Background and Objectives: Angiographic assessment of coronary stenosis severity using quantitative coronary angiography (QCA) is often inconsistent with that based on fractional flow reserve (FFR) or intravascular ultrasound (IVUS). We investigated the incidence of discrepancies between QCA and FFR or IVUS, and the outcomes of FFR- and IVUS-guided strategies in discordant coronary lesions. Methods: This study was a post-hoc analysis of the FLAVOUR study. We used a QCA-derived diameter stenosis (DS) of 60% or greater, the highest tertile, to classify coronary lesions as concordant or discordant with FFR or IVUS criteria for percutaneous coronary intervention (PCI). The patient-oriented composite outcome (POCO) was defined as a composite of death, myocardial infarction, or revascularization at 24 months. Results: The discordance rate between QCA and FFR or IVUS was 30.2% (n=551). The QCAFFR discordance rate was numerically lower than the QCA-IVUS discordance rate (28.2% vs. 32.4%, p=0.050). In 200 patients with ≥60% DS, PCI was deferred according to negative FFR (n=141) and negative IVUS (n=59) (15.3% vs. 6.5%, p<0.001). The POCO incidence was comparable between the FFR- and IVUS-guided deferral strategies (5.9% vs. 3.4%, p=0.479).Conversely, 351 patients with DS <60% underwent PCI according to positive FFR (n=118) and positive IVUS (n=233) (12.8% vs. 25.9%, p<0.001). FFR- and IVUS-guided PCI did not differ in the incidence of POCO (9.5% vs. 6.5%, p=0.294). Conclusions The proportion of QCA-FFR or IVUS discordance was approximately one third for intermediate coronary lesions. FFR- or IVUS-guided strategies for these lesions were comparable with respect to POCO at 24 months.

Background: The Korean government is implementing policy to reduce medical costs and improve treatment related for human immunodeficiency virus (HIV) patients. The level of cost reduction and the benefits provided vary depending on how individuals with HIV utilize the system. This study aims to determine exact HIV prevalence by analyzing healthcare utilization patterns and examining differences in healthcare usage based on how individuals pay for their medical expenses. Materials and Methods: We analyzed National Health Insurance Service (NHIS) claims data from 2002 to 2021. From a total of 106,675 individuals with at least one HIV-related claim, 22,779 participants were selected for this study. Results: Data from Korea Disease Control and Prevention Agency annual reports indicated that 93% of HIV patients were male, while NHIS data showed 84%. In the analysis of those exempted from registration, it was found that the registration rate for female patients is notably low, with adults between the ages of 20 and 40 making up 80% of the total. The registration rate in Gangwon State was lower than Seoul. The treatment experience rate was much higher in the registered group (93.0%) than the unregistered group (4.9%). Also, there was a big difference in treatment continuity rates: 76.2% for registered individuals and 2.8% for non-registered individuals. Conclusion The exempt calculation system for health insurance improves HIV care. However, those diagnosed anonymously or with reduced medical costs may be less likely to continue HIV treatment, so a new policy is needed to ensure anonymity and treatment continuity.

Background and Objectives: Angiographic assessment of coronary stenosis severity using quantitative coronary angiography (QCA) is often inconsistent with that based on fractional flow reserve (FFR) or intravascular ultrasound (IVUS). We investigated the incidence of discrepancies between QCA and FFR or IVUS, and the outcomes of FFR- and IVUS-guided strategies in discordant coronary lesions. Methods: This study was a post-hoc analysis of the FLAVOUR study. We used a QCA-derived diameter stenosis (DS) of 60% or greater, the highest tertile, to classify coronary lesions as concordant or discordant with FFR or IVUS criteria for percutaneous coronary intervention (PCI). The patient-oriented composite outcome (POCO) was defined as a composite of death, myocardial infarction, or revascularization at 24 months. Results: The discordance rate between QCA and FFR or IVUS was 30.2% (n=551). The QCAFFR discordance rate was numerically lower than the QCA-IVUS discordance rate (28.2% vs. 32.4%, p=0.050). In 200 patients with ≥60% DS, PCI was deferred according to negative FFR (n=141) and negative IVUS (n=59) (15.3% vs. 6.5%, p<0.001). The POCO incidence was comparable between the FFR- and IVUS-guided deferral strategies (5.9% vs. 3.4%, p=0.479).Conversely, 351 patients with DS <60% underwent PCI according to positive FFR (n=118) and positive IVUS (n=233) (12.8% vs. 25.9%, p<0.001). FFR- and IVUS-guided PCI did not differ in the incidence of POCO (9.5% vs. 6.5%, p=0.294). Conclusions The proportion of QCA-FFR or IVUS discordance was approximately one third for intermediate coronary lesions. FFR- or IVUS-guided strategies for these lesions were comparable with respect to POCO at 24 months.

