High incidence of left atrial dysfunction and low voltage zone in patients requiring multiple atrial fibrillation ablation

Background

While multiple catheter ablation for recurrent atrial fibrillation (AF) is effective for the maintenance of sinus rhythm, some of patients have ablation-refractory AF. Left atrial (LA) dysfunction and the presence of low voltage zone (LVZ) are associated with recurrence after AF ablation. The association between recurrence and LA dysfunction/ LVZ among patients undergoing multiple AF ablation remains unclear.

Purpose

We aimed to compare (i)LA function, (ii)the prevalence of LVZ among patients undergoing first, second and third or more AF ablation procedures. Further, we investigated whether LA dysfunction and LVZ are associated with recurrence after multiple procedures.

Methods

We retrospectively analyzed 460 patients undergoing AF ablation procedures including first, second and third or more sessions from January 2017 to October 2019 in our institute. Before each session, 256-slice MDCT was performed under sinus rhythm to measure pre-ablation LA emptying fraction (LAEF) as the representative of LA function. At the end of each session, we checked the presence of LVZ, which was defined as regions where bipolar peak-to-peak voltage was <0.5mV. All patients underwent pulmonary vein isolation (PVI). If necessary, additional ablation (e.g. linear ablation, non-PV foci ablation and LVZ ablation) was performed.

Results

Out of 460 sessions, 295 were first (follow-up years: 1.5 [0.8, 2.0]), 134 were second (1.0 [0.5, 1.8]), and 31 were third or more sessions (1.2 [0.7, 2.0]). As the number of sessions increased, the recurrence rate was increased (19% vs. 31% vs. 61%, first vs. second vs. ≥third, P<0.0001), LAEF decreased (39.7±10.5% vs. 32.6±10.1% vs. 25.3±11.8%, P<0.0001) and the incidence of LVZ increased (18% vs. 34% vs. 68%, P<0.0001) (Figure 1). In patients with recurrence (N=104) after multiple ablation (second or more sessions), LAEF was lower and the prevalence of LVZ was higher than those without recurrence (N=61) (LAEF: 27.3±10.3% vs. 33.5±10.5%, with vs. without, P=0.0003; LVZ: 57% vs. 31%, P=0.0014).

Conclusions

As the number of sessions increased, the recurrence rate was increased. The prevalence of LA dysfunction and LVZ was high in patients requiring multiple ablation procedure. LA dysfunction and LVZ possibly reflect arrhytmogenic substrate causing recurrence of ablation-refractory AF. We should carefully consider repeated AF ablation in patients with severe LA dysfunction and extensive LVZ.

Figure 1

Funding Acknowledgement

Type of funding source: None

Pre-ablation left atrial function predicts the presence of low voltage zone in patients undergoing paroxysmal atrial fibrillation ablation: OLAF-LVZ predictive score

Background

Preoperative left atrial (LA) function is associated with paroxysmal atrial fibrillation (PAF) ablation outcome. The presence of left atrial low voltage zone (LVZ) is also associated with recurrence. We hypothesized that reduced pre-ablation LA function reflects the presence of LVZ.

Purpose

We investigated the association between baseline LA function and the presence of LVZ in patients undergoing initial PAF ablation. Further, we sought to create the new predictive scoring for the presence of LVZ.

Methods

Consecutive 305 patients who underwent LA voltage mapping during initial PAF ablation from January 2017 to October 2019 in our institute were retrospectively analyzed. We performed 256-slice MDCT at baseline. As the representative of LA function, we calculated LA emptying fraction (LAEF), where LAEF = {[(maximum LAV) − (minimum LAV)]/(maximum LAV)} x 100. LVZ was defined as regions where bipolar peak-to-peak voltage was <0.5mV. We performed the univariate and multivariate analysis to assess the association between LAEF and the presence of LVZ. Second, we performed receiver operating characteristic (ROC) analysis for the prediction of LVZ. We combined multivariate predictors and created the predictive scoring for LVZ.

