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 and Objectives: Ultimaster™, a third-generation sirolimus-eluting stent using biodegradable polymer, has been introduced to overcome long term adverse vascular events, such as restenosis or stent thrombosis. In the present study, we aimed to evaluate the 12-month clinical outcomes of Ultimaster™ stents in Korean patients with coronary artery disease. Methods: This study is a multicenter, prospective, observational registry across 12 hospitals. To reflect real-world clinical evidence, non-selective subtypes of patients and lesions were included in this study. The study end point was target lesion failure (TLF) (the composite of cardiac death, target vessel myocardial infarction [MI], and target lesion revascularization [TLR]) at 12-month clinical follow up. Results: A total of 576 patients were enrolled between November 2016 and May 2021. Most of the patients were male (76.5%), with a mean age of 66.0±11.2 years. Among the included patients, 40.1% had diabetes mellitus (DM) and 67.9% had acute coronary syndrome (ACS).At 12 months, the incidence of TLF was 4.1%. The incidence of cardiac death was 1.5%, MI was 1.0%, TLR was 2.7%, and stent thrombosis was 0.6%. In subgroup analysis based on the presence of ACS, DM, hypertension, dyslipidemia, or bifurcation, there were no major differences in the incidence of the primary endpoint. Conclusions The present registry shows that Ultimaster™ stent is safe and effective for routine real-world clinical practice in non-selective Korean patients, having a low rate of adverse events at least up to 12 months.

Background/Aims: The ursodeoxycholic acid (UDCA) response score (URS) was developed to identify poor responders to UDCA before treatment, in order to offer timely and proactive intervention. However, validation of the URS in Asian population is warranted. Methods: A total of 173 Asian patients diagnosed with primary biliary cholangitis (PBC) between 2007 and 2016 at seven academic institutions in Korea who started UDCA treatment were analyzed to validate the performance of URS. UDCA response was defined as an alkaline phosphatase level less than 1.67 times the upper limit of normal after 1-year of UDCA treatment. In addition, prognostic performance of URS for liver-related events, defined as newly developed hepatic decompensation or hepatocellular carcinoma was evaluated. Results: After 1 year of UDCA treatment, 133 patients (76.9%) achieved UDCA response. UDCAresponse rate was 98.7% for those with URS ≥1.41 (n=76) and 58.8% for those with URS <1.41(n=97). The area under the receiver operating characteristic curve of URS in predicting UDCAresponse was 0.84 (95% confidence interval, 0.78 to 0.88). During a median follow-up of 6.5years, liver-related events developed in 18 patients (10.4%). Among 117 patients with PBC stage I-III by histological evaluation, the 5-year liver-related event-free survival rate differed accordingto the URS; 100% for URS ≥1.41 and 86.5% for URS <1.41 (p=0.005). Conclusions URS demonstrated good performance in predicting a UDCA treatment response in Asian PBC patients. In addition, the risk of liver-related events differed according to the URS for the PBC stage. Thus, URS can be used to predict the response and clinical outcome in patients with PBC.

Background/Aims: This study aimed to investigate whether pretransplant frailty can predict postoperative morbidity and mortality after liver transplantation (LT) in patients with cirrhosis. Methods: We retrospectively reviewed 242 patients who underwent LT between 2018 and 2020 at a tertiary hospital in Korea. Results: Among them, 189 patients (78.1%) received LT from a living donor. Physical frailty at baseline was assessed by the Short Physical Performance Battery (SPPB), by which patientswere categorized into two groups: frail (SPPB <10) and non-frail (SPPB ≥10). Among the whole cohort (age, 55.0±9.2 years; male, 165 [68.2%]), 182 patients were classified as non-frail and 60 patients were classified as frail. Posttransplant survival was shorter in the frail group than the non-frail group (9.3 months vs 11.6 months). Postoperative intensive care unit stay was longer in the frail group than in the non-frail group (median, 6 days vs 4 days), and the 30-day complication rate was higher in the frail group than in the non-frail group (78.3% vs 59.3%). Frailty was an independent risk factor for posttransplant mortality (adjusted hazard ratio, 2.38; 95% confidence interval, 1.02 to 5.57). In subgroup analysis, frail patients showed lower posttransplant survival regardless of history of hepatocellular carcinoma and donor type. Conclusions Assessment of pretransplant frailty, as measured by SPPB, provides important prognostic information for clinical outcomes in cirrhotic patients undergoing LT.

