Cardiac organoids have emerged as invaluable tools for assessing the impact of diverse substances on heart function.This report introduces guidelines for general requirements for manufacturing cardiac organoids and conducting cardiac organoid-based assays, encompassing protocols, analytical methodologies, and ethical considerations. In the quest to employ recently developed three-dimensional cardiac organoid models as substitutes for animal testing, it becomes imperative to establish robust criteria for evaluating organoid quality and conducting toxicity assessments. This guideline addresses this need, catering to regulatory requirements, and describes common standards for organoid quality and toxicity assessment methodologies, commensurate with current technological capabilities. While acknowledging the dynamic nature of technological progress and the potential for future comparative studies, this guideline serves as a foundational framework. It offers a comprehensive approach to standardized cardiac organoid testing, ensuring scientific rigor, reproducibility, and ethical integrity in investigations of cardiotoxicity, particularly through the utilization of human pluripotent stem cell-derived cardiac organoids.

Background: This study aimed to generate a Z score calculation model for coronary artery diameter of normal children and adolescents to be adopted as the standard calculation method with consensus in clinical practice. Methods: This study was a retrospective, multicenter study that collected data from multiple institutions across South Korea. Data were analyzed to determine the model that best fit the relationship between the diameter of coronary arteries and independent demographic parameters. Linear, power, logarithmic, exponential, and square root polynomial models were tested for best fit. Results: Data of 2,030 subjects were collected from 16 institutions. Separate calculation models for each sex were developed because the impact of demographic variables on the diameter of coronary arteries differs according to sex. The final model was the polynomial formula with an exponential relationship between the diameter of coronary arteries and body surface area using the DuBois formula. Conclusion A new coronary artery diameter Z score model was developed and is anticipated to be applicable in clinical practice. The new model will help establish a consensus-based Z score model.

Background: Limited data are available on the mortality rates of patients receiving extracorporeal membrane oxygenation (ECMO) support for coronavirus disease 2019 (COVID-19). We aimed to analyze the relationship between COVID-19 and clinical outcomes for patients receiving ECMO. Methods: We retrospectively investigated patients with COVID-19 pneumonia requiring ECMO in 19 hospitals across Korea from January 1, 2020 to August 31, 2021. The primary outcome was the 90-day mortality after ECMO initiation. We performed multivariate analysis using a logistic regression model to estimate the odds ratio (OR) of 90-day mortality. Survival differences were analyzed using the Kaplan–Meier (KM) method. Results: Of 127 patients with COVID-19 pneumonia who received ECMO, 70 patients (55.1%) died within 90 days of ECMO initiation. The median age was 64 years, and 63% of patients were male. The incidence of ECMO was increased with age but was decreased after 70 years of age. However, the survival rate was decreased linearly with age. In multivariate analysis, age (OR, 1.048; 95% confidence interval [CI], 1.010–1.089; P = 0.014) and receipt of continuous renal replacement therapy (CRRT) (OR, 3.069; 95% CI, 1.312–7.180; P = 0.010) were significantly associated with an increased risk of 90-day mortality. KM curves showed significant differences in survival between groups according to age (65 years) (log-rank P = 0.021) and receipt of CRRT (log-rank P = 0.004). Conclusion Older age and receipt of CRRT were associated with higher mortality rates among patients with COVID-19 who received ECMO.

Background: The study aimed to review the initiatives and activities of the Korean Blood Safety Project Group (KBSPG) from 2012 to 2021 to present its work domestically and internationally, and to set up future directions for the KBSPG. Methods: Details of the KBSPG’s projects were organized by task. This project was supported by the Korean Ministry of Health and Welfare. The final annual reports and data posted on the website of the KBSPG were used for analysis. Results: The KBSPG completed 14 tasks, including training and sharing of the latest information with workers of blood centers and transfusion services in medical institutes, external proficiency surveys for donor blood screening tests, and maintenance of a national registration system. The results of these tasks have contributed to the fulfillment of work of the relevant national departments, the establishment and operation of related websites, the publication of annual reports, the implementation of workshops and training programs, the operation of regional networks for blood transfusion management, and the production and distribution of information leaflets and training videos.Additionally, the KBSPG has developed and revised guidelines and standards and published related papers. Conclusion The KBSPG’s continuous efforts improved the quality of blood centers and transfusion services in medical institutes, thus contributing to the national blood management services. To further improve blood management work and ensure blood safety, the KBSPG must expand its scope and continue to pursue its important mission. (Korean J Blood Transfus 2023;34:1-11)

