1.Explainable paroxysmal atrial fibrillation diagnosis using an artificial intelligence-enabled electrocardiogram
Yeongbong JIN ; Bonggyun KO ; Woojin CHANG ; Kang-Ho CHOI ; Ki Hong LEE
The Korean Journal of Internal Medicine 2025;40(2):251-261
Background/Aims:
Atrial fibrillation (AF) significantly contributes to global morbidity and mortality. Paroxysmal atrial fibrillation (PAF) is particularly common among patients with cryptogenic strokes or transient ischemic attacks and has a silent nature. This study aims to develop reliable artificial intelligence (AI) algorithms to detect early signs of AF in patients with normal sinus rhythm (NSR) using a 12-lead electrocardiogram (ECG).
Methods:
Between 2013 and 2020, 552,372 ECG traces from 318,321 patients were collected and split into training (n = 331,422), validation (n = 110,475), and test sets (n = 110,475). Deep neural networks were then trained to predict AF onset within one month of NSR. Model performance was evaluated using the area under the receiver operating characteristic curve (AUROC). An explainable AI technique was employed to identify the inference evidence underlying the predictions of deep learning models.
Results:
The AUROC for early diagnosis of PAF was 0.905 ± 0.007. The findings reveal that the vicinity of the T wave, including the ST segment and S-peak, significantly influences the ability of the trained neural network to diagnose PAF. Additionally, comparing the summarized ECG in NSR with those in PAF revealed that nonspecific ST-T abnormalities and inverted T waves were associated with PAF.
Conclusions
Deep learning can predict AF onset from NSR while detecting key features that influence decisions. This suggests that identifying undetected AF may serve as a predictive tool for PAF screening, offering valuable insights into cardiac dysfunction and stroke risk.
2.Cost-effectiveness of Fractional Flow Reserve Versus Intravascular Ultrasound to Guide Percutaneous Coronary Intervention: Results From the FLAVOUR Study
Doyeon HWANG ; Hea-Lim KIM ; Jane KO ; HyunJin CHOI ; Hanna JEONG ; Sun-ae JANG ; Xinyang HU ; Jeehoon KANG ; Jinlong ZHANG ; Jun JIANG ; Joo-Yong HAHN ; Chang-Wook NAM ; Joon-Hyung DOH ; Bong-Ki LEE ; Weon KIM ; Jinyu HUANG ; Fan JIANG ; Hao ZHOU ; Peng CHEN ; Lijiang TANG ; Wenbing JIANG ; Xiaomin CHEN ; Wenming HE ; Sung Gyun AHN ; Ung KIM ; You-Jeong KI ; Eun-Seok SHIN ; Hyo-Soo KIM ; Seung-Jea TAHK ; JianAn WANG ; Tae-Jin LEE ; Bon-Kwon KOO ;
Korean Circulation Journal 2025;55(1):34-46
Background and Objectives:
The Fractional Flow Reserve and Intravascular UltrasoundGuided Intervention Strategy for Clinical Outcomes in Patients with Intermediate Stenosis (FLAVOUR) trial demonstrated non-inferiority of fractional flow reserve (FFR)-guided percutaneous coronary intervention (PCI) compared with intravascular ultrasound (IVUS)-guided PCI. We sought to investigate the cost-effectiveness of FFR-guided PCI compared to IVUS-guided PCI in Korea.
Methods:
A 2-part cost-effectiveness model, composed of a short-term decision tree model and a long-term Markov model, was developed for patients who underwent PCI to treat intermediate stenosis (40% to 70% stenosis by visual estimation on coronary angiography).The lifetime healthcare costs and quality-adjusted life-years (QALYs) were estimated from the healthcare system perspective. Transition probabilities were mainly referred from the FLAVOUR trial, and healthcare costs were mainly obtained through analysis of Korean National Health Insurance claims data. Health utilities were mainly obtained from the Seattle Angina Questionnaire responses of FLAVOUR trial participants mapped to EQ-5D.
Results:
From the Korean healthcare system perspective, the base-case analysis showed that FFR-guided PCI was 2,451 U.S. dollar lower in lifetime healthcare costs and 0.178 higher in QALYs compared to IVUS-guided PCI. FFR-guided PCI remained more likely to be cost-effective over a wide range of willingness-to-pay thresholds in the probabilistic sensitivity analysis.
Conclusions
Based on the results from the FLAVOUR trial, FFR-guided PCI is projected to decrease lifetime healthcare costs and increase QALYs compared with IVUS-guided PCI in intermediate coronary lesion, and it is a dominant strategy in Korea.