Objective: This study aimed to investigate the impact of baseline values and temporal changes in body composition parameters, including skeletal muscle index (SMI) and visceral adipose tissue area (VAT), measured using serial computed tomography (CT) imaging on the prognosis of operable breast cancers in Asian patients. Materials and Methods: This study retrospectively included 627 Asian female (mean age ± standard deviation [SD], 53.6 ± 8.3 years) who underwent surgery for stage I–III breast cancer between January 2011 and September 2012. Body composition parameters, including SMI and VAT, were semi-automatically calculated on baseline abdominal CT at the time of diagnosis and follow-up CT for post-treatment surveillance. Serial changes in SMI and VAT were calculated as the delta values. Multivariable Cox regression analysis was used to evaluate the association of baseline and delta SMI and VAT values with disease-free survival. Results: Among 627 patients, 56 patients (9.2%) had breast cancer recurrence after a median of 40.5 months. The mean value ± SD of the baseline SMI and baseline VAT were 43.7 ± 5.8 cm2 /m2 and 72.0 ± 46.0 cm2 , respectively. The mean value of the delta SMI was -0.9 cm2 /m2 and the delta VAT was 0.5 cm2 . The baseline SMI and VAT were not significantly associated with disease-free survival (adjusted hazard ratio [HR], 0.983; 95% confidence interval [CI], 0.937–1.031; p = 0.475 and adjusted HR, 1.001; 95% CI, 0.995–1.006; p = 0.751, respectively). The delta SMI and VAT were also not significantly associated with disease-free survival (adjusted HR, 0.894; 95% CI, 0.766–1.043; p = 0.155 and adjusted HR, 1.001; 95% CI, 0.989–1.014; p = 0.848, respectively). Conclusion Our study revealed that baseline and early temporal changes in SMI and VAT were not independent prognostic factors regarding disease-free survival in Asian patients undergoing surgery for breast cancer.

Purpose: To determine the incidence of atypical ductal hyperplasia (ADH) in needle biopsy and the upgrade rate to carcinoma, and to evaluate difference in findings between the upgrade and non-upgrade groups. Materials and Methods: Among 9660 needle biopsies performed over 48 months, we reviewed the radiologic and histopathologic findings of ADH and compared the differences in imaging findings (mammography and breast US) and biopsy methods between the upgrade and non-upgrade groups. Results: The incidence of ADH was 1.7% (169/9660). Of 112 resected cases and 30 cases followed-up for over 2 years, 35 were upgraded to carcinoma (24.6%, 35/142). The upgrade rates were significantly different according to biopsy methods: US-guided core needle biopsy (US-CNB) (40.7%, 22/54) vs. stereotactic-vacuum-assisted biopsy (S-VAB) (16.0%, 12/75) vs. US-guided VAB (US-VAB) (7.7%, 1/13) (p = 0.002). Multivariable analysis showed that only US-CNB (odds ratio = 5.19, 95% confidence interval: 2.16–13.95, p < 0.001) was an independent predictor for pathologic upgrade. There was no upgrade when a sonographic mass was biopsied by US-VAB (n = 7) Conclusion The incidence of ADH was relatively low (1.7%) and the upgrade rate was 24.6%. Surgical excision should be considered because of the considerable upgrade rate, except in the case of US-VAB.

BACKGROUND: Autologous fat grafting is one of the most common procedures used in plastic surgery to correct soft tissue deficiency or depression deformity. However, its clinical outcomes are often suboptimal, and lack of metabolic and architectural support at recipient sites affect fat survival leading to complications such as cyst formation, calcification.Extracellular matrix-based scaffolds, such as allograft adipose matrix (AAM) and poly(lactic-co-glycolic) acid (PLGA), have shown exceptional clinical promise as regenerative scaffolds. Magnesium hydroxide (MH), an alkaline ceramic, has attracted attention as a potential additive to improve biocompatibility. We attempted to combine fat graft with regenerative scaffolds and analyzed the changes and viability of injected fat graft in relation to the effects of injectable natural, and synthetic (PLGA/MH microsphere) biomaterials. METHODS: In vitro cell cytotoxicity, angiogenesis of the scaffolds, and wound healing were evaluated using human dermal fibroblast cells. Subcutaneous soft-tissue integration of harvested fat tissue was investigated in vivo in nude mouse with random fat transfer protocol Fat integrity and angiogenesis were identified by qRT-PCR and immunohistochemistry. RESULTS: In vitro cell cytotoxicity was not observed both in AAM and PLGA/MH with human dermal fibroblast.PLGA/MH and AAM showed excellent wound healing effect. in vivo, the AAM and PLGA/MH retained volume compared to that in the only fat group. And the PLGA/MH showed the highest angiogenesis and anti-inflammation. CONCLUSION In this study, a comparison of the volume retention effect and angiogenic ability between autologous fat grafting, injectable natural, and synthetic biomaterials will provide a reasonable basis for fat grafting.

