Pressure-induced reconstitution of Fermi surfaces and spin fluctuations in S-substituted FeSe

FeSe is a unique high-\documentclass[12pt]{minimal} \usepackage{amsmath} \usepackage{wasysym} \usepackage{amsfonts} \usepackage{amssymb} \usepackage{amsbsy} \usepackage{mathrsfs} \usepackage{upgreek} \setlength{\oddsidemargin}{-69pt} \begin{document}$$T_c$$\end{document}Tc iron-based superconductor in which nematicity, superconductivity, and magnetism are entangled with each other in the P-T phase diagram. We performed \documentclass[12pt]{minimal} \usepackage{amsmath} \usepackage{wasysym} \usepackage{amsfonts} \usepackage{amssymb} \usepackage{amsbsy} \usepackage{mathrsfs} \usepackage{upgreek} \setlength{\oddsidemargin}{-69pt} \begin{document}$$^{77}$$\end{document}77Se-nuclear magnetic resonance measurements under pressures of up to 3.9 GPa on 12% S-substituted FeSe, in which the complex overlap between the nematicity and magnetism are resolved. A pressure-induced Lifshitz transition was observed at 1.0 GPa as an anomaly of the density of states and as double superconducting (SC) domes accompanied by different types of antiferromagnetic (AF) fluctuations. The low-\documentclass[12pt]{minimal} \usepackage{amsmath} \usepackage{wasysym} \usepackage{amsfonts} \usepackage{amssymb} \usepackage{amsbsy} \usepackage{mathrsfs} \usepackage{upgreek} \setlength{\oddsidemargin}{-69pt} \begin{document}$$T_{\mathrm{c}}$$\end{document}Tc SC dome below 1 GPa is accompanied by strong AF fluctuations, whereas the high-\documentclass[12pt]{minimal} \usepackage{amsmath} \usepackage{wasysym} \usepackage{amsfonts} \usepackage{amssymb} \usepackage{amsbsy} \usepackage{mathrsfs} \usepackage{upgreek} \setlength{\oddsidemargin}{-69pt} \begin{document}$$T_{\mathrm{c}}$$\end{document}Tc SC dome develops above 1 GPa, where AF fluctuations are fairly weak. These results suggest the importance of the \documentclass[12pt]{minimal} \usepackage{amsmath} \usepackage{wasysym} \usepackage{amsfonts} \usepackage{amssymb} \usepackage{amsbsy} \usepackage{mathrsfs} \usepackage{upgreek} \setlength{\oddsidemargin}{-69pt} \begin{document}$$d_{xy}$$\end{document}dxy orbital and its intra-orbital coupling for the high-\documentclass[12pt]{minimal} \usepackage{amsmath} \usepackage{wasysym} \usepackage{amsfonts} \usepackage{amssymb} \usepackage{amsbsy} \usepackage{mathrsfs} \usepackage{upgreek} \setlength{\oddsidemargin}{-69pt} \begin{document}$$T_{\mathrm{c}}$$\end{document}Tc superconductivity.

Surgical Outcomes in Patients With Centrally Located Non-small Cell Lung Cancer

BACKGROUND/AIM

Identification of prognostic factors is helpful in selecting optimal treatment for centrally-located non-small cell lung cancer (NSCLC). This study aimed to detect prognostic factors in patients with centrally-located NSCLC.

PATIENTS AND METHODS

NSCLCs in the hilar area requiring pneumonectomy or sleeve lobectomy for complete removal are defined as centrally-located NSCLCs. We retrospectively investigated the clinical courses of 45 patients with such lesions.

RESULTS

Sleeve lobectomies were performed on 33 patients and pneumonectomies on 12. Three and five-year survival rates were 72% and 62%, respectively. Presence of comorbidities (p=0.013), severe symptoms (p=0.001), high white cell count (p=0.001), and pathological T3-4 stage (p=0.004) were identified as independent predictors of poor prognosis. Operative procedures did not correlate with outcomes (p=0.722).

CONCLUSION

Presence of comorbidities, severe symptoms, high white cell counts, and pathological T stage are independent predictors of poor prognosis. These data can contribute in selecting appropriate treatments for such lesions.

