Background and Objectives: Concerns remain that early aspirin cessation may be associated with potential harm in subsets at high risk of ischemic events. This study aimed to assess the effects of P2Y12 inhibitor monotherapy after 3-month dual antiplatelet therapy (DAPT) vs.prolonged DAPT (12-month or longer) based on the ischemic risk stratification, the CHADSP2A2RC, after percutaneous coronary intervention (PCI). Methods: This was a sub-study of the SMART-CHOICE trial. The effect of the randomized antiplatelet strategies was assessed across 3 CHADS-P2A2RC risk score categories. The primary outcome was a major adverse cardiac and cerebral event (MACCE), a composite of all-cause death, myocardial infarction, or stroke. Results: Up to 3 years, the high CHADS-P2A2RC risk score group had the highest incidence of MACCE (105 [12.1%], adjusted hazard ratio [HR], 2.927; 95% confidence interval [CI], 1.358–6.309; p=0.006) followed by moderate-risk (40 [1.4%], adjusted HR, 1.786; 95% CI, 0.868–3.674; p=0.115) and low-risk (9 [0.5%], reference). In secondary analyses, P2Y12 inhibitor monotherapy reduced the Bleeding Academic Research Consortium (BARC) types 2, 3, or 5 bleeding without increasing the risk of MACCE as compared with prolonged DAPT across the 3 CHADS-P2A2RC risk strata without significant interaction term (interaction p for MACCE=0.705 and interaction p for BARC types 2, 3, or 5 bleeding=0.055). Conclusions The CHADS-P2A2RC risk score is valuable in discriminating high-ischemicrisk patients. Even in such patients with a high risk of ischemic events, P2Y12 inhibitor monotherapy was associated with a lower incidence of bleeding without increased risk of ischemic events compared with prolonged DAPT.

Background: Remifentanil can be used as adjuvants during remimazolam induction without neuromuscular blockade. We evaluated the 95% effective concentration (EC) of remifentanil effect-site concentration (Ce) for the successful insertion of an i-gel using the biased-coin up-and-down method in adult patients during remimazolam induction. Methods: Forty 19–65 year-old patients scheduled to undergo surgery using i-gel were enrolled. Anesthesia was induced using remimazolam infusion (12 mg/kg/h). Simultaneously, remifentanil was infused at a predetermined Ce. After 5 min of anesthesia induction, the i-gel was inserted. The 95% EC (EC95) of remifentanil in each patient was determined using a biased-coin up-and-down method based on a successful insertion in a preceding patient. The step size of remifentanil Ce was 0.4 ng/ml. If the insertion failed, remifentanil Ce was increased in the next patient. Following successful insertions, the corresponding concentration decreased in subsequent patients with a probability of 1/19 or was maintained with a probability of 18/19. The time from remimazolam infusion initiation to a bispectral index (BIS) < 60 (time to BIS60) and hemodynamic variables were measured and recorded. Results: The EC95 (95% CI) of Ce was 2.07 (1.94, 2.87) ng/ml. The overall time to BIS60 was 154.0 ± 39.9 s. No patient experienced significant hypotension or bradycardia during remimazolam induction. Conclusions The EC95 of remifentanil Ce was 2.07 (1.94, 2.87) ng/ml for successful i-gel insertion during remimazolam induction at 12 mg/kg/h without hemodynamic instability in adult patients. Future studies should measure remifentanil Ce in elderly patients or using remimazolam at various infusion doses.

Purpose: The aim of this study was to investigate the epidemiologic features of pediatric dental injury according to age groups using Korean national data. Methods: We reviewed the data from 2015 to 2019 Emergency Department-based Injury In-depth Surveillance registry, which involves 23 emergency departments in Korea. We included children aged 18 years or younger with the International Classification of Disease, 10th Revision codes related to dental injury. Other or combined codes were excluded. The children were classified by age groups: infants (< 1 year), preschoolers (2-6), schoolers (7-12), and adolescents (13-18). As per the age groups, we compared the clinical characteristics, injury event profiles, and outcomes. Results: The study population (n = 33,020) consisted of 8,900 infants (27.0%), 15,705 preschoolers (47.6%), 5,295 schoolers (16.0%), and 3,120 adolescents (9.4%). Their median age was 3 years (interquartile range, 1-7), and boys accounted for 64.2%. The most common mechanism, type of activity, and place were slip down (14,274 [43.2%]), daily activity (23,777 [72.0%]), and home (19,980 [60.5%]), respectively. Among the injury types, soft tissue injury was most common (24,357 [73.8%]). As for the outcomes, 32,841 (99.5%) children were discharged, and 332 (1.0%) children had severe injury. As the age increased, the frequencies changed as follows. As for the place and type, household injury and soft tissue injury decreased while outdoor injury, such as road traffic injury, and tooth fracture increased (P < 0.001). As for the type of activity, injuries related to exercise/sports and education increased (P < 0.001). Of the sports activity, ball sports increased while kickboard/cycle decreased (P < 0.001). Conclusion Using the epidemiologic features of pediatric dental injury, it is advisable to establish injury prevention strategies according to the age groups.