Background/Aims: Chronic hepatitis C (CHC) is the second leading cause of liver-related mortality and is more prevalent in the elderly population in Korea. Decisions to initiate treatment and selection of proper antiviral agents may be challenging among elderly patients due to relevant comorbidities, comedications, and drug-drug interaction (DDI). It may be helpful to understand the current demographic status and comorbidities of CHC patients in the country. Methods: Patients aged ≥ 18 years and diagnosed with CHC (KCD-7 code B18.2) were extracted from the Korean Health Insurance Review & Assessment Service database in 2018. Data on comorbidities and comedications were assessed and potential DDIs were analyzed. Results: A total of 50,476 patients with CHC, with a mean age of 60.3 years and 46.7% male patients were identified. The proportion of patients with cirrhosis, hepatocellular carcinoma, and liver transplantation was 6.0%, 4.1%, and 0.3%, respectively and 37.2% of patients were more than 65 years of age. The three most common comorbidities were diseases of the digestive system (83.7%), respiratory system (58.2%), and musculoskeletal system and connective tissue (57.6%). The three most common comedications were analgesics (91.6%), gastrointestinal agents (85%), and antibacterials (80.3%). Lipid-lowering agents and anticonvulsants were prescribed in 28.5% and 14.8% of patients. Rate of potential DDI for contraindication was 2.2%, 13.1%, and 15.6% with sofosbuvir/velpatasvir, ledipasvir/sofosbuvir, and glecaprevir/pibrentasvir. Conclusions With the increasing age of patients with CHC, comorbidity, comedication, and potential DDI should be considered when choosing antivirals in Korea. Sofosbuvir-based regimens showed favorable DDI profiles among Korean patients.

Background/Aims: Our study aimed to evaluate the long-term outcomes and risk factors forrelapse after anti-tumor necrosis factor (TNF)-α cessation in inflammatory bowel disease (IBD) patients because they are not well established. Methods: A retrospective multicenter cohort study was conducted involving patients with Crohn’s disease (CD) or ulcerative colitis (UC) from 10 referral hospitals in Korea who discontinued firstline anti-TNF therapy after achieving clinical remission. Results: A total of 109 IBD patients (71 CD and 38 UC) with a median follow-up duration of 56months were analyzed. The cumulative relapse rates at 1, 3, and 5 years were 11.3%, 46.7%, and 62.5% for CD patients and 28.9%, 45.3%, and 60.9% for UC patients. Multivariable Coxanalysis revealed that discontinuation owing to the clinician’s decision was associated with lower risk of relapse (vs patient’s preference: hazard ratio [HR], 0.13; 95% confidence interval [CI], 0.04 to 0.48; p=0.002) and adalimumab use was associated with higher risk of relapse (vs infliximab: HR, 4.42; 95% CI, 1.24 to 17.74; p=0.022) in CD patients. Mucosal healing was associated with lower risk of relapse (vs nonmucosal healing: HR, 0.12; 95% CI, 0.02 to 0.83; p=0.031) in UC patients. Anti-TNF re-induction was provided to 52 patients, and a response was obtained in 50 patients. However, 25 of them discontinued retreatment owing to a loss of response (n=15), the patient’s preference (n=6), and other factors (n=4). Conclusions More than 60% of IBD patients in remission under anti-TNF therapy relapsed within 5 years of treatment cessation. Anti-TNF re-induction was effective. However, half of the patients discontinued anti-TNF therapy, and 50% of these patients discontinued treatment owing to loss of response.

Background/Aims: Our study aimed to evaluate the long-term outcomes and risk factors forrelapse after anti-tumor necrosis factor (TNF)-α cessation in inflammatory bowel disease (IBD) patients because they are not well established. Methods: A retrospective multicenter cohort study was conducted involving patients with Crohn’s disease (CD) or ulcerative colitis (UC) from 10 referral hospitals in Korea who discontinued firstline anti-TNF therapy after achieving clinical remission. Results: A total of 109 IBD patients (71 CD and 38 UC) with a median follow-up duration of 56months were analyzed. The cumulative relapse rates at 1, 3, and 5 years were 11.3%, 46.7%, and 62.5% for CD patients and 28.9%, 45.3%, and 60.9% for UC patients. Multivariable Coxanalysis revealed that discontinuation owing to the clinician’s decision was associated with lower risk of relapse (vs patient’s preference: hazard ratio [HR], 0.13; 95% confidence interval [CI], 0.04 to 0.48; p=0.002) and adalimumab use was associated with higher risk of relapse (vs infliximab: HR, 4.42; 95% CI, 1.24 to 17.74; p=0.022) in CD patients. Mucosal healing was associated with lower risk of relapse (vs nonmucosal healing: HR, 0.12; 95% CI, 0.02 to 0.83; p=0.031) in UC patients. Anti-TNF re-induction was provided to 52 patients, and a response was obtained in 50 patients. However, 25 of them discontinued retreatment owing to a loss of response (n=15), the patient’s preference (n=6), and other factors (n=4). Conclusions More than 60% of IBD patients in remission under anti-TNF therapy relapsed within 5 years of treatment cessation. Anti-TNF re-induction was effective. However, half of the patients discontinued anti-TNF therapy, and 50% of these patients discontinued treatment owing to loss of response.

