OBJECTIVES: The escalating burden of cardiovascular disease (CVD) is a critical public health issue worldwide. CVD, especially acute myocardial infarction (AMI) and stroke, is the leading contributor to morbidity and mortality in Korea. We aimed to develop algorithms for identifying AMI and stroke events from the National Health Insurance Service (NHIS) database and validate these algorithms through medical record review. METHODS: We first established a concept and definition of “hospitalization episode,” taking into account the unique features of health claims-based NHIS database. We then developed first and recurrent event identification algorithms, separately for AMI and stroke, to determine whether each hospitalization episode represents a true incident case of AMI or stroke. Finally, we assessed our algorithms’ accuracy by calculating their positive predictive values (PPVs) based on medical records of algorithm- identified events. RESULTS: We developed identification algorithms for both AMI and stroke. To validate them, we conducted retrospective review of medical records for 3,140 algorithm-identified events (1,399 AMI and 1,741 stroke events) across 24 hospitals throughout Korea. The overall PPVs for the first and recurrent AMI events were around 92% and 78%, respectively, while those for the first and recurrent stroke events were around 88% and 81%, respectively. CONCLUSIONS We successfully developed algorithms for identifying AMI and stroke events. The algorithms demonstrated high accuracy, with PPVs of approximately 90% for first events and 80% for recurrent events. These findings indicate that our algorithms hold promise as an instrumental tool for the consistent and reliable production of national CVD statistics in Korea.

OBJECTIVES: Cardiovascular diseases are a leading cause of mortality worldwide, and acute myocardial infarction (AMI) is particularly fatal condition. We evaluated the incidence and case fatality rates of AMI in Korea from 2011 to 2020. METHODS: We utilized data from the National Health Insurance Services to calculate crude, age-standardized, and age-specific incidence rates, along with 30-day and 1-year case fatality rates, of AMI from 2011 to 2020. Age-standardized incidence rates were determined using direct standardization to the 2005 population. RESULTS: The crude incidence rate of AMI per 100,000 person-years consistently increased from 44.7 in 2011 to 68.3 in 2019, before decreasing slightly to 66.2 in 2020. The age-standardized incidence rate of AMI displayed a 19% rise from 2011 to 2019, followed by a slight decline in 2020. The increasing trend for AMI incidence was more pronounced in males than in females. Both 30-day and 1-year case fatality rates remained stable among younger individuals but showed a decrease among older individuals. There was a minor surge in case fatality in 2020, particularly among recurrent AMI cases. CONCLUSIONS Over the past decade, the AMI incidence rate in Korea has consistently increased, with a slight downturn in 2020. The case fatality rate has remained relatively stable except for a minor increase in 2020. This study provides data for continuous surveillance, the implementation of targeted interventions, and the advancement of research aimed at AMI in Korea.

Background: Coronary artery disease patients undergoing percutaneous coronary intervention (PCI) often exhibit reduced left ventricular ejection fraction (LVEF). However, the impact of LV dysfunction status in conjunction with platelet reactivity on clinical outcomes has not been previously investigated. Methods: From the multicenter PTRG-DES (Platelet function and genoType-Related long-term prognosis in DES-treated patients) consortium, the patients were classified as preserved-EF (PEF: LVEF ≥ 50%) and reduced-EF (REF: LVEF< 5 0%) group by echocardiography. Platelet reactivity was measured using VerifyNow P2Y 12 assay and high platelet reactivity (HPR) was defined as PRU ≥ 252. The major adverse cardiac and cerebrovascular events (MACCEs) were a composite of death, myocardial infarction, stent thrombosis and stroke at 5 years after PCI. Major bleeding was defined as Bleeding Academic Research Consortium bleeding types 3–5. Results: A total of 13,160 patients from PTRG-DES, 9,319 (79.6%) patients with the results of both PRU and LVEF were analyzed. The incidence of MACCE and major bleeding was higher in REF group as compared with PEF group (MACCEs: hazard ratio [HR] 2.17, P < 0.001, 95% confidence interval [CI] 1.85–2.55; major bleeding: HR 1.78, P < 0.001, 95% CI 1.39–2.78).The highest rate of MACCEs was found in patients with REF and HPR, and the difference between the groups was statistically significant (HR 3.14 in REF(+)/HPR(+) vs. PEF(+)/HPR(-) group,P <0.01, 95% CI 2.51–3.91). The frequency of major bleeding was not associated with the HPR in either group. Conclusion LV dysfunction was associated with an increased incidence of MACCEs and major bleeding in patients who underwent PCI. The HPR status further exhibited significant increase of MACCEs in patients with LV dysfunction in a large, real-world registry.Trial Registration: ClinicalTrials.gov Identifier: NCT04734028

