Background: and Purpose Treatments for neuromyelitis optica spectrum disorder (NMOSD) such as eculizumab, ravulizumab, satralizumab, and inebilizumab have significantly advanced relapse prevention, but they remain expensive. Rituximab is an off-label yet popular alternative that offers a cost-effective solution, but its real-world efficacy needs better quantification for guiding the application of newer approved NMOSD treatments (ANTs). This study aimed to determine real-world rituximab failure rates to anticipate the demand for ANTs and aid in resource allocation. Methods: We conducted a nationwide retrospective study involving 605 aquaporin-4-antibody-positive NMOSD patients from 22 centers in South Korea that assessed the efficacy and safety of rituximab over a median follow-up of 47 months. Results: The 605 patients treated with rituximab included 525 (87%) who received continuous therapy throughout the follow-up period (median=47 months, interquartile range=15–87 months). During this period, 117 patients (19%) experienced at least 1 relapse. Notably, 68 of these patients (11% of the total cohort) experienced multiple relapses or at least 1 severe relapse.Additionally, 2% of the patients discontinued rituximab due to adverse events, which included severe infusion reactions, neutropenia, and infections. Conclusions This study has confirmed the efficacy of rituximab in treating NMOSD, as evidenced by an 87% continuation rate among patients over a 4-year follow-up period. Nevertheless, the occurrence of at least one relapse in 19% of the cohort, including 11% who experienced multiple or severe relapses, and a 2% discontinuation rate due to adverse events highlight the urgent need for alternative therapeutic options.

Background: and Purpose To determine whether the RNF213 p.R4810K mutation modifies the number of moyamoya disease manifestations and recurrent strokes in isolated intracranial arterial steno-occlusive disease (ICAD). Methods: This retrospective case–control study analyzed patients who visited the Asan Medical Center with steno-occlusive lesions in the M1 segment of the middle cerebral artery and terminal internal carotid artery, and underwent RNF213 genetic testing for screening moyamoya disease between January 2010 and November 2022. Patients with supportive findings of moyamoya disease or moderate-to-severe stenosis in the extracranial arteries were excluded.After matching antiplatelet drugs, the presentation of moyamoya disease and stroke recurrence were analyzed using chi-squared analysis and Kaplan–Meier survival curve analysis. Results: The 1,567 patients who underwent evaluations of RNF213 polymorphisms included 753 with ICAD, among whom females predominated (n=452, 60.0%) and 289 (38.4%) had an RNF213 mutation. The follow-up period was 2.47±3.51 years (mean±standard deviation; median=1.00 year, interquartile range=0–4 years). The risk of progression to moyamoya disease was higher in the RNF213-related-vasculopathy group than the RNF213-negative stenosis group (n=27 [9.3%] versus n=6 [1.3%], p<0.01), as were the risks of ischemic stroke (n=13 [4.5%] versus n=7 [1.5%], p=0.01) and hemorrhagic stroke (n=5 [1.7%] versus n=1 [0.2%], p=0.02, respectively). Furthermore, the presence of an RNF213 mutation was significantly associated with the risk of stroke recurrence (odds ratio=2.34, 95% confidence interval=1.44–3.80, p< 0.01). Conclusions Evaluations of RNF213 polymorphisms may help to identify patients with isolated ICAD at a high risk of progression to moyamoya disease and stroke.

Background: and Purpose We aimed to determine the proportion of Korean patients with early Alzheimer’s disease (AD) who are eligible to receive lecanemab based on the United States Appropriate Use Recommendations (US AUR), and also identify the barriers to this treatment. Methods: We retrospectively enrolled 6,132 patients with amnestic mild cognitive impairment or mild amnestic dementia at 13 hospitals from June 2023 to May 2024. Among them, 2,058 patients underwent amyloid positron emission tomography (PET) and 1,199 (58.3%) of these patients were amyloid-positive on PET. We excluded 732 patients who did not undergo brain magnetic resonance imaging between June 2023 and May 2024. Finally, 467 patients were included in the present study. Results: When applying the criteria of the US AUR, approximately 50% of patients with early AD were eligible to receive lecanemab treatment. Among the 467 included patients, 36.8% did not meet the inclusion criterion of a Mini-Mental State Examination (MMSE) score of ≥22. Conclusions Eligibility for lecanemab treatment was not restricted to Korean patients with early AD except for those with an MMSE score of ≥22. The MMSE criteria should therefore be reconsidered in areas with a higher proportion of older people, who tend to have lower levels of education.

Purpose: This study evaluated the postoperative quality of life (QoL) after various types of gastrectomy for gastric cancer. Materials and Methods: A multicenter prospective observational study was conducted in Korea using the Korean Quality of Life in Stomach Cancer Patients Study (KOQUSS)-40, a new QoL assessment tool focusing on postgastrectomy syndrome. Overall, 496 patients with gastric cancer were enrolled, and QoL was assessed at 5 time points: preoperatively and at 1, 3, 6, and 12 months after surgery. Results: Distal gastrectomy (DG) and pylorus-preserving gastrectomy (PPG) showed significantly better outcomes than total gastrectomy (TG) and proximal gastrectomy (PG) with regard to total score, indigestion, and dysphagia. DG, PPG, and TG also showed significantly better outcomes than PG in terms of dumping syndrome and worry about cancer. Postoperative QoL did not differ significantly according to anastomosis type in DG, except for Billroth I anastomosis, which achieved better bowel habit change scores than the others. No domains differed significantly when comparing double tract reconstruction and esophagogastrostomy after PG. The total QoL score correlated significantly with postoperative body weight loss (more than 10%) and extent of resection (P<0.05 for both).Reflux as assessed by KOQUSS-40 did not correlate significantly with reflux observed on gastroscopy 1 year postoperatively (P=0.064). Conclusions Our prospective observation using KOQUSS-40 revealed that DG and PPG lead to better QoL than TG and PG. Further study is needed to compare postoperative QoL according to anastomosis type in DG and PG.

Purpose: This study investigated the effects of a nursing leadership program on self-leadership, interpersonal relationships, clinical performance, problem-solving abilities, and nursing professionalism among nursing students in South Korea. Methods: A quasi-experimental study was conducted. The Practice-Driven Nursing Leadership Program for Students (PDNLP-S) was developed based on the ADDIE model (analysis, design, development, implementation, and evaluation). This quasi-experimental study design included 60 nursing students. The experimental group (n=30) participated in the PDNLP-S for 120-minute sessions over 5 weeks, while the control group (n=30) received usual lectures. The PDNLP-S included lectures, discussions, and individual and group activities to cultivate core nursing leadership competencies such as individual growth, collaboration, nursing excellence, creative problem-solving, and influence. Data were analyzed using descriptive statistics, the Mann-Whitney U-test, and the independent t-test with IBM SPSS Windows ver. 26.0. Results: The experimental group demonstrated significant improvements in self-leadership (t=3.28, p=.001), interpersonal relationships (t=3.07, p=.002), clinical performance (U=268.50, p=.004), and problem-solving abilities (t=2.20, p=.017) compared to the control group. No significant difference was observed in nursing professionalism (t=0.50, p=.311). Conclusion This study demonstrates that the PDNLP-S improved nursing students’ self-leadership, interpersonal relationships, clinical performance, and problem-solving abilities. The PDNLP-S can play a significant role in cultivating future nurse leaders by enhancing these nursing leadership competencies among nursing students.

Purpose: This study aimed to identify the most delirium assessment tool with high predictive validity for elderly patients with stroke. Methods: This was a prospective observational study. The subjects were 219 stroke patients aged 60 years or older admitted to the neurology ward of a general hospital and data collection was conducted from August 2022 to February 2023. The collected data were analyzed using descriptive statistics, x 2 -test, independent t-test, and Fisher's exact test. The predictive validity of the Delirium Observation Screening Scale (DOS), the Nursing Delirium Screening Scale(Nu-DESC), and the 4'A's test (4AT) were assessed based on the sensitivity, specificity, positive and negative predictive values, and area under the receiver operating characteristic curve (AUC). Results: Of the 38 patients screened for delirium using delirium assessment tools, 32 (14.6%) were diagnosed with delirium by a neurologist. The sensitivity, specificity, positive predictive value, and negative predictive value were 84.4%, 91.1%, 71.1%, and 97.2% for DOS; 93.8%, 96.8%, 83.3%, and 98.9% for Nu-DESC; and 100.0%, 96.8%, 84.2%, and 100.0% for 4AT, respectively. The AUC was shown to be 0.89 for the DOS, 0.95 for the Nu-DESC, and 0.98 for the 4AT. Conclusion The results indicate that the 4AT was the most valid delirium assessment tool for elderly patients with stroke. Therefore, the active use of 4AT by nurses to screen for delirium of elderly stroke patients in clinical settings can contribute to the prevention and early management of delirium.

Objective: It has been 1 year since the start of the worldwide coronavirus disease-19 (COVID-19) pandemic. This study analyzed the indirect effects of COVID-19 on treating patients with non-infectious diseases by comparing the incidence of complicated appendicitis before and after the pandemic. Methods: The target group included patients aged at least 16 years diagnosed with acute appendicitis between February 23 and July 31, 2020. Patients diagnosed during the same period in 2019 were selected as the control group. The differences in the incidence of complicated appendicitis before and after COVID-19 were investigated, and the association with various variables was analyzed using the odds ratios and 95% confidence intervals (CIs). Results: The study included 120 subjects in 2019 (pre-COVID group) and 119 cases in 2020 (post-COVID group). The pre-COVID group included 25 cases (20.8%) of complicated appendicitis, while the post-COVID group included 48 cases (40.3%). The median time from symptom onset to visit (pre-hospital time) increased from 15 to 22 hours, and the median time from the visit to surgery (in-hospital time) increased from 7 to 11 hours. Multivariate regression analysis of the three variables revealed odds ratios (95% CIs) of pre-hospital time, erythrocyte sedimentation rate, and inclusion in the post-COVID group of 1.02 (1.01-1.02), 2.07 (1.11-3.86), and 2.15 (1.12-4.11), respectively. Conclusion The incidence of complicated appendicitis increased after the COVID-19 pandemic. Therefore, a healthcare system that can minimize the delay in treating non-infectious emergency patients is needed.

Purpose: To identify US findings suggestive of malignancy in thyroid nodules with follicular lesions of undetermined significance (FLUS) or follicular neoplasm (FN) on fine-needle aspiration cytology (FNAC) and evaluate the diagnostic performance. Materials and Methods: Seventy FLUS (n = 57) or FN (n = 13) nodules on FNAC that underwent surgical excision between February 2018 and November 2020 were selected. US findings were retrospectively reviewed. Orientation, margin, echogenicity, calcification, additional findings of the rim, echogenicity, heterogeneity of the solid portion, and the ratio of anterior posterior diameter to lateral diameter (criteria) were assessed. The diagnostic performances of US findings, criteria, and the Korean Society of Thyroid Radiology Thyroid Imaging Reporting and Data System (K-TIRADS) were evaluated using logistic regression analysis. Results: Microcalcification, homogeneous solid echotexture, and thickened rims were suggestive of malignancy. Our criteria showed a highest area under the ROC curve (AUC) value of 0.771, sensitivity of 97.14%, accuracy of 77.14%, positive predictive value of 93.33%, negative predictive value of 95.24%, and specificity of 97.14%. The criteria showed a significantly higher AUC value than K-TIRADS. Conclusion US findings of homogenous solid portions, thick rims, and microcalcifications suggested malignancy in nodules with FLUS or FN on FNAC. These additional US findings could improve the diagnostic performance of K-TIRADS.

Background: Complete revascularization has demonstrated better outcomes in patients with acute myocardial infarction (AMI) and multivessel disease. However, in the case of left main (LM) culprit lesion AMI with multivessel disease, there is limited evidence to suggest that complete revascularization is better. Methods: We reviewed 16,831 patients in the Korea Acute Myocardial Infarction Registry who were treated from July 2016 to June 2020, and 399 patients were enrolled with LM culprit lesion AMI treated with percutaneous coronary intervention. We categorized the patients as those treated with complete revascularization (n=295) or incomplete revascularization (n=104). The study endpoint was major adverse cardiac and cerebrovascular events (MACCE), a composite of all-cause death, myocardial infarction, ischemia-driven revascularization, stent thrombosis, and stroke. We performed propensity score matching (PSM) and analyzed the incidence of MACCE at 1 year. Results: After PSM, the two groups were well balanced. There was no significant difference between the two groups in MACCE at 1 year (12.1% vs. 15.2%; hazard ratio, 1.28; 95% confidence interval, 0.60–2.74; p=0.524) after PSM. The components of MACCE and major bleeding were also not significantly different. Conclusion There was no significant difference in clinical outcomes between the groups treated with complete or incomplete revascularization for LM culprit lesion AMI with multivessel disease.

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.