Purpose: The purpose of this study was to update the previously developed nursing practice guideline for enteral nutrition (EN). Methods: The guideline update was done in 22 steps using standardized methodology for nursing practice guidelines. Results: The updated EN guideline consisted of 16 domains and 228 recommendations. The domains and number of recommendations in each domain were for IDSA (Infectious Diseases Society of America): 8 on general instruction, 9 on general instruction for special nutrition, 9 on general instruction for EN, 3 on assessment of EN, 10 on access to EN, 18 on EN device insertion, 16 on selection and preparation of nutritional supplements, 46 on administration and stopping EN, 22 on maintenance and management of EN, 9 on monitoring EN, 16 on prevention and management of complications of EN, 18 on medication administration, 20 on EN in various situations, 20 on prevention of errors, 1 on nursing education, and 3 on nursing documentation. For the levels of evidence, there were 9.7% for level I, 13.1% for level II, 62.5% for level III and 1.1% for GRADE (Grading of Recommendations Assessment, Development and Evaluation): 3.3% for low, 0.8% for moderate, 9.3% for very low. A total of 133 recommendations were newly developed and 10 previous recommendations were modified. Conclusion This updated EN nursing practice guideline can be used to enhance evidence-based practice in fundamentals of nursing practice and it should be disseminated to nurses nationwide in order to improve the efficiency of EN practice.

Background: In February 2020, a coronavirus disease 2019 (COVID-19) outbreak was reported in fitness centers in Cheonan, Korea. Methods: From February 24 to March 13, an epidemiological investigation was conducted on the fitness center outbreak. All those who were screened were tested for severe acute respiratory syndrome coronavirus-2 (SARS CoV-2) using real-time reverse transcriptase polymerase chain reaction. Contacts were traced and self-isolated for 14 days. We determined the epidemiological characteristics of confirmed cases of SARS-CoV-2 infection, and estimated the time-dependent reproduction number to assess the transmission dynamics of the infection. Results: A total of 116 cases were confirmed, and 1,687 contacts were traced. The source cases were 8 Zumba instructors who led aerobics classes in 10 fitness centers, and had the largest average number of contacts. A total of 57 Zumba class participants, 37 of their family members, and 14 other contacts were confirmed as cases. The attack rate was 7.3%. The contacts at Zumba classes and homes had a higher attack rate than other contacts. The mean serial interval (± standard deviation) were estimated to be 5.2 (± 3.8) days. The time-dependent reproduction number was estimated to be 6.1 at the beginning of the outbreak, but it dropped to less than 1, 2 days after the epidemiological investigation was launched. Conclusion The results suggest that the COVID-19 outbreak was effectively contained with rigorous contact tracing, isolating, and testing in combination with social distancing without a lock-down.

Background: Although hypertension (HTN) is a well-established major risk factor for renal progression in patients with chronic kidney disease (CKD), few studies investigating its role in renal deterioration in the general population with normal renal function (NRF) have been published. Here, we analyzed the correlation between blood pressure (BP) and impaired renal function (IRF) in Korean adults with NRF. Methods: Data for the study were collected from the national health screening database of the Korean National Health Insurance Service. Patients whose baseline estimated glomerular filtration rate (eGFR) was less than 60 mL/min/1.73 m 2 or whose baseline urinalysis showed evidence of proteinuria were excluded. IRF was defined as an eGFR below 60 mL/min/1.73 m 2 . We performed follow up for eGFR for 6 years from 2009 to 2015 and investigated IRF incidence according to baseline BP status. We categorized our study population into two groups of IRF and NRF according to eGFR level in 2015. Results: During 6 years of follow-up examinations, IRF developed in 161,044 (2.86%) of 5,638,320 subjects. The IRF group was largely older, and the incidence was higher in females and patients with low income, HTN, diabetes mellitus, dyslipidemia, and obesity compared with the NRF group. Subjects whose systolic BP was more than 120 mmHg or whose diastolic BP was more than 70 mmHg had an increased risk of developing IRF compared with subjects with lower BP (odds ratio [OR], 1.037; 95% confidence interval [CI], 1.014–1.061 vs. OR, 1.021; 95% CI, 1.004–1.038). Conclusion BP played a major role in renal progression in the general population with NRF.Strict BP control may help prevent CKD in the general population.