P–131 Significance of the phenomenon of blastomere exclusion from compaction: Its relation to irregular cleavage, blastocyst development rate, and pregnancy rate

Study question

When does blastomere exclusion from compaction increase and what effect does it have on the embryo?

Summary answer

More blastomere were excluded from compaction in embryos with irregular cleavage, resulting in lower blastocyst development rates, but no decrease in pregnancy rates at transfer.

What is known already

It has been reported that many of the chromosome analysis results of blastomere excluded from compaction were aneuploid, and pointed out that this exclusion may be related to the repair of blastocyst euploidy, but the effect of the number of excluded blastomere has not been reported.

Study design, size, duration

This is a retrospective study of 578 embryos that developed into morula with time-lapse monitoring by EmbryoScope (Vitrolife) in 2018–2019.

Participants/materials, setting, methods

The target embryos were classified into two groups: embryos with normal first and second cleavage (normal cleavage group) and embryos with irregular cleavage (dynamics of one cell dividing into three or more cells), called “direct cleavage”, at either cleavage (DC group), and the number of blastomere excluded from compaction during morula formation was recorded and compared. The blastocyst development rate and single blastocyst transfer pregnancy rates of the two groups were compared.

Main results and the role of chance

There are 286 in the normal cleavage group and 292 in the DC group. The mean number of excluded blastomere was 0.76 and 3.55, respectively, which was significantly higher in the DC group (P < 0.01). Good blastocyst (Gardner classification 4 or higher) development rate was 84.5% (239/283) and 65.8% (181/275), respectively, and high grade blastocyst (Gardner classification BB or higher) development rate was 43.9% (105/239) and 14.9% (27/181) of them, both significantly higher in the normal cleavage group (P < 0.01). The single blastocyst transfer pregnancy rates were 31.6% (25/79) and 32.4% (11/34), and the miscarriage rates were 24.0% (6/25) and 27.3% (3/11), respectively, neither was there a significant difference between the two groups. So, direct cleavage increased the number of blastomere excluded from compaction, decreased the rate of morula to good blastocyst development and reduced blastocyst grade, but did not affect blastocyst transfer pregnancy rate and miscarriage rate.

Limitations, reasons for caution

Please note that all target embryos must have developed into morula or larger (embryos that did not develop into morula will not be included in the study).

Wider implications of the findings: Severe chromosomal aberrant blastomeres formed by direct cleavage were excluded from compaction, and the blastocyst development rate decreased due to a decrease in the amount of viable cells, but it is suggested that this blastomere exclusion mechanism is not related to euploidy after blastocyst development.

Trial registration number

Not applicable

Half-integer quantized anomalous thermal Hall effect in the Kitaev material candidate α-RuCl3

Half-integer thermal quantum Hall conductance has recently been reported for the two-dimensional honeycomb material α-RuCl₃ We found that the half-integer thermal Hall plateau appears even for a magnetic field with no out-of-plane components. The measured field-angular variation of the quantized thermal Hall conductance has the same sign structure as the topological Chern number of the pure Kitaev spin liquid. This observation suggests that the non-Abelian topological order associated with fractionalization of the local magnetic moments persists even in the presence of non-Kitaev interactions in α-RuCl₃.

Sympathetic cooling of a trapped proton mediated by an LC circuit

Efficient cooling of trapped charged particles is essential to many fundamental physics experiments1,2, to high-precision metrology3,4 and to quantum technology5,6. Until now, sympathetic cooling has required close-range Coulomb interactions7,8, but there has been a sustained desire to bring laser-cooling techniques to particles in macroscopically separated traps5,9,10, extending quantum control techniques to previously inaccessible particles such as highly charged ions, molecular ions and antimatter. Here we demonstrate sympathetic cooling of a single proton using laser-cooled Be+ ions in spatially separated Penning traps. The traps are connected by a superconducting LC circuit that enables energy exchange over a distance of 9 cm. We also demonstrate the cooling of a resonant mode of a macroscopic LC circuit with laser-cooled ions and sympathetic cooling of an individually trapped proton, reaching temperatures far below the environmental temperature. Notably, as this technique uses only image-current interactions, it can be easily applied to an experiment with antiprotons1, facilitating improved precision in matter-antimatter comparisons11 and dark matter searches12,13.