Results

Out of 305 pts, 56 pts (18%) had LVZ in LA. In univariate analysis, low body mass index, higher percentage of female sex, higher age, higher E/e', larger maximum LA volume and lower LAEF (29.3±11.8% vs. 41.2±9.7, P<0.0001) was associated with the presence of LVZ. In multivariate logistic regression analysis, Low LAEF revealed the strongest predictor for LVZ (LAEF; Odds ratio [OR]/10% increase: 0.54, 95% CI: 0.39–0.82, P=0.0016). High age and female sex also remained as the independent predictors (Age; OR/10 y.o. increase: 1.80, 1.23–3.03, P=0.0042, Female; OR: 2.51, 1.15–5.49, P=0.0213). In ROC analysis, LAEF had moderate predictive accuracy for the presence of LVZ. (Area under the ROC curve: 0.77, Best cut-off value: 31%, P<0.0001) (Figure 1). We created OLAF-LVZ predictive score by combining Old age (1 point, ≥65), LAEF (2 points, LAEF ≤31%) and Female sex (1 point). OLAF score had gradient effect on the incidence of LVZ (2%, 11%, 25%, 45%, 71%, OLAF score; 0, 1, 2, 3, 4, respectively, P<0.0001) (Figure 2).

Conclusions

In PAF patients, preoperative LAEF was strongly associated with the presence of LVZ. LVZ might reflect the myocardial injury causing LA dysfunction. OLAF-LVZ predictive score: combination of Old age (≥65), Female sex, and LAEF (≤31%) could be useful to stratify the risk of the presence of LVZ.

Funding Acknowledgement

Type of funding source: None

Aggressive lipid lowering therapy with pitavastatin and ezetimibe improve cardiovascular outcomes in patients with ST segment elevation myocardial infarction: insights from the HIJ-PROPER Study

Aims

The purpose of this study was to evaluate the effect of aggressive lipid-lowering therapy with pitavastatin and ezetimibe in patients with ST-segment elevation myocardial infarction (STEMI) as compared with those with other classification of an acute coronary syndrome (ACS) including non-STEMI (NSTEMI) and unstable angina pectoris (UA).

Methods

This is a post hoc sub-analysis of the HIJ-PROPER study. In the original study, ACS patients with dyslipidemia were randomized to either pitavastatin + ezetimibe therapy or pitavastatin monotherapy. In the present analysis, we divided HIJ-PROPER participants into the STEMI group (n=880) and NSTEMI + UA group (n=841). Cardiovascular events were analyzed between the two groups. The primary endpoint was a composite of major advanced cardiovascular events (MACE; all-cause death, non-fatal myocardial infarction, non-fatal stroke, unstable angina pectoris, and ischemia-driven revascularization)

Result

During median follow-up period of 3.4 years, the cumulative incidence of the primary endpoint in STEMI group was 31.9% in the pitavastatin+ezetimibe therapy, compared with 39.7% in the pitavastatin-monotherapy (HR, 0.77; 95% CI, 0.62–0.97; p=0.02). However, there was no effect of pitavastatin+ezetimibe therapy on the primary endpoint in the NSTEMI + UA group. Concerning the individual components of the primary endpoint in STEMI group, the percentage of occurrence of all-cause death was significantly lower in the pitavastatin+ezetimibe therapy compared to pitavastatin mono-therapy (14 patients (3.2%) vs. 31 patients (6.9%), respectively; HR, 0.45; 95% CI, 0.23–1.84, p=0.01). Multivariate analysis revealed that use of ezetimibe and prevalence of diabetes mellitus at baseline were independent predictors of primary endpoints in STEMI group (HR, 0.79; 95% CI, 0.63–0.99; p=0.04 for use of ezetimibe, HR 1.54; 95% CI, 1.22–1.94, p=0.0003 for diabetes mellitus).

Conclusion

Patients with pitavastatin+ezetimibe therapy as compared with pitavastatin-monotherapy had lower cardiovascular event in patients with ST-segment elevation myocardial infarction.

Kaplan-Meier curves for primary endpoint

Funding Acknowledgement

Type of funding source: None

Quantitative analysis of dyssynchrony assessed by multidetector computed tomography can predict clinical outcome after cardiac resynchronization therapy

Background

The degree of mechanical dyssynchrony has been suggested as a predictor for long-term survival after cardiac resynchronization therapy (CRT). There have been little reports of dyssynchrony assessment with the use of cardiac computed tomography (CCT).

Methods

We studied 35 heart failure (HF) patients (average age 67±10 years) referred for CRT with NYHA III-IV heart failure, left ventricular (LV) ejection fraction (EF) 20±10% (all ≤35%), and QRS duration 156±22 ms (all ≥120ms). Electrocardiogram-gated contrast-enhanced 256-slice multidetector CT was performed before CRT. Based on CCT, the LV endocardial boundaries from short-axis images reconstructed at 5% increments of cardiac cycle were automatically detected, and the time from R-wave to maximal wall motion was calculated for each of the 16 standardized segments for all slices using software “Myocardial Contraction Map”. The standard deviation modified by mean heart rate (%SD) was respectively calculated as the global parameter of dyssynchrony. LVEF was also measured using MDCT. The predefined primary end-point was the first HF hospitalization or death over 2 years.

