1.Individualized strategy of treatment for ruptured abdominal aortic aneurysm using causal inference model: a retrospective observational study
Youngki SOHN ; Youngje WOO ; Sangkyun MOK ; Eunju JANG ; Ki-Yoon MOON ; Sun Cheol PARK ; Sang Seob YUN ; Jang Yong KIM
Annals of Surgical Treatment and Research 2026;110(4):259-272
Purpose:
This study was performed to predict individualized treatment strategies in ruptured abdominal aortic aneurysm (rAAA) by estimating the survival benefit of endovascular aneurysm repair (EVAR) and open surgical repair (OSR) based on anatomical and physiological features using a causal inference model.
Methods:
This retrospective study included 45 patients with de novo rAAA who underwent EVAR or OSR between 2012 and 2024. Thirty-three variables were analyzed. The model estimated individualized treatment effects (ITE) for 30-day survival.Model interpretability was assessed using Shapley Additive Explanations (SHAP) analysis. Five-fold cross-validation, receiver operating characteristic (ROC) analysis, and calibration plots were used for model evaluation. A clinical decision tree was developed to derive simplified decision rules.
Results:
The mean ITE was 0.22 ± 0.42, with 33% of patients classified as OSR-benefit candidates. SHAP analysis revealed that suprarenal angle, infrarenal angle, iliac anatomy, and proximal neck characteristics strongly influenced treatment effects. However, some predictors, such as low hemoglobin and systolic blood pressure favoring OSR, conflicted with clinical intuition. ROC analysis showed an area under the curve of 1.00, but calibration suggested overfitting due to a small sample size. Treatment-matched patients had a higher 30-day mortality rate than mismatched patients, suggesting potential bias or unmeasured confounding. The decision tree identified clinically relevant features but displayed structural inconsistencies and impractical cutoff values due to the limited sample size.
Conclusion
The X-learner model demonstrated the feasibility of individualized treatment prediction in rAAA but suffered from overfitting and limited generalizability. Validation with larger multicenter cohorts is necessary to confirm clinical applicability.
2.Clinical Outcomes and Use of Implantable Cardioverter-Defibrillator in Ischemic Heart Failure Patients with Reduced Ejection Fraction:A Retrospective Observational Study
Kyung Hoon CHO ; Ki Hong LEE ; Yong-Kyu LEE ; Seok OH ; Yongwhan LIM ; Joon Ho AHN ; Seung Hun LEE ; Dae Young HYUN ; Min Chul KIM ; Doo Sun SIM ; Young Joon HONG ; Ju Han KIM ; Youngkeun AHN ; Jang Hoon LEE ; Joo-Yong HAHN ; Yu-Ri KIM ; Nam Sik YOON ; Hyung Wook PARK ; Weon KIM ; Myung Ho JEONG ;
Chonnam Medical Journal 2026;62(2):55-63
Limited data exist regarding the real-world practices and clinical outcomes in patients with ischemic heart failure with reduced left ventricular ejection fractions (LVEFs).Using nationwide registry data from South Korea, we aimed to investigate long-term outcomes and clinical practices, especially implantable cardioverter defibrillators (ICDs) implantation, in patients with reduced LVEFs at least 40 days after acute myocardial infarction (AMI). Of 13,056 patients with AMI between 2011 and 2015, we analyzed 350 (median age, 66 years [interquartile range, 56-75]) who had LVEFs <40% on follow-up transthoracic echocardiogram 40 days after the index event. The primary outcome was cardiac-cause mortality at 3 years. Secondary outcomes comprised major cardiovascular events as well as outcomes defined by the use of ICDs, cardiac resynchronization therapy defibrillators (CRT-Ds), and electrophysiology studies. Among 350 patients, 39 (11.1%) died from cardiac causes during 3 years of follow-up. Eleven (3.1%) were hospitalized for ventricular tachycardia. The rate of ICD or CRT-D implantation up to 3 years was 5.7% (20/350). Cox time-to-event analysis revealed older age, LVEF <30%, diabetes mellitus, and previous MI or revascularization as positively associated with cardiac death, whereas the use of statins and body weight <67 kg were negatively associated. This nationwide Korean registry demonstrated that only 5.7% of patients who had reduced LVEFs after 40 days of AMI underwent ICD implantations over 3 years. Considering the high mortality, concerted efforts are needed to improve clinical outcomes for patients who may have been candidates for ICD implantation.
