pH Dependence of HSF1 trimerization is shaped by intramolecular interactions

Heat shock factor 1 (HSF1) primarily regulates various cellular stress responses. Previous studies have shown that low pH within the physiological range directly activates HSF1 function in vitro. However, the detailed molecular mechanisms remain unclear. This study proposes a molecular mechanism based on the trimerization behavior of HSF1 at different pH values. Extensive mutagenesis of human and goldfish HSF1 revealed that the optimal pH for trimerization depended on the identity of residue 103. In particular, when residue 103 was occupied by tyrosine, a significant increase in the optimal pH was observed, regardless of the rest of the sequence. This behavior can be explained by the protonation state of the neighboring histidine residues, His101 and His110. Residue 103 plays a key role in trimerization by forming disulfide or non-covalent bonds with Cys36. If tyrosine resides at residue 103 in an acidic environment, its electrostatic interactions with positively charged histidine residues prevent effective trimerization. His101 and His110 are neutralized at a higher pH, which releases Tyr103 to interact with Cys36 and drives the effective trimerization of HSF1. This study showed that the protonation state of a histidine residue can regulate the intramolecular interactions, which consequently leads to a drastic change in the oligomerization behavior of the entire protein.

Comprehensive stability analysis of 13 β-lactams and β-lactamase inhibitors in in vitro media, and novel supplement dosing strategy to mitigate thermal drug degradation

Non-clinical antibiotic development relies on in vitro susceptibility and infection model studies. Validating the achievement of the targeted drug concentrations is essential to avoid under-estimation of drug effects and over-estimation of resistance emergence. While certain β-lactams (e.g., imipenem) and β-lactamase inhibitors (BLIs; clavulanic acid) are believed to be relatively unstable, limited tangible data on their stability in commonly used in vitro media are known. We aimed to determine the thermal stability of 10 β-lactams and 3 BLIs via LC-MS/MS in cation-adjusted Mueller Hinton broth at 25 and 36°C as well as agar at 4 and 37°C, and in water at -20, 4, and 25°C. Supplement dosing algorithms were developed to achieve broth concentrations close to their target over 24 h. During incubation in broth (pH 7.25)/agar, degradation half-lives were 16.9/21.8 h for imipenem, 20.7/31.6 h for biapenem, 29.0 h for clavulanic acid (studied in broth only), 23.1/71.6 h for cefsulodin, 40.6/57.9 h for doripenem, 46.5/64.6 h for meropenem, 50.8/97.7 h for cefepime, 61.5/99.5 h for piperacillin, and >120 h for all other compounds. Broth stability decreased at higher pH. All drugs were ≥90% stable for 72 h in agar at 4°C. Degradation half-lives in water at 25°C were >200 h for all drugs except imipenem (14.7 h, at 1,000 mg/L) and doripenem (59.5 h). One imipenem supplement dose allowed concentrations to stay within ±31% of their target concentration. This study provides comprehensive stability data on β-lactams and BLIs in relevant in vitro media using LC-MS/MS. Future studies are warranted applying these data to antimicrobial susceptibility testing and assessing the impact of β-lactamase-related degradation.

Digital coincidence counting with 4πβ(PPC)-γ for the standardization of 60Co

A 4πβ(PPC)-γ coincidence system has been made at KRISS based on a digital DAQ. 60Co sources were measured to verify the system. The maximum detection efficiency for beta particles was estimated to be 96.7 %. Massic activities for sample sources had 0.005 % of the sample variability error, which was well within the expanded standard uncertainty of 0.54 % (k = 2).

Longitudinal Change of Cup to Disc Ratio in Premature Infants with Enlarged Cup to Disc Ratio and Normal Intraocular Pressure

PURPOSE

To evaluate the longitudinal change of cup to disc ratio (CDR) in premature infants with enlarged CDR and normal intraocular pressure (IOP).

METHODS

This retrospective, observational study included 283 eyes of 283 premature infants at single center. Infants were divided into enlarged CDR and control groups. Data on demographics, gestational age (GA), birth weight (BW), vertical cup to disc ratio (vCDR), IOP, and corneal diameter were analyzed.

RESULTS

Of the 283 patients, 38 (13.4%) and 245 (86.6%) were in the enlarged CDR and control groups, respectively. In the enlarged CDR group, the vCDR and baseline IOP was 0.63 ± 0.12 and 12.7 ± 2.2 mmHg, respectively. In the control group, the vCDR and baseline IOP was 0.18 ± 0.05 and 10.9 ± 1.7 mmHg, respectively. The IOP at a GA of 40 weeks and at 1 and 2 years of age were significantly lower than that at baseline. The differences in vCDR between baseline and each follow-up visit were not significant. vCDR was negatively correlated with GA and BW; however, these correlations were not significant.

CONCLUSIONS

The vCDR did not significantly change up to age of 2 years of age in premature infants with enlarged CDR and normal IOP. However, close follow-up is needed until other reliable glaucoma examinations, such as optical coherence tomography and visual fields, can be possible.

Macrophage activation syndrome in neonatal lupus presenting with fever and rash

Neonatal lupus can occur in infants born to mother with autoimmune disorders through transplacental auto-antibodies. Clinical manifestations in neonatal lupus include cutaneous lesions and hematologic or hepatobiliary findings resembling those seen in systemic lupus erythematosus. In autoimmune state, macrophage activation syndrome (MAS) represent a critical and potentially fatal complication that can result in mortality if not immediately identified and managed with the appropriate care. Here we present a 33-day-old girl diagnosed with neonatal lupus and serious MAS. She was delivered by a primipara mother who did not exhibit any autoimmune symptoms. The patient visited the hospital due to fever and pancytopenia. Laboratory data were compatible with MAS, including pancytopenia, high level of ferritin, soluble interleukin-2, and decreased natural killer cell activity. In addition, autoimmune study showed positive results for anti-nuclear antibody (ANA), anti-Sjogren syndrome antigen A (SSA), and SSB, The autoimmune study for mother also showed positive results for ANA, anti-SSA, and SSB. The patient recovered after she received high dose steroid and supportive care. Our case indicates that neonatal lupus should be taken into consideration when fever, erythematous skin rash, and pancytopenia are observed in infants, even if their mothers have no prior history of autoimmune conditions.

Novel modeling approach integrating population pharmacokinetics and interspecies scaling to predict human pharmacokinetics of the new anti-tuberculosis agent telacebec (Q203)

Telacebec is a new anti-tuberculosis agent with promising therapeutic activity and a favorable safety profile. This study aimed to characterize the pharmacokinetics of telacebec via interspecies scaling and population pharmacokinetic modeling for the prediction of human pharmacokinetics. Preclinical pharmacokinetic data were obtained from mice, rats, and dogs following intravenous and oral doses of telacebec. A population pharmacokinetic model was developed to describe the pharmacokinetic data from all three species. The disposition parameters were well correlated with the body weight for all species using an allometric equation. Thus, the allometric scaling was incorporated into the population pharmacokinetic model, which could simultaneously describe the plasma concentration vs. time data from all preclinical studies as well as the Phase 1A clinical study. The developed model was used to predict the pharmacokinetics of telacebec after IV injection, including the clearance (CL) of 168.58 [118.86 - 238.73] mL/min and volume of distribution (Vss) of 968.84 [396.87 - 2831.31] L for 80-kg human. The absolute bioavailability of telacebec in humans in the fed state was estimated as 70.34 ± 9.91%. Finally, the population pharmacokinetic model with allometric scaling was utilized to simulate the plasma concentration vs. time profiles of telacebec after multiple oral doses in humans. The model-predicted profiles well agreed with the observed data in Phase 1B clinical trial. The present pharmacokinetic model may help better understand the activity of telacebec, leading to the design of optimal dosing regimens and new formulation development.

The Sagittal Balance of Cervical Spine : Comprehensive Review of Recent Update

The cervical spine plays a critical role in supporting the skull, maintaining horizontal gaze, and facilitating walking. Its unique characteristics, including the widest range of motion among spinal segments, have led to extensive research on cervical sagittal alignment. Various parameters have been proposed to evaluate cervical alignment, with studies investigating their clinical significance, correlation with symptoms, and implications for surgical interventions. Recent findings suggest that cervical sagittal alignment not only impacts the cervical spine but also influences global spine-pelvic alignment through compensatory mechanisms. This comprehensive review examines classical and new parameters of cervical sagittal alignment and considers the dynamic and muscular factors associated with it.

Outcomes of Salvage Therapy for Oropharyngeal Cancer Recurrence Following Upfront Radiation Therapy and Prognostic Factors

PURPOSE

This study aimed to investigate the oncologic outcomes and prognostic factors of salvage treatments in patients with recurrent oropharyngeal squamous cell carcinoma (OPSCC) after radiotherapy (RT)-based treatment.

MATERIALS AND METHODS

A cancer registry was used to retrieve the records of 337 patients treated with definitive RT or concurrent chemoradiotherapy (CRT) from 2008 to 2018 at a single institution. The poor-responder group (PRG) was defined as patients with residual or recurrent disease after primary treatment, and the oncologic outcomes for each salvage treatment method were analyzed. In addition, prognostic indicators of recurrence-free survival (RFS) and overall survival (OS) were identified in patients who underwent salvage treatment.

RESULTS

After initial (C)RT, the PRG comprised 71 of the 337 patients (21.1%): 18 patients had residual disease, and 53 had recurrence after primary treatment (mean time to recurrence 19.5 months). Of these, 63 patients received salvage treatment (surgery 57.2%, re-(C)RT 23.8%, and chemotherapy 19.0%), and the salvage success rate was 47.6% at the last follow-up. The overall 2-year OS for salvage treatments was 56.4% (60.8% for the salvage surgery group and 46.2% for the salvage re-(C)RT). Salvage surgery patients with negative resection margins had better oncologic outcomes than those with close/positive resection margins. Using multivariate analyses, locoregional recurrence and residual disease after primary surgery were associated with poor outcome after salvage treatment. In Kaplan-Meier analyses, p16 status was significantly associated with OS in the initial treatment setting but not in the salvage setting.