Results

%SD was feasible in all patients, respectably. There were 16 events over 2 years; 11 HF hospitalizations and 5 deaths. Patients with %SD ≥22% (optimal cutoff for outcome by ROC curve analysis) had a better clinical outcome than patients with %SD <22% (p=0.01, Figure).

Conclusion

Patients who had %SD ≥22% assessed by MDCT had a particularly favorable event-free survival following CRT, and this appears to be an important prognostic marker.

Funding Acknowledgement

Type of funding source: None

Evaluation of the local atrial function by regional speckle tracking imaging using intracardiac echocardiography

Background

It has been reported that low voltage areas and conduction abnormalities detected by electrophysiology catheters in the left atrium (LA) represent regional degeneration and fibrosis of the atrium and are related to a poor atrial fibrillation (AF) ablation outcome. Assessment of the local atrial function is clinically useful because atrial degeneration does not occur uniformly throughout the atrium. Though evaluating the global atrial function using speckle tracking imaging (STI) by transthoracic echocardiography (TTE) has been attempted, TTE does not have a sufficient image quality to assess local atrial STI.

Purpose

To evaluate the local atrial function by STI using intracardiac echocardiography (ICE) and to elucidate the characteristics of the STI in normal and abnormal voltage regions in the LA.

Methods

We included 9 patients undergoing AF ablation with written informed consent for this prospective observational study. After pulmonary vein isolation, we performed voltage mapping of the LA in sinus rhythm using a CARTO system (Biosense). Abnormal regions and normal regions were defined as those with low voltage areas (<0.5 mV) and those with normal voltages, respectively. Echo images were recorded by an ACUSON SC2000 (Siemens) and SOUNDSTAR catheter (Biosense). We inserted the SOUNDSTAR catheter into the LA to obtain clear images, recorded the STI of the anterior and inferior wall, and performed an offline analysis of the atrial strain with an eSie VVI work station (Siemens) and the LA voltage data with CARTO system at each site simultaneously (left figure). We compared the strain during the atrial contraction phase (Sct) between the normal and abnormal regions.

Results

Among the study population, 5 patients had low voltage areas in the LA. We evaluated the STI at 26 normal regions and 44 abnormal regions. The typical regional speckle tracking waveform in the normal region was similar to a jugular vein pressure waveform (right figure). There was a difference in the amplitude of the Sct between the groups; it was significantly smaller in the abnormal regions (normal and abnormal regions, 9.8±5.0% and 5.6±3.8%, p=0.0001). The duration of the Sct was significantly more prolonged in the abnormal regions than normal regions (98.8±26.3ms and 118.2±33.9ms, p=0.015).

Conclusions

This pilot study demonstrated that the local atrial function was evaluable by STI using ICE and that the regional strain tracking waveform during the atrial contraction phase in abnormal voltage regions was smaller and more prolonged than that in normal regions. An evaluation of the regional STI with an ICE may be useful to detect regional abnormalities of the atrium.

Representative case

Funding Acknowledgement

Type of funding source: None

Screening for obstructive sleep apnea in atrial fibrillation patients at their home before catheter ablation using watch peripheral arterial tonometry

Background

Catheter ablation of atrial fibrillation (AF) is effective, but certain patients experience AF recurrences. Obstructive sleep apnea (OSA) is a risk factor for AF recurrence. Watch peripheral arterial tonometry (WP) has a good correlation with polysomnography (PSG) in terms of the apnea-hypopnea index (AHI) and is easier to perform than PSG. Patients in AF have a high prevalence of OSA. Whether all patients with AF should be evaluated for OSA before catheter ablation is still controversial.

Purpose

To elucidate the prevalence and predictors of OSA using WP as a home sleep apnea test in AF patients before catheter ablation.

Methods

This study was conducted under a retrospective, single-center, observational design. Patients who received AF ablation without a prior diagnosis of sleep apnea and assessment of their AHI using WP were included in this analysis. The patients were mounted with a WP device by themselves at their own home. Twenty-two patients who were already diagnosed with OSA were excluded.