3.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.
4.The KAPARD guidelines for atopic dermatitis in children and adolescents:Part II. Systemic treatment, novel therapeutics, and adjuvant therapy
Hwan Soo KIM ; Eun LEE ; Kyunghoon KIM ; Taek Ki MIN ; Dong In SUH ; Yoon Ha HWANG ; Sungsu JUNG ; Minyoung JUNG ; Young A PARK ; Minji KIM ; In Suk SOL ; You Hoon JEON ; Sung-Il WOO ; Yong Ju LEE ; Jong Deok KIM ; Hyeon-Jong YANG ; Gwang Cheon JANG ;
Allergy, Asthma & Respiratory Disease 2025;13(1):3-11
Atopic dermatitis is the most common chronic inflammatory skin disease in children and adolescents. The Korean Academy of Pediatric Allergy and Respiratory Disease published the Atopic Dermatitis Treatment Guideline in 2008, which has been helpful in atopic dermatitis treatment until now. Various reports on the development and effectiveness of new drugs have suggested that there is a need to develop and revise old treatment guidelines. Part 1 aimed to provide evidence-based recommendations for skin care management and topical treatment for atopic dermatitis. Part 2 focuses on systemic treatment, novel therapeutics, and adjuvant therapy. The goal of this guideline is intended to assist front-line doctors treating pediatric and adolescent atopic dermatitis patients make safer, more effective, and more rational decisions regarding systemic treatment, novel therapeutics, and adjuvant therapy by providing evidence-based recommendations with a clear level of evidence and benefit regarding treatment.
5.The KAPARD guidelines for atopic dermatitis in children and adolescents:Part II. Systemic treatment, novel therapeutics, and adjuvant therapy
Hwan Soo KIM ; Eun LEE ; Kyunghoon KIM ; Taek Ki MIN ; Dong In SUH ; Yoon Ha HWANG ; Sungsu JUNG ; Minyoung JUNG ; Young A PARK ; Minji KIM ; In Suk SOL ; You Hoon JEON ; Sung-Il WOO ; Yong Ju LEE ; Jong Deok KIM ; Hyeon-Jong YANG ; Gwang Cheon JANG ;
Allergy, Asthma & Respiratory Disease 2025;13(1):3-11
Atopic dermatitis is the most common chronic inflammatory skin disease in children and adolescents. The Korean Academy of Pediatric Allergy and Respiratory Disease published the Atopic Dermatitis Treatment Guideline in 2008, which has been helpful in atopic dermatitis treatment until now. Various reports on the development and effectiveness of new drugs have suggested that there is a need to develop and revise old treatment guidelines. Part 1 aimed to provide evidence-based recommendations for skin care management and topical treatment for atopic dermatitis. Part 2 focuses on systemic treatment, novel therapeutics, and adjuvant therapy. The goal of this guideline is intended to assist front-line doctors treating pediatric and adolescent atopic dermatitis patients make safer, more effective, and more rational decisions regarding systemic treatment, novel therapeutics, and adjuvant therapy by providing evidence-based recommendations with a clear level of evidence and benefit regarding treatment.