CONCLUSION

In recurrent OPSCC after RT-based treatment, successful salvage was achieved in 56.4% patients who had undergone salvage surgery and radiation treatment. Salvage treatment methods should be selected carefully, given recurrence site as a prognostic factor for RFS.

Establishment of an LC-MS/MS method for quantification of lifitegrast in rabbit plasma and ocular tissues and its application to pharmacokinetic study

Lifitegrast, a lymphocyte function-associated antigen 1 antagonist, was approved by the FDA for the treatment of dry eye disease. Cornea and conjunctiva have been reported to be the sites of action of lifitegrast. To investigate the pharmacokinetics of lifitegrast, a sensitive analytical method for the determination of lifitegrast in various biological matrices such as plasma and ocular tissues is required. However, only limited information about the analytical method for lifitegrast in biological samples is available. In the present study, we aimed to develop a new liquid chromatography-tandem mass spectrometry method for the determination of lifitegrast in rabbit plasma, cornea, conjunctiva, and sclera. Lifitegrast-d6 was used as an internal standard (IS). To prepare the biological samples, protein precipitation using acetonitrile was utilized. Analytes were separated from endogenous interferences on an Atlantis dC18 (5 µm, 2.1 × 150 mm), and a mixture of 0.1 % formic acid and acetonitrile was used as the mobile phase. The mass transition of precursor to product ion was monitored at 615.2 → 145.0 for lifitegrast and 621.2 → 145.1 for IS. The calibration curves were linear over the concentration range from 2 to 500 ng/mL for plasma and 5 to 500 ng/mL in ocular tissue homogenates. Intra- and inter-day accuracy ranged from 95.76 to 106.80 % in the plasma and 94.42 to 112.80 % in the ocular tissues. Precision was within 8.56 % in the plasma and 9.72 % in the ocular tissues. The short-term, long-term, auto-sampler, and freeze-thaw stabilities of lifitegrast were validated. The developed method was applied to a pharmacokinetic study of lifitegrast in rabbits. Following ophthalmic administration, only 3.26 % of administered lifitegrast was absorbed into the systemic circulation. Peak tissue concentrations were observed at 0.5 h after dosing, and topically administered lifitegrast was mainly distributed in the cornea and conjunctiva. The finding of this study is expected to be used in further pharmacokinetic studies and formulation development.

Applicability and limitations of quality indicator-based assessment of appropriateness in antimicrobial use: a comparison with expert opinion

BACKGROUND

The effective implementation of antimicrobial stewardship requires an a-priori assessment of the appropriateness of antimicrobial prescriptions.

AIM

To evaluate the effectiveness of quality indicators (QIs) in determining the appropriateness of antimicrobial prescriptions compared to that of expert opinions.

METHODS

The study assessed antimicrobial use in 20 hospitals in Korea, with infectious disease specialists rating the appropriateness based on QIs and expert opinions. The selected QIs were (1) taking two blood cultures, (2) taking cultures from suspected sites of infection, (3) prescribing empirical antimicrobials according to guidelines, and (4) changing from empirical to pathogen-directed therapy for hospitalized patients and (2, 3, and 4) for ambulatory patients. Applicability, compliance with QIs, and agreement between QIs and expert opinions were investigated.

FINDINGS

Overall, 7999 therapeutic uses of antimicrobials were investigated at the study hospitals. The experts rated 20.5% (1636/7999) as inappropriate use. For hospitalized patients, antimicrobial use was assessed based on all four QIs in 28.8% (1798/6234) of the cases. For ambulatory care patients, only 7.5% (102/1351) of the antimicrobial use cases were assessed using all three QIs. The agreement between expert opinions and all four QIs for hospitalized patients was minimal (κ = 0.332), whereas that between expert opinions and all three QIs for ambulatory patients was weak (κ = 0.598).

CONCLUSION

QIs have limitations in determining the appropriateness of antimicrobial use, and the degree of agreement with expert opinions was low. Therefore, these QI limitations should be considered when determining the appropriateness of antimicrobial use.

The use of artificial intelligence models to predict survival in patients with laryngeal squamous cell carcinoma

Most recent survival prediction has been based on TNM staging, which does not provide individualized information. However, clinical factors including performance status, age, sex, and smoking might influence survival. Therefore, we used artificial intelligence (AI) to analyze various clinical factors to precisely predict the survival of patients with larynx squamous cell carcinoma (LSCC). We included patients with LSCC (N = 1026) who received definitive treatment from 2002 to 2020. Age, sex, smoking, alcohol consumption, Eastern Cooperative Oncology Group (ECOG) performance status, location of tumor, TNM stage, and treatment methods were analyzed using deep neural network (DNN) with multi-classification and regression, random survival forest (RSF), and Cox proportional hazards (COX-PH) model for prediction of overall survival. Each model was confirmed with five-fold cross validation, and performance was evaluated using linear slope, y-intercept, and C-index. The DNN with multi-classification model demonstrated the highest prediction power (1.000 ± 0.047, 0.126 ± 0.762, and 0.859 ± 0.018 for slope, y-intercept, and C-index, respectively), and the prediction survival curve showed the strongest agreement with the validation survival curve, followed by DNN with regression (0.731 ± 0.048, 9.659 ± 0.964, and 0.893 ± 0.017, respectively). The DNN model produced with only T/N staging showed the poorest survival prediction. When predicting the survival of LSCC patients, various clinical factors should be considered. In the present study, DNN with multi-class was shown to be an appropriate method for survival prediction. AI analysis may predict survival more accurately and improve oncologic outcomes.

Novel LC-MS/MS analysis of the GLP-1 analog semaglutide with its application to pharmacokinetics and brain distribution studies in rats

Semaglutide, one of the most potent glucagon-like peptide (GLP)-1 analogs, has widely been used to treat type II diabetes mellitus and obesity. Recent studies have shown that semaglutide also works on the brain, suggesting its potential utility for various diseases, including Parkinson's disease and Alzheimer's disease. This study aimed to develop a novel liquid chromatography-tandem mass spectrometry (LC-MS/MS) analysis of semaglutide in both plasma and brain to characterize the pharmacokinetics and brain distribution in rats. Semaglutide was extracted by simple protein precipitation with methanol from plasma and by solid phase extraction from brain tissue. Liraglutide was used as an internal standard. Gradient elution profiles with mobile phases comprising 0.1 % formic acid in water and acetonitrile were used for chromatographic separation. The lower limit of quantification (LLOQ) of the LC-MS/MS assay was 0.5 ng/mL for both rat plasma and brain. Intra- and inter-day accuracy ranged 89.20-109.50 % in the plasma and 92.00-105.00 % in the brain. Precision was within 8.92 % in the plasma and 7.94 % in the brain. Sprague-Dawley rats were given semaglutide by intravenous (IV, 0.02 mg/kg) and subcutaneous (SC, 0.1 and 0.2 mg/kg) injection. Plasma concentrations of semaglutide showed a multi-exponential decline with an average half-life of 7.22-9.26 hr in rats. The subcutaneous bioavailability of semaglutide was 76.65-82.85 %. The brain tissue to plasma partition coefficient (K_p) value of semaglutide was estimated as <0.01. Among the different regions of the brain, semaglutide concentrations were significantly higher in the hypothalamus. The analytical method and pharmacokinetic information may be helpful toward a better understanding of the effect of semaglutide in the brain and further development of GLP-1 analogs for various brain diseases.

Development of an LC-MS/MS Assay and Toxicokinetic Characterization of Hexamethylenetetramine in Rats

Hexamethylenetetramine, an aldehyde-releasing agent, is used as a preservative in various food, cosmetics, and medical treatments, such as a treatment for urinary tract infections. It has been reported to be allergenic on contact with the skin, with the additional possibility of causing toxicity once absorbed systemically. Despite its potential toxicity, there are no reports on the in vivo bioavailability of hexamethylenetetramine following oral or dermal administration. In this study, we developed a new simple and sensitive LC-MS/MS method for the determination of hexamethylenetetramine in plasma and applied this method to characterize the toxicokinetics. The developed assay had a sufficient specificity and sensitivity for toxicokinetic characterization, and its accuracy and precision were verified. Following iv injection, the plasma concentration of hexamethylenetetramine showed mono exponential decay, with an elimination half-life of about 1.3 h. Following oral administration, the T_max reached an average of 0.47 h and bioavailability was estimated as 89.93%. After percutaneous administration, it reached C_max on average at 2.9-3.6 h. Although the absorption rate was relatively slow, its average bioavailability was calculated as 77.19-78.91%. Overall, most of the orally and percutaneously administered hexamethylenetetramine was absorbed into systemic circulation. The derived results in this study are expected to be utilized as the scientific evidence for further toxicokinetic study and risk assessment.