Results

Seven hundred seventy-four (65±11 years, 567 males, 440 paroxysmal AF) out of 776 patients were successfully mounted with WP devices on their own and underwent an OSA assessment. Their mean body mass index (BMI) was 24.1±3.5 kg/m2. The mean AHI was 20.1±15.6. Only 88 (11.4%) patients had a normal AHI (AHI<5). Mild OSA (5≤AHI<15), moderate OSA (15≤AHI<30), and severe OSA (AHI≥30) were observed in 274 (35.4%), 252 (32.6%), and 160 (20.7%) patients, respectively. A BMI≥25 (odds ratio [OR]; 2.42, 95% confidence interval [CI]; 1.74–3.37, p<0.001), male sex (1.70, 1.19–2.44, p=0.0037), non-paroxysmal AF (1.90, 1.35–2.66, p=0.0002), hypertension (1.70, 1.24–2.33, p=0.009), and left atrial volume index ≥30 (OR=1.51, CI 1.06–2.16, p=0.022) were significant predictors of moderate or severe OSA by a multivariate analysis, while an Epworth sleepiness scale ≥11 was not a predictor of moderate or severe OSA (OR=0.99, CI 0.66–1.49, p=0.95). However, 44.2% of non-obese patients (BMI <25) had moderate-severe OSA.

Conclusion Almost

All patients successfully underwent WP to diagnose OSA. AF patients had a high prevalence of OSA, and screening OSA would be important in AF patients receiving ablation even if patients do not have sleepiness or are obese. We cannot deny OSA in AF patients before catheter ablation without performing screening tests for OSA.

Funding Acknowledgement

Type of funding source: None

Sex differences in the predictors of recurrent atrial fibrillation after catheter ablation: insights from the Kansai Plus Atrial Fibrillation (KPAF) registry

Background

The impact of sex differences on the clinical outcomes of radiofrequency catheter ablation (RFCA) of atrial fibrillation (AF) is controversial. We previously reported that females experienced more frequent AF recurrences than males after the index and last RFCA procedures.

Purpose

To identify the risk factors associated with recurrent AF in females and males after RFCA of AF.

Methods

We conducted a large-scale, prospective, multicenter, observational study (Kansai Plus Atrial Fibrillation Registry). We enrolled 5010 consecutive patients who underwent an initial RFCA of AF at 26 centers (64±10 years; 1369 [27.3%] females; non-paroxysmal AF, 35.7%). The median follow-up duration was 2.9 years.

Results

The incidence of AF recurrences after a single procedure was 43.3% in females and 39.0% in males. After a multivariate adjustment at baseline, the significant predictors of AF recurrence in females after the index RFCA were non-paroxysmal AF (hazard ration [HR],1.59; 95% confidence interval [CI],1.31–1.93, p<0.0001), a history of AF ≥2 years (HR,1.47; 95% CI,1.24–1.74, p<0.0001), coronary artery disease (HR,1.43; 95% CI,1.03–1.98, p=0.0035), and an estimated glomerular filtration rate (eGFR)<60 mL/min/1.73m2 (HR,1.46; 95% CI,1.10–1.95, p=0.0086). On the other hand, significant predictors of AF recurrence in males after the index RFCA were non-paroxysmal AF (HR,1.54; 95% CI,1.37–1.73, p<0.0001), a history of AF ≥2 years (HR,1.40; 95% CI,1.26–1.56, p<0.0001), the number of antiarrhythmic drugs (HR,1.06; 95% CI,1.003–1.13, p=0.040), a left atrial diameter≥40mm (HR,1.13; 95% CI,1.007–1.27, p=0.038), and dilated cardiomyopathy (HR,1.55; 95% CI,1.07–2.26, p=0.021), however, an eGFR<60 mL/min/1.73m2 was not associated with AF recurrence in males (HR, 1.00; 95% CI, 0.88–1.13, p=0.97).

Conclusion

The Kansai Plus Atrial Fibrillation Registry revealed a distinct sex difference in terms of the predictors of recurrent AF after RFCA. Non-Paroxysmal AF and a long history of AF were common risk factors both in females and males. However, renal dysfunction was a significant predictor of AF recurrence in females, while it was not a risk of recurrence in males.

Funding Acknowledgement

Type of funding source: Foundation. Main funding source(s): Research Institute for Production Development in Kyoto, Japan.

Transient ischemic attack without self-awareness of symptoms witnessed by bystanders: analysis of the PROMISE-TIA registry

Background and purpose

A transient ischemic attack (TIA) can occur without self‐awareness of symptoms. We aimed to investigate characteristics of patients with a tissue‐based diagnosis of TIA but having no self‐awareness of their symptoms and whose symptoms were witnessed by bystanders.

Methods

We used data from the multicenter registry of 1414 patients with a clinical diagnosis of TIA. For patients without evidence of ischemic lesions on imaging, clinical characteristics were compared between patients with and without self‐awareness of their TIA symptoms.