Background: The purpose of this study is to construct a job-exposure matrix for lead that accounts for industry and work processes within industries using a nationwide exposure database. Methods: We used the work environment measurement data (WEMD) of lead monitored nationwide from 2015 to 2016. Industrial hygienists standardized the work process codes in the database to 37 standard process and extracted key index words for each process. A total of 37 standardized process codes were allocated to each measurement based on an automated key word search based on the degree of agreement between the measurement information and the standard process index. Summary statistics, including the arithmetic mean, geometric mean, and 95th percentile level (X95), was calculated according to industry, process, and industry process. Using statistical parameters of contrast and precision, we compared the similarity of exposure groups by industry, process, and industry process. Results: The exposure intensity of lead was estimated for 583 exposure groups combined with 128 industry and 35 process. The X95 value of the “casting” process of the “manufacture of basic precious and non-ferrous metals” industry was 53.29 μg/m3, exceeding the occupational exposure limit of 50 μg/m3. Regardless of the limitation of the minimum number of samples in the exposure group, higher contrast was observed when the exposure groups were by industry process than by industry or process. Conclusion We evaluated the exposure intensities of lead by combination of industry and process. The results will be helpful in determining more accurate information regarding exposure in lead-related epidemiological studies.

Background/Aims: Anti-hepatitis B virus (HBV) therapy is required for patients with HBV infection receiving biologics because of the high risk of HBV reactivation. However, it is unclear when to start biologics after anti-HBV treatment. We investigated the risk of HBV reactivation according to the timing of biologics initiation after anti-HBV treatment in immune-mediated inflammatory disease (IMID) patients with HBV infection. Methods: We retrospectively evaluated the incidence of HBV reactivation in IMID patients who received biologics between July 2005 and April 2020. The patients were divided into two groups (within 1-week and after 1-week) according to the timing of biologics initiation after anti-HBV treatment. The cumulative probabilities and factors associated with HBV reactivation were evaluated. Results: A total of 60 hepatitis B surface antigen-positive patients with IMID received biologics (within 1-week group, n=23 [38%]; after 1-week group, n=37 [62%]). During a median follow-up of 34 months (interquartile range, 20 to 74 months), three patients (5%) developed HBV reactivation. In univariate analysis, the timing of biologics after anti-HBV treatment was not significantly associated with the risk of HBV reactivation (hazard ratio, 0.657; 95% confidence interval, 0.059 to 7.327; p=0.733). The cumulative probabilities of HBV reactivation did not significantly differ according to the timing of biologics (p=0.731). Conclusions The risk of HBV reactivation was not significantly associated with the timing of biologics administration after anti-HBV treatment. Thus, biologics may be initiated early in patients with IMID undergoing treatment for HBV.

Objective: Previous studies investigating the beneficial effect of rituximab on lupus nephritis (LN) reported controversial results. There have been few reports of renal response to rituximab according to renal function. We investigated the efficacy of rituximab in refractory/relapsing LN and the role of renal function as a predictor of renal response. Methods: From 2016 to 2019, we retrospectively reviewed 22 patients with refractory/relapsing LN receiving rituximab. Renal responses (complete and partial) at 6 and 12 months were compared between normal (glomerular filtration rate [GFR]≥90 mL/min/1.73 m2 , n=11) and decreased (GFR＜90 mL/min/1.73 m2 , n=11) GFR groups. Multivariate Cox regression analysis was used to assess predictors of renal response. Results: At baseline, the decreased GFR group had a higher urine proteinuria to creatinine ratio (p=0.008) and proportion of refractory LN (p=0.010) and previous cyclophosphamide therapy (p=0.035) than the normal GFR group. The overall renal response rate was 45.5% (10 patients) at 6 months and 54.5% (12 patients) at 12 months. Renal response rates were higher in the normal GFR group (81.8% and 90.9% at 6 and 12 months, respectively) than in the decreased GFR group (9.1% and 18.2% at 6 and 12 months, respectively; p＜0.001). Normal GFR and anti-La were associated with renal response to rituximab, with hazard ratios of 9.256 (p=0.008) and 5.478 (p=0.041), respectively. Conclusion Rituximab is an effective therapy for refractory/relapsing LN, particularly in patients with preserved renal function.