Long-term Clinical Course of Amniotic Membrane after Permanent Amniotic Membrane Transplantation

Purpose: To investigate the long-term clinical outcomes of transplanted amniotic membrane in patients who underwent permanent amniotic membrane transplantation (P-AMT) on cornea.Methods: From April 2014 to March 2021, medical records and digital photographs of 68 patients (72 eyes) who underwent P-AMT were analyzed retrospectively. The duration of complete re-epithelization of cornea and wearing therapeutic contact lense (T-lens) after surgery were investigated, the size of preserved amniotic membrane (AM) excluding the melted portion was analyzed using the Image J program every year up to 6 years after surgery, and it was compared by dividing into a single-layer group and a double-layer group. In addition, when the AM melts, the cause, time, and related factors of melting were analyzed.Results: The average duration to complete re-epithelialization after surgery was 12.2 ± 11.0 days, and T-lens were worn on average up to 8.7 ± 8.5 months after surgery. In total group, the average ratio of preserved AM annually up to 6 years after surgery was 94.9%, 94.3%, 97.8%, 96.4%, 95.8%, 91.6% respectively, and there was no significant difference between the single-layer group and the double-layer group. AM melting appeared in 38.9% (28 eyes) of the total group, and melting was first observed on average 16.4 ± 17.2 months after surgery. The formation and rupture of bullae was the most common cause of melting at 71.4% (20 eyes), and there were no statistically significant related factors involved in the formation of bullae.Conclusions: In the case of P-AMT performed in various diseases of the cornea, the transplanted AM is partially melt but considered to be well preserved up to 6 years after surgery to form a stable ocular surface.

Sex differences in hearing impairment due to diet-induced obesity in CBA/Ca mice

BACKGROUND

Obesity is an independent risk factor for hearing loss. Although attention has focused on major obesity comorbidities such as cardiovascular disease, stroke, and type 2 diabetes, the impact of obesity on sensorineural organs, including the auditory system, is unclear. Using a high-fat diet (HFD)-induced obese mouse model, we investigated the impact of diet-induced obesity on sexual dimorphism in metabolic alterations and hearing sensitivity.

METHODS

Male and female CBA/Ca mice were randomly assigned to three diet groups and fed, from weaning (at 28 days) to 14 weeks of age, a sucrose-matched control diet (10 kcal% fat content diet), or one of two HFDs (45 or 60 kcal% fat content diets). Auditory sensitivity was evaluated based on the auditory brainstem response (ABR), distortion product otoacoustic emission (DPOAE), and ABR wave 1 amplitude at 14 weeks of age, followed by biochemical analyses.

RESULTS

We found significant sexual dimorphism in HFD-induced metabolic alterations and obesity-related hearing loss. Male mice exhibited greater weight gain, hyperglycemia, increased ABR thresholds at low frequencies, elevated DPOAE, and lower ABR wave 1 amplitude compared to female mice. The hair cell (HC) ribbon synapse (CtBP2) puncta showed significant sex differences. The serum concentration of adiponectin, an otoprotective adipokine, was significantly higher in female than in male mice; cochlear adiponectin levels were elevated by HFD in female but not male mice. Adiponectin receptor 1 (AdipoR1) was widely expressed in the inner ear, and cochlear AdipoR1 protein levels were increased by HFD, in female but not male mice. Stress granules (G3BP1) were significantly induced by the HFD in both sexes; conversely, inflammatory (IL-1β) responses were observed only in the male liver and cochlea, consistent with phenotype HFD-induced obesity.

CONCLUSIONS

Female mice are more resistant to the negative effects of an HFD on body weight, metabolism, and hearing. Females showed increased peripheral and intra-cochlear adiponectin and AdipoR1 levels, and HC ribbon synapses. These changes may mediate resistance to HFD-induced hearing loss seen in female mice.

Toxicokinetics, Percutaneous Absorption and Tissue Distribution of Benzophenone-3, an UV Filtering Agent, in Rats

The aim of this study was to evaluate in vitro skin permeation and deposition, in vivo toxicokinetics, percutaneous absorption and tissue distribution of benzophenone-3 (BP-3) in rats. Four transdermal formulations containing BP-3 were prepared and evaluated for in vitro skin permeation and deposition of BP-3 using Franz diffusion cells. A gel formulation was used in subsequent in vivo percutaneous absorption due to its high in vitro skin permeation and deposition. Compared to intravenous (i.v.) injection, the prolonged terminal t_1/2 (3.1 ± 1.6 h for i.v. injection and 18.3 ± 5.8 h for topical application) was observed indicating occurrence of flip-flop kinetics after topical application. The bioavailability of BP-3 after topical application was 6.9 ± 1.8%. The tissue-to-plasma partition coefficient (kp) for testis, considered a toxic target for BP-3, was less than 1.. Overall, findings of this study may be useful for risk assessment of BP-3.

Anti-Metastatic Effect of Pyruvate Dehydrogenase Kinase 4 Inhibition in Bladder Cancer via the ERK, SRC, and JNK Pathways

Bladder cancer is a common global cancer with a high percentage of metastases and high mortality rate. Thus, it is necessary to identify new biomarkers that can be helpful in diagnosis. Pyruvate dehydrogenase kinase 4 (PDK4) belongs to the PDK family and plays an important role in glucose utilization in living organisms. In the present study, we evaluated the role of PDK4 in bladder cancer and its related protein changes. First, we observed elevated PDK4 expression in high-grade bladder cancers. To screen for changes in PDK4-related proteins in bladder cancer, we performed a comparative proteomic analysis using PDK4 knockdown cells. In bladder cancer cell lines, PDK4 silencing resulted in a lower rate of cell migration and invasion. In addition, a PDK4 knockdown xenograft model showed reduced bladder cancer growth in nude mice. Based on our results, PDK4 plays a critical role in the metastasis and growth of bladder cancer cells through changes in ERK, SRC, and JNK.

Impact of Low Skeletal Muscle Mass and Obesity on Hearing Loss in Asymptomatic Individuals: A Population-Based Study

The relationship between low muscle mass (LMM) with obesity and hearing loss has been poorly studied. We aimed to investigate the association of LMM and obesity on hearing loss in the general population. A total of 265,792 adults who underwent a hearing test and body composition analyses were included. Pre-sarcopenia was defined as having an appendicular muscle mass index <5.7 kg/m2 for women and <7.0 kg/m2 for men, and obesity as a body mass index ≥25 kg/m2, while pre-sarcopenic obesity was defined as the co-presence of LMM and obesity. Participants were divided into four groups according to the presence of pre-sarcopenia and/or obesity. The prevalence of hearing loss was 1.8% in the control, 2.5% in the pre-sarcopenia alone, 3.0% in the obesity alone, and 6.2% in the pre-sarcopenic obesity group (p < 0.001). Hearing Thresholds were the highest in the pre-sarcopenic obesity group compared with the other three groups. In multivariable-adjusted models, the risk of hearing loss was the highest in the pre-sarcopenic obesity group (odds ratio: 1.30 [95% confidence interval: 1.10−1.56]), followed by the obesity alone (1.20 [1.12−1.28]) and pre-sarcopenia alone (1.19 [1.06−1.34]) group compared with the control group (p < 0.001). Pre-sarcopenic obesity was independently associated with a higher prevalence of hearing loss, supporting pre-sarcopenic obesity itself as a risk for the decline in hearing function.

Prediction of response to cardiac resynchronization therapy using cardiac magnetic resonance imaging in non-ischemic dilated cardiomyopathy

Background

Cardiac resynchronization therapy (CRT) is a well-established therapy for symptomatic heart failure with reduced ejection fraction, but the response is different for individuals. Although many modalities have been conducted to predict CRT response, cardiac magnetic resonance (CMR) to predict CRT response has still insufficient usefulness.

Purpose

We determine whether the parameters including late gadolinium enhancement (LGE) identified in CMR could act as predictors of CRT response.

Methods

We retrospectively investigated 124 patients with non-ischemic dilated cardiomyopathy who underwent CMR before CRT implantation between Jan 2010 and July 2021 in a single center. CRT response was defined as a decrease in left ventricular end-systolic volume (LVESV) &gt;15% on echocardiography after at least 3 months after CRT implantation.

Results

Among the study population (mean age 65.7±11.2 years, mean EF 25±6.5%, 50% of female), 85 (69%) patients were defined as CRT responder. The CRT responders had more left bundle branch block (LBBB) compared with non-responders [79 (92.9%) vs. 23 (59.0%), p&lt;0.001], but there was a no difference of QRS duration (158.7 vs 165.0ms, p=0.054) between two groups. CMR analysis showed that there were no significant differences in the left ventricular (LV) chamber volume and LV ejection fraction between CRT-responder and non-responder. However, the right ventricular (RV) chamber volume was smaller (RV end-diastolic volume index, 86.3 vs 103.5 ml/m2, p=0.039; RV end-systolic volume index, 49.3 vs 68.5 ml/m2, p=0.013) and the RV ejection fraction (RVEF) was higher (46.9 vs 37.6%, p=0.002) in CRT-responders compared with non-responders. The LGE on CMR was more shown in non-responders than in CRT-responders [33 (84.6%) vs 45 (52.9%), p&lt;0.001]. In CMR parameters, RV dysfunction (RVEF &lt;45%) [Odds ratio (OR), 0.21 (0.05–0.93), p=0.045] and LGE [OR, 0.21 (0.05–0.58), p=0.01] were significantly associated with poor CRT response.

Conclusions

The presence of LGE and RV dysfunction on CMR were associated with poor CRT response in patients with non-ischemic dilated cardiomyopathy. Further investigation with CMR for pre-CRT patients is needed to support these results.

Funding Acknowledgement

Type of funding sources: None.

Blunted atrial reverse remodeling a year after catheter ablation for atrial fibrillation and their long-term rhythm outcome

Background

Although active rhythm control by atrial fibrillation (AF) catheter ablation (AFCA) reduces left atrial (LA) dimension, blunted atrial reverse remodeling can be observed in patients with significant atrial myopathy. We explored the characteristics and long-term outcomes of AF patients who showed blunted atrial reverse remodeling despite no AF recurrence within a year after AFCA.

Methods

Among a total of 2,756 patients with AFCA, we included 1,685 patients (74.8% male, 60.2±10.1 years old, 54.5% paroxysmal AF) who underwent both baseline and 1-year follow-up echocardiogram, baseline LA&gt;40mm, and did not recur within a year. We divided them into tertile groups (T1–T3) based on one-year percent change of LA dimension after propensity matching for age, sex, AF type, and baseline LA dimension. We also investigated the patients' genetic characteristics with blunted LA reverse remodeling (T1) using a genome-wide association study (GWAS).