Results

Among 896 patients (559 men, median age of 70 years), 59 (6.6%) were unaware of their TIA symptoms, but had those symptoms witnessed by bystanders. Patients without self‐awareness of symptoms were older and more frequently female, and more likely to have previous history of stroke, premorbid disability, and atrial fibrillation, but less likely to have dyslipidemia than those with self‐awareness. Patients without self‐awareness of symptoms arrive at hospitals earlier than those with self‐awareness (P < 0.001). ABCD² score was higher in patients without self‐awareness of symptoms than those with self‐awareness (median 5 vs. 4, P = 0.002). Having no self‐awareness of symptoms was a significant predictor of ischemic stroke within 1 year after adjustment for sex, ABCD² score, and onset to arrival time (hazard ratio = 2.44, 95% confidential interval: 1.10–4.83), but was not significant after further adjustment for arterial stenosis or occlusion.

Conclusions

Patients with a TIA but having no self‐awareness of their symptoms might have higher risk of subsequent ischemic stroke rather than those with self‐awareness, suggesting urgent management is needed even if patients have no self‐awareness of symptoms.

A multi-center, randomized controlled trial by the Integrative Management in Japan for Epidemic Disease (IMJEDI study-RCT) on the use of Kampo medicine, kakkonto with shosaikotokakikyosekko, in mild-to-moderate COVID-19 patients for symptomatic relief and prevention of severe stage: a structured summary of a study protocol for a randomized controlled trial

OBJECTIVES

We aimed to test our hypothesis that additional administration of traditional Japanese (Kampo) medicine, kakkonto (kakkon-to: KT) and shosaikotokakikyosekko (sho-saiko-to-ka-kikyo-sekko: SSKKS), is more effective in relieving symptoms and preventing the onset of severe infection in mild-to-moderate COVID-19 patients compared to those treated only with conventional treatment.

TRIAL DESIGN

The study is designed as a multi-center, interventional, parallel-group, randomized (1:1 ratio), investigator-sponsored, two-arm study.

PARTICIPANTS

Patients and inpatients will be recruited from 8 Japanese academic and non-academic hospitals. The inclusion and exclusion criteria are as follows: Inclusion criteria: 1. Diagnosed as positive for severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) 2. Clinical stages of mild-to-moderate COVID-19 3. Symptomatic 4. ≥ 20 years of age 5. Male or female 6. Ability to communicate in Japanese 7. Outpatients and inpatients 8. Provided informed consent Exclusion criteria: 1. Difficulty in providing informed consent due to dementia, psychosis, or psychiatric symptoms 2. Allergic to Kampo or Western medicines used in this study 3. Pregnant and lactating 4. Unable to follow up 5. Participating in another clinical trial or interventional study 6. Hypokalemic or taking oral furosemide or steroids 7. Determined unsuitable for this study by the physician INTERVENTION AND COMPARATOR: Patients in the control group will receive conventional treatment with antipyretics, painkillers, or antitussives for symptoms that occurred after they contracted the SARS-CoV-2 infection. Patients in the Kampo group will receive 2.5 g of KT (TJ-1@TSUMURA and Co.) and 2.5 g of SSKKS (TJ-109@TSUMURA and Co.) 3 times a day, orally, for 14 days in addition to the conventional treatment as mentioned above.

MAIN OUTCOMES

The number of days till at least one of the symptoms (fever, cough, sputum, malaise, shortness of breath) improves in the first 14 days of treatment. To assess the cough, sputum, malaise, and shortness of breath, a numeric rating scale will be used to define improvement in terms of a 2-point decrease in the number of days from the start of treatment for at least 2 days. Fever will be defined as an improvement when the temperature is less than 37 °C.

RANDOMIZATION

Patients are randomized (1:1 ratio) to each group using the minimization method, with balancing of the arms with severity of disease stage and patient age (< 65, 65 to < 75, or ≥ 75 years). Computer-generated random numbers will be used for the minimization method.

BLINDING (MASKING)

Open-label with no blinding NUMBERS TO BE RANDOMIZED (SAMPLE SIZE): The main research hypothesis of this study is that the combination of Kampo medicine and conventional treatment will significantly improve the patients' symptoms (fever, fatigue, cough, sputum, and shortness of breath) during the first 14 days of treatment as compared with conventional treatment alone. Concerning the analysis of the primary endpoint, the duration of time before improvement of at least one of the common cold-like symptoms (fever, malaise, cough, sputum, and shortness of breath) will be estimated using the Kaplan-Meier method, and the survival curves will be compared between groups using the log-rank test. Assuming this method of analysis and based on previous studies reporting the efficacy of Kampo medicine for COVID-19 and H1N1 influenza patients, the median survival time in the Kampo medicine group is estimated as 3 days; this time will be 1.5 times longer in the control group. Assuming a one-sided significance level of 5%, a power of 70%, and an allocation ratio of 1:1, the required sample size is calculated as 126 cases. To compensate for a loss in follow-up, we plan to include 150 cases in both groups (Kampo group = 75, control group = 75).

