This report presents the latest statistics on the stroke population in South Korea, sourced from the Clinical Research Collaborations for Stroke in Korea-National Institute for Health (CRCS-K-NIH), a comprehensive, nationwide, multicenter stroke registry. The Korean cohort, unlike western populations, shows a male-to-female ratio of 1.5, attributed to lower risk factors in Korean women. The average ages for men and women are 67 and 73 years, respectively.Hypertension is the most common risk factor (67%), consistent with global trends, but there is a higher prevalence of diabetes (35%) and smoking (21%). The prevalence of atrial fibrillation (19%) is lower than in western populations, suggesting effective prevention strategies in the general population. A high incidence of large artery atherosclerosis (38%) is observed, likely due to prevalent intracranial arterial disease in East Asians and advanced imaging techniques.There has been a decrease in intravenous thrombolysis rates, from 12% in 2017–2019 to 10% in 2021, with no improvements in door-to-needle and door-to-puncture times, worsened by the coronavirus disease 2019 pandemic. While the use of aspirin plus clopidogrel for noncardioembolic stroke and direct oral anticoagulants for atrial fibrillation is well-established, the application of direct oral anticoagulants for non-atrial fibrillation cardioembolic strokes in the acute phase requires further research. The incidence of early neurological deterioration (13%) and the cumulative incidence of recurrent stroke at 3 months (3%) align with global figures. Favorable outcomes at 3 months (63%) are comparable internationally, yet the lack of improvement in dependency at 3 months highlights the need for advancements in acute stroke care.

Background: This study investigated the impact of premorbid functional dependency on post-stroke mortality in patients with anterior circulation stroke (ACS) and posterior circulation stroke (PCS). Methods: This study enrolled 9,698 patients who experienced ischemic stroke between January 2011 and December 2022. The patients were classified into the ACS and PCS groups. Premorbid functional dependency was defined as modified Rankin Scale of ≥3. The risks of premorbid functional dependency and mortality at 3 months and 1-year post-stroke were assessed. A subgroup analysis was further performed to evaluate the risk of premorbid functional dependency in patients who underwent intravenous thrombolysis and endovascular treatment (EVT). Results: Among 6,358 patients with ACS and 3,340 with PCS, those with premorbid dependency were older, predominantly female, and had a higher proportion of vascular risk factors and stroke severity. Premorbid functional dependency was associated with increased mortality at both 3 months and 1 year in the PCS (odds ratio [OR], 1.79; 95% confidence interval [CI], 1.00–3.13; P=0.04 and OR, 2.87; 95% CI, 1.86–4.38; P<0.001, respectively), but not in the ACS (OR, 1.08; 95% CI, 0.77–1.51; P=0.639 and OR, 1.22; 95% CI, 0.93–1.59; P=0.140, respectively) group. Among patients who underwent EVT, premorbid functional dependency increased the risk of mortality at 1 year in the ACS group (OR, 1.80; 95% CI, 1.04–3.08; P=0.034), but was not associated with the risk in the PCS group (OR 2.56; 95% CI 0.64–10.15; P=0.176). Conclusion Premorbid functional dependency increases the risk of mortality in patients with PCS.

Background: For acute ischemic stroke (AIS) patients with history of prior stroke (PS) and diabetes mellitus (DM), intravenous recombinant tissue plasminogen activator (IV-tPA) therapy in the 3- to 4.5-hour window is off-label in Korea. This study aimed to assess the safety and efficacy of IV-tPA in these patients. Methods: Using data from a prospective multicenter stroke registry between January 2009 and March 2021, we identified AIS patients who received IV-tPA in the 3- to 4.5-hour window, and compared the outcomes of symptomatic intracranial hemorrhage (SICH), 3-month mortality, 3-month modified Rankin Scale (mRS) score 0-1 and 3-month mRS distribution between patients with both PS and DM (PS/DM, n=56) versus those with neither PS nor DM, or with only one (non-PS/DM, n=927). Results: The PS/DM group versus the non-PS/DM group was more likely to have a prior disability, hypertension, hyperlipidemia, coronary heart disease and less likely to have atrial fibrillation. The PS/DM and the non-PS/DM groups had comparable rates of SICH (0% vs. 1.7%; p>0.999) and 3-month mortality (10.7% vs. 10.2%; p=0.9112). The rate of 3-month mRS 0-1 was non-significantly lower in the PS/DM group than in the non-PS/DM group (30.4% vs. 40.7%; adjusted odds ratio [95% confidence interval], 0.81 [0.41-1.59]). Conclusions In the 3- to 4.5-hour window, AIS patients with PS/DM, as compared to those with non-PS/DM, might benefit less from IV-tPA. However, given the similar risks of SICH and mortality, IV-tPA in the late time window could be considered in patients with both PS and DM.