Results

Patients with blunted LA reverse remodeling (T1, n=424) were independently associated with body mass index (OR 1.082 [1.010–1.160], p=0.025), LA peak pressure (OR 1.010 [1.002–1.019], p=0.019), LA wall thickness (OR 0.448 [0.252–0.789], p=0.006), LA voltage (OR 0.651 [0.463–0.907], p=0.012), and pericardial fat volume (OR 1.004 [1.001–1.008], p=0.014). Throughout 65.9±37.4 months of follow-up, the incidence of AF recurrence a year after the procedure was significantly higher in the T1 group than in T2 or T3 groups (Log-rank p&lt;0.001). Among 894 patients with GWAS, ATXN1, XPO7, KRR1_PHLDA1, ZFHX3, and their polygenic risk score were associated with blunted LA reverse remodeling.

Conclusions

Patients with blunted LA reverse remodeling after AFCA were independently associated with low LA voltage, thin wall thickness, high LA pressure, and fat volume, and have a genetic background. Long-term clinical recurrence a year after AFCA was higher in this patient group with suspicious atrial myopathy.

Funding Acknowledgement

Type of funding sources: Public grant(s) – National budget only. Main funding source(s): Ministry of Health and WelfareNational Research Foundation of Korea

Oral anticoagulation therapy in atrial fibrillation patients with advanced chronic kidney disease: CODE-AF Registry

Background and objectives

Advanced chronic kidney disease (CKD), including end-stage renal disease (ESRD) on dialysis, increases thromboembolic risk among patients with atrial fibrillation (AF). This study examined the comparative safety and efficacy of direct-acting oral anticoagulant (DOAC) compared to warfarin or no OAC among AF patients with advanced CKD or ESRD on dialysis.

Methods

Using data from the COmparison study of Drugs for symptom control and complication prEvention of AF (CODE-AF) registry, 260 non-valvular AF patients with advanced CKD (defined as estimated glomerular filtration rate [eGFR] &lt;3 0ml/min per 1.73 m2) or ESRD on dialysis were enrolled from June 2016 to July 2020. The study population was categorized into DOAC, warfarin, and no OAC group, and differences in major or clinically relevant non-major (CRNM) bleeding, stroke/systemic embolism (SE), myocardial infarction/critical limb ischemia (CLI), and death were assessed.

Results

During a median 24 months of follow-up, major or CRNM bleeding risk was significantly reduced in the DOAC group compared to the warfarin group (hazard ratio [HR] 0.21, 95% confidence interval [CI] 0.05 to 0.95, p=0.042). In addition, the risk of composite adverse clinical outcome (major or CRNM bleeding, stroke/SE, myocardial infarction/CLI, and death) was significantly reduced in the DOAC group compared to the no OAC group (HR 0.32, 95% CI 0.11 to 0.96, p=0.043).

Conclusion

Among AF patients with advanced CKD or ESRD on dialysis, DOAC was associated with a lower risk of major or CRNM bleeding compared to warfarin and a lower risk of composite adverse clinical outcome compared to no OAC.

Funding Acknowledgement

Type of funding sources: Public grant(s) – National budget only. Main funding source(s): Korean Healthcare Technology R&D project funded by the Ministry of Health & Welfare (HI15C1200, HC19C0130)

Effects of early recurrence and extra-PV triggers on long-term recurrence after catheter ablation for atrial fibrillation

Background

Although early recurrence (ER) within 3 months after atrial fibrillation (AF) catheter ablation (AFCA) was recently reported to be a reliable predictor of late recurrence (LR), the mechanism is not clear.

Purpose

We explored the characteristics of patients with ER and compared the long-term late recurrence (LR) pattern depending on the existence of extra-pulmonary vein trigger (ExPV-trigger).

Methods

Among 3643 patients who underwent de novo AFCA, we included 1249 patients (59.2±11.0 years old, 31.3% persistent AF) who underwent isoproterenol provocation and regular follow-up over three years after AFCA. We evaluated the risk factors for ER and compared the patients with ER alone (10.1%), LR alone (16.6%), and ER+LR (15.9%), and the outcome of repeat procedure.

Results

Overall ER (ER alone and ER+LR) was independently associated with persistent AF (OR 1.58 [1.16–2.14], p=0.003), extra-PV triggers (OR 2.80 [1.90–4.13], p&lt;0.001), and empirical extra-PV ablation (OR 1.54 [1.15–2.07], p=0.004). Overall LR (LR alone and ER+LR) risk was significantly higher in the ER with ExPV-trigger group than in ER without ExPV-trigger or no ER groups (Log-rank p&lt;0.001). The rhythm outcome of the second procedure did not differ between ER+LR and LR alone groups (Log-rank p=0.160), but was worse in the ER+LR ExPV-trigger than in ER+LR without ExPV-trigger or LR alone groups (Log-rank p=0.005).

Conclusion

ER was independently associated with LR after de novo AFCA. ExPV-trigger played crucial roles in ER and LR after de novo AFCA and worse rhythm outcome after redo AFCA.

Funding Acknowledgement

Type of funding sources: None.

Effect of the epicardial fat volume on the outcomes after a left atrial posterior wall isolation in addition to pulmonary vein isolation in patients with persistent atrial fibrillation

Background

While the effect of a circumferential pulmonary vein isolation (CPVI) alone is unsatisfactory, that of an additional electrical posterior wall box isolation (POBI) is controversial in persistent atrial fibrillation (PeAF) patients. Increased epicardial adipose tissue (EAT) is associated with higher recurrence rates after AF catheter ablation (AFCA).

Purpose

We investigated the possible effects of a POBI on rhythm outcomes with varying EAT volumes.

Methods

We included 1,187 patients with PeAF undergoing a de novo AFCA (79.6% male, median age 60 years) into two groups including those receiving a CPVI alone (n=687) and those an additional POBI (n=500). The rhythm outcomes at two years post-AFCA were compared in subgroups stratified by the total EAT volume using propensity overlap weighting.

Results

A reduced total EAT volume was linearly associated with more favorable rhythm outcomes for an additional POBI treatment than for a CPVI alone (P for interaction=0.002). Among the patients with smaller EAT volumes (≤116.23 ml, the median value, n=594), an additional POBI was associated with a reduced AF recurrence risk as compared to a CPVI only (weighted hazard ratio [HR] 0.74, 95% confidence interval [CI] 0.56–0.99; weighted log-rank P=0.039). In contrast, among the remaining 593 patients with greater EAT volumes (&gt;116.2 3mL), there was no difference in the AF recurrence risk between an additional POBI and CPVI alone (weighted HR 1.13, 95% CI 0.84–1.52; weighted log-rank P=0.410). Among 185 patients with a repeat ablation, the POBI reconnection rate tended to be higher in the large EAT group (75.0%) than small EAT group (55.4%, P=0.060).

Conclusion

While PeAF patients with a smaller EAT volume averted AF recurrence by an additional POBI after the CPVI, no benefit of the POBI was observed in those with a greater EAT volume. The EAT volume might identify AF patients likely to benefit from linear ablation in addition to the CPVI.

Funding Acknowledgement

Type of funding sources: Public grant(s) – National budget only. Main funding source(s): Korean Ministry of Science, ICT & Future Planning (MSIP)Korean Ministry of Health and Welfare

Rice NAC17 transcription factor enhances drought tolerance by modulating lignin accumulation

Land plants have developed a comprehensive system to cope with the drought stress, and it is operated by intricate signaling networks, including transcriptional regulation. Herein, we identified the function of OsNAC17, a member of NAC (NAM, ATAF, and CUC2) transcription factor family, in drought tolerance. OsNAC17 is localized to the nucleus, and its expression was significantly induced under drought conditions. A transactivation assay in yeast revealed that the OsNAC17 is a transcriptional activator, harboring an activation domain in the C-terminal region. Overexpressing (OsNAC17^OX) transgenic plants showed drought-tolerant, and knock-out (OsNAC17^KO) plants exhibited drought susceptible phenotype compared to non-transgenic plants. Further investigation revealed that OsNAC17 positively regulates several lignin biosynthetic genes and promotes lignin accumulation in leaves and roots. Together, our results show that OsNAC17 contributes to drought tolerance through lignin biosynthesis in rice.

Impact of Pulmonary Function on Voice Outcomes After Injection Laryngoplasty for Unilateral Vocal Fold Paralysis

OBJECTIVES

Pulmonary function is closely associated with voice quality especially in patients with voice disorder including unilateral vocal fold paralysis (UVFP). Injection laryngoplasty (IL) is the standard treatment for patients with UVFP. We investigated the subjective and objective voice outcomes according to pulmonary function test (PFT) before IL in patients with UVFP.

METHOD

We retrospectively analyzed the patients who underwent IL for UVFP between 2004 and 2021 (N = 1201), and finally investigated 261 patients with PFT results before IL. The patients were classified into three groups according to results of PFT: normal (n = 189, 72%), mild (n = 40, 15%), and moderate (n = 32, 13%) obstructive pattern. Aspiration symptoms and subjective and objective voice parameters of voice handicap index (VHI), GRBAS score, maximal phonation time (MPT), Jitter, Shimmer, and noise to harmonic ratio (NHR) were compared between normal and abnormal (mild or moderate obstructive pattern) PFT groups.