6.The KAPARD guidelines for atopic dermatitis in children and adolescents:Part II. Systemic treatment, novel therapeutics, and adjuvant therapy
Hwan Soo KIM ; Eun LEE ; Kyunghoon KIM ; Taek Ki MIN ; Dong In SUH ; Yoon Ha HWANG ; Sungsu JUNG ; Minyoung JUNG ; Young A PARK ; Minji KIM ; In Suk SOL ; You Hoon JEON ; Sung-Il WOO ; Yong Ju LEE ; Jong Deok KIM ; Hyeon-Jong YANG ; Gwang Cheon JANG ;
Allergy, Asthma & Respiratory Disease 2025;13(1):3-11
Atopic dermatitis is the most common chronic inflammatory skin disease in children and adolescents. The Korean Academy of Pediatric Allergy and Respiratory Disease published the Atopic Dermatitis Treatment Guideline in 2008, which has been helpful in atopic dermatitis treatment until now. Various reports on the development and effectiveness of new drugs have suggested that there is a need to develop and revise old treatment guidelines. Part 1 aimed to provide evidence-based recommendations for skin care management and topical treatment for atopic dermatitis. Part 2 focuses on systemic treatment, novel therapeutics, and adjuvant therapy. The goal of this guideline is intended to assist front-line doctors treating pediatric and adolescent atopic dermatitis patients make safer, more effective, and more rational decisions regarding systemic treatment, novel therapeutics, and adjuvant therapy by providing evidence-based recommendations with a clear level of evidence and benefit regarding treatment.
7.The KAPARD guidelines for atopic dermatitis in children and adolescents:Part II. Systemic treatment, novel therapeutics, and adjuvant therapy
Hwan Soo KIM ; Eun LEE ; Kyunghoon KIM ; Taek Ki MIN ; Dong In SUH ; Yoon Ha HWANG ; Sungsu JUNG ; Minyoung JUNG ; Young A PARK ; Minji KIM ; In Suk SOL ; You Hoon JEON ; Sung-Il WOO ; Yong Ju LEE ; Jong Deok KIM ; Hyeon-Jong YANG ; Gwang Cheon JANG ;
Allergy, Asthma & Respiratory Disease 2025;13(1):3-11
Atopic dermatitis is the most common chronic inflammatory skin disease in children and adolescents. The Korean Academy of Pediatric Allergy and Respiratory Disease published the Atopic Dermatitis Treatment Guideline in 2008, which has been helpful in atopic dermatitis treatment until now. Various reports on the development and effectiveness of new drugs have suggested that there is a need to develop and revise old treatment guidelines. Part 1 aimed to provide evidence-based recommendations for skin care management and topical treatment for atopic dermatitis. Part 2 focuses on systemic treatment, novel therapeutics, and adjuvant therapy. The goal of this guideline is intended to assist front-line doctors treating pediatric and adolescent atopic dermatitis patients make safer, more effective, and more rational decisions regarding systemic treatment, novel therapeutics, and adjuvant therapy by providing evidence-based recommendations with a clear level of evidence and benefit regarding treatment.
8.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.
9.The KAPARD guidelines for atopic dermatitis in children and adolescents:Part II. Systemic treatment, novel therapeutics, and adjuvant therapy
Hwan Soo KIM ; Eun LEE ; Kyunghoon KIM ; Taek Ki MIN ; Dong In SUH ; Yoon Ha HWANG ; Sungsu JUNG ; Minyoung JUNG ; Young A PARK ; Minji KIM ; In Suk SOL ; You Hoon JEON ; Sung-Il WOO ; Yong Ju LEE ; Jong Deok KIM ; Hyeon-Jong YANG ; Gwang Cheon JANG ;
Allergy, Asthma & Respiratory Disease 2025;13(1):3-11
Atopic dermatitis is the most common chronic inflammatory skin disease in children and adolescents. The Korean Academy of Pediatric Allergy and Respiratory Disease published the Atopic Dermatitis Treatment Guideline in 2008, which has been helpful in atopic dermatitis treatment until now. Various reports on the development and effectiveness of new drugs have suggested that there is a need to develop and revise old treatment guidelines. Part 1 aimed to provide evidence-based recommendations for skin care management and topical treatment for atopic dermatitis. Part 2 focuses on systemic treatment, novel therapeutics, and adjuvant therapy. The goal of this guideline is intended to assist front-line doctors treating pediatric and adolescent atopic dermatitis patients make safer, more effective, and more rational decisions regarding systemic treatment, novel therapeutics, and adjuvant therapy by providing evidence-based recommendations with a clear level of evidence and benefit regarding treatment.
10.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.

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