TRIAL STATUS

Protocol version 1.2 as of August 20, 2020 Recruitment start (expected): October 1, 2020 Recruitment finish (expected): October 31, 2023 TRIAL REGISTRATION: Japan Registry of Clinical Trials (jRCT) jRCTs021200020 . Registered on August 25, 2020 FULL PROTOCOL: The full protocol is attached as an additional file and is accessible from the Trials website (Additional file 1). In the interest of expediting the dissemination of this material, the familiar formatting has been eliminated; this Letter serves as a summary of the key elements of the full protocol.

The acrid raphides in tuberous root of Pinellia ternata have lipophilic character and are specifically denatured by ginger extract

Unprocessed dried tuberous root of Pinellia ternata (Pinellia Tuber) has been used as a component of traditional Japanese Kampo medicine, while this crude drug is usually used after processing with Ginger in traditional Chinese medicine (TCM). It is known that the raphides contained in unprocessed Pinellia Tuber can induce severe acrid irritation of the oral and laryngopharynx mucosa when it is boiled insufficiently. However, the mechanism of the inducing irritation by the raphides nor that of the detoxification by heat or processing with Ginger have been left unclear, mainly because of the difficulties in the extraction and the purification of the raphides and in the assays of acridity. In this study, we developed an easy protocol that can be used to collect raphides from unprocessed Pinellia Tuber and an assay protocol that can be used to evaluate the acridity of the raphides in vitro. The raphides of Pinellia Tuber were discovered to have a lipophilic character and to be collected easily by the extraction using petroleum ether. It was also found that the denaturation of the raphides could be assayed by the dispersity of them in petroleum ether layer of the water/petroleum ether partition, and the acridity of the raphides was found to be in correlation with the assayed denaturation. The raphides were denatured by heat, methanol, or Ginger extract and the denaturing activity of Ginger on raphides was found to be attributable to its lipophilic and thermostable components, which may explain the meaning of the processing of Pinellia Tuber with Ginger in TCM, and may lead to the development of an easier and safer protocol to administer Pinellia Tuber. In addition, it was found that rinsing the mouth with salad oil can effectively relieve irritation of the oral mucosa caused by unprocessed Pinellia Tuber, probably due to the lipophilicity of the raphides.

Control of High-Harmonic Generation by Tuning the Electronic Structure and Carrier Injection

High-harmonic generation (HHG), which is the generation of light with multiple optical harmonics, is an unconventional nonlinear optical phenomenon beyond the perturbation regime. HHG, which was initially observed in gaseous media, has recently been demonstrated in solid-state materials. Determining how to control such extreme nonlinear optical phenomena is a challenging subject. Here, we demonstrate the control of HHG through tuning the electronic structure and carrier injection using single-walled carbon nanotubes (SWCNTs). We reveal systematic changes in the high-harmonic spectra of SWCNTs with a series of electronic structures ranging from a metal structure to a semiconductor structure. We demonstrate enhancement or reduction of harmonic generation by more than 1 order of magnitude by tuning the electron and hole injection into the semiconductor SWCNTs through electrolyte gating. These results open a path toward the control of HHG in the context of field-effect transistor devices.

Devil's staircase transition of the electronic structures in CeSb

Solids with competing interactions often undergo complex phase transitions with a variety of long-periodic modulations. Among such transition, devil's staircase is the most complex phenomenon, and for it, CeSb is the most famous material, where a number of the distinct phases with long-periodic magnetostructures sequentially appear below the Néel temperature. An evolution of the low-energy electronic structure going through the devil's staircase is of special interest, which has, however, been elusive so far despite 40 years of intense research. Here, we use bulk-sensitive angle-resolved photoemission spectroscopy and reveal the devil's staircase transition of the electronic structures. The magnetic reconstruction dramatically alters the band dispersions at each transition. Moreover, we find that the well-defined band picture largely collapses around the Fermi energy under the long-periodic modulation of the transitional phase, while it recovers at the transition into the lowest-temperature ground state. Our data provide the first direct evidence for a significant reorganization of the electronic structures and spectral functions occurring during the devil's staircase.