Purpose: The aim of this study was to compare the diameter and volume of liver metastases on CT images in relation to overall survival and tumor response in patients with gastric cancer liver metastases (GCLM) treated with chemotherapy. Materials and Methods: We recruited 43 patients with GCLM who underwent chemotherapy as a first-line treatment. We performed a three-dimensional quantification of the metastases for each patient. An independent survival analysis using the Response Evaluation Criteria in Solid Tumors (RECIST) was performed and compared to volumetric measurements. Overall survival was evaluated using Kaplan-Meier analysis and compared using Cox proportional hazard ratios following univariate analyses. Results: When patients were classified as responders or non-responders based on volumetric criteria, the median overall survival was 23.6 months [95% confidence interval (CI), 8.63–38.57] and 7.6 months (95% CI, 3.78–11.42), respectively (p = 0.039). The volumetric analysis and RECIST of the non-progressing and progressing groups showed similar results based on the Kaplan-Meier method (p = 0.006) and the Cox proportional hazard model (p = 0.008). Conclusion Volumetric assessment of liver metastases could be an alternative predictor of overall survival for patients with GCLM treated with chemotherapy.

Objective: . Hydronephrosis, a common complication of idiopathic retroperitoneal fibrosis (iRPF), may lead to poor renal outcomes unless resolved in a timely manner. IgG4-related diseases characterized by elevated serum IgG4 levels are responsible for a few iRPF cases. However, the underlying immunologic features of most iRPF cases have not been clearly defined, and these cases exhibit varied responses to medical treatment. Thus, we investigated the predictive factors for hydronephrosis-associated outcomes among iRPF patients. Methods: . We retrospectively included 18 iRPF patients with hydronephrosis in a tertiary referral hospital from 2012 to 2019. Hydronephrosis improvement was assessed on images taken 6 months after diagnosis. Categorical variables were compared using chi-square or Fisher’s exact test. Continuous variables were compared using Mann–Whitney U-test. Results: . On follow-up images, 8 patients (44.4%) showed an improvement in hydronephrosis. Patients with improvement more frequently had reverse serum IgG4/IgG3 ratio (87.5% vs. 30%, p=0.025), abdominal aorta involvement (87.5% vs. 30%, p=0.025) and glucocorticoid treatment administration (87.5% vs. 30%, p=0.025) than those without improvement. The proportion of elevated serum IgG4 level did not differ between the two groups.Even in the 14 cases with normal serum IgG4 levels, reverse serum IgG4/IgG3 ratio was more frequently observed in patients with improvement than in those without improvement (83.3% vs. 12.5%, p=0.026). Conclusion . The reverse serum IgG4/IgG3ratio was associated with hydronephrosis improvement in iRPF patients, suggesting it to be a suitable serologic marker for predicting favourable responses to glucocorticoid treatment.

Purpose: The aim of this study was to compare the diameter and volume of liver metastases on CT images in relation to overall survival and tumor response in patients with gastric cancer liver metastases (GCLM) treated with chemotherapy. Materials and Methods: We recruited 43 patients with GCLM who underwent chemotherapy as a first-line treatment. We performed a three-dimensional quantification of the metastases for each patient. An independent survival analysis using the Response Evaluation Criteria in Solid Tumors (RECIST) was performed and compared to volumetric measurements. Overall survival was evaluated using Kaplan-Meier analysis and compared using Cox proportional hazard ratios following univariate analyses. Results: When patients were classified as responders or non-responders based on volumetric criteria, the median overall survival was 23.6 months [95% confidence interval (CI), 8.63–38.57] and 7.6 months (95% CI, 3.78–11.42), respectively (p = 0.039). The volumetric analysis and RECIST of the non-progressing and progressing groups showed similar results based on the Kaplan-Meier method (p = 0.006) and the Cox proportional hazard model (p = 0.008). Conclusion Volumetric assessment of liver metastases could be an alternative predictor of overall survival for patients with GCLM treated with chemotherapy.

Purpose: Intensive care unit (ICU) bed availability is key to critical patient care. In many countries, older patients generally account for a significant proportion of hospitalizations and ICU admissions. Therefore, considering the rapidly increasing aging population in South Korea, it is important to establish whether the demand for critical care is currently met by available ICU beds. Materials and Methods: We evaluated a 9-year trend in ICU bed supply and ICU length of stay in South Korea between 2011 and 2019 in a population-based cross-sectional analysis, using data from the Korean Health Insurance Review & Assessment Service and Statistics database. We described the changes in ICU bed rates in adult (≥20 years) and older adult (≥65 years) populations. ICU length of stay was categorized similarly and was used to predict future ICU bed demands. Results: The ICU bed rate per 100000 adults increased from 18.5 in 2011 to 19.5 in 2019. In contrast, the ICU bed rate per 100000 older adults decreased from 127.6 in 2011 to 104.0 in 2019. ICU length of stay increased by 43.8% for adults and 55.6% for older adults. In 2019, the regional differences in the ICU bed rate nearly doubled, and the ICU length of stay increased six-fold. The ICU bed occupancy rate in South Korea is expected to rise to 102.7% in 2030. Conclusion The discrepancy between the demand and supply of ICU beds in South Korea requires urgent action to anticipate future ICU demands.