Background: The Korean government is implementing policy to reduce medical costs and improve treatment related for human immunodeficiency virus (HIV) patients. The level of cost reduction and the benefits provided vary depending on how individuals with HIV utilize the system. This study aims to determine exact HIV prevalence by analyzing healthcare utilization patterns and examining differences in healthcare usage based on how individuals pay for their medical expenses. Materials and Methods: We analyzed National Health Insurance Service (NHIS) claims data from 2002 to 2021. From a total of 106,675 individuals with at least one HIV-related claim, 22,779 participants were selected for this study. Results: Data from Korea Disease Control and Prevention Agency annual reports indicated that 93% of HIV patients were male, while NHIS data showed 84%. In the analysis of those exempted from registration, it was found that the registration rate for female patients is notably low, with adults between the ages of 20 and 40 making up 80% of the total. The registration rate in Gangwon State was lower than Seoul. The treatment experience rate was much higher in the registered group (93.0%) than the unregistered group (4.9%). Also, there was a big difference in treatment continuity rates: 76.2% for registered individuals and 2.8% for non-registered individuals. Conclusion The exempt calculation system for health insurance improves HIV care. However, those diagnosed anonymously or with reduced medical costs may be less likely to continue HIV treatment, so a new policy is needed to ensure anonymity and treatment continuity.

Background and Objectives: Angiographic assessment of coronary stenosis severity using quantitative coronary angiography (QCA) is often inconsistent with that based on fractional flow reserve (FFR) or intravascular ultrasound (IVUS). We investigated the incidence of discrepancies between QCA and FFR or IVUS, and the outcomes of FFR- and IVUS-guided strategies in discordant coronary lesions. Methods: This study was a post-hoc analysis of the FLAVOUR study. We used a QCA-derived diameter stenosis (DS) of 60% or greater, the highest tertile, to classify coronary lesions as concordant or discordant with FFR or IVUS criteria for percutaneous coronary intervention (PCI). The patient-oriented composite outcome (POCO) was defined as a composite of death, myocardial infarction, or revascularization at 24 months. Results: The discordance rate between QCA and FFR or IVUS was 30.2% (n=551). The QCAFFR discordance rate was numerically lower than the QCA-IVUS discordance rate (28.2% vs. 32.4%, p=0.050). In 200 patients with ≥60% DS, PCI was deferred according to negative FFR (n=141) and negative IVUS (n=59) (15.3% vs. 6.5%, p<0.001). The POCO incidence was comparable between the FFR- and IVUS-guided deferral strategies (5.9% vs. 3.4%, p=0.479).Conversely, 351 patients with DS <60% underwent PCI according to positive FFR (n=118) and positive IVUS (n=233) (12.8% vs. 25.9%, p<0.001). FFR- and IVUS-guided PCI did not differ in the incidence of POCO (9.5% vs. 6.5%, p=0.294). Conclusions The proportion of QCA-FFR or IVUS discordance was approximately one third for intermediate coronary lesions. FFR- or IVUS-guided strategies for these lesions were comparable with respect to POCO at 24 months.

Background: The Korean government is implementing policy to reduce medical costs and improve treatment related for human immunodeficiency virus (HIV) patients. The level of cost reduction and the benefits provided vary depending on how individuals with HIV utilize the system. This study aims to determine exact HIV prevalence by analyzing healthcare utilization patterns and examining differences in healthcare usage based on how individuals pay for their medical expenses. Materials and Methods: We analyzed National Health Insurance Service (NHIS) claims data from 2002 to 2021. From a total of 106,675 individuals with at least one HIV-related claim, 22,779 participants were selected for this study. Results: Data from Korea Disease Control and Prevention Agency annual reports indicated that 93% of HIV patients were male, while NHIS data showed 84%. In the analysis of those exempted from registration, it was found that the registration rate for female patients is notably low, with adults between the ages of 20 and 40 making up 80% of the total. The registration rate in Gangwon State was lower than Seoul. The treatment experience rate was much higher in the registered group (93.0%) than the unregistered group (4.9%). Also, there was a big difference in treatment continuity rates: 76.2% for registered individuals and 2.8% for non-registered individuals. Conclusion The exempt calculation system for health insurance improves HIV care. However, those diagnosed anonymously or with reduced medical costs may be less likely to continue HIV treatment, so a new policy is needed to ensure anonymity and treatment continuity.

Background and Objectives: Angiographic assessment of coronary stenosis severity using quantitative coronary angiography (QCA) is often inconsistent with that based on fractional flow reserve (FFR) or intravascular ultrasound (IVUS). We investigated the incidence of discrepancies between QCA and FFR or IVUS, and the outcomes of FFR- and IVUS-guided strategies in discordant coronary lesions. Methods: This study was a post-hoc analysis of the FLAVOUR study. We used a QCA-derived diameter stenosis (DS) of 60% or greater, the highest tertile, to classify coronary lesions as concordant or discordant with FFR or IVUS criteria for percutaneous coronary intervention (PCI). The patient-oriented composite outcome (POCO) was defined as a composite of death, myocardial infarction, or revascularization at 24 months. Results: The discordance rate between QCA and FFR or IVUS was 30.2% (n=551). The QCAFFR discordance rate was numerically lower than the QCA-IVUS discordance rate (28.2% vs. 32.4%, p=0.050). In 200 patients with ≥60% DS, PCI was deferred according to negative FFR (n=141) and negative IVUS (n=59) (15.3% vs. 6.5%, p<0.001). The POCO incidence was comparable between the FFR- and IVUS-guided deferral strategies (5.9% vs. 3.4%, p=0.479).Conversely, 351 patients with DS <60% underwent PCI according to positive FFR (n=118) and positive IVUS (n=233) (12.8% vs. 25.9%, p<0.001). FFR- and IVUS-guided PCI did not differ in the incidence of POCO (9.5% vs. 6.5%, p=0.294). Conclusions The proportion of QCA-FFR or IVUS discordance was approximately one third for intermediate coronary lesions. FFR- or IVUS-guided strategies for these lesions were comparable with respect to POCO at 24 months.

Background/Aims: Tegoprazan is a novel potassium-competitive acid blocker that has beneficial effects on acid-related disorders such as gastroesophageal reflux and peptic ulcer diseases.This study aimed to validate the effect of tegoprazan on endoscopic submucosal dissection (ESD)-induced artificial ulcers. Methods: Patients from 16 centers in Korea who underwent ESD for gastric neoplasia were enrolled. After ESD, pantoprazole was administered intravenously for 48 hours. The patients were randomly allocated to either the tegoprazan or esomeprazole group. Tegoprazan 50 mg or esomeprazole 40 mg were administered for 4 weeks, after which gastroscopic evaluation was performed. If the artificial ulcer had not healed, the same dose of tegoprazan or esomeprazole was administered for an additional 4 weeks, and a gastroscopic evaluation was performed. Results: One hundred sixty patients were enrolled in this study. The healing rates of artificial ulcers at 4 weeks were 30.3% (23/76) and 22.1% (15/68) in the tegoprazan and esomeprazole groups, respectively (p=0.006). At 8 weeks after ESD, the cumulative ulcer healing rates were 73.7% (56/76) and 77.9% (53/68) in the tegoprazan and esomeprazole groups, respectively (p=0.210). Delayed bleeding occurred in two patients in the tegoprazan group (2.6%) and in one patient in the esomeprazole group (1.5%). Other adverse events were negligible in both groups. Conclusions Tegoprazan showed similar effects on post-ESD artificial ulcer healing in comparison with esomeprazole.