Controlling unconventional superconductivity in artificially engineeredf-electron Kondo superlattices

Unconventional superconductivity and magnetism are intertwined on a microscopic level in a wide class of materials, including high-T_ccuprates, iron pnictides, and heavy-fermion compounds. Interactions between superconducting electrons and bosonic fluctuations at the interface between adjacent layers in heterostructures provide a new approach to this most fundamental and hotly debated subject. We have been able to use a recent state-of-the-art molecular-beam-epitaxy technique to fabricate superlattices consisting of different heavy-fermion compounds with atomic thickness. These Kondo superlattices provide a unique opportunity to study the mutual interaction between unconventional superconductivity and magnetic order through the atomic interface. Here, we design and fabricate hybrid Kondo superlattices consisting of alternating layers of superconducting CeCoIn₅withd-wave pairing symmetry and nonmagnetic metal YbCoIn₅or antiferromagnetic heavy fermion metals such as CeRhIn₅and CeIn₃. In these Kondo superlattices, superconducting heavy electrons are confined within the two-dimensional CeCoIn₅block layers and interact with neighboring nonmagnetic or magnetic layers through the interface. Superconductivity is strongly influenced by local inversion symmetry breaking at the interface in CeCoIn₅/YbCoIn₅superlattices. The superconducting and antiferromagnetic states coexist in spatially separated layers in CeCoIn₅/CeRhIn₅and CeCoIn₅/CeIn₃superlattices, but their mutual coupling via the interface significantly modifies the superconducting and magnetic properties. The fabrication of a wide variety of hybrid superlattices paves a new way to study the relationship between unconventional superconductivity and magnetism in strongly correlated materials.

Metachronous multiple pulmonary nodules 9 years after esophagectomy: a case report

A 79-year-old man was referred to our hospital for further examination. He had undergone radical esophagectomy with right thoracotomy 9 years ago. Four cycles of chemotherapy (CDDP +5-FU) were also performed for him. Eight years after esophagectomy, two nodules were identified in the upper lobe of the right lung on chest computed tomography (CT). Owing to the possibility of new primary lung cancer, partial resection was performed. Histopathological examination revealed squamous cell carcinoma. One year and two months later, follow-up chest CT scan revealed a nodule shadow of 1.5 cm in the left apex and a nodule shadow of 0.9 cm below the S9 pleura. Hence, partial left lung resection was performed. Five months after left lung resection, a metastatic liver tumor was found on abdominal CT and left lobectomy of the liver was performed. One year after hepatectomy, the patient died due to peritoneal dissemination.

Safety and feasibility of minimally invasive esophagectomy for elderly esophageal cancer patients

The number of elderly patients with esophageal cancer has increased in recent years. The use of thoracoscopic esophagectomy has also increased, and its minimal invasiveness is believed to contribute to postoperative outcomes. However, the short- and long-term outcomes in elderly patients remain unclear. This study aimed to elucidate the safety and feasibility of minimally invasive esophagectomy in elderly patients. This retrospective study included 207 patients who underwent radical thoracoscopic esophagectomy for thoracic esophageal squamous cell carcinoma at Kobe University Hospital between 2005 and 2014. Patients were divided into non-elderly (<75 years) and elderly (≥75 years) groups. A propensity score matching analysis was performed for sex and clinical T and N stage, with a total of 29 matched pairs. General preoperative data, surgical procedures, intraoperative data, postoperative complications, in-hospital death, cancer-specific survival, and overall survival were compared between groups. The elderly group was characterized by lower preoperative serum albumin levels and higher American Society of Anesthesiologists grade. Intraoperative data and postoperative complications did not differ between the groups. The in-hospital death rate was 4% in the elderly group, which did not significantly differ from the non-elderly group. Cancer-specific survival was similar between the two groups. Although overall survival tended to be poor in the elderly group, it was not significantly worse than that of the non-elderly group. In conclusion, the short- and long-term outcomes of minimally invasive esophagectomy in elderly versus non-elderly patients were acceptable. Minimally invasive esophagectomy is a safe and feasible modality for elderly patients with appropriate indications.

