1.Mortality and Risk Factors for Emphysematous Pyelonephritis in Korea: A Multicenter Retrospective Cohort Study
Seung-Kwon CHOI ; Jeong Woo LEE ; Seung Il JUNG ; Eu Chang HWANG ; Joongwon CHOI ; Woong Bin KIM ; Jung Sik HUH ; Jin Bong CHOI ; Yeonjoo KIM ; Jae Min CHUNG ; Ju-Hyun SHIN ; Jae Hung JUNG ; Hong CHUNG ; Sangrak BAE ; Tae-Hyoung KIM
Urogenital Tract Infection 2025;20(1):34-41
Purpose:
Emphysematous pyelonephritis (EPN) is a life-threatening disease requiring immediate treatment. This multicenter retrospective cohort study aimed to analyze the mortality rate and risk factors associated with EPN.
Materials and Methods:
Between January 2011 and February 2021, 217 patients diagnosed with EPN via computed tomography who visited 14 teaching hospitals were retrospectively analyzed. Clinical data, including age, sex, comorbidities, Huang and Tseng classification, hydronephrosis, acute kidney injury, blood and urine tests, surgical interventions, percutaneous drainage, and conservative treatments, were compared between the survival and death groups. Risk factors for mortality due to EPN were analyzed using univariate and multivariate methods.
Results:
The mean age of survivors and deceased patients was 67.8 and 69.0 years, respectively (p=0.136). The sex distribution (male/female) was 48/146 and 8/15, respectively (p=0.298). Of the 217 patients, 23 died, resulting in a mortality rate of 10.6%. In univariate analysis, the Huang and Tseng classification (p=0.004), platelet count (p=0.005), and acute kidney injury (p=0.007) were significantly associated with mortality from EPN. In multivariate analysis, only the Huang and Tseng classification (p=0.029) was identified as a risk factor. Mortality rates according to the Huang and Tseng classification were as follows: class I (5.88%), class II (7.50%), class IIIa (14.28%), class IIIb (25.00%), and class IV (23.07%).
Conclusions
EPN is associated with a high mortality rate. Among various clinical factors, the Huang and Tseng classification was the most significant indicator for predicting mortality.
2.Predisposing Risk Factors Affecting Reversibility of Left Ventricular Diastolic Filling Pattern in Patients with Preserved Ejection Fraction
Dong-Gil KIM ; Sungsoo CHO ; Seongjin PARK ; Gi Rim KIM ; Kyu-Yong KO ; Sung Eun KIM ; Ji-won HWANG ; Joon-Hyung DOH ; Sung Uk KWON ; Jae-Jin KWAK ; June NAMGUNG ; Sung Woo CHO
Yonsei Medical Journal 2025;66(1):1-8
Purpose:
Improvement of left ventricular (LV) diastolic dysfunction (DD) is known to be a good prognostic factor in patients with heart failure with reduced ejection fraction (EF). In the present study, we investigated the predisposing risk factors affecting the reversibility of LV diastolic filling pattern (DFP) in patients with preserved EF.
Materials and Methods:
A total of 600 patients with pseudonormal LVDFP and preserved EF who underwent follow-up echocardiography were enrolled between 2011 and 2020. We compared their index and follow-up echocardiography findings and determined the predisposing risk factor affecting the reversibility of LVDFP.
Results:
Comparing the index and follow-up echocardiography findings showed that 379 (63%) patients had improved to normal or impaired relaxation LVDFP (improved group) and 221 (37%) patients had maintained or worsened LVDFP (unimproved group).The incidence of paroxysmal atrial fibrillation (PAF) was significantly higher in the unimproved group than in the improved group (4.7% vs. 9.5%, p=0.026). After adjustment for relevant clinical risk factors of diastolic dysfunction, PAF was determined to be an independent predisposing risk factor for the unimproved LVDFP (odds ratio: 2.10, 95% confidence interval: 1.06–4.15, p=0.033).Among the parameters of diastolic dysfunction in follow-up echocardiography, the left atrial volume index, mean E/A ratio, and E/e' were significantly improved in patients without PAF but remained in patients with PAF.
Conclusion
We identified that PAF was an independent predisposing risk factor of the unimproved LVDFP in patients with pseudonormal LVDFP and preserved EF. Therefore, early detection and management of PAF might be required in patients with LVDD and preserved EF to prevent adverse cardiovascular events.
3.Digital Phenotyping of Rare Endocrine Diseases Across International Data Networks and the Effect of Granularity of Original Vocabulary
Seunghyun LEE ; Namki HONG ; Gyu Seop KIM ; Jing LI ; Xiaoyu LIN ; Sarah SEAGER ; Sungjae SHIN ; Kyoung Jin KIM ; Jae Hyun BAE ; Seng Chan YOU ; Yumie RHEE ; Sin Gon KIM
Yonsei Medical Journal 2025;66(3):187-194
Purpose:
Rare diseases occur in <50 per 100000 people and require lifelong management. However, essential epidemiological data on such diseases are lacking, and a consecutive monitoring system across time and regions remains to be established. Standardized digital phenotypes are required to leverage an international data network for research on rare endocrine diseases. We developed digital phenotypes for rare endocrine diseases using the observational medical outcome partnership common data model.
Materials and Methods:
Digital phenotypes of three rare endocrine diseases (medullary thyroid cancer, hypoparathyroidism, pheochromocytoma/paraganglioma) were validated across three databases that use different vocabularies: Severance Hospital’s electronic health record from South Korea; IQVIA’s United Kingdom (UK) database for general practitioners; and IQVIA’s United States (US) hospital database for general hospitals. We estimated the performance of different digital phenotyping methods based on International Classification of Diseases (ICD)-10 in the UK and the US or systematized nomenclature of medicine clinical terms (SNOMED CT) in Korea.
Results:
The positive predictive value of digital phenotyping was higher using SNOMED CT-based phenotyping than ICD-10-based phenotyping for all three diseases in Korea (e.g., pheochromocytoma/paraganglioma: ICD-10, 58%–62%; SNOMED CT, 89%). Estimated incidence rates by digital phenotyping were as follows: medullary thyroid cancer, 0.34–2.07 (Korea), 0.13–0.30 (US); hypoparathyroidism, 0.40–1.20 (Korea), 0.59–1.01 (US), 0.00–1.78 (UK); and pheochromocytoma/paraganglioma, 0.95–1.67 (Korea), 0.35–0.77 (US), 0.00–0.49 (UK).
Conclusion
Our findings demonstrate the feasibility of developing digital phenotyping of rare endocrine diseases and highlight the importance of implementing SNOMED CT in routine clinical practice to provide granularity for research.
4.Non-Inferiority Analysis of Electrocardiography Analysis Application vs. Point-of-Care Ultrasound for Screening Left Ventricular Dysfunction
Jin Hee KIM ; Jae Yun JUNG ; Joonghee KIM ; Youngjin CHO ; Eunkyoung LEE ; Dahyeon SON
Yonsei Medical Journal 2025;66(3):172-178
Purpose:
Point-of-care ultrasound (POCUS) is widely used for heart function evaluation in emergency departments (EDs), but requires specific equipment and skilled operators. This study evaluates the diagnostic accuracy of a mobile application for estimating left ventricular (LV) systolic dysfunction [left ventricular ejection fraction (LVEF) <40%] using electrocardiography (ECG) and tests its non-inferiority to POCUS.
Materials and Methods:
Patients (aged ≥20 years) were included if they had both a POCUS-based EF evaluation and an ECG within 24 hours of their ED visit between January and May 2022, along with formal echocardiography within 2 weeks before or after the visit. A mobile app (ECG Buddy, EB) estimated LVEF (EF from EB) and the risk of LV dysfunction (LV-Dysfunction score) from ECG waveforms, which were compared to NT-proBNP levels and POCUS-evaluated LVEF (EF from POCUS). A non-inferiority margin was set at an area under the curve (AUC) difference of 0.05.
Results:
Of the 181 patients included, 37 (20.4%) exhibited LV dysfunction. The AUCs for screening LV dysfunction using POCUS and NT-proBNP were 0.885 and 0.822, respectively. EF from EB and LV-Dysfunction score outperformed NT-proBNP, with AUCs of 0.893 and 0.884, respectively (p=0.017 and p=0.030, respectively). EF from EB was non-inferior to EF from POCUS, while LV-Dysfunction score narrowly missed the mark. A subgroup analysis of sinus-origin rhythm ECGs supported the non-inferiority of both EF from EB and LV-Dysfunction score to EF from POCUS.
Conclusion
A smartphone application that analyzes ECG image can screen for LV dysfunction with a level of accuracy comparable to that of POCUS.
5.Feasibility of a Machine Learning Classifier for Predicting Post-Induction Hypotension in Non-Cardiac Surgery
Insun PARK ; Jae Hyon PARK ; Young Hyun KOO ; Chang-Hoon KOO ; Bon-Wook KOO ; Jin-Hee KIM ; Ah-Young OH
Yonsei Medical Journal 2025;66(3):160-171
Purpose:
To develop a machine learning (ML) classifier for predicting post-induction hypotension (PIH) in non-cardiac surgeries.