3.Erratum: Correction of Text in the Article “The Long-term Outcomes and Risk Factors of Complications After Fontan Surgery: From the Korean Fontan Registry (KFR)”
Sang-Yun LEE ; Soo-Jin KIM ; Chang-Ha LEE ; Chun Soo PARK ; Eun Seok CHOI ; Hoon KO ; Hyo Soon AN ; I Seok KANG ; Ja Kyoung YOON ; Jae Suk BAEK ; Jae Young LEE ; Jinyoung SONG ; Joowon LEE ; June HUH ; Kyung-Jin AHN ; Se Yong JUNG ; Seul Gi CHA ; Yeo Hyang KIM ; Youngseok LEE ; Sanghoon CHO
Korean Circulation Journal 2025;55(3):256-257
4.Prediction of Hemifacial Spasm Re-Appearing Phenomenon after Microvascular Decompression Surgery in Patients with Hemifacial Spasm Using Dynamic Susceptibility Contrast Perfusion Magnetic Resonance Imaging
Seung Hoon LIM ; Xiao-Yi GUO ; Hyug-Gi KIM ; Hak Cheol KO ; Soonchan PARK ; Chang-Woo RYU ; Geon-Ho JAHNG
Journal of Korean Neurosurgical Society 2025;68(1):46-59
Objective:
: Hemifacial spasm (HFS) is treated by a surgical procedure called microvascular decompression (MVD). However, HFS re-appearing phenomenon after surgery, presenting as early recurrence, is experienced by some patients after MVD. Dynamic susceptibility contrast (DSC) perfusion magnetic resonance imaging (MRI) and two analytical methods : receiver operating characteristic (ROC) curve and machine learning, were used to predict early recurrence in this study.
Methods:
: This study enrolled 60 patients who underwent MVD for HFS. They were divided into two groups : group A consisted of 32 patients who had early recurrence and group B consisted of 28 patients who had no early recurrence of HFS. DSC perfusion MRI was undergone by all patients before the surgery to obtain the several parameters. ROC curve and machine learning methods were used to predict early recurrence using these parameters.
Results:
: Group A had significantly lower relative cerebral blood flow than group B in most of the selected brain regions, as shown by the region-of-interest-based analysis. By combining three extraction fraction (EF) values at middle temporal gyrus, posterior cingulate, and brainstem, with age, using naive Bayes machine learning method, the best prediction model for early recurrence was obtained. This model had an area under the curve value of 0.845.
Conclusion
: By combining EF values with age or sex using machine learning methods, DSC perfusion MRI can be used to predict early recurrence before MVD surgery. This may help neurosurgeons to identify patients who are at risk of HFS recurrence and provide appropriate postoperative care.
5.Prediction of Hemifacial Spasm Re-Appearing Phenomenon after Microvascular Decompression Surgery in Patients with Hemifacial Spasm Using Dynamic Susceptibility Contrast Perfusion Magnetic Resonance Imaging
Seung Hoon LIM ; Xiao-Yi GUO ; Hyug-Gi KIM ; Hak Cheol KO ; Soonchan PARK ; Chang-Woo RYU ; Geon-Ho JAHNG
Journal of Korean Neurosurgical Society 2025;68(1):46-59
Objective:
: Hemifacial spasm (HFS) is treated by a surgical procedure called microvascular decompression (MVD). However, HFS re-appearing phenomenon after surgery, presenting as early recurrence, is experienced by some patients after MVD. Dynamic susceptibility contrast (DSC) perfusion magnetic resonance imaging (MRI) and two analytical methods : receiver operating characteristic (ROC) curve and machine learning, were used to predict early recurrence in this study.
Methods:
: This study enrolled 60 patients who underwent MVD for HFS. They were divided into two groups : group A consisted of 32 patients who had early recurrence and group B consisted of 28 patients who had no early recurrence of HFS. DSC perfusion MRI was undergone by all patients before the surgery to obtain the several parameters. ROC curve and machine learning methods were used to predict early recurrence using these parameters.
Results:
: Group A had significantly lower relative cerebral blood flow than group B in most of the selected brain regions, as shown by the region-of-interest-based analysis. By combining three extraction fraction (EF) values at middle temporal gyrus, posterior cingulate, and brainstem, with age, using naive Bayes machine learning method, the best prediction model for early recurrence was obtained. This model had an area under the curve value of 0.845.
Conclusion
: By combining EF values with age or sex using machine learning methods, DSC perfusion MRI can be used to predict early recurrence before MVD surgery. This may help neurosurgeons to identify patients who are at risk of HFS recurrence and provide appropriate postoperative care.