Middle meningeal artery embolization for chronic subdural hematoma with cerebrospinal fluid hypovolemia: A report of 2 cases

BACKGROUND

Chronic subdural hematoma (CSDH) with cerebrospinal fluid hypovolemia syndrome (CHS) remains refractory to standard treatment with hematoma drainage by burr hole and irrigation and/or epidural blood patch. Previously, we reported the utility of middle meningeal artery (MMA) embolization for intractable CSDH. In this study, we present the usefulness of MMA embolization as a treatment for CSDHs with CHSs.

CASES

We present two cases of CSDHs with CHSs occurring in patients, 1 treated with burr hole craniotomy and irrigation, and the other treated with the epidural blood patch. Both patients exhibited similar-appearing bilateral relatively-thin hematomas, hyperplasia, and enhanced contrast effects in the dura mater, and extradural hygroma in the cervical portion on enhanced magnetic resonance imaging scans. Also, to reviewing prior literature and imaging findings, they had already undergone conventional treatment. We added MMA embolization treatment and they followed a good course.

RESULTS

Despite the known intractable outcomes of patients with CSDHs with CHSs, MMA embolization worked well in the current case series.

CONCLUSION

MMA embolization might be considered as a preferred therapeutic option for CSDHs with CHSs in order to buy time before the epidural blood patch starts working.

Bicarbonate in Arteries Measured Preoperatively for Cadaveric Single-lung Transplantation is Related to Intraoperative Extra-Corporeal Membrane Oxygenation Use: A Retrospective Preliminary Study

Background

There are no known predictors of extracorporeal membrane oxygenation (ECMO) induction for single lung transplantation.

Objective

The purpose of the present study was to clarify the relationship between variables and ECMO requirements in single lung transplantation.

Methods

This study included adult patients who underwent cadaveric single lung transplantation between 2010 and 2019. After general anesthesia, the transplanted lungs were ventilated in all cases. The analysis included 38 patients in the ECMO required (RQ) group and 12 patients in the ECMO non-required (FR) group. Comparisons were made between the two groups for data affecting ECMO implementation, and data that were significantly different were subjected to multivariate analysis.

Results

Prior to anesthesia, the bicarbonate (HCO3-) value of the FR group was lower than that of the RQ group (24.6±2.7 vs. 29.7±5.3 mmol/L, p=0.005). Multivariate analysis showed that the cut-off bicarbonate value was 29.6. The area under the receiver operating characteristic curve (AUROC) of the model was 0.869 (R2: 0.331), with a sensitivity of 79% and a specificity of 88%. The odds ratio was 1.63 for every unit increase in the bicarbonate value (95%CI: 1.11-2.39, p<0.001). Further, the FR group had higher arterial blood pressure (mean: 79.0±11.5 vs. 68.9±8.3 mmHg, p=0.030), less blood loss (432±385 vs. 1,623±1,997 g, p<0.001), shorter operation time (417±44 vs. 543±111 min, p<0.001), and shorter ICU stay (11±9 vs. 25±38 days, p=0.039).

Conclusion

Preoperative evaluation of bicarbonate could predict the need for ECMO for single lung transplantation.

Coexistence of osteoporosis and atherosclerosis in pheochromocytoma: new insights into its long-term management

Osteoporosis and atherosclerosis frequently coexist in patients with pheochromocytoma. The presence of osteoporosis may predict that of atherosclerosis and vice versa in patients with PHEO. These findings have implications for the long-term management of the pheochromocytoma and its potential chronic complications.

INTRODUCTION

Pheochromocytoma (PHEO), a catecholamine-producing tumor, is often found incidentally, and it may be present for years before it is diagnosed. However, long-term exposure to catecholamines excess may induce chronic complications, such as osteoporosis and atherosclerosis. We aimed to evaluate concomitant osteoporosis and atherosclerosis in patients with PHEO.

METHODS

Fifty-one patients with PHEO and 51 patients with a non-functional adrenal tumor were compared radiographically for the prevalence of vertebral fracture (VF), a typical osteoporotic fracture, and abdominal aortic calcification (AAC).