Apurinic/apyrimidinic endonuclease 1/redox factor-1 (APE1/Ref-1) is a multipotent protein that plays essential roles in cellular responses to oxidative stress. Methods: To examine the role of APE1/Ref-1 in ischemia-reperfusion (I/R) injuries and hydrogen peroxide (H2O2)-induced renal tubular apoptosis, we studied male C57BL6 mice and human proximal tubular epithelial (HK-2) cells treated with H2O2 at different concentrations. The colocalization of APE1/Ref-1 in the proximal tubule, distal tubule, thick ascending limb, and collecting duct was observed with confocal microscopy. The overexpression of APE1/Ref-1 with knockdown cell lines using an APE1/Ref-1–specific DNA or small interfering RNA (siRNA) was used for the apoptosis assay. The promotor activity of nuclear factor kappa B (NF-κB) was assessed and electrophoretic mobility shift assay was conducted. Results: APE1/Ref-1 was predominantly localized to the renal tubule nucleus. In renal I/R injuries, the levels of APE1/Ref-1 protein were increased compared with those in kidneys subjected to sham operations. The overexpression of APE1/Ref-1 in HK-2 cells enhanced the Bax/Bcl-2 ratio as a marker of apoptosis. Conversely, the suppression of APE1/Ref-1 expression by siRNA in 1-mM H2O2-treated HK-2 cells decreased the Bax/Bcl-2 ratio, the phosphorylation of extracellular signal-regulated kinase (ERK) 1/2, p38, c-Jun N-terminal kinase (JNK) 1/2, and NF-κB. In HK-2 cells, the promoter activity of NF-κB increased following H2O2 exposure, and this effect was further enhanced by APE1/Ref-1 transfection. Conclusion: The inhibition of APE1/Ref-1 with siRNA attenuated H2O2-induced apoptosis through the modulation of mitogen-activated protein kinase pathways mediated by ERK, JNK, and p38 and the nuclear activation of NF-κB and proapoptotic factors.

Background: Programmed death ligand 1 (PD-L1) expression cannot currently be predicted through radiological findings. This study aimed to develop a prediction model capable of differentiating between positive and negative PD-L1 expression through a radiomics-based investigation of computed tomography (CT) images in patients with urothelial carcinoma. Methods: Sixty-four patients with urothelial carcinoma who underwent immunohistochemical testing for PD-L1 were retrospectively reviewed. The number of patients in the positive and negative PD-L1 groups (PD-L1 expression >5%) was 14 and 50, respectively. CT images obtained 90 seconds after contrast medium administration were selected for radiomic extraction. For all tumors, 1,691 radiomic features were extracted from CT using a manually segmented three-dimensional volume of interest. Univariate and multivariate logistic regression analyses were performed to identify radiomic features that were significant predictors of PD-L1 expression. For the radiomics-based model, a receiver operating characteristic (ROC) analysis was performed. Results: Among 64 patients, 14 were included in the PD-L1 positive group. Logistic regression analysis found that the following radiomic features significantly predicted PD-L1 expression: wavelet-low-pass, low-pass, and high-pass filters (LLH)_gray-level size-zone matrix (GLSZM)_SmallAreaEmphasis, wavelet-LLH_firstorder_Energy, log-sigma-0-5-mm-3D_GLSZM_SmallAreaHighGrayLevelEmphasis, original_shape_Maximum2DDiameterColumn, wavelet-low-pass, low-pass, and low-pass filters (LLL)_gray-level run-length matrix (GLRLM)_ShortRunEmphasis, and exponential_firstorder_Kurtosis. The radiomics signature was –4.0934+21.6224 (wavelet-LLH_GLSZM_SmallAreaEmphasis)+0.0044 (wavelet-LLH_firstorder_Energy)–4.7389 (log-sigma-0-5-mm-3D_GLSZM_SmallAreaHighGrayLevelEmphasis)+0.0573 (original_shape_Maximum2DDiameterColumn)–29.5892 (wavelet-LLL_GLRLM_ShortRunEmphasis)–0.4324 (exponential_firstorder_Kurtosis). The area under the ROC curve model representing the radiomics signature for differentiating cases that were deemed PD-L1 positive based on immunohistochemistry was 0.96. Conclusions This preliminary radiomics model derived from contrast-enhanced CT predicted PD-L1 positivity in patients with urothelial cancer.

Purpose: In a preclinical study using a swine myocardial infarction (MI) model, a delayed enhancement (DE)-multi-detector computed tomography (MDCT) scan was performed using a hybrid system alongside diagnostic invasive coronary angiography (ICA) without the additional use of a contrast agent, and demonstrated an excellent correlation in the infarct area compared with histopathologic specimens. In the present investigation, we evaluated the feasibility and diagnostic accuracy of a myocardial viability assessment by DE-MDCT using a hybrid system comprising ICA and MDCT alongside diagnostic ICA without the additional use of a contrast agent. Materials and Methods: We prospectively enrolled 13 patients (median age: 67 years) with a previous MI (>6 months) scheduled to undergo ICA. All patients underwent cardiac magnetic resonance (CMR) imaging before diagnostic ICA. MDCT viability scans were performed concurrently with diagnostic ICA without the use of additional contrast. The total myocardial scar volume per patient and average transmurality per myocardial segment measured by DE-MDCT were compared with those from DE-CMR. Results: The DE volume measured by MDCT showed an excellent correlation with the volume measured by CMR (r=0.986, p<0.0001). The transmurality per segment by MDCT was well-correlated with CMR (r=0.900, p<0.0001); the diagnostic performance of MDCT in differentiating non-viable from viable myocardium using a 50% transmurality criterion was good with a sensitivity, specificity, positive predictive value, negative predictive value, and accuracy of 87.5%, 99.5%, 87.5%, 99.5%, and 99.1%, respectively. Conclusion The feasibility of the DE-MDCT viability assessment acquired simultaneously with conventional ICA was proven in patients with chronic MI using DE-CMR as the reference standard.

Background: Although almost all interventional pulmonologists agree that rigid bronchoscopy is irreplaceable in the field of interventional pulmonology, less is known about the types of diseases that the procedure is used for and what difficulties the operators face during the procedure. The purpose of this study is to evaluate what diseases rigid bronchoscopy is used for, whether it is widely used, and what challenges the operators face in Korea. Methods: We enrolled 14 hospitals in this retrospective cohort of patients who underwent rigid bronchoscopy between 2003 and 2020. An online survey was conducted with 14 operators to investigate the difficulties associated with the procedure. Results: While the number of new patients at Samsung Medical Center (SMC) increased from 189 in 2003–2005 to 468 in 2018–2020, that of other institutions increased from 0 to 238.The proportion of SMC patients in the total started at 100% and steadily decreased to 59.2%.The proportion of malignancy as the indication for the procedure steadily increased from 29.1% to 43.0%, whereas post-tuberculous stenosis (25.4% to 12.9%) and post-intubation stenosis (19.0% to 10.9%) steadily decreased (all P for trends < 0.001). In the online survey, half of the respondents stated that over the past year they performed less than one procedure per month. The fewer the procedures performed within the last year, the more likely collaboration with other departments was viewed as a recent obstacle (Spearman correlation coefficient, r s = −0.740, P = 0.003) and recent administrative difficulties were encountered (r s = −0.616, P = 0.019). Conclusion This study demonstrated that the number of patients undergoing rigid bronchoscopy has been increasing, especially among cancer patients. For this procedure to be used more widely, it will be important for beginners to systematically learn about the procedure itself as well as to achieve multidisciplinary consultation.