Purpose: The treatment of male breast cancer (MBC) has been extrapolated from female breast cancer (FBC) because of its rarity despite their different clinicopathologic characteristics. We aimed to investigate the distribution of intrinsic subtypes based on immunohistochemistry, their clinical impact, and treatment pattern in clinical practice through a multicenter study in Korea. Materials and Methods: We retrospectively analyzed clinical data of 248 MBC patients from 18 institutions across the country from January 1995 to July 2016. Results: The median age of MBC patients was 63 years (range, 25 to 102 years). Among 148 intrinsic subtype classified patients, 61 (41.2%), 44 (29.7%), 29 (19.5%), and 14 (9.5%) were luminal A, luminal B, human epidermal growth factor receptor 2, and triple-negative breast cancer, respectively. Luminal A subtype showed trends for superior survival compared to other subtypes. Most hormone receptor-positive patients (166 patients, 82.6%) received adjuvant endocrine treatment. Five-year completion of adjuvant endocrine treatment was associated with superior disease-free survival (DFS) in patients classified with an intrinsic subtype (hazard ratio [HR], 0.15; 95% confidence interval [CI], 0.04 to 0.49; p=0.002) and in all patients (HR, 0.16; 95% CI, 0.05 to 0.54; p=0.003). Conclusion Distribution of subtypes of MBC was similar to FBC and luminal type A was most common. Overall survival tended to be improved for luminal A subtype, although there was no statistical significance. Completion of adjuvant endocrine treatment was associated with prolonged DFS in intrinsic subtype classified patients. MBC patients tended to receive less treatment. MBC patients should receive standard treatment according to guidelines as FBC patients.

Purpose: Oxaliplatin, a component of the capecitabine plus oxaliplatin (XELOX) regimen, has a more favorable toxicity profile than cisplatin in patients with advanced gastric cancer (GC). However, oxaliplatin can induce sensory neuropathy and cumulative, dose-related toxicities. Thus, the capecitabine maintenance regimen may achieve the maximum treatment effect while reducing the cumulative neurotoxicity of oxaliplatin. This study aimed to compare the survival of patients with advanced GC between capecitabine maintenance and observation after 1st line XELOX chemotherapy. Materials and Methods: Sixty-three patients treated with six cycles of XELOX for advanced GC in six hospitals of the Catholic University of Korea were randomized 1:1 to receive capecitabine maintenance or observation. The primary endpoint was progression-free survival (PFS), analyzed using a two-sided log-rank test stratified at a 5% significance level. Results: Between 2015 and 2020, 32 and 31 patients were randomized into the maintenance and observation groups, respectively. After randomization, the median number of capecitabine maintenance cycles was 6. The PFS was significantly higher in the maintenance group than the observation group (6.3 vs. 4.1 months, P=0.010). Overall survival was not significantly different between the 2 groups (18.2 vs. 16.5 months, P=0.624). Toxicities, such as hand-foot syndrome, were reported in some maintenance group patients. Maintenance treatment was a significant factor associated with PFS in multivariate analysis (hazard ratio, 0.472; 95% confidence interval, 0.250–0.890; P=0.020). Conclusions After 6 cycles of XELOX chemotherapy, capecitabine maintenance significantly prolonged PFS compared with observation, and toxicity was manageable. Maintenance treatment was a significant prognostic factor associated with PFS.

Background: This study focuses on the establishment and operation of a stroke patient hotline program to help patients and their caregivers determine when acute neurological changes require emergency attention.Method: The stroke hotline was established at the Gyeonggi Regional Cerebrovascular Center, Seoul National University Bundang Hospital, in June 2016. Patients diagnosed with stroke during admission or in outpatient clinics were registered and provided with stroke education. Consulting nurses managed hotline calls and made decisions about outpatient schedules or emergency room referrals, consulting physicians when necessary. The study analyzed consultation records from June 2016 to December 2020, assessing consultation volumes and types. Outcomes and hotline satisfaction were also evaluated. Results: Over this period, 6,851 patients were registered, with 1,173 patients (18%) undergoing 3,356 hotline consultations. The average monthly consultation volume increased from 29.2 cases in 2016 to 92.3 cases in 2020. Common consultation types included stroke symptoms (22.3%), blood pressure/glucose inquiries (12.8%), and surgery/procedure questions (12.6%). Unexpected outpatient visits decreased from 103 cases before the hotline to 81 cases after. Among the 2,244 consultations between January 2019 and December 2020, 9.6% were recommended hospital visits, with two cases requiring intra-arterial thrombectomy. Patient satisfaction ratings of 9–10 points increased from 64% in 2019 to 69% in 2020. Conclusion The stroke hotline program effectively reduced unexpected outpatient visits and achieved high patient satisfaction.Expanding the program could enhance the management of stroke-related neurological symptoms and minimize unnecessary healthcare resource utilization.