Materials and Methods:
Preoperative data and early vital signs were obtained from 3669 cases in the VitalDB database, an opensource registry. PIH was defined as sustained mean arterial pressure (MAP) <65 mm Hg within 20 minutes since induction or from induction to incision. Six different ML algorithms were used to create binary classifiers to predict PIH. The primary outcome was the area under the receiver operating characteristic curve (AUROC) of ML classifiers.
Results:
A total of 2321 (63.3%) cases exhibited PIH. Among ML classifiers, the random forest regressor and extremely gradient boosting regressor showed the highest AUROC, both recording a value of 0.772. Excluding these models, the light gradient boosting machine regressor showed the second highest AUROC [0.769; 95% confidence interval (CI), 0.767–0.771], followed by the gradient boosting regressor (0.768; 95% CI, 0.763–0.772), AdaBoost regressor (0.752; 95% CI, 0.743–0.761), and automatic relevance determination regression (0.685; 95% CI, 0.669–0.701). The top three important features were mean diastolic blood pressure (DBP), minimum MAP, and minimum DBP from anesthetic induction to tracheal intubation, and these features were lower in cases with PIH (all p<0.001).
Conclusion
ML classifiers exhibited moderate performance in predicting PIH, and have the potential for real-time prediction.
6.Enhanced radiofrequency ablation for recurrent hepatocellular carcinoma post-transarterial chemoembolization: a prospective study utilizing twin internally cooled-perfusion electrodes
Sungjun HWANG ; Jae Hyun KIM ; Sae-Jin PARK ; Su Jong YU ; Yoon Jun KIM ; Jung-Hwan YOON ; Jeong Min LEE
Journal of Liver Cancer 2025;25(1):91-98
Background:
s/Aims: Radiofrequency ablation (RFA) is widely employed for managing recurrent hepatocellular carcinoma (HCC) following transarterial chemoembolization (TACE). However, local tumor progression (LTP) after treatment remains a significant challenge. This study evaluates the efficacy of saline-perfused bipolar RFA using twin internally cooled-perfusion (TICP) electrodes in managing recurrent HCC post-TACE.
Methods:
Between September 2017 and January 2019, 100 patients with 105 nodules (mean diameter, 1.6±0.5 cm) were prospectively enrolled. Bipolar RFA with TICP electrodes was performed under ultrasound-computed tomography/magnetic resonance fusion guidance. The primary outcome was the 2-year cumulative incidence of LTP.
Results:
The technical success and technique efficacy rates were 100% and 97%, respectively. During a median follow-up period of 34.0 months (range, 3-41), the estimated LTP rates were 13.3% at 1 year and 17.7% at 2 years. Progression-free survival rates were 37.8% and 27.7% at 1 year and 2 years, respectively.
Conclusions
Saline-perfused bipolar RFA using TICP electrodes demonstrates promising results for recurrent HCC after TACE, achieving high technical success and effective local tumor control rates.
7.Autosomal Recessive Spastic Ataxia of Charlevoix-Saguenay Masquerading as Charcot-Marie-Tooth Disease: A Case Study and Literature Review of Korean Patients
Yongmoo KIM ; Seungbok LEE ; Jae So CHO ; Jihoon G YOON ; Sheehyun KIM ; Man Jin KIM ; Jong Hee CHAE ; Manho KIM ; Jangsup MOON
Journal of Movement Disorders 2025;18(1):93-95
8.Incidence and Clinical Course of Post-infectious Irritable Bowel Syndrome in Patients Admitted to University Hospitals: 1-year Prospective Follow-up Study
Jae Gon LEE ; Sang Pyo LEE ; Hyun Joo JANG ; Sea Hyub KAE ; Woon Geon SHIN ; Seung In SEO ; Hyun LIM ; Ho Suk KANG ; Jae Seung SOH ; Chang Seok BANG ; Young Joo YANG ; Gwang Ho BAIK ; Jin Bae KIM ; Yu Jin KIM ; Chang Kyo OH ; Hallym Gastrointestinal Study Group
Journal of Neurogastroenterology and Motility 2025;31(1):110-118
Background/Aims:
Post-infectious irritable bowel syndrome (PI-IBS) is characterized by chronic gastrointestinal symptoms that arise following an episode of infectious enteritis. The incidence rates vary, ranging from 5% to 32% and the risk factors are not well known. We aim to investigate the incidence and risk factors of PI-IBS in enteritis patients admitted to university hospitals in Korea.