Background: Guselkumab is a monoclonal antibody that selectively blocks the p19 subunit of interleukin-23. It has shown good efficacy and safety profile in several clinical trials of plaque psoriasis. However, studies on the efficacy of guselkumab in patients treated with other biologics are lacking. Objective: We aimed to investigate the efficacy and safety profile of guselkumab in patients with moderate-to-severe plaque psoriasis. We also compared the efficacy of guselkumab between biologic-naïve (Bio-Naïve) and biologicexperienced (Bio-Ex) patients. Methods: This multicenter, retrospective study included 72 patients treated with guselkumab. The patients’ clinical characteristics and psoriasis area and severity index (PASI) scores were recorded at each visit. The PASI90 and PASI100 responses and mean PASI scores were compared between the Bio-Naïve and Bio-Ex groups. Results: Fifty-five Bio-Naïve patients and 17 Bio-Ex patients were included in the study. At week 20, there were no significant differences in the PASI90 (64.2% vs. 53.8%) and PASI100 (28.3% vs. 15.4%) responses between the groups. However, at weeks 36 and 44, the PASI90 response (week 36: 89.2% vs. 36.4% and week 44: 97.8% vs. 63.6%) and the PASI100 response (week 36: 64.9% vs. 18.2% and week 44: 68.9% vs. 27.3%) were significantly higher in the Bio-Naïve group (p＜0.05). There were no differences in PASI90 and PASI100 responses between the groups in terms of other clinical characteristics and comorbidities at week 20. Conclusion The efficacy of guselkumab remained consistent among patients in whom other biologics had failed. However, the efficacy was slightly lower in the Bio-Ex group than in the Bio-Naïve group.

Objective: We aimed to present the study design and baseline cross-sectional participant characteristics of biobank innovations for chronic cerebrovascular disease with Alzheimer’s disease study (BICWALZS) participants. Methods: A total of 1,013 participants were enrolled in BICWALZS from October 2016 to December 2020. All participants underwent clinical assessments, basic blood tests, and standardized neuropsychological tests (n=1,013). We performed brain magnetic resonance imaging (MRI, n=817), brain amyloid positron emission tomography (PET, n=713), single nucleotide polymorphism microarray chip (K-Chip, n=949), locomotor activity assessment (actigraphy, n=200), and patient-derived dermal fibroblast sampling (n=175) on a subset of participants. Results: The mean age was 72.8 years, and 658 (65.0%) were females. Based on clinical assessments, total of 168, 534, 211, 80, and 20 had subjective cognitive decline, mild cognitive impairment (MCI), Alzheimer’s dementia, vascular dementia, and other types of dementia or not otherwise specified, respectively. Based on neuroimaging biomarkers and cognition, 199, 159, 78, and 204 were cognitively normal (CN), Alzheimer’s disease (AD)-related cognitive impairment, vascular cognitive impairment, and not otherwise specified due to mixed pathology (NOS). Each group exhibited many differences in various clinical, neuropsychological, and neuroimaging results at baseline. Baseline characteristics of BICWALZS participants in the MCI, AD, and vascular dementia groups were generally acceptable and consistent with 26 worldwide dementia cohorts and another independent AD cohort in Korea. Conclusion The BICWALZS is a prospective and longitudinal study assessing various clinical and biomarker characteristics in older adults with cognitive complaints. Details of the recruitment process, methodology, and baseline assessment results are described in this paper.

Background/Aims: Previous studies have reported the protective effects of tauroursodeoxycholic acid (TUDCA) on gastric epithelial cells in some animal models, but the precise mechanisms are unclear. This study examined the effects of TUDCA on NF-κB signaling in gastric epithelial cells. Moreover, the protective effects of TUDCA in experimental gastritis models induced by ethanol and NSAID were evaluated and compared with ursodeoxycholic acid (UDCA). Methods: After a pretreatment with TUDCA or UDCA, human gastric epithelial MKN-45 cells were stimulated with tumor necrosis factor (TNF)-α to activate NF-κB signaling. A real-time PCR (RT-PCR) for human interleukin (IL)-1 mRNA was performed. An electrophoretic mobility shift assay (EMSA) and immunoblot analyses were carried out. In murine models, after a pretreatment with TUDCA or UDCA, ethanol and indomethacin were administered via oral gavage. Macroscopic and microscopic assessments were performed to evaluate the preventive effects of TUDCA and UDCA on murine gastritis. Results: A pretreatment with TUDCA downregulated the IL-1α mRNA levels in MKN-45 cells stimulated with TNF-α, as assessed by RT-PCR. As determined using EMSA, a pretreatment with TUDCA reduced the TNF-α-induced NF-κB DNA binding activity. A pretreatment with TUDCA inhibited IκBα phosphorylation induced by TNF-α, as assessed by immunoblot analysis. TUDCA attenuated the ethanol-induced and NSAID-induced gastritis in murine models, as determined macroscopically and microscopically. Conclusions TUDCA inhibited NF-κB signaling in gastric epithelial cells and ameliorated ethanol- and NSAID-induced gastritis in murine models. These results support the potential of TUDCA for the prevention of gastritis in humans.