Background and Objectives: Atherectomy as a pretreatment has the potential to improve the outcomes of drug-coated balloon (DCB) treatment by reducing and modifying atherosclerotic plaques. The present study investigated the outcomes of atherectomy plus DCB (A+DCB) compared with DCB alone for the treatment of femoropopliteal artery disease. Methods: A total of 311 patients (348 limbs) underwent endovascular therapy using DCB for native femoropopliteal artery lesions at two endovascular centers. Of these, 82 limbs were treated with A+DCB and 266 limbs with DCB alone. After propensity score matching based on clinical and lesion characteristics, a total of 82 pairs was compared for immediate and mid-term outcomes. Results: For the matched study groups, the lesion length was 172.7±111.2 mm, and severe calcification was observed in 43.3%. The technical success rate was higher in the A+DCB group than in the DCB group (80.5% vs. 62.2%, p=0.015). However, the A+DCB group showed more procedure-related minor complications (37.0% vs. 13.4%, p=0.047). At 2-year follow-up, primary clinical patency (73.8% vs. 82.6%, p=0.158) and the target lesion revascularization (TLR)-free survival (84.3% vs. 88.2%, p=0.261) did not differ between the two groups. In Cox proportional hazard analysis, atherectomy showed no significant impact on the outcome of DCB treatments. Conclusions The pretreatment with atherectomy improved technical success of DCB treatment; however, it was associated with increased minor complications. In this study, A+DCB showed no clinical benefit in terms of TLR-free survival or clinical patency compared with DCB treatment alone.

Background: Liquid chromatography coupled to tandem mass spectrometry (LC-MS/MS) is increasingly used for immunosuppressive drug tests. However, most LC-MS/MS tests are laboratory-developed and their agreement is unknown in different Korean laboratories.This interlaboratory comparison study evaluated test reproducibility and identified potential error sources. Methods: Test samples containing three concentrations of tacrolimus, sirolimus, everolimus, cyclosporine, and mycophenolic acid were prepared by pooling surplus samples from patients undergoing routine therapeutic drug monitoring and tested in duplicate in the participating 10 clinical laboratories. Reconstitution and storage experiments were conducted for the commonly used commercial calibrator set. The robust estimators of reproducibility parameters were calculated. Spearman’s rank correlation coefficient (rho, ρ) was used to evaluate the correlation between drugs. Multiple linear regression was used to determine whether the experimental conditions alter the calibration curves. Results: The reproducibility coefficient of variation exceeded 10% only for sirolimus concentrations 1 and 2 (10.8% and 12.5%, respectively) and everolimus concentrations 1 and 2 (12.3% and 11.4%, respectively). The percent difference values showed weak correlations between sirolimus and everolimus (ρ = 0.334, P = 0.175). The everolimus calibration curve slope was significantly altered after reconstitution following prolonged 5°C storage (P = 0.015 for 14 days; P = 0.025 for 28 days); the expected differences at 6 ng/mL were 0.598% for 14 days and 0.384% for 28 days. Conclusions LC-MS/MS test reproducibility for immunosuppressive drugs seems to be good in the Korean clinical laboratories. Continuous efforts are required to achieve test standardization and harmonization, especially for sirolimus and everolimus.

Objective: Overcrowded emergency departments (ED) are a worldwide problem, which could cause treatment delays and increased mortality of patients. This study aimed at evaluating the effect of admission decisions by emergency physicians without consultation of an internal medicine doctor on the emergency department length of stay (ED LOS) and survival rate of patients diagnosed with medical disease. Methods: The study was a retrospective observational study comparing the ED LOS of patients admitted to the internal medicine (IM) department before and after the policy change regarding admission decisions, implemented in July 2017. During and after the policy change, emergency physicians took decisions on the arrangements and treatment for patients by processing their admission and providing follow-up care without further specialist consultations. The ED LOS and rate of admission to the IM department were compared between the study period (October 2017 to October 2018) and the control period (June 2016 to June 2017). Results: The median ED LOS of patients admitted to the IM department decreased from 164.0 minutes (interquartile range [IQR], 118.0-234.0) in the control period to 114.0 minutes (IQR, 104.0-208.0) in the study period. After propensity score matching, the median ED LOS of patients admitted to the IM department decreased from 187.0 minutes (IQR, 136.0-253.0) in the control period to 144.0 minutes (IQR, 104.0-208.0) in the study period. Conclusion The admission decisions made by emergency physicians reduced the ED and hospital LOS of patients visiting the ED and diagnosed with medical disease.