Although percutaneous coronary intervention (PCI) for chronic total occlusion (CTO) has been increasing in recent years, CTO PCI is still one of the most challenging procedures with relatively higher rates of procedural complications and adverse clinical events after PCI. Due to the innate limitations of invasive coronary angiography, intravascular imaging (IVI) has been used as an adjunctive tool to complement PCI, especially in complex coronary artery disease. Considering the complexity of CTO lesions, the role of IVI is particularly important in CTO intervention. IVI has been a useful adjunctive tool in every step of CTO PCI including assisted wire crossing, confirmation of wire location within CTO segment, and stent optimization. The meticulous use of IVI has been one of the greatest contributors to recent progress of CTO PCI. Nevertheless, studies evaluating the role of IVI during CTO PCI are limited. The current review provides a comprehensive overview of the mechanistic advantages of IVI in CTO PCI, summarizes previous studies and trials, and presents future perspective of IVI in CTO PCI.

Elevated blood cholesterol and triglyceride levels induced by secondary causes are frequently observed. The identification and appropriate handling of these causes are essential for secondary dyslipidemia treatment. Major secondary causes of hypercholesterolemia and hypertriglyceridemia include an unhealthy diet, diseases and metabolic conditions affecting lipid levels, and therapeutic side effects. It is imperative to correct secondary causes prior to initiating conventional lipid-lowering therapy. Guideline-based lipid therapy can then be administered based on the subsequent lipid levels.

Cancer treatment-induced bone loss (CTBL) is associated with anti-tumor treatments, including endocrine therapies, chemotherapeutic treatments, radiotherapy, glucocorticoids, and tyrosine kinase inhibitors. Osteoporosis, characterized by the loss of bone mass, can increase the risk of fractures, leading to mortality and long-term disability, even after cancer remission. Cancer and osteoporosis have marked clinical and pathogenetic similarities. Both have a multifactorial etiology, affect the geriatric population, and markedly influence quality of life. Lifestyle management, including calcium and vitamin D supplementation, is recommended but the supporting evidence is limited. Oral and injectable bisphosphonates are effective for osteoporosis and malignant bone disease. Bisphosphonates increase bone mineral density (BMD) in patients with CTBL. Denosumab is also used in the management of CTBL; in clinical trials, it improved BMD and reduced the risk of fracture. Currently, there are no bone anabolic therapies for patients with cancer. Appropriate therapies are necessary to maintain optimal bone health, particularly in patients at heightened risk.

The emerging field of gut-lung axis research has revealed a complex interplay between the gut microbiota and respiratory health, particularly in asthma. This review comprehensively explored the intricate relationship between these two systems, focusing on their influence on immune responses, inflammation, and the pathogenesis of respiratory diseases. Recent studies have demonstrated that gut microbiota dysbiosis can contribute to asthma onset and exacerbation, prompting investigations into therapeutic strategies to correct this imbalance. Probiotics and prebiotics, known for their ability to modulate gut microbial compositions, were discussed as potential interventions to restore immune homeostasis. The impact of antibiotics and metabolites, including short-chain fatty acids produced by the gut microbiota, on immune regulation was examined. Fecal microbiota transplantation has shown promise in various diseases, but its role in respiratory disorders is not established. Innovative approaches, including mucus transplants, inhaled probiotics, and microencapsulation strategies, have been proposed as novel therapeutic avenues. Despite challenges, including the sophisticated adaptability of microbial communities and the need for mechanistic clarity, the potential for microbiota-based interventions is considerable. Collaboration between researchers, clinicians, and other experts is essential to unravel the complexities of the gut-lung axis, paving a way for innovative strategies that could transform the management of respiratory diseases.

Background/Aims: Limited knowledge exists regarding the optimal timing and relative advantages of primary surgery compared to medical treatment in ileocecal Crohn's disease (CD). This study aimed to compare long-term outcomes between medication-based treatment versus surgery in newly diagnosed ileocecal CD patients in an Asian population. Methods: Among the 885 patients diagnosed with CD and enrolled in the study site hospital cohort between 1980 and 2013, 93 (10.5%) had ileocecal CD. Patients were categorized into either the surgical or medical remission group based on their initial management strategy that led to remission. The rates of relapse, hospitalization, and surgery after achieving remission were compared using Kaplan-Meier curves. Results: The numbers of patients assigned to surgical and medical remission groups were 15 (17.0%) and 73 (83.0%), respectively. The surgical remission group exhibited a lower relapse rate and longer maintenance of remission (10.7 vs. 3.7 yr; p = 0.017) during a median follow-up of 6.6 years. Hospitalization after the first remission tended to be lower in the surgical remission group (p = 0.054). No cases required repeated intestinal resection after the initial surgical remission, whereas a 23% surgery rate was reported at 5 years after initial medical treatment (p = 0.037). In the multivariable analysis, the initial medication-based treatment was significantly associated with relapse (hazard ratio = 3.23, p = 0.039). Conclusions: In selected cases of localized ileocecal CD, ileocolic resection might be a favorable alternative to medