Background: and Purpose Previous research on patients with acute ischemic stroke (AIS) has shown a 0.5% incidence of major gastrointestinal bleeding (GIB) requiring blood transfusion during hospitalization. The existing literature has insufficiently explored the long-term incidence in this population despite the decremental impact of GIB on stroke outcomes. Methods: We analyzed the data from a cohort of patients with AIS admitted to 14 hospitals as part of a nationwide multicenter prospective stroke registry between 2011 and 2013. These patients were followed up for up to 6 years. The occurrence of major GIB events, defined as GIB necessitating at least two units of blood transfusion, was tracked using the National Health Insurance Service claims data. Results: Among 10,818 patients with AIS (male, 59%; mean age, 68±13 years), 947 (8.8%) experienced 1,224 episodes of major GIB over a median follow-up duration of 3.1 years. Remarkably, 20% of 947 patients experienced multiple episodes of major GIB. The incidence peaked in the first month after AIS, reaching 19.2 per 100 person-years, and gradually decreased to approximately one-sixth of this rate by the 2nd year with subsequent stabilization. Multivariable analysis identified the following predictors of major GIB: anemia, estimated glomerular filtration rate <60 mL/min/1.73 m2 , and a 3-month modified Rankin Scale score of ≥4. Conclusion Patients with AIS are susceptible to major GIB, particularly in the first month after the onset of AIS, with the risk decreasing thereafter. Implementing preventive strategies may be important, especially for patients with anemia and impaired renal function at stroke onset and those with a disabling stroke.

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: 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.

Auricular vagus nerve stimulation (aVNS) is one of the promising neuromodulation techniques due to its non-invasiveness, convenience, and effectiveness. aVNS has been suggested as a potential treatment for neurodegenerative diseases showing impaired cerebrospinal fluid (CSF) dynamics. Improving CSF flow has been proposed as a key mechanism of the therapeutic effect on neurodegenerative diseases. However, aVNS parameters have been set empirically and the effective parameter that maximize the effect remains elusive. Here we show that 30 minutes of low-frequency aVNS increased arterial vasomotion events and enhanced cortical CSF influx along the branches of middle cerebral arteries. By using in vivo two photon imaging or widefield fluorescence microscopy with plasma and CSF tracers for visualizing blood vessels and perivascular spaces, arterial vasomotion and cortical CSF influx dynamics were acquired. The low-frequency (2 Hz) aVNS, but not middleand high-frequency (40 and 100 Hz) aVNS, significantly increased the number of vasomotion events compared to the sham group. Accordingly, in the CSF imaging, 2 Hz of aVNS markedly enhanced the CSF influx. Our findings demonstrate that lowfrequency aVNS is the effective parameter in respect to modulating vasomotion and CSF influx, resulting in brain clearance effect.

Purpose: This study investigated the recurrence patterns and timing in patients with pathologic N2 (pN2) non-small cell lung cancer (NSCLC) according to the residual tumor (R) descriptor proposed by the International Association for the Study of Lung Cancer (IASLC). Materials and Methods: From 2004 to 2021, patients with pN2 NSCLC who underwent anatomical resection were analyzed according to the IASLC R criteria using medical records from a single center. Survival analysis was performed using Cox proportional hazards models. Recurrence patterns between complete (R0) and uncertain resections (R[un]) were compared. Results: In total, 1,373 patients were enrolled in this study: 576 (42.0%) in R0, 286 (20.8%) in R(un), and 511 (37.2%) in R1/R2 according to the IASLC R criteria. The most common reason for R(un) classification was positivity for the highest lymph node (88.8%). In multivariable analysis, the hazard ratios for recurrence in R(un) and R1/R2 compared to R0 were 1.18 (95% confidence interval [CI], 0.96–1.46) and 1.58 (1.31–1.90), respectively. The hazard rate curves displayed similar patterns among groups, peaking at approximately 12 months after surgery. There was a significant difference in distant recurrence patterns between R0 and R(un). Further analysis after stratification with the IASLC N2 descriptor showed significant differences in distant recurrence patterns between R0 and R(un) in patients pN2a1 and pN2a2 disease, but not in those with pN2b disease. Conclusion The IASLC R criteria has prognostic relevance in patients with pN2 NSCLC. R(un) is a highly heterogeneous group, and the involvement of the highest mediastinal lymph node can affect distant recurrence patterns.

Purpose: The International Association for the Study of Lung Cancer suggests further subdivision of pathologic N (pN) category in non–small-cell lung cancer (NSCLC) by incorporating the location and number of involved lymph node (LN) stations. We reclassified patients with the station-based N2b disease into single-zone and multi-zone N2b groups and compared survival outcomes between the groups. Materials and Methods: This retrospective study included patients with pN2 NSCLC who underwent lobectomy from 2006 to 2019. The N2 disease was subdivided into four categories: single-station N2 without N1 (N2a1), single-station N2 with N1 (N2a2), multiple-station N2 with single zone involvement (single-zone N2b), and multiple-station N2 with multiple zone involvement (multi-zone N2b). LN zones included in the subdivision of N2 disease were upper mediastinal, lower mediastinal, aortopulmonary, and subcarinal. Results: Among 996 eligible patients, 211 (21.2%), 394 (39.6%), and 391 (39.3%) were confirmed to have pN2a1, pN2a2, and pN2b disease, respectively. In multivariable analysis after adjustment for sex, age, pT category, and adjuvant chemotherapy, overall survival was significantly better with single-zone N2b disease (n=125, 12.6%) than with multi-zone N2b disease (n=266, 26.7%) (hazard ratio [HR], 0.67; 95% confidence interval [CI], 0.49 to 0.90; p=0.009) and was comparable to that of N2a2 disease (HR, 1.12; 95% CI, 0.83 to 1.49; p=0.46). Conclusion Prognosis of single-zone LN metastasis was better than that of multiple-zone LN metastasis in patients with N2b NSCLC. Along with the station-based N descriptors, zone-based descriptors might ensure optimal staging, enabling the most appropriate decision-making on adjuvant therapy for patients with pN2 NSCLC.

Auricular vagus nerve stimulation (aVNS) is one of the promising neuromodulation techniques due to its non-invasiveness, convenience, and effectiveness. aVNS has been suggested as a potential treatment for neurodegenerative diseases showing impaired cerebrospinal fluid (CSF) dynamics. Improving CSF flow has been proposed as a key mechanism of the therapeutic effect on neurodegenerative diseases. However, aVNS parameters have been set empirically and the effective parameter that maximize the effect remains elusive. Here we show that 30 minutes of low-frequency aVNS increased arterial vasomotion events and enhanced cortical CSF influx along the branches of middle cerebral arteries. By using in vivo two photon imaging or widefield fluorescence microscopy with plasma and CSF tracers for visualizing blood vessels and perivascular spaces, arterial vasomotion and cortical CSF influx dynamics were acquired. The low-frequency (2 Hz) aVNS, but not middleand high-frequency (40 and 100 Hz) aVNS, significantly increased the number of vasomotion events compared to the sham group. Accordingly, in the CSF imaging, 2 Hz of aVNS markedly enhanced the CSF influx. Our findings demonstrate that lowfrequency aVNS is the effective parameter in respect to modulating vasomotion and CSF influx, resulting in brain clearance effect.

Auricular vagus nerve stimulation (aVNS) is one of the promising neuromodulation techniques due to its non-invasiveness, convenience, and effectiveness. aVNS has been suggested as a potential treatment for neurodegenerative diseases showing impaired cerebrospinal fluid (CSF) dynamics. Improving CSF flow has been proposed as a key mechanism of the therapeutic effect on neurodegenerative diseases. However, aVNS parameters have been set empirically and the effective parameter that maximize the effect remains elusive. Here we show that 30 minutes of low-frequency aVNS increased arterial vasomotion events and enhanced cortical CSF influx along the branches of middle cerebral arteries. By using in vivo two photon imaging or widefield fluorescence microscopy with plasma and CSF tracers for visualizing blood vessels and perivascular spaces, arterial vasomotion and cortical CSF influx dynamics were acquired. The low-frequency (2 Hz) aVNS, but not middleand high-frequency (40 and 100 Hz) aVNS, significantly increased the number of vasomotion events compared to the sham group. Accordingly, in the CSF imaging, 2 Hz of aVNS markedly enhanced the CSF influx. Our findings demonstrate that lowfrequency aVNS is the effective parameter in respect to modulating vasomotion and CSF influx, resulting in brain clearance effect.