Transfer of orbital angular momentum of light to plasmonic excitations in metamaterials

The emergence of the vortex beam with orbital angular momentum (OAM) has provided intriguing possibilities to induce optical transitions beyond the framework of the electric dipole interaction. The uniqueness stems from the OAM transfer from light to material, as demonstrated in electronic transitions in atomic systems. In this study, we report on the OAM transfer to electrons in solid-state systems, which has been elusive to date. Using metamaterials (periodically textured metallic disks), we show that multipolar modes of the surface electromagnetic excitations (so-called spoof localized surface plasmons) are selectively induced by the terahertz vortex beam. Our results reveal selection rules governed by the conservation of the total angular momentum, which is confirmed by numerical simulations. The efficient transfer of light's OAM to elementary excitations in solid-state systems at room temperature opens up new possibilities of OAM manipulation.

Transition between Isotope-Mixing and Nonmixing States in Hydrogen-Deuterium Mixture Plasmas

The transition between isotope-mixing and nonmixing states in hydrogen-deuterium mixture plasmas is observed in the isotope (hydrogen and deuterium) mixture plasma in the Large Helical Device. In the nonmixing state, the isotope density ratio profile is nonuniform when the beam fueling isotope species differs from the recycling isotope species and the profile varies significantly depending on the ratio of the recycling isotope species, although the electron density profile shape is unchanged. The fast transition from nonmixing state to isotope-mixing state (nearly uniform profile of isotope ion density ratio) is observed associated with the change of electron density profile from peaked to hollow profile by the pellet injection near the plasma periphery. The transition from nonmixing to isotope-mixing state strongly correlates with the increase of turbulence measurements and the transition of turbulence state from TEM to ion temperature gradient is predicted by gyrokinetic simulation.

1677 Global longitudinal strain during dobutamine stress echocardiography can predict left ventricular remodeling after anterior wall acute myocardial infarction

Background

Although dobutamine stress echocardiography (DSE) at the early stage of acute myocardial infarction (AMI) is useful for the prediction of functional and clinical prognosis, the interpretation requires expertise. In this study, we sought to investigate if global longitudinal strain (GLS) during DSE after AMI can predict left ventricular remodeling (LVR).

Methods

Consecutive 30 patients with anterior wall AMI (18 male, age = 58 ± 13 years) were performed DSE 3 days after AMI. GLS was calculated as an averaged value of peak longitudinal strain in the apical 4- and 2-chamber views at baseline echocardiography, low-dose DSE (10 μg/kg/min) using available software (QLAB, Philips Medical Systems). Left ventricular remodeling (LVR) was defined as an echocardiographically determined increase in both EDVI and ESVI of 20% or more from baseline to the 6 month follow-up echocardiography.

Results

12 patients (40%) evolved with LVR. The change in GLS during low-dose DSE was significantly different between the remodeling and non-remodeling group (8 ± 5% v.s. 27 ± 20%, p &lt; 0.05). Interestingly, it predicted LVR with sensitivity of 88%, specificity of 92% at the cut-off value of 12% (Area under the curve = 0.94, p &lt; 0.0001).

Conclusion

The change in GLS during low-dose DSE can be used as a predictor for the LVR after AMI. This observation has promise for clinical applications.

Abstract 1677 Figure.

P10 A possible link between sarcopenia and major bleeding risk among patients with atrial fibrillation treated with oral anticoagulation undergoing coronary stenting

Background/Introduction

In patients with atrial fibrillation (AF) undergoing percutaneous coronary intervention (PCI) with stent implantation, oral anticoagulation (OAC) plus dual antiplatelet therapy (DAPT) increases the risk of bleeding. The PRECISE-DAPT (P-DAPT) and DAPT scores were created to predict increased bleeding versus ischemic risk in patients undergoing DAPT. However, not much information is available on predicting bleeding risk associated with OAC concomitant with DAPT in patients with AF treated with coronary stents. Physical frailty or sarcopenia is considered an emerging predictor for bleeding in AF patients.

Purpose

To investigate the relationship between skeletal muscle mass and major bleeding risk in AF patients undergoing PCI and subsequent OAC and DAPT.