Purpose: To evaluate the accuracy of magnetic resonance imaging (MRI)-guided breast biopsy. Methods: We retrospectively reviewed the clinical data of 111 consecutive patients referred for MRI-guided breast biopsy after mammography and breast ultrasound between May 2009 and April 2019. After excluding 37 patients without follow-up images (> 2 years), 74 patients (74 lesions) were finally included. We reviewed the histologic results of MRI-guided biopsy and subsequent surgery, post-biopsy management, and breast cancer development during followup. We investigated the false-negative rate, ductal carcinoma in situ (DCIS) underestimation, atypical ductal hyperplasia (ADH) underestimation rate, and technical failure rate of MRIguided biopsy. Results: Among 74 scheduled MRI-guided biopsies, six were canceled because biopsy was deemed unnecessary, while three failed due to technical difficulties (technical failure rate:3/68, 4.4%). MRI-guided biopsy was performed in 65 patients, of which 18 patients were diagnosed with malignant lesions, 46 with benign lesions, and one with ADH bordering on DCIS. Subsequent surgery (n = 27) showed DCIS underestimation in three cases (3/7, 43%), ADH underestimation in two cases (1/2, 50%), as well as seven concordant benign and 11 concordant malignant lesions. The overall false-negative rate was 4.3% (2/46). Thirty-eight out of 48 benign lesions were followed-up (median period, 5.8 years; interquartile range, 4.1 years) without subsequent surgery. Thirty-seven concordant benign lesions were stable (n = 27) or disappeared (n = 10); however, the size of one discordant benign lesion increased on follow-up MRI and it was diagnosed as DCIS after 1 year. Conclusion MRI-guided biopsy is an accurate method for exclusion of malignancy with a very low false-negative rate.

Purpose: To evaluate the accuracy of magnetic resonance imaging (MRI)-guided breast biopsy. Methods: We retrospectively reviewed the clinical data of 111 consecutive patients referred for MRI-guided breast biopsy after mammography and breast ultrasound between May 2009 and April 2019. After excluding 37 patients without follow-up images (> 2 years), 74 patients (74 lesions) were finally included. We reviewed the histologic results of MRI-guided biopsy and subsequent surgery, post-biopsy management, and breast cancer development during followup. We investigated the false-negative rate, ductal carcinoma in situ (DCIS) underestimation, atypical ductal hyperplasia (ADH) underestimation rate, and technical failure rate of MRIguided biopsy. Results: Among 74 scheduled MRI-guided biopsies, six were canceled because biopsy was deemed unnecessary, while three failed due to technical difficulties (technical failure rate:3/68, 4.4%). MRI-guided biopsy was performed in 65 patients, of which 18 patients were diagnosed with malignant lesions, 46 with benign lesions, and one with ADH bordering on DCIS. Subsequent surgery (n = 27) showed DCIS underestimation in three cases (3/7, 43%), ADH underestimation in two cases (1/2, 50%), as well as seven concordant benign and 11 concordant malignant lesions. The overall false-negative rate was 4.3% (2/46). Thirty-eight out of 48 benign lesions were followed-up (median period, 5.8 years; interquartile range, 4.1 years) without subsequent surgery. Thirty-seven concordant benign lesions were stable (n = 27) or disappeared (n = 10); however, the size of one discordant benign lesion increased on follow-up MRI and it was diagnosed as DCIS after 1 year. Conclusion MRI-guided biopsy is an accurate method for exclusion of malignancy with a very low false-negative rate.

Background/Aims: Glecaprevir/pibrentasvir (G/P) is the first pan-genotypic direct-acting antiviral combination therapy approved in Korea. An integrated analysis of five phase II and III trials was conducted to evaluate the efficacy and safety of G/P in Korean patients with chronic hepatitis C virus (HCV) infection. Methods: The study analyzed pooled data on Korean patients with HCV infection enrolled in the ENDURANCE 1 and 2, SURVEYOR II part 4 and VOYAGE I and II trials, which evaluated the efficacy and safety of 8 or 12 weeks of G/P treatment. The patients were either treatment-naïve or had received sofosbuvir or interferon-based treatment. Efficacy was evaluated by assessing the rate of sustained virologic response at 12 weeks posttreatment (SVR12). Safety was evaluated by monitoring adverse events (AEs) and laboratory assessments. Results: The analysis included 265 patients; 179 (67.5%) were HCV treatment-naïve, and most patients were either subgenotype 1B (48.7%) or 2A (44.5%). In the intention-to-treat population, 262 patients (98.9%) achieved SVR12. Three patients did not achieve SVR12: one had virologic failure and two had non-virologic failures. Most AEs were grade 1/2; eight patients (3.0%) expe-rienced at least one grade ≥3 AE. No serious AEs related to G/P treatment were reported, and grade ≥3 hepatic laboratory abnormalities were rare (0.8%). Conclusions G/P therapy was highly efficacious and well tolerated in Korean patients with HCV infection, with most patients achieving SVR12. The safety profile was comparable to that observed in a pooled analysis of a global pan-genotypic population of patients with HCV infection who received G/P.