Background: Barriers to treatment with intravenous thrombolysis (IVT) for patients with acute ischemic stroke (AIS) in South Korea remain incompletely characterized. We analyze a nationwide prospective cohort to determine patient-level features associated with delayed presentation and non-treatment of potential IVT-eligible patients. Methods: We identified consecutive patients with AIS from 01/2011 to 08/2023 from a multicenter and prospective acute stroke registry in Korea. Patients were defined as IVT candidates if they presented within 4.5 hours from the last known well, had no lab evidence of coagulopathy, and had National Institute of Health Stroke Scale (NIHSS) ≥ 4. Multivariable generalized linear mixed regression models were used to investigate the associations between their characteristics and the IVT candidates or the use of IVT among the candidates. Results: Among 84,103 AIS patients, 41.0% were female, with a mean age of 69 ± 13 years and presentation NIHSS of 4 [interquartile range, 1–8]. Out of these patients, 13,757 (16.4%) were eligible for IVT, of whom 8,179 (59.5%) received IVT. Female sex (adjusted risk ratio [RR], 0.90; 95% confidence interval [CI], 0.86–0.94) and lower years of education (adjusted RR, 0.90; 95% CI, 0.84–0.97 for 0–3 years, compared to ≥ 13 years) were associated with a decreased likelihood of presenting as eligible for IVT after AIS; meanwhile, young age (adjusted RR, 1.12; 95% CI, 1.01–1.24 for ≤ 44 years, compared to 75–84 years) was associated with an increased likelihood of being an IVT candidate. Among those who were eligible for IVT, only age was significantly associated with the use of IVT (adjusted RR, 1.09; 95% CI, 1.03–1.16 for age 65–74 and adjusted RR, 0.83; 95% CI, 0.76–0.90 for ≥ 85 years, respectively). Conclusion Most patients with AIS present outside IVT eligibility in South Korea, and only 60% of eligible patients were ultimately treated. We identified increased age, female sex and lower education as key features on which to focus interventions for improving IVT utilization.

Background: Healthcare-associated infections impose a significant burden on antibiotic usage, healthcare expenditures, and morbidity. Therefore, it is crucial to revise policies to minimize such losses. This nationwide survey aimed to evaluate infection prevention and control (IPC) components in healthcare facilities and encourage improvements in acute care hospitals with inadequate infection prevention settings. This study aims to enhance the infection control capabilities of healthcare facilities. Methods: From December 27, 2021, to May 13, 2022, we conducted a survey of 1,767 acute care hospitals in the Republic of Korea. A survey was conducted to evaluate the infection control components in 1,767 acute care hospitals. Infection control officers provided direct responses to a systematically developed questionnaire. Subsequently, 10% of the respondents were randomly selected for the site investigation. Results: Overall, 1,197 (67.7%) hospitals responded to the online survey. On-site investigations were conducted at 125 hospitals. Hospitals with ≥ 150 beds are advised to have an IPC team under Article 3 of the Medical Service Act; however, only 87.0% (598/687) of hospitals with ≥ 100 beds had one. Conversely, 22.7% (116/510) of hospitals with < 100 beds had an IPC team. Regulations for hand hygiene, waste management, healthcare worker protection and safety, environmental cleaning, standard precautions, and prevention of the transmission of multidrug-resistant pathogens were present in 84.2%, 80.1%, 77.4%, 76.2%, 75.8%, and 63.5% of the hospitals, respectively. Hospitals with < 100 beds had low availability of all categories of standard operating procedures. Conclusion This study is the first national survey of acute care hospitals in the Republic of Korea. The data presented in the current study will improve the understanding of IPC status and will help establish a survey system. Our survey provides a basis for improving policies related to IPC in healthcare facilities.