1.The Impact of COVID-19 on Admissions and In-hospital Mortality of Patients With Stroke in Korea: An Interrupted Time Series Analysis
Youngs CHANG ; Soo-Hee HWANG ; Haibin BAI ; Seowoo PARK ; Eunbyul CHO ; Dohoung KIM ; Hyejin LEE ; Jin Yong LEE
Journal of Preventive Medicine and Public Health 2025;58(1):60-71
Objectives:
This study aimed to investigate the impact of coronavirus disease 2019 (COVID-19) on admission rates and in-hospital mortality among patients with ischemic and hemorrhagic stroke.
Methods:
We constructed a dataset detailing the monthly hospitalizations and mortality rates of inpatients with stroke from January 2017 to December 2021. Employing an interrupted time series analysis, we explored the impact of COVID-19 on hospitalizations and 30-day in-hospital mortality among stroke patients.
Results:
The number of ischemic stroke admissions decreased by 18.5%, from 5335 to 4348, immediately following the COVID-19 outbreak (p<0.001). The in-hospital mortality rate for ischemic stroke increased slightly from 3.3% to 3.4% immediately after the outbreak, although it showed a decreasing trend over time. The number of hemorrhagic stroke admissions fell by 7.5%, from 2014 to 1864, immediately following the COVID-19 outbreak. The 30-day in-hospital mortality rate for hemorrhagic stroke initially decreased from 12.9% to 12.7%, but subsequently showed an increasing trend.
Conclusions
We confirmed that COVID-19 impacted both the admission and death rates of stroke patients. The admission rate for both ischemic and hemorrhagic strokes decreased, while in-hospital mortality increased. Specifically, in-hospital mortality from ischemic stroke rose initially after the outbreak before stabilizing. Additionally, our findings indicate variable effects based on sex, age, and socioeconomic status, suggesting that certain groups may be more susceptible. This underscores the need to identify and support vulnerable populations to mitigate adverse health outcomes.
2.Risk of acute myocardial infarction associated with antirheumatic agents in patients with rheumatoid arthritis: a nationwide population-based case-control study
Soo Min AHN ; Seonok KIM ; Ye-Jee KIM ; Seokchan HONG ; Chang-Keun LEE ; Bin YOO ; Ji Seon OH ; Yong-Gil KIM
Journal of Rheumatic Diseases 2025;32(2):113-121
Objective:
Using a nationally representative cohort of medical claims data in Korea, this study aimed to analyze the association between the use of various anti-rheumatic agents and the risk of acute myocardial infarction (AMI) in patients with rheumatoid arthritis (RA).
Methods:
This nested case-control study used the Korean Health Insurance Review and Assessment data of 35,133 patients newly diagnosed with RA between 2011 and 2020. Incident AMI patients were identified and matched at a 1:4 ratio with randomly selected controls. The usage of anti-rheumatic agents was measured from the date of RA diagnosis to the index date and stratified based on exposure time and duration. The risk of AMI associated with each anti-rheumatic agent was estimated using conditional logistic regression, adjusted for comorbidities and concomitant drug use.
Results:
Of the 35,133 patients with RA, 484 were diagnosed with AMI. In total, 484 AMI patients and 1,924 controls with newly diagnosed RA were included in the analysis. Current exposure and long-term exposure to glucocorticoids (adjusted odds ratio [aOR]: 2.301, 95% confidence interval [CI]: 1.741~3.041; aOR: 1.792, 95% CI: 1.378~2.330) and leflunomide (aOR: 1.525, 95% CI: 1.196~1.944; aOR: 1.740, 95% CI: 1.372~2.207) were associated with an increased risk of AMI.
Conclusion
The study demonstrates a significant association between the current and long-term use of glucocorticoids and leflunomide and an increased risk of AMI in patients with RA. These findings underscore the importance of careful consideration of cardiovascular risks when selecting anti-rheumatic agents for RA treatment.