RESULTS

Age (68.0 ± 9.1 and 61.2 ± 12.6, respectively) was significantly higher and males were more common (84.7% and 57.7%, respectively) in abnormal PFT than in normal PFT. Aspiration showed significant improvement in all groups. The subjective and objective voice parameters significantly improved after IL in normal and mild obstruction groups, but MPT, Shimmer, and VHI did not significantly improve in the moderate obstruction group. The improvement in VHI-30 after IL was significantly higher in the normal group (20.0 ± 29.5) than in the mild (10.3 ± 32.8) or moderate (9.9 ± 33.2) obstruction group (P = 0.035). Improved amounts of MPT, Jitter, Shimmer, and NHR were not significantly different among the groups, but improvement of VHI was smallest in the moderate obstructive pattern group.

CONCLUSION

Voice parameters showed significant improvement after IL in both normal and mild obstructive pattern groups, but MPT and VHI did not significantly improve in the moderate obstructive pattern group. In addition, patients with normal pulmonary function had marked improvement of subjective symptoms after IL in comparison with patients with abnormal pulmonary function.

Thyroid Gland Flap for Prevention of Pharyngocutaneous Fistula After Total Laryngectomy

OBJECTIVES

Pharyngocutaneous fistula (PCF) is the one of the major complications after total laryngectomy (TL), which can result in saliva leakage, rupture of major vessels, and increased hospitalization. Several flaps have been tried to prevent PCF during TL, and they are usually associated with donor site morbidity and uncertain viability in case of previously irradiated patients. This study aimed to report a novel bilateral pedicled thyroid gland flap (TGF) technique for delicate and effective reinforcement of neopharynx suture line after TL.

METHODS

Bilateral pedicled TGF was performed for the reinforcement of neopharynx T-shape suture sites after TL in this case series.

RESULTS

A total of five cases of the TGF were performed during TL, with four of them being salvage setting following previous chemoradiation therapy (CRT). The well-adapted and viable TGF status was confirmed by post-operative computed tomography scan and normally preserved thyroid hormone levels in all patients. No post-operative infections, hemorrhage, hypothyroidism, hypoparathyroidism, or PCF were reported.

CONCLUSION

The TGF is an effective and reliable flap in TL patents and should be considered as a method in neopharynx reconstruction, even in salvage TL following prior CRT.

Contrast Sensitivity Changes after Phototherapeutic Keratectomy in Heterozygote Granular Corneal Dystrophy Type 2

Purpose: Contrast sensitivity, the ability to distinguish the relative difference in luminance of an object from its surrounding or adjacent objects, is a useful measure of visual function. In granular corneal dystrophy type 2 (GCD2), opacity of the corneal stroma causes deterioration in visual function. We compared the contrast sensitivity of GCD2 patients before and after phototherapeutic keratectomy (PTK) to evaluate the perioperative visual function in these patients.Methods: This study included 22 eyes of heterozygote GCD2 patients. The visual acuity and contrast sensitivity were measured before and after PTK. The contrast sensitivity was measured in mesopic and photopic background luminances, with glare (G) levels of 0-2 (G0, G1, and G2, respectively) and spatial frequencies at 1.5, 3, 6, 12, and 18 cycles per degree (cpd).Results: The contrast sensitivity increased after PTK at 1.5 and 3 cpd in mesopic and photopic conditions with G0-2 glare (p < 0.05). At 6 cpd, the contrast sensitivity increased in the mesopic condition with G1 glare, and in the photopic condition with G0-2 glare (p < 0.05). However, there was no change in contrast sensitivity at any glare level at 12 and 18 cpd after PTK.Conclusions: In GCD2 patients, the contrast sensitivity increased significantly after PTK. The vision of GCD2 patients, which is decreased due to corneal opacity, is improved after PTK.

Establishment of Level a In Vitro-In Vivo Correlation (IVIVC) via Extended DoE-IVIVC Model: A Donepezil Case Study

This study aimed to establish an extended design of experiment (DoE)-in vitro in vivo correlation (IVIVC) model that defines the relationship between formulation composition, in vitro dissolution, and in vivo pharmacokinetics. Fourteen sustained-release (SR) tablets of a model drug, donepezil, were designed by applying a mixture design of DoE and prepared by the wet granulation method. The in vitro dissolution patterns of donepezil SR tablets were described by Michaelis-Menten kinetics. The mathematical relationship describing the effects of SR tablet compositions on the in vitro dissolution parameter, i.e., the in vitro maximum rate of release (V_max), was derived. The predictability of the derived DoE model was validated by an additional five SR tablets with a mean prediction error (PE%) of less than 3.50% for in vitro V_max. The pharmacokinetics of three types of donepezil SR and the immediate-release (IR) tablets was assessed in Beagle dogs following oral administration (n = 3, each). Based on the plasma concentration-time profile, a population pharmacokinetic model was developed, and the in vivo dissolution of SR tablets, represented by in vivo V_max, was estimated. By correlating the in vitro and in vivo V_max, level A IVIVC was established. Finally, the extended DoE-IVIVC model was developed by integrating the DoE equation and IVIVC into the population pharmacokinetic model. The extended DoE-IVIVC model allowed one to predict the maximum plasma concentration (C_max) and the area under the plasma concentration-time curve (AUC) of donepezil SR tablets with PE% less than 10.30% and 5.19%, respectively, by their formulation composition as an input. The present extended DoE-IVIVC model may provide a valuable tool to predict the effect of formulation changes on in vivo pharmacokinetic behavior, leading to the more efficient development of SR formulations. The application of the present modeling approaches to develop other forms of drug formulation may be of interest for future studies.

Resting heart rate and cardiovascular outcomes in patients with atrial fibrillation: CODE-AF registry

Funding Acknowledgements

Type of funding sources: None.

Background

The prognostic significance of resting heart rate and its therapeutic target in atrial fibrillation (AF) is uncertain.

Purpose

The aim of this study was to investigate the relationships between resting heart rate and cardiovascular outcomes in patients with AF.

Methods

A total of 8,886 patients with AF was included from the COmparison study of Drugs for symptom control and complication prEvention of AF (CODE-AF) registry. Patients were categorized according to baseline heart rate, and cardiovascular outcomes were accessed during a median follow-up of 30 months. The primary outcome was a composite of cardiovascular death, hospitalization due to heart failure, and myocardial infarction/critical limb ischemia.

Results

Compared to heart rate ≥100 beats per minute (bpm), heart rate 80-99 bpm was associated with the lowest risk of primary outcome (adjusted hazard ratio [HR] 0.56, 95% confidence interval [CI] 0.40-0.79, p=0.001). In subgroup of patients with heart failure with preserved ejection fraction (HFpEF), heart rate between 80-99 bpm was associated with reduced risk of primary outcome compared to heart rate ≥100 bpm (HR 0.40, 95% CI 0.16-0.98, p=0.045). However, in patients with heart failure with reduced ejection fraction (HFrEF), there was no association between resting heart rate and cardiovascular outcomes (P for interaction 0.001).

Conclusion

Resting heart rate was associated with cardiovascular outcomes in patients with AF, and those with a resting heart rate between 80-99 bpm had the lowest risk of adverse events. The impact of resting heart rate on adverse events persisted in patients with concomitant HFpEF but was not apparent in those with concomitant HFrEF.

Comparative effectiveness of early rhythm control versus rate control for cardiovascular outcomes according to sex in patients with atrial fibrillation

Funding Acknowledgements

Type of funding sources: Public grant(s) – National budget only. Main funding source(s): Ministry of Health & Welfare, Republic of Korea

Background

Rhythm control is associated with better cardiovascular outcomes than usual care among patients recently diagnosed with atrial fibrillation (AF). However, there are limited data on the outcomes of AF ablation according to sex. The purpose of this study was to evaluate gender differences in the effects of early rhythm control compared to rate control on the primary composite outcome of cardiovascular death, ischaemic stroke, hospitalisation for heart failure (HF), or myocardial infarction.

Methods

We conducted a retrospective population-based cohort study including 22635 patients with AF newly treated with rhythm control (antiarrhythmic drugs or ablation) or rate control in 2011-2015 from the Korean National Health Insurance Service database. Propensity overlap weighting was used.

Results

Among patients with early AF treatment (initiated within 1 year since diagnosis), compared with rate control, rhythm control was associated with a similar lower risk of the primary composite outcome both women (weighted incidence rate per 100 person-years: 8.68 in rhythm control vs. 10.3 in rate control; hazard ratio [HR] 0.79, 95% confidence interval [CI] 0.69 to 0.90; P&lt;0.001) and men (weighted incidence rate per 100 person-years: 6.33 in rhythm control vs. 8.32 in rate control; HR 0.77, 95% CI 0.67 to 0.88; P&lt;0.001). However, the effective initiation time for rhythm control therapy was within 6 and 11 months after AF diagnosis in female and male patients, respectively. Moreover, the effective times for other outcomes were different between genders (hospitalization for HF; female within 2 months, male within 9 months/ ischemic stroke; female within 11 months, male immediately).

Conclusions

Early initiation of rhythm control was associated with a lower risk of primary outcome in both genders. However, the effective rhythm control treatment initiation time for primary outcome, stroke and HF-related admission was different in both genders. For rhythm control treatment to be effective, women should start treatment earlier than men.

Learning curve of left bundle branch area pacing with standard stylet-driven pacing leads: a single center prospective observational study in Korea

Funding Acknowledgements

Type of funding sources: None.

Background

Although cardiac pacing is an essential therapy for bradycardia, conventional right ventricular pacing (CRVP) can cause electrical-mechanical dyssynchrony. Left Bundle Branch Area Pacing (LBBAP) is a new conduction system pacing strategy that includes a normal conduction system and therefore maintains synchronous ventricular contraction. Most of the experience with LBBAP is done in a lumen-less lead with fixed helix design, and this device is not available in sometimes.

Purpose

This study aimed to evaluate the learning curve of LBBAP using standard stylet-driven lead with extendable helix design.