Viral load and the duration of viral shedding of severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) are important determinants of the transmission of coronavirus disease 2019.In this study, we examined the effects of viral doses on the lung and spleen of K18-hACE2 transgenic mice by temporal histological and transcriptional analyses. Approximately, 1×105 plaque-forming units (PFU) of SARS-CoV-2 induced strong host responses in the lungs from 2 days post inoculation (dpi) which did not recover until the mice died, whereas responses to the virus were obvious at 5 days, recovering to the basal state by 14 dpi at 1×102 PFU. Further, flow cytometry showed that number of CD8+ T cells continuously increased in 1×102 PFU-virusinfected lungs from 2 dpi, but not in 1×105 PFU-virus-infected lungs. In spleens, responses to the virus were prominent from 2 dpi, and number of B cells was significantly decreased at 1×105PFU; however, 1×102 PFU of virus induced very weak responses from 2 dpi which recovered by 10 dpi. Although the defense responses returned to normal and the mice survived, lung histology showed evidence of fibrosis, suggesting sequelae of SARS-CoV-2 infection. Our findings indicate that specific effectors of the immune response in the lung and spleen were either increased or depleted in response to doses of SARS-CoV-2. This study demonstrated that the response of local and systemic immune effectors to a viral infection varies with viral dose, which either exacerbates the severity of the infection or accelerates its elimination.

Background: The severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) Omicron variant (B.1.1.529) is dominating coronavirus disease 2019 (COVID-19) worldwide. The waning protective effect of available vaccines against the Omicron variant is a critical public health issue. This study aimed to assess the impact of the third COVID-19 vaccination on immunity against the SARS-CoV-2 Omicron BA.1 strain in older individuals. Materials and Methods: Adults aged ≥60 years who had completed two doses of the homologous COVID-19 vaccine with either BNT162b2 (Pfizer/BioNTech, New York, NY, USA, BNT) or ChAdOx1 nCoV (SK bioscience, Andong-si, Gyeongsangbuk-do, Korea, ChAd) were registered to receive the third vaccination. Participants chose either BNT or mRNA-1273 (Moderna, Norwood, MA, USA, m1273) mRNA vaccine for the third dose and were categorized into four groups: ChAd/ChAd/BNT, ChAd/ChAd/m1273, BNT/BNT/BNT, and BNT/BNT/m1273. Four serum specimens were obtained from each participant at 0, 4, 12, and 24 weeks after the third dose (V1, V2, V3, and V4, respectively).Serum-neutralizing antibody (NAb) activity against BetaCoV/Korea/KCDC03/2020 (NCCP43326, ancestral strain) and B.1.1.529 (NCCP43411, Omicron BA.1 variant) was measured using plaque reduction neutralization tests. A 50% neutralizing dilution (ND 50 ) >10 was considered indicative of protective NAb titers. Results: In total, 186 participants were enrolled between November 24, 2021, and June 30, 2022. The respective groups received the third dose at a median (interquartile range [IQR]) of 132 (125 - 191), 123 (122 - 126), 186 (166 -193), and 182 (175 - 198) days after the second dose. Overall, ND 50 was lower at V1 against Omicron BA.1 than against the ancestral strain. NAb titers against the ancestral strain and Omicron BA.1 variant at V2 were increased at least 30-fold (median [IQR], 1235.35 [1021.45 - 2374.65)] and 129.8 [65.3 - 250.7], respectively). ND 50 titers against the ancestral strain and Omicron variant did not differ significantly among the four groups (P= 0.57). NAb titers were significantly lower against the Omicron variant than against the ancestral strain at V3 (median [IQR], 36.4 (17.55 - 75.09) vs. 325.9 [276.07 - 686.97]; P = 0.012). NAb titers against Omicron at V4 were 16 times lower than that at V3. Most sera exhibited a protective level (ND 50 >10) at V4 (75.0% [24/32], 73.0% [27/37], 73.3% [22/30], and 70.6% [12/17] in the ChAd/ChAd/BNT, ChAd/ChAd/m1273, BNT/BNT/BNT, and BNT/BNT/m1273 groups, respectively), with no significant differences among groups (P = 0.99). Conclusion A third COVID-19 mRNA vaccine dose restored waning NAb titers against Omicron BA.1. Our findings support a third-dose vaccination program to prevent the waning of humoral immunity to SARS-CoV-2.