RESULTS

In patients with PHEO, the prevalence of AAC was higher in those with VF (58%) than in those without (6%, p < 0.001). AAC was associated with VF after adjusting for age and sex (odds ratio, 1.53; 95% confidence interval, 1.07-2.46; p = 0.003) in patients with PHEO. The degree of catecholamine excess correlated with the presence of VF and AAC (p = 0.007). The prevalence of VF was higher in patients with PHEO (37%) than those with non-functional AT (12%, p = 0.005), but the prevalence of AAC was comparable between the two groups (25% and 19%, p = 0.636). VF and AAC more frequently coexisted in patients with PHEO (22%) than in those with non-functional AT (2%, p = 0.003).

CONCLUSION

This study represents the first demonstration that osteoporosis and atherosclerosis frequently coexist in patients with PHEO. The presence of osteoporosis may predict that of atherosclerosis and vice versa in patients with PHEO. These findings have implications for the long-term management of the PHEO and its potential chronic complications.

Above 25 nm emission wavelength shift in blue-violet InGaN quantum wells induced by GaN substrate misorientation profiling: towards broad-band superluminescent diodes

We report a thorough study of InGaN quantum wells spatially modified by varying the local misorientation of the GaN substrate prior to the epitaxial growth of the structure. More than 25 nm shift of emission wavelength was obtained, which is attributed to indium content changes in the quantum wells. Such an active region is promising for broadening of the emission spectrum of (In,Al,Ga)N superluminescent diodes. We observed that the light intensity changes with misorientation, being stable around 0.5° to 2° and decreasing above 2°. This relation can be used as a base for future device designing.

Evidence for an Fulde-Ferrell-Larkin-Ovchinnikov State with Segmented Vortices in the BCS-BEC-Crossover Superconductor FeSe

We present resistivity and thermal-conductivity measurements of superconducting FeSe in intense magnetic fields up to 35 T applied parallel to the ab plane. At low temperatures, the upper critical field μ_{0}H_{c2}^{ab} shows an anomalous upturn, while thermal conductivity exhibits a discontinuous jump at μ_{0}H^{*}≈24  T well below μ_{0}H_{c2}^{ab}, indicating a first-order phase transition in the superconducting state. This demonstrates the emergence of a distinct field-induced superconducting phase. Moreover, the broad resistive transition at high temperatures abruptly becomes sharp upon entering the high-field phase, indicating a dramatic change of the magnetic-flux properties. We attribute the high-field phase to the Fulde-Ferrel-Larkin-Ovchinnikov (FFLO) state, where the formation of planar nodes gives rise to a segmentation of the flux-line lattice. We point out that strongly orbital-dependent pairing as well as spin-orbit interactions, the multiband nature, and the extremely small Fermi energy are important for the formation of the FFLO state in FeSe.

Measuring magnetic field texture in correlated electron systems under extreme conditions

Pressure is a clean, continuous, and systematic tuning parameter among the competing ground states in strongly correlated electron systems such as superconductivity and magnetism. However, owing to the restricted access to samples enclosed in high-pressure devices, compatible magnetic field sensors with sufficient sensitivity are rare. We used nitrogen vacancy centers in diamond as a spatially resolved vector field sensor for material research under pressure at cryogenic temperatures. Using a single crystal of BaFe2(As0.59P0.41)2 as a benchmark, we extracted the superconducting transition temperature, the local magnetic field profile in the Meissner state, and the critical fields. The method developed in this work offers a distinct tool for probing and understanding a range of quantum many-body systems.

P4711The prognostic impact of infrapopliteal arterial calcification on wound healing in patients with critical limb ischemia

Background

Critical limb ischemia (CLI) is the most progressed manifestation of peripheral artery disease. Although patients with CLI commonly complicate with severely calcified lesions in infrapopliteal lesions, the prognostic impact of infrapopliteal arterial calcification on wound healing in patients with CLI has not been systematically studied.

Purpose

The aim of current study was to elucidate the prognostic impact of infrapopliteal arterial calcification on wound healing in CLI undergoing endovascular therapy (EVT).

Methods

This study enrolled 639 CLI patients with tissue loss (age 74±10 years, male 62%, diabetes 69%, hemodialysis 57%, Rutherford class 5 77%, class 6 23%) primarily treated with EVT for the infrapopliteal lesions between April 2010 and December 2015. Arterial calcification was assessed by high intensity fluoroscopy and classified into 3 groups as follows; 1) none, 2) unilateral and 3) bilateral calcification. The primary outcome measure was complete wound healing. The predictors of the outcome were evaluated by Cox proportional hazards regression analysis.