Methods:
This multi-center prospective study was conducted in patients hospitalized for infectious enteritis. Each patient underwent 1 outpatient visit and 3 telephone surveys during the first year after discharge to determine if PI-IBS occurred within the follow-up period.
Results:
In the 3-month survey, 7 out of 354 patients (2%) were diagnosed with PI-IBS, and after 1 year, only 1 patient met the criteria for IBS.No statistically significant difference was found between the PI-IBS group and the non-PI-IBS group in terms of age, sex, underlying diseases, medication history, gastrointestinal symptoms, enteritis location, causative strain, hospitalization and treatment periods, and laboratory findings. Female sex (P = 0.003), enteropathogenic Escherichia coli (EPEC) infection (P = 0.044), and a longer total treatment period (P = 0.018) were independent risk factors for diarrhea lasting ≥ 3 months after enteritis.
Conclusions
The incidence of PI-IBS in Korea was relatively low, and most cases improved over time. No risk factors associated with the development of PI-IBS were found. However, persistent diarrhea after enteritis was associated with female sex, EPEC infection, and severe or long-lasting enteritis. IBS symptoms may persist after severe enteritis but usually improve with time.
9.Ratio of Skeletal Muscle Mass to Visceral Fat Area Is a Useful Marker for Assessing Left Ventricular Diastolic Dysfunction among Koreans with Preserved Ejection Fraction: An Analysis of the Random Forest Model
Jin Kyung OH ; Yuri SEO ; Wonmook HWANG ; Sami LEE ; Yong-Hoon YOON ; Kyupil KIM ; Hyun Woong PARK ; Jae-Hyung ROH ; Jae-Hwan LEE ; Minsu KIM
Journal of Obesity & Metabolic Syndrome 2025;34(1):54-64
Background:
Although the presence of both obesity and reduced muscle mass presents a dual metabolic burden and additively has a negative effect on a variety of cardiometabolic parameters, data regarding the associations between their combined effects and left ventricular diastolic function are limited. This study investigated the association between the ratio of skeletal muscle mass to visceral fat area (SVR) and left ventricular diastolic dysfunction (LVDD) in patients with preserved ejection fraction using random forest machine learning.
Methods:
In total, 1,070 participants with preserved left ventricular ejection fraction who underwent comprehensive health examinations, including transthoracic echocardiography and bioimpedance body composition analysis, were enrolled. SVR was calculated as an index of sarcopenic obesity by dividing the appendicular skeletal muscle mass by the visceral fat area.
Results:
In the random forest model, age and SVR were the most powerful predictors of LVDD. Multivariate logistic regression analysis demonstrated that older age (adjusted odds ratio [OR], 1.11; 95% confidence interval [CI], 1.07 to 1.15) and lower SVR (adjusted OR, 0.08; 95% CI, 0.01 to 0.57) were independent risk factors for LVDD.SVR showed a significant improvement in predictive performance and fair predictability for LVDD, with the highest area under the curve noted in both men and women, with statistical significance. In non-obese and metabolically healthy individuals, the lowest SVR tertile was associated with a greater risk of LVDD compared to the highest SVR tertile.
Conclusion
Decreased muscle mass and increased visceral fat were significantly associated with LVDD compared to obesity, body fat composition, and body muscle composition indices.
10.Necessity of Analyzing the Korea Community Health Survey Using 7 Local Government Types
Seowoo PARK ; Haibin BAI ; Jae-ryun LEE ; Soomin KIM ; Hyemin JUNG ; Jin Yong LEE
Journal of Preventive Medicine and Public Health 2025;58(1):83-91
Objectives:
This study examined the potential of a new analytical framework for the Korea Community Health Survey (KCHS) with classification criteria for the sub-national governmental level, the degree of urbanization including an urban-rural multimodal category, and population size as a more effective tool to address local health problems and deduce practical implications.
Methods:
Retrospective survey data from 2023 KCHS were obtained. Frequency analyses were performed for self-rated good health status, current smoking status, and unmet medical needs as proxies for health status, as well as health behavior and healthcare utilization, utilizing individual weights to represent national community residents.
Results:
We established a new classification of local governments into 7 types to facilitate regional comparisons. These local government types are presumably composed of populations showing statistically significant differences in demographic characteristics. There were evident differences in health status, health behavior, and healthcare utilization in comparisons of groups categorized by local government types.
Conclusions
This study suggests that regional disparities can be analyzed using a new typology of local governments. This practically effective approach could be used in decision-making for community-centered health projects in terms of community health planning. Future research should conduct analyses of KCHS data that use these 7 local government types to comprehensively reflect regional characteristics.

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