migdal effect and bremsstrahlung using data from the XENON1T experiment. Besides the approach of detecting both scintillation and ionization signals, we exploit an approach that uses ionization signals only, which allows for a lower detection threshold. This analysis significantly enhances the sensitivity of XENON1T to light dark matter previously beyond its reach.

P2696Clinical characteristics of late catch-up phenomenon after implantation of 2nd generation drug eluting stent

Introduction

Late catch-up phenomenon (LCU) of 1st generation drug eluting stent (DES) has been increasing yearly despite the rate of restenosis in 1 year has reduced compared with bare metal stent (BMS). 2nd generation DES was more improved than 1st generation DES and suggested more benefits about clinical outcome.

Purpose

To investigate the incidence and predictor of LCU after implantation of 2nd generation DES and to evaluate the association between LCU phenomenon and adverse events.

Methods

Between August 2012 and July 2013, a total of 1665 consecutive patients (1956 lesions with elective/urgent PCI) were enrolled in SHINANO 5 years Registry (a prospective observational multicenter cohort study) from 13 institutions in Nagano, Japan. 711 patients that were treated with 2nd generation DES and 576 patients with BMS were selected. Exclusion criterias were cases of 1st DES, only POBA, only aspiration and chronic total occulusion.

Results

There were significant difference about patients background between BMS and 2nd generation DES groups. Those groups were matched with propensity score. After matching, 822 patients (BMS group 411 patients, 2nd generation group 411 patients) were analyzed. The rates of 2nd DES and BMS restenosis 5 years after initial PCI were 9.2% and 8.5% (p=0.572), those of LCU were 2.6% and 5.6% (p=0.043) by 1 year landmark analysis. Cox proportional hazards analysis revealed that the DES in-stent restenosis (ISR) lesion and higher HbA1c were independent predictors for LCU from 1year to 5year (HR 5.304, p=0.009, HR 1.254, p=0.015), but 2nd generation DES was not. Kaplan Meier curve showed no association between LCU phenomenon and all cause death (p=0.446). Cox regression analysis showed LCU was not independent predictor for all cause death (p=0.414).

Conclusions

Implantation to DES-ISR lesion with 2nd generation DES was associated with higher LCU. Despite of more complex lesions with 2nd generation DES, there were no differences of LCU incidence between 2nd generation DES and BMS.

Acknowledgement/Funding

None