Results

During a mean follow-up period of 22±19 months, 1-year wound healing rate were 59.0%. In Kaplan-Meier analysis, 1-year wound healing rate was worse in patients with bilateral calcification than in those with unilateral or none calcification (Figure, 46.2% versus 55.1% versus 67.8%, P<0.001). After multivariate analysis, the predictors of wound healing were non-ambulatory status (hazard ratio (HR) 0.67 [95% confidential interval (CI) 0.53–0.85], P=0.001) and bilateral calcification (HR 0.75 [95% CI 0.47–0.98], versus none or unilateral calcification, P=0.036).

Figure 1

Conclusion

Infrapopliteal Arterial calcification as well as non-ambulatory status was associated with wound healing in patients with CLI.

P6439Clinical outcomes of acute coronary syndrome with intact-fibrous cap plaque at the culprit lesions in diabetic and non-diabetic patients

Background

Previous studies revealed that the morphological substrates of the culprit lesion assessed by optical coherence tomography (OCT) in acute coronary syndrome (ACS), which includes ruptured plaque (RP) and intact fibrous cap (IFC) plaque, are associated with subsequent clinical outcomes. Nevertheless, the impact of culprit morphology on clinical outcomes has not been evaluated in patients with diabetes mellitus (DM), which is one of the major determinants of clinical prognosis.

Purpose

We sought to investigate the association of the culprit lesion morphology with clinical outcomes in patients with DM and those without DM.

Methods

We retrospectively investigated a total of 508 patients with acute myocardial infarction (AMI) experiencing their first episode of ACS in whom OCT-guided, primary percutaneous coronary intervention (PCI) was performed and a culprit lesion was observed by OCT with sufficient image quality. Patients were divided into two groups according to the culprit lesion morphology into patients with RP (RP group) and those without RP (IFC group). The rate of major adverse cardiac events (MACE) including death, myocardial infarction, target or non-target lesion revascularizations were compared between RP and IFC groups in patients with DM (DM) and those without DM (non-DM), separately.

Results

MACE was captured in 80 patients during the median follow-up of 505 (IQR 274–1300) days. In non-DM, RP group showed significantly worse MACE-free rate than in IFC group (Figure), In DM, there was no significant difference between RP and IFC groups (Figure).

Figure 1

Conclusion

Culprit lesion morphology assessed by OCT was not associated with clinical outcomes in DM patients unlike non-DM patients. Distinct strategy for secondary prevention may be required for DM patients.

P3386Angioscopic comparison between polymer-free biolimus A9-coated stent and durable polymer drug-eluting stent 10 months after the implantation

Background

Polymer-free biolimus A9-coated stent (DCS) has currently emerged as expected better arterial healing compared to durable polymer drug-eluting stent (DP-DES). However, superiority of DCS on arterial healing over DP-DES has not been well elucidated using intracoronary images.

Methods

This study examined 288 stents in 224 patients with de novo coronary artery lesions. We angioscopically compared 55 DCS from 35 patients with 233 DP-DES from 189 patients 10±2 months after the implantation. We assessed thrombus adhesion, which is a marker of incomplete re-endothelialization. Dominant neointimal coverage (NIC) grade, heterogeneity of NIC and maximum yellow color of plaque underneath the stent were also evaluated. Neointimal coverage was graded as follows: grade 0, stent struts exposed; grade 1, struts bulged into the lumen, although covered; grade 2, struts embedded by the neointima, but translucent; grade 3, struts fully embedded and invisible. NIC was judged as heterogeneous when differences in the NIC grade became apparent. Yellow plaque was graded as follows: grade 0, white; grade 1, light yellow; grade 2, yellow; grade 3, intensive yellow.

Results

Thrombus adhesion was similar between DCS and DP-DES (29% versus 23%, P=0.32). Dominant NIC was greater in DCS than in BP-DES (P<0.001), while NIC was more heterogeneous in DCS than in BP-DES (P=0.001, Figure). Maximum yellow color of stented segment was similar between DCS and DP-DES (P=0.09).