6.ERRATUM: Imaging follow-up strategy after endovascular treatment of intracranial aneurysms: A literature review and guideline recommendations
Yong-Hwan CHO ; Jaehyung CHOI ; Chae-Wook HUH ; Chang Hyeun KIM ; Chul Hoon CHANG ; Soon Chan KWON ; Young Woo KIM ; Seung Hun SHEEN ; Sukh Que PARK ; Jun Kyeung KO ; Sung-kon HA ; Hae Woong JEONG ; Hyen Seung KANG ;
Journal of Cerebrovascular and Endovascular Neurosurgery 2025;27(1):80-80
7.A Novel Point-of-Care Prediction Model for Steatotic Liver Disease:Expected Role of Mass Screening in the Global Obesity Crisis
Jeayeon PARK ; Goh Eun CHUNG ; Yoosoo CHANG ; So Eun KIM ; Won SOHN ; Seungho RYU ; Yunmi KO ; Youngsu PARK ; Moon Haeng HUR ; Yun Bin LEE ; Eun Ju CHO ; Jeong-Hoon LEE ; Su Jong YU ; Jung-Hwan YOON ; Yoon Jun KIM
Gut and Liver 2025;19(1):126-135
Background/Aims:
The incidence of steatotic liver disease (SLD) is increasing across all age groups as the incidence of obesity increases worldwide. The existing noninvasive prediction models for SLD require laboratory tests or imaging and perform poorly in the early diagnosis of infrequently screened populations such as young adults and individuals with healthcare disparities. We developed a machine learning-based point-of-care prediction model for SLD that is readily available to the broader population with the aim of facilitating early detection and timely intervention and ultimately reducing the burden of SLD.
Methods:
We retrospectively analyzed the clinical data of 28,506 adults who had routine health check-ups in South Korea from January to December 2022. A total of 229,162 individuals were included in the external validation study. Data were analyzed and predictions were made using a logistic regression model with machine learning algorithms.
Results:
A total of 20,094 individuals were categorized into SLD and non-SLD groups on the basis of the presence of fatty liver disease. We developed three prediction models: SLD model 1, which included age and body mass index (BMI); SLD model 2, which included BMI and body fat per muscle mass; and SLD model 3, which included BMI and visceral fat per muscle mass. In the derivation cohort, the area under the receiver operating characteristic curve (AUROC) was 0.817 for model 1, 0.821 for model 2, and 0.820 for model 3. In the internal validation cohort, 86.9% of individuals were correctly classified by the SLD models. The external validation study revealed an AUROC above 0.84 for all the models.
Conclusions
As our three novel SLD prediction models are cost-effective, noninvasive, and accessible, they could serve as validated clinical tools for mass screening of SLD.
8.Impact of iron-deficiency anemia on short-term outcomes after resection of colorectal cancer liver metastasis: a US National (Nationwide) Inpatient Sample (NIS) analysis
Ko-Chao LEE ; Yu-Li SU ; Kuen-Lin WU ; Kung-Chuan CHENG ; Ling-Chiao SONG ; Chien-En TANG ; Hong-Hwa CHEN ; Kuan-Chih CHUNG
Annals of Coloproctology 2025;41(2):119-126
Purpose:
Colorectal cancer (CRC) often spreads to the liver, necessitating surgical treatment for CRC liver metastasis (CRLM). Iron-deficiency anemia is common in CRC patients and is associated with fatigue and weakness. This study investigated the effects of iron-deficiency anemia on the outcomes of surgical resection of CRLM.
Methods:
This population-based, retrospective study evaluated data from adults ≥20 years old with CRLM who underwent hepatic resection. All patient data were extracted from the 2005–2018 US National (Nationwide) Inpatient Sample (NIS) database. The outcome measures were in-hospital outcomes including 30-day mortality, unfavorable discharge, and prolonged length of hospital stay (LOS), and short-term complications such as bleeding and infection. Associations between iron-deficiency anemia and outcomes were determined using logistic regression analysis.
Results:
Data from 7,749 patients (representing 37,923 persons in the United States after weighting) were analyzed. Multivariable analysis revealed that iron-deficiency anemia was significantly associated with an increased risk of prolonged LOS (adjusted odds ratio [aOR], 2.76; 95% confidence interval [CI], 2.30–3.30), unfavorable discharge (aOR, 2.42; 95% CI, 1.83–3.19), bleeding (aOR, 5.05; 95% CI, 2.92–8.74), sepsis (aOR, 1.60; 95% CI, 1.04–2.46), pneumonia (aOR, 2.54; 95% CI, 1.72–3.74), and acute kidney injury (aOR, 1.71; 95% CI, 1.24–2.35). Subgroup analyses revealed consistent associations between iron-deficiency anemia and prolonged LOS across age, sex, and obesity status categories.