Methods

This study enrolled patients who underwent permanent cardiac pacemaker implantation at a University Hospital in South Korea from December 2020 to October 2021. LBBAP was performed with a 5.6Fr stylet-driven pacing lead with an extendable helix. The learning curve was assessed by analyzing fluoroscopy time and procedure time.

Results

In 65 patients who underwent LBBAP during the observation period, mean fluoroscopy time and procedural time were 17.1 ± 17.2 minutes and 64.2 ± 33.5 minutes, respectively in this study. The learning curve for achieving LBBAP appears to plateau after around 24th case with a progressive reduction in procedure time. This is a significantly shorter period of time when compared to the previously reported learning curves of his bundle pacing (30-50cases), previously developed conduction system pacing strategy.

Conclusion

During initial experience with LBBAP, fluoroscopy and procedural time continue to improve with operator experience. For physicians who are experienced at cardiac pacemaker implantation, the steepest part of the learning curve of LBBAP appears to be over the first 20-25 cases.

Comparison of the exposure assessment of di(2-ethylhexyl) phthalate between the PBPK model-based reverse dosimetry and scenario-based analysis: A Korean general population study

Di (2-ethylhexyl) phthalate (DEHP), classified as a reproductive toxicant, is a ubiquitous pollutant in foodstuffs, dust, and commercial products. In this study, to provide a useful cross-check on the accuracy of the exposure assessment, the estimated daily intake of DEHP was compared using reverse dosimetry with a physiologically-based pharmacokinetic (PBPK) model and a scenario-based probabilistic estimation model for six subpopulations in Korea. For reverse dosimetry analysis, the concentrations of urinary DEHP metabolites, namely mono (2-ethyl-5-hydroxyhexyl) phthalate (MEHHP) and mono (2-ethyl-5-oxohexyl)phthalate (MEOHP), from three human biomonitoring program datasets were used. For the scenario-based model, we evaluated the various exposure sources of DEHP, including diet, air, indoor dust, soil, and personal care products (PCPs), and also determined its levels based on the literature review and measurements of indoor dust. The DEHP exposure doses using both exposure assessment approaches were similar in all cases, except for the 95th percentile exposure doses in toddlers (1-2 years) and young children (3-6 years). The PBPK-reverse dosimetry estimated daily intakes at the 95th percentile ranged between 22.53 and 29.90 μg/kg/day for toddlers and young children. These exceeded the reference dose (RfD) of 20 μg/kg bw/day of the US Environmental Protection Agency (EPA) based on the increased relative liver weight. Although, food was considered the primary source of DEHP, contributing to a total exposure of 50.8-75.1%, the effect of exposure to indoor dust should not be overlooked. The occurrence of high levels of DEHP in indoor dust collected from Korean homes suggests the use of a wide variety of consumer products containing DEHP. Furthermore, more attention should be paid to the high exposure levels of DEHP, especially in young children. Therefore, it is necessary to perform continuous monitoring of the indoor dust, consumer products, and the body burden of children.

MBP-11901 Inhibits Tumor Growth of Hepatocellular Carcinoma through Multitargeted Inhibition of Receptor Tyrosine Kinases

Simple Summary

Although various treatments such as surgery and chemotherapy exist for advanced or unresectable HCC, most patients suffer from intractable diseases, having a poor prognosis. While immunotherapy using immune checkpoint inhibitors was recently proposed for HCC, only a small percentage of patients respond. Thus, there remains an unmet need for the development of therapeutic agents for the treatment of liver cancer. Here, we presented multi-RTKi MBP-11901, an innovative targeted anticancer agent for HCC, suggesting it as a new therapeutic strategy for the treatment of liver cancer.

Abstract

Hepatocellular carcinomas (HCCs) are aggressive tumors with a poor prognosis. Approved first-line treatments include sorafenib, lenvatinib, and a combination of atezolizumab and bevacizumab; however, they do not cure HCC. We investigated MBP-11901 as a drug candidate for HCC. Cell proliferation and cytotoxicity were evaluated using normal and cancer human liver cell lines, while Western blotting and flow cytometry evaluated apoptosis. The anticancer effect of MBP-11901 was verified in vitro through migration, invasion, colony formation, and JC-1 MMP assays. In mouse models, the tumor volume, tumor weight, and bodyweight were measured, and cancer cell proliferation and apoptosis were analyzed. The toxicity of MBP-11901 was investigated through GOT/GPT and histological analyses in the liver and kidney. The signaling mechanism of MBP-11901 was investigated through kinase assays, phosphorylation analysis, and in silico docking simulations. Results. MBP-11901 was effective against various human HCC cell lines, leading to the disappearance of most tumors when administered orally in animal models. This effect was dose-dependent, with no differences in efficacy according to administration intervals. MBP-11901 induced anticancer effects by targeting the signaling mechanisms of FLT3, VEGFR2, c-KIT, and PDGFRβ. MBP-11901 is suggested as a novel therapeutic agent for the treatment of advanced or unresectable liver cancer.

Pharmacokinetics of Nafamostat, a Potent Serine Protease Inhibitor, by a Novel LC-MS/MS Analysis

Nafamostat, a synthetic serine protease inhibitor, has been used for the treatment of inflammatory diseases such as pancreatitis. Recently, an increasing number of studies have shown the promising antiviral effects of nafamostat for the treatment of coronavirus disease-19 (COVID-19). This study aimed to develop a novel liquid chromatography–tandem mass spectrometry (LC-MS/MS) analysis and to characterize the pharmacokinetics of nafamostat in rats. Nafamostat in the rat plasma was extracted by solid phase extraction, and ¹³C₆-nafamostat was used as an internal standard. The quantification limit of nafamostat in the rat plasma was 0.5 ng/mL. The LC-MS/MS method was fully validated and applied to characterize the pharmacokinetics of nafamostat in rats. Following intravenous injection (2 mg/kg), nafamostat in the plasma showed a multiexponential decline with an average elimination half-life (t_1/2) of 1.39 h. Following oral administration of nafamostat solutions (20 mg/kg) in 10% dimethyl sulfoxide (DMSO) and in 10% DMSO with 10% Tween 80, nafamostat was rapidly absorbed, and the average oral bioavailability was 0.95% and 1.59%, respectively. The LC-MS/MS method and the pharmacokinetic information of nafamostat could be helpful for the further preclinical and clinical studies of nafamostat.

Development of a high-resolution typing method for SLA-3, swine MHC class I antigen 3

We developed a high-resolution and comprehensive typing method for swine leukocyte antigen 3 (SLA-3), an MHC class I gene, employing locus-specific genomic PCR followed by subsequent direct sequencing. A total of 292 individuals from nine pure, one cross-breed and six cell lines were successfully typed. A total of 21 SLA-3 alleles were identified, of which four were found to be novel alleles. However, the allelic diversity of SLA-3 was lower than that of previously reported class I genes, SLA-1 and -2. More SLA-3 alleles were observed in the Landrace and Yorkshire breeds than the other breeds. SLA-3*04:01 was identified in seven out of nine breeds and was the most widely distributed allele across all breeds. Therefore, the typing method reported in this study completes our efforts to develop high-resolution typing methods for major SLA molecules, facilitating the combined analysis of major SLA genes from field samples, which is important to understand the relationship between the adaptive immune responses against pathogens and the immunogenetic makeup of an individual.

Urease and nitrification inhibitors with pig slurry effects on ammonia and nitrous oxide emissions, nitrate leaching, and nitrogen use efficiency in perennial ryegrass sward

OBJECTIVE

The present study was conducted to assess the effect of urease inhibitor (hydroquinone [HQ]) and nitrification inhibitor (dicyandiamide [DCD]) on nitrogen (N) use efficiency of pig slurry for perennial ryegrass regrowth yield and its environmental impacts.

METHODS

A micro-plot experiment was conducted using pig slurry-urea 15N treated with HQ and/or DCD and applied at a rate of 200 kg N/ha. The flows of N derived from the pig slurry urea to herbage regrowth and soils as well as soil N mineralization were estimated by tracing pig slurry-urea 15N, and the N losses via ammonia (NH3), nitrous oxide (N2O) emission, and nitrate (NO3-) leaching were quantified for a 56 d regrowth of perennial ryegrass (Lolium perenne) sward.

RESULTS

Herbage dry matter at the final regrowth at 56 d was significantly higher in the HQ and/or DCD applied plots, with a 24.5% to 42.2% increase in 15N recovery by herbage compared with the control. Significant increases in soil 15N recovery were also observed in the plots applied with the inhibitors, accompanied by the increased N content converted to soil inorganic N (NH4+ +NO3-) (17.3% to 28.8% higher than that of the control). The estimated loss, which was not accounted for in the herbage-soil system, was lower in the plots applied with the inhibitors (25.6% on average) than that of control (38.0%). Positive effects of urease and/or nitrification inhibitors on reducing N losses to the environment were observed at the final regrowth (56 d), at which cumulative NH3 emission was reduced by 26.8% (on average 3 inhibitor treatments), N2O emission by 50.2% and NO3- leaching by 10.6% compared to those of the control.

CONCLUSION

The proper application of urease and nitrification inhibitors would be an efficient strategy to improve the N use efficiency of pig slurry while mitigating hazardous environmental impacts.

Serum selenium levels in patients with Graves' disease: associations with clinical activity and severity in a retrospective case-control study

Objectives

To compare serum selenium levels in Graves' patients and non-Graves' control participants and to evaluate associations between serum selenium levels and clinical features of Graves' orbitopathy (GO).

Methods

We conducted a single-centre, retrospective case-control study among 31 patients with diagnosed GO, 33 patients with Graves' disease without GO (GD), and 27 unaffected healthy participants enrolled between 2013 and 2020 at Severance Hospital. We compared serum selenium concentrations between the GD, GO, and healthy control groups, and analysed associations between serum selenium and GO patients' clinical activity scores (CAS), severity (assessed through modified NOSPECS scores), and other clinical features using multivariate linear regression analysis.