Conclusion

DCS provided similar thrombus adhesion to DP-DES, which suggested similar re-endothelialization 10 months after implantation. However, DCS showed thick and heterogeneous NIC compared to DP-DES. The specific feature of polymer-free and Biolimus A9 would cause the difference, and further investigation is necessary to evaluate the longer-term safety and efficacy.

Acknowledgement/Funding

None

6111Optical coherence tomography derived predictors of restenosis after non-stenting coronary intervention with drug-coated balloon

Background

One of the limitations of metallic stents including contemporary drug eluting stents lies in the permanent existence of metallic materials within the coronary arteries, which may lead to neoatherosclerosis and a long-term use of dual antiplatelet therapy. Some reports have recently suggested the efficacy and safety of non-stent strategy with drug-coated balloon (DCB) angioplasty in combination with debulking devices for de novo lesions. However, little is known about the potential risk of restenosis after percutaneous coronary intervention (PCI) with DCB.

Purpose

We sought to assess the predictive factors of restenosis by optical coherence tomography (OCT) after PCI with DCB instead of metallic stents.

Methods

We retrospectively investigated 49 de novo lesions in 38 patients treated by DCB without stent implantation in whom OCT was performed immediately after PCI and follow-up angiography was performed at median of 5.6 (3.7–6.9) months. OCT findings after PCI and the incidence of restenosis at follow-up angiography were evaluated. By means of OCT images, medial coronary dissection was defined as a dissection which reached the medial layer of the vessel, and major dissection was defined as a dissection with more than 60 degrees of the circumference of the vessel or more than 3mm in length. Restenosis was defined as more than 50% diameter stenosis evaluated by Quantitative Coronary Angiography.

Results

Restenosis was observed in 13 of 49 lesions (27%). In univariate logistic regression analysis, major dissection and medial dissection at the final OCT were associated with restenosis (Odds ratio [OR] 10.0; 95% confidence interval [CI] 2.5–52.6; p<0.01 and OR 5.8; 95% CI 1.5–25.1; p=0.01, respectively). Lesion preparation prior to DCB were performed with rotational atherectomy (n=9), orbital atherectomy (n=2), directional atherectomy (n=4), excimer laser angioplasty (n=17), scoring balloon angioplasty (n=13), or balloon angioplasty (n=4). OCT-defined major dissection remained a significant predictor for restenosis independent of debulking devices used for the preparation (OR 8.1; 95% CI 1.2–70.2; p=0.03).

Conclusions

Major dissection was associated with restenosis after non-stenting PCI with DCB. Stent implantation should be considered in cases of OCT-defined major dissection.

Acknowledgement/Funding

None

P1916A novel echo-guided approach of cryoballoon ablation without using contrast medium

Background

Pulmonary vein isolation (PVI) using cryoballoon requires contrast medium injection for the confirmation of appropriate venous occlusion. However, some patients have contra-indications against contrast use such as allergy for contrast medium, bronchial asthma or renal dysfunction. We hypothesized that intra-cardiac echocardiographic observation of microbubble leakage after saline injection from the cryoballoon lumen can be used as a maker of incomplete venous occlusion.

Purpose

The aim of this study was to assess the effect of echo-guided approach using saline injection on the acute clinical outcomes as well as the amount of contrast medium.

Methods

Twenty consecutive patients with paroxysmal atrial fibrillation (AF) were studied. They had any reason to avoid using contrast medium. Plain CT scan was performed in all cases to understand the anatomical features. Intra-cardiac echocardiography was used in all cases to guide transseptal puncture and to confirm pulmonary-vein occlusion. Procedural results and clinical outcomes were compared with patients who were performed by the conventional method (n=279).

Results

In all study patients, we could perform PVI without using contrast medium. A total of 2 patients required touch-up ablation using radiofrequency ablation catheter. The procedure time (85±23 vs 86±27 min, P=0.84), the dose of radiation exposure (108±78 vs. 140±133 mmGy/m2, P=0.29), and ratio of requiring touch-up ablation (5% vs 4%, P=0.81) were similar between the study group and the reference group. There was no significant difference in the AF-free survival rate (73% vs. 76%, P=0.79) during a follow-up period of 14±6 months.

Images of ICE

Conclusion

Echo-guided approach using saline infusion was effective and less invasive in terms of reduction of contrast use.