3.Daily Life Difficulties and Disease Awareness of Patients With Narcolepsy
Yong Su CHANG ; Namoh KIM ; Ki-Young JUNG
Journal of Sleep Medicine 2025;22(1):1-7
Narcolepsy significantly affects the daily life of individuals due to excessive daytime sleepiness and cataplexy, reducing the quality of life and increasing the risk of accidents and social difficulties. Despite its profound impact on daily life, only a few studies have investigated the specific difficulties and awareness of patients with narcolepsy. Therefore, in this study, we aimed to assess the daily challenges and disease awareness of patients with narcolepsy. Methods: We conducted an online survey of 299 patients with narcolepsy. The survey included questions on patient demographics, clinical characteristics, difficulties, and disease awareness. Results: The patients reported considerable difficulties in academic performance, memory, and driving, with those with narcolepsy type 1 reporting greater difficulties than those with narcolepsy type 2. Older age and depression were positively associated with higher difficulty scores, whereas female sex was associated with lower difficulty scores. Notably, disease awareness varied, with 30.4% and 5.4% of participants showing moderate and no awareness of narcolepsy, respectively. Conclusions: Overall, this study highlights the daily life challenges and varying disease awareness of patients with narcolepsy. Our findings emphasize the need for targeted education and effective policy interventions to reduce the difficulties and improve the quality of life of patients with narcolepsy.
4.A Real-World, Prospective, Observational Study of Rivaroxaban on Prevention of Stroke and Non-Central Nervous Systemic Embolism in Renally Impaired Korean Patients With Non-Valvular Atrial Fibrillation:XARENAL
Il-Young OH ; Chang Hoon LEE ; Eue-Keun CHOI ; Hong Euy LIM ; Yong-Seog OH ; Jong-Il CHOI ; Min-Soo AHN ; Ju Youn KIM ; Nam-Ho KIM ; Namsik YOON ; Martin SANDMANN ; Kee-Joon CHOI
Korean Circulation Journal 2025;55(2):121-131
Background and Objectives:
Several real-world studies have been done in patients with nonvalvular atrial fibrillation (NVAF); however, information on its safety profile in patients with renal impairment is limited. XARENAL, a real-world study, aimed to prospectively investigate the safety profile of rivaroxaban in patients with NVAF with renal impairment (creatinine clearance [CrCl], 15–49 mL/min).
Methods:
XARENAL is an observational single-arm cohort study in renal impairment NVAF patients. Patients were followed up approximately every 3 months for 1 year or until 30 days following early discontinuation. The primary endpoint was major bleeding events. All adverse events, symptomatic thromboembolic events, treatment duration, and renal function change from baseline were the secondary endpoints.
Results:
XARENAL included 888 patients from 29 study sites. Overall, 713 (80.3%) had moderate renal impairment (CrCl, 30–49 mL/min), and 175 (19.7%) had severe renal impairment (CrCl, 15–29 mL/min) with a mean estimated glomerular filtration rate (eGFR) of 45.2±13.0 mL/min/1.73 m 2 . The mean risk scores were 3.3±1.4 and 1.7±0.9 for CHA 2 DS 2 -VASc score and HAS-BLED score, respectively. An incidence proportion of 5.6% (6.2 events per 100 patient-years) developed major bleeding; however, fatal bleeding occurred in 0.5% (0.5 events per 100 patient-years). The mean change in the eGFR was 2.22±26.47 mL/min/1.73 m 2 per year.
Conclusions
XARENAL observed no meaningful differences in major bleeding events from other previous findings as well as renal function changes in rivaroxaban-treated NVAF patients with renal impairment, which is considered to be acceptable in clinical practice.
5.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.
6.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
7.Therapeutic Effects of Intravitreal Methotrexate Injection for Intraocular Lymphoma Diagnosed Using Immunocytochemical Staining
Yong Jin NA ; Kun Young KWON ; Kook Young KIM ; Young Suk CHANG ; Jung Tae KIM
Journal of the Korean Ophthalmological Society 2025;66(2):101-113
Purpose:
This study evaluated the therapeutic efficacy of intravitreal methotrexate (MTX) injections in patients diagnosed with intraocular lymphoma via vitrectomy and immunocytochemical staining.