Results

Mean serum selenium levels were 109.30 ± 16.39 ng/mL, 111.39 ± 14.04 ng/mL, and 126.09 ± 21.09 ng/mL in GO patients, GD patients, and healthy control participants, respectively. Mean serum selenium levels in Graves' patients with and without orbitopathy were significantly lower than those in the healthy control group (p < 0.05), and mean selenium levels were slightly lower in GO than those in GD patients (p = 0.594). Serum selenium levels were significantly lower in GO patients with eyelid retraction than in patients without retraction (p = 0.038). However, serum selenium levels were not associated with CAS and modified NOSPECS scores (p = 0.241 and 0.801, respectively).

Conclusion

Serum selenium levels were significantly lower in Graves' patients with or without GO, compared to non-Graves' control participants. Selenium levels were not associated with CAS or NOSPECS scores, though we observed an association with eyelid retraction.

Exophiala Endophthalmitis after Cataract Surgery

Purpose: To report a case of Exophiala endophthalmitis after cataract surgery, which has not been reported previously in Korea.Case summary: A 70-year-old woman visited the hospital 7 days after cataract surgery in her right eye with unilateral vision impairment. At the time of the visit, visual acuity of the right eye was hand motion, and the fundus was not clearly observed due to numerous inflammatory cells with hypopyon in the anterior chamber. With an initial diagnosis of suspected bacterial endophthalmitis, vitrectomy was performed immediately with intravitreal injection of antibiotics and steroid. On day 14 after vitrectomy, inflammation in the anterior chamber and vitreous opacity worsened, and complete vitrectomy, including of the vitreous base, and removal of the intraocular lens and capsule was performed. Exophiala was detected in the biopsy specimen on day 6 after the second surgery, and the patient was discharged with a prescription for voriconazole eye drops. On day 23 after the second surgery, the best-corrected visual acuity in the right eye had improved to 1.0, and there was no evidence of endophthalmitis recurrence and no observed additional abnormal findings of the fundus until 6 months after second surgery.Conclusions: In a case of fungal endophthalmitis that occurred after cataract surgery, good results were obtained by vitrectomy involving complete removal of the peripheral vitreous body, including the intraocular lens and lens capsule, which was the basis for growth of the fungus in the early stage of endophthalmitis.

Junctional Modulation of Round Window Membrane Enhances Dexamethasone Uptake into the Inner Ear and Recovery after NIHL

Delivery of substances into the inner ear via local routes is increasingly being used in clinical treatment. Studies have focused on methods to increase permeability through the round window membrane (RWM) and enhance drug diffusion into the inner ear. However, the clinical applications of those methods have been unclear and few studies have investigated the efficacy of methods in an inner ear injury model. Here, we employed the medium chain fatty acid caprate, a biologically safe, clinically applicable substance, to modulate tight junctions of the RWM. Intratympanic treatment of sodium caprate (SC) induced transient, but wider, gaps in intercellular spaces of the RWM epithelial layer and enhanced the perilymph and cochlear concentrations/uptake of dexamethasone. Importantly, dexamethasone co-administered with SC led to significantly more rapid recovery from noise-induced hearing loss at 4 and 8 kHz, compared with the dexamethasone-only group. Taken together, our data indicate that junctional modulation of the RWM by SC enhances dexamethasone uptake into the inner ear, thereby hastening the recovery of hearing sensitivity after noise trauma.

Use of Quantitative Vertebral Bone Marrow Fat Fraction to Assess Disease Activity and Chronicity in Patients with Ankylosing Spondylitis

Objective

We quantitatively measured the fat fraction (FF) in the vertebrae of patients with ankylosing spondylitis (AS) using magnetic resonance imaging (MRI) and investigated the role of FF as an indicator of both active inflammation and chronicity.

Materials and Methods

A total of 52 patients with AS who underwent spinal MRI were retrospectively evaluated. The FF values of the anterosuperior and anteroinferior corners of the bone marrow in the L1-S1 spine were assessed using the modified Dixon technique. AS activity was measured using the Bath Ankylosing Spondylitis Disease Activity Index (BASDAI), Bath Ankylosing Spondylitis Functional Index (BASFI), AS Disease Activity Score (ASDAS), and serum inflammatory marker levels. AS disease chronicity was assessed by AS disease duration and the modified Stoke Ankylosing Spondylitis Spinal Score (mSASSS). Univariable and multivariable regression analyses were conducted to investigate the correlation between FF and other clinical characteristics.

Results

The mean FF ± standard deviation of the total lumbar spine was 43.0% ± 11.3%. At univariable analysis, spinal FF showed significant negative correlation with BASDAI (β = −0.474, p = 0.002) and ASDAS with C-reactive protein (ASDAS-CRP; β = −0.478, p = 0.002) and a significant positive correlation with AS disease duration (β = 0.440, p = 0.001). After adjusting for patient age, sex, and total mSASSS score, spinal FF remained significantly negatively correlated with BASDAI (β = −0.543, p < 0.001), ASDAS-CRP (β = −0.568, p < 0.001), and ASDAS with erythrocyte sedimentation rate (β = −0.533, p = 0.001). Spinal FF was significantly lower in patients with very high disease activity (ASDAS-CRP > 3.5) than in those with only high disease activity (2.1 ≤ ASDAS-CRP ≤ 3.5) (p = 0.010).

Conclusion

Spinal FF may help assess both AS disease activity and chronicity.

Effect of 0.15% Preservative-free Sodium Hyaluronate on Dry Eye Disease after Femtosecond Laser-assisted Cataract Surgery

Purpose: The efficacy of using preservative-free 0.15% sodium hyaluronate eyedrops for dry eye disease after femtosecond laser- assisted cataract surgery (FLACS) was evaluated. Methods: This prospective randomized study was conducted on patients with dry eye who were scheduled for FLACS among those with Tear Film & Ocular Surface Society Dry Eye Workshop II Dry Eye Levels 1 and 2. In total, 37 eyes scheduled for FLACS were randomized to the treatment group (n = 19) or control group (n = 18). Corneal and conjunctival fluorescein staining (CFS), tear breakup time (TBUT), Schirmer I test (SIT) value, ocular surface disease index (OSDI), meibomian gland evaluation result, and lipid layer thickness were evaluated for all patients, preoperatively and at 1 and 3 months postoperatively. Results: In the treatment group, the OSDI and CFS scores were significantly lower at 3 months postoperatively than at baseline, but the TBUT and SIT values were significantly increased. In the control group, TBUT was significantly shorter at 3 months postoperatively than at baseline, SIT values were significantly decreased at 1 and 3 months postoperatively compared with the baseline, and meibum quality was significantly aggravated at 1 month postoperatively compared with the baseline. In the treatment group, OSDI improved significantly from baseline at 1 and 3 months. TBUT increased significantly in the treatment group at postoperative 3 months. Meibomian gland quality showed clinically better results in the treatment group than in the control group at postoperative 3 months. There were no significant differences in corneal and CFS, lipid layer thickness, and other dry eye disease parameters between the treatment and control groups. Conclusions: Preservative-free 0.15% sodium hyaluronate eyedrops were effective for improving dry eye symptoms and tear film stability after FLACS.

Antiarrhythmic drug responders among patients with recurrent atrial fibrillation after catheter ablation

Funding Acknowledgements

Type of funding sources: Public Institution(s). Main funding source(s): The Ministry of Health and Welfare The National Research Foundation of Korea (NRF)

Backgroud

Sinus rhythm (SR) can be maintained with antiarrhythmic drugs (AADs) in a considerable number of patients with recurrent atrial fibrillation (AF) after AF catheter ablation (AFCA).

Purpose

We explored the characteristics and long-term outcomes of patients who maintained clinically acceptable rhythm control with AADs for 2 years.

Methods

Among 2,935 consecutive AAD-resistant patients who underwent a de novo AFCA, we included 512 recurrent patients (73.0% men, 59.2 ± 10.5 years old, 56.4% paroxysmal AF) who were followed up for over 2 years under AAD medications.

Results

In total, 218 patients remained in SR (AAD-responders[2-yrs], 42.6%) and 294 had recurrent AF among whom, 162 underwent repeat procedures (redo-AFCA[AAD failure-2-yrs]). We also compared the AAD-responders[2-yrs] with 40 patients who underwent AFCA before AADs (redo-AFCA[Before AAD]). AAD-responders[2-yrs] were independently associated with an old age (odds ratio [OR] 1.02 [1.00-1.04] p = 0.037), paroxysmal AF (OR 1.51 [1.04-2.19] p = 0.003), and a delayed recurrence timing of &gt; 18 months (OR 1.52 [1.04-2.22] p = 0.032). When comparing the AAD-responder[2-yrs] and redo-AFCA[AAD failure-2-yrs] groups, the recurrence pattern showed a convergence after 7 years. The overall rhythm outcome was better in the redo-AFCA[Before AAD] group than AAD group (log rank p = 0.013).