Methods

A total of 1,234 consecutive patients after PCI using newer-generation drug eluting stents were evaluated. An anti-thrombotic regimen without OAC was given to 1,077 patients, whereas OAC was required in 157 patients (12.7%) including AF (n = 96). The P-DAPT, DAPT, and HAS-BLED scores were calculated for each of the patients. Any out-of-hospital major bleeding events were identified based on BARC criteria during a median follow-up of 2.9 years. The fat-free mass index (FFMI; kg/m2) was calculated to evaluate skeletal muscle mass as follows: (7.38 + 0.02908 × urinary creatinine (mg/day)) / (height squared (m2)). A Cox proportional hazards model was used to test the significance of the FFMI and these risk scores as predictors of major bleeding, defined as BARC 3 or 5 events in AF patients. The receiver operating characteristic curve (ROC) analyses were used to examine the predictive ability of the FFMI and these scores to identify patients with major bleeding events.

Results

Major bleeding events were observed in 9 (9.3%) patients. Major bleeding was associated with a lower FFMI (hazard ratio [HR] 0.53; 95% confidence interval [CI] 0.36-0.79; p = 0.002), and higher P-DAPT score (HR, 1.07; 95% CI, 1.02-1.11; p = 0.003), but not with the DAPT (HR, 0.71; 95% CI, 0.45-1.12; p = 0.147) and the HAS-BLED score (HR, 1.00; 95% CI, 0.48-2.09; p = 0.990). In the non-OAC cohort, major bleeding was related to a higher P-DAPT score (HR, 1.05; 95% CI, 1.02-1.07; p &lt; 0.0001), but the FFMI (HR, 0.89; 95% CI, 0.73-1.09; p = 0.265) and the DAPT score were not correlated. C-statistics for major bleeding events were 0.82 (95% CI, 0.71-0.93, p = 0.001) for the FFMI and 0.79 (95% CI, 0.68-0.90, p = 0.004) for the P-DAPT score.

Conclusions

Assessment of the FFMI for screening sarcopenia is useful to predict major bleedings specifically in patients with AF undergoing coronary stenting. Both the FFMI and P-DAPT could successfully predict major bleedings in AF patients after PCI. Whether novel bleeding risk scores combined with measuring body composition adequately identify high risk patients needs to be validated.

Modulation of methotrexate-induced intestinal mucosal injury by dietary factors

Methotrexate (MTX)-induced intestinal mucosal injury in animals has been studied to understand how MTX can cause gastrointestinal disorders, but the pathogenesis of gastrointestinal disorders is still uncertain. We have attempted to reveal how dietary factors influence intestinal toxicity due to MTX. Mice were fed normal chow (NC) or a high-fat high-sucrose diet (HFHSD) before oral administration of MTX. While MTX significantly decreased the survival rates of mice fed HFHSD, the intestinal epithelial injury was detected. MTX excretion in the feces of mice fed HFHSD was reduced. Change of diets between NC and HFHSD influences the survival. The survival rates of the mice fed a high-sucrose diet or control diet were higher than those fed HFHSD. Higher survival rates were observed in mice fed a high-fat high-sucrose diet modified (HFHSD-M) in which casein was replaced by soybean-derived proteins. The survival rates of mice treated with vancomycin were lower than those administered neomycin. Microbiome and metabolome analyses on feces suggest a similarity of the intestinal environments of mice fed NC and HFHSD-M. HFHSD may modify MTX-induced toxicity in intestinal epithelia on account of an altered MTX distribution as a result of change in the intestinal environment.

DWI for Monitoring the Acute Response of Malignant Gliomas to Photodynamic Therapy

BACKGROUND AND PURPOSE

Photodynamic therapy is a novel treatment that provides effective local control, but little is known about photodynamic therapy-induced changes on MR imaging. The aim of this study was to assess the utility of DWI and ADC in monitoring the response of malignant gliomas to photodynamic therapy.

MATERIALS AND METHODS

Time-dependent changes in DWI and ADC values after photodynamic therapy were analyzed in a group that received photodynamic therapy in comparison with a group that did not.

RESULTS

Twenty-four patients were enrolled (photodynamic therapy, n = 14; non-photodynamic therapy, n = 10). In all patients who received photodynamic therapy, linear high signals on DWI in the irradiated area were detected adjacent to the resection cavity and were 5-7 mm in depth from 1 day posttreatment and disappeared in about 30 days without any neurologic deterioration. The non-photodynamic therapy group did not show this change. The photodynamic therapy group had significantly lower ADC values from 1 day posttreatment (P < .001), which increased steadily and disappeared by 30 days. There was no decline or time-dependent change in ADC values in the non-photodynamic therapy group.

CONCLUSIONS

The acute response of malignant gliomas to photodynamic therapy was detected as linear high signals on DWI and as a decrease in ADC values. These findings were asymptomatic and transient. Although the photodynamic therapy-induced acute response on MR imaging disappeared after approximately 30 days, it may be helpful for confirming the photodynamic therapy-irradiated area.