Methods:
In a retrospective analysis of medical records, we reviewed data from four patients (six eyes) diagnosed with intraocular lymphoma cytologically after undergoing vitrectomy at our hospital between December 2021 and December 2023. Each case was followed for a minimum of 6 months after treatment, with comparisons made between pre- and post-treatment observations
Results:
The mean age of the patients was 63.5 ± 9.8 years, with an average interval of 29.3 ± 32.0 months from initial symptom onset to intraocular lymphoma diagnosis. Diagnosis was confirmed through cytological and immunocytochemical analysis of vitreous specimens, identifying diffuse large B-cell lymphoma in four eyes and atypical lymphoid cells in two eyes. On average, 14.0 ± 1.7 intravitreal MTX injections were administered per eye. The mean best-corrected visual acuity improved from 1.18 ± 0.90 pre-treatment to 0.37 ± 0.70 post-treatment. Ophthalmic complications included toxic keratopathy in three eyes and retinal hemorrhage in one eye. Additionally, nasal cavity lymphoma was diagnosed in two patients.
Conclusions
Diagnostic vitrectomy combined with cytology and immunocytochemical staining is essential for the early diagnosis of intraocular lymphoma and differentiation from inflammatory diseases, such as uveitis. Intravitreal MTX injections can induce clinical remission in intraocular lymphoma cases.
9.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
10.Discordance in Claudin 18.2Expression Between Primary and Metastatic Lesions in Patients With Gastric Cancer
Seung-Myoung SON ; Chang Gok WOO ; Ok-Jun LEE ; Sun Kyung LEE ; Minkwan CHO ; Yong-Pyo LEE ; Hongsik KIM ; Hee Kyung KIM ; Yaewon YANG ; Jihyun KWON ; Ki Hyeong LEE ; Dae Hoon KIM ; Hyo Yung YUN ; Hye Sook HAN
Journal of Gastric Cancer 2025;25(2):303-317
Purpose:
Claudin 18.2 (CLDN18.2) has emerged as a promising therapeutic target for CLDN18.2-expressing gastric cancer (GC). We sought to examine the heterogeneity of CLDN18.2 expression between primary GC (PGC) and metastatic GC (MGC) using various scoring methods.
Materials and Methods:
We retrospectively analyzed data from 102 patients with pathologically confirmed paired primary and metastatic gastric or gastroesophageal junction adenocarcinomas. CLDN18.2 expression was evaluated through immunohistochemistry on formalin-fixed paraffin-embedded tissue samples. We assessed CLDN18.2 positivity using multiple scoring approaches, including the immunoreactivity score, H-score, and the percentage of tumor cells showing moderate-to-strong staining intensity. We analyzed the concordance rates between PGC and MGC and the association of CLDN18.2 positivity with clinicopathological features.
Results:
CLDN18.2 positivity varied from 25% to 65% depending on the scoring method, with PGC consistently showing higher expression levels than MGC. Intratumoral heterogeneity was noted in 25.5% of PGCs and 19.6% of MGCs. Intertumoral heterogeneity, manifesting as discordance in CLDN18.2 positivity between PGC and MGC, was observed in about 20% of cases, with moderate agreement across scoring methods (κ=0.47 to 0.60).In PGC, higher CLDN18.2 positivity correlated with synchronous metastasis, presence of peritoneal metastasis, poorly differentiated grade, and biopsy specimens. In MGC, positivity was associated with synchronous metastasis, presence of peritoneal metastasis, and metastatic peritoneal tissues.
Conclusions
CLDN18.2 expression demonstrates significant heterogeneity between PGC and MGC, with a 20% discordance rate. Comprehensive tissue sampling and reassessment of CLDN18.2 status are crucial, especially before initiating CLDN18.2-targeted therapies.

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