Conclusion

Among the patients with recurrent AF after AFCA, over 40% remained in SR with AADs for 2 years, especially those who were old, those with a paroxysmal type, and those who had a delayed recurrence timing of &gt;18 months after the de novo procedure. UnivariateMultivariateOdds Ratio(95% CI)p valueOdds Ratio(95% CI)p valueAge1.02 (1.00-1.04)0.0231.02 (1.00-1.04)0.037Female1.64 (1.11-2.42)0.0141.29 (0.85-1.95)0.236PAF1.58 (1.11-2.26)0.0121.51 (1.04-2.19)0.030Time to recurrence after the initial AFCA &gt;18mo*1.59 (1.11-2.30)0.0131.52 (1.04-2.22)0.032LA dimension, mm0.99 (0.96-1.02)0.360LV ejection fraction, %1.03 (1.01-1.06)0.0111.02 (0.997-1.046)0.081Heart failure0.65 (0.34-1.24)0.192Hypertension1.18 (0.83-1.67)0.358Diabetes1.01 (0.65-1.71)0.844Stroke or TIA0.96 (0.56-1.66)0.879Vascular disease1.43 (0.88-2.31)0.151Logistic regression analysis for AAD responders Abstract Figure. K-M analysis of AF-free survival rate

Malnutrition and risk of procedural complication in patients with atrial fibrillation undergoing catheter ablation

Funding Acknowledgements

Type of funding sources: Public grant(s) – National budget only. Main funding source(s): Ministry of Health and Welfare of Korea Ministry of Science, ICT & Future Planning of Korea

Background

Malnutrition is common in the elderly, even in developed countries, and increases mortality.

Purpose

 To investigate the prevalence and prognostic value of malnutrition among patients with atrial fibrillation (AF) which is a type of metabolic disease.

Methods

We included 3,239 patients (age 58.5 ± 10.8 years, 73.2% male, 67.7% paroxysmal type) undergoing de novo AF catheter ablation (AFCA) between 2009 and 2020. Nutritional status was assessed using controlling nutritional status (CONUT) score. The associations between malnutrition and the risk of AFCA complications or long-term rhythm outcome were evaluated by multivariable logistic regression.

Results

Among 3,239 patients, 1,005 (31.0%) patients had malnutrition; 991 (30.6%) with mild (CONUT scores 2-4) and 14 (0.4%) with moderate-to-severe (CONUT scores ≥5) malnutrition. Overall complication rates after AFCA were 3.3% in normal nutrition, 4.2% in mild malnutrition, and 21.4% in moderate to severe malnutrition, respectively (P for trend = 0.031). Major complication rates were 1.9%, 2.6%, and 14.3% in normal nutrition, mild malnutrition, and moderate to severe malnutrition (P for trend = 0.042). After multivariable adjustment, moderate-to-severe malnutrition status was associated with increased risks of overall (OR 8.215 [2.199-30.691], P = 0.002) and major (OR 7.392 [1.568-34.837], P = 0.011) complications compared with normal nutrition. However, CONUT score did not affect the long-term rhythm outcome during the mean follow-up of 40 (interquartile range 18-74) months (log-rank P = 0.760).

Conclusion

Malnutrition is common in patients undergoing AFCA. Those with moderate-to-severe malnutrition status were at substantially higher risk of complications after AFCA. Abstract Figure. Overall and major complication rates

Sex differences in mapping and rhythm outcomes of a repeat atrial fibrillation ablation

Funding Acknowledgements

Type of funding sources: None.

Introduction

The risk of procedure-related complications and rhythm outcomes differ between men and women after atrial fibrillation catheter ablation (AFCA). We evaluated whether consistent sex differences existed in mapping and rhythm outcomes in repeat ablation procedures.

Methods

Among 3,282 patients in the registry, we analysed 443 consecutive patients (24.6% female, 58.5 ± 10.3 years old, 61.5% paroxysmal AF) who underwent a second AFCA. We compared the clinical factors, mapping, left atrial (LA) pressure, complications, and long-term clinical recurrences after propensity score matching.

Results

The LA volume index (43.1 ± 18.6 vs. 35.8 ± 11.6 ml/m2, p &lt; 0.001) was higher, but LA dimension (40.0 ± 6.8 vs. 41.6 ± 6.3mm, p = 0.018), LA voltage (0.94 ± 0.55 vs. 1.20 ± 0.68 mV, p = 0.002), and pericardial fat volume (89.5 ± 43.1 vs. 122.1 ± 53.9 cm3, p &lt; 0.001) lower in women with a repeat ablation than in their male counterparts. The pulmonary vein (PV) reconnections were lower (58.7% vs. 74.9%, p = 0.001), but the proportion of extra-PV triggers (27.5% vs. 17.0%, p = 0.026) and elevated LA pulse pressures (79.7% vs. 63.7%, p = 0.019) was significantly higher in women than men. There was no significant sex difference in the procedure-related complication rate (4.6% vs. 4.2%, p = 0.791). During a 31(8∼60) month median follow-up, clinical recurrences were significantly higher in women after both the de novo procedure (log rank p = 0.039, antiarrhythmic drug [AAD]-free log rank p &lt; 0.001) and second procedure (log rank p = 0.006, AAD-free log rank p = 0.093). A female sex (HR 1.51 [1.06-2.15], p = 0.023), non-paroxysmal AF (HR 1.78 [1.30-2.34], p &lt; 0.010), and extra-PV triggers (HR 1.88 [1.28-2.75], p = 0.001) were independently associated with clinical recurrences after repeat procedures.

Conclusions

During the repeat AFCA procedures, PV reconnections were lower in women than men, and the existence of extra-PV triggers and an LA pressure elevation was more significant, which resulted in poor rhythm outcomes.

Artificial intelligence-predicted poor responders to catheter ablation for atrial fibrillation

Funding Acknowledgements

Type of funding sources: None.

Introduction

Although atrial fibrillation (AF) catheter ablation is effective for rhythm control, in some patients it is hard to maintain sinus rhythm in spite of repeated AF catheter ablation (AFCA) procedures and anti-arrhythmic drugs (AADs). We explored the pre-procedural predictors for poor responders to AFCA and tested whether artificial intelligence (AI) assists the prediction of poor responders in the independent cohort by determining the invasive parameters.

Methods

Among 1,214 patients who underwent AFCA and regular rhythm follow-up for 56.2 ± 33.8 months (59 ± 11 years, 73.5% male, 68.6% paroxysmal AF), we differentiated 92 poor responders defined as those with sustained AF despite repeat AFCAs, AADs, or electrical cardioversion. Using the Youden index, we identified advanced LA remodeling with lower LA voltage under 1.109mV. AI model, which was derived from development cohort using medical record, was applied to predict LA voltage &lt;1.109mV in the independent cohort (n = 634, poor responders = 24) using a grad-cam score.

Results

The patients with lower LA voltage under 1.109mV showed significantly poorer rhythm outcomes (Log-rank p &lt; 0.001). We determined invasive parameter LA voltage by using the multiple variables (age, female sex, AF type, CHA2DS2VASc score, LA dimension, E/em, hemoglobin, PR interval) and achieved relatively good prediction power of AI for LA voltage &lt;1.109mV (AUC = 0.734, sensitivity 0.729, specificity 0.643) in the test cohort. In the independent cohort, the AI model showed good discrimination power for poor responders (AUC 0.751, p &lt; 0.001) by estimating LA voltage, which is an invasive variable. The patients with predicted lower LA voltage (grad-cam score &lt;0) showed poorer rhythm outcome after active rhythm control (Log-rank p &lt; 0.001)

Conclusions

The patients with advanced atrial remodeling with low LA voltage, which can be predicted by an AI, showed significantly higher recurrence of AF after AFCA with AADs or cardioversion. AI may assist to select these poor responder patients before the AFCA procedure. Abstract Figure.

Left atrial wall stress and the outcome of catheter ablation for atrial fibrillation: artificial intelligence-based prediction of clinical outcome

Funding Acknowledgements

Type of funding sources: None.

Background/Introduction: Left atrial (LA) wall stress (LAW-str) may contribute to the mechanism of atrial fibrillation (AF).

Purpose

We explored the clinical characteristics and the rhythm outcome of AF depending on LAW-str among the patients who underwent AF catheter ablation (AFCA). We also tested whether artificial intelligence (AI) properly estimate LAW-str without invasive parameters.

Methods

We included 2223 patients (72.8% male, 59.0 [52.0–67.0] years old, 28.7% with persistent AF [PeAF]) who underwent radiofrequency catheter ablation (RFCA). LAW-str was calculated by the Law of Laplace using LA diameter (echocardiogram), peak LA pressure, and mean LA wall thickness (computed tomography) measured by customized software. Based on the quartile (Q1–4) or AI-estimated values of LAW-str, we compared clinical characteristics and rhythm outcome.

Results

LAW-str was independently associated with PeAF (p &lt; 0.001), diabetes (p = 0.012) and vascular disease (p = 0.002), body mass index (p &lt; 0.001), E/Em (p &lt; 0.001), and mean LA voltage (p &lt; 0.001). During 26.0 (12.0–52.0) months follow-up, clinical recurrence of AF was significantly higher in the Q4 of LAW-str group (log rank p = 0.001). LAW-str was independently associated with clinical recurrence after AFCA (HR 1.001 [1.000–1.002], p = 0.013). AI-based model using non-invasive parameters predicted Q4 of LAW-str with area under the curve (AUC) 0.734, which was similar to logistic regression based predictive model using all data including invasive parameters (AUC 0.726). Patients in Q4 of LAW-str showed consistently worse rhythm outcome regardless of the type of AF, sex, or AI-based prediction (p = 0.039).

Conclusions

The LAW-str seems to be associated with rhythm outcome of AFCA and AI can predict this complex parameter with moderate accuracy. TableMultivariateβ (95% CI)PPersistent AF31.08 (21.77-40.39)&lt;0.001Diabetes mellitus15.36 (3.35-27.38)0.012Vascular disease22.27 (8.4-36.14)0.002Body mass index2.91 (1.53-4.29)&lt;0.001E/Em4.95 (3.87-6.02)&lt;0.001Mean LA voltage-22.24 (-27.96–16.52)&lt;0.001Linear regression analysis for clinical variables predictive of LA wall stress (10^3 dyn/cm2).Abstract Figure. AF recurrence by LAW-str, AI-prediction