Conclusion
In patients undergoing hepatic resection for CRLM, iron-deficiency anemia is an independent risk factor for prolonged LOS, unfavorable discharge, and several critical postoperative complications. These findings underscore the need for proactive anemia management to optimize surgical outcomes.
9.Impact of iron-deficiency anemia on short-term outcomes after resection of colorectal cancer liver metastasis: a US National (Nationwide) Inpatient Sample (NIS) analysis
Ko-Chao LEE ; Yu-Li SU ; Kuen-Lin WU ; Kung-Chuan CHENG ; Ling-Chiao SONG ; Chien-En TANG ; Hong-Hwa CHEN ; Kuan-Chih CHUNG
Annals of Coloproctology 2025;41(2):119-126
Purpose:
Colorectal cancer (CRC) often spreads to the liver, necessitating surgical treatment for CRC liver metastasis (CRLM). Iron-deficiency anemia is common in CRC patients and is associated with fatigue and weakness. This study investigated the effects of iron-deficiency anemia on the outcomes of surgical resection of CRLM.
Methods:
This population-based, retrospective study evaluated data from adults ≥20 years old with CRLM who underwent hepatic resection. All patient data were extracted from the 2005–2018 US National (Nationwide) Inpatient Sample (NIS) database. The outcome measures were in-hospital outcomes including 30-day mortality, unfavorable discharge, and prolonged length of hospital stay (LOS), and short-term complications such as bleeding and infection. Associations between iron-deficiency anemia and outcomes were determined using logistic regression analysis.
Results:
Data from 7,749 patients (representing 37,923 persons in the United States after weighting) were analyzed. Multivariable analysis revealed that iron-deficiency anemia was significantly associated with an increased risk of prolonged LOS (adjusted odds ratio [aOR], 2.76; 95% confidence interval [CI], 2.30–3.30), unfavorable discharge (aOR, 2.42; 95% CI, 1.83–3.19), bleeding (aOR, 5.05; 95% CI, 2.92–8.74), sepsis (aOR, 1.60; 95% CI, 1.04–2.46), pneumonia (aOR, 2.54; 95% CI, 1.72–3.74), and acute kidney injury (aOR, 1.71; 95% CI, 1.24–2.35). Subgroup analyses revealed consistent associations between iron-deficiency anemia and prolonged LOS across age, sex, and obesity status categories.
Conclusion
In patients undergoing hepatic resection for CRLM, iron-deficiency anemia is an independent risk factor for prolonged LOS, unfavorable discharge, and several critical postoperative complications. These findings underscore the need for proactive anemia management to optimize surgical outcomes.
10.Proposal of age definition for early-onset gastric cancer based on the Korean Gastric Cancer Association nationwide survey data: a retrospective observational study
Seong-A JEONG ; Ji Sung LEE ; Ba Ool SEONG ; Seul-gi OH ; Chang Seok KO ; Sa-Hong MIN ; Chung Sik GONG ; Beom Su KIM ; Moon-Won YOO ; Jeong Hwan YOOK ; In-Seob LEE ;
Annals of Surgical Treatment and Research 2025;108(4):245-255
Purpose:
This study aimed to define an optimal age cutoff for early-onset gastric cancer (EOGC) and compare its characteristics with those of late-onset gastric cancer (LOGC) using nationwide survey data.
Methods:
Using data from a nationwide survey, this comprehensive population-based study analyzed data spanning 3 years (2009, 2014, and 2019). The joinpoint analysis and interrupted time series (ITS) methodology were employed to identify age cutoffs for EOGC based on the sex ratio and tumor histology. Clinicopathologic characteristics and surgical outcomes were compared between the EOGC and LOGC groups.
Results:
The age cutoff for defining EOGC was suggested to be 50 years, supported by joinpoint and ITS analyses. Early gastric cancer was predominantly present in the EOGC and LOGC groups. Patients with EOGC comprised 20.3% of the total study cohort and demonstrated a more advanced disease stage compared to patients with LOGC. However, patients with EOGC underwent more minimally invasive surgeries, experienced shorter hospital stays, and had lower postoperative morbidity and mortality rates.
Conclusion
This study proposes an age of ≤50 years as a criterion for defining EOGC and highlights its features compared to LOGC. Further research using this criterion should guide tailored treatment strategies and improve outcomes for young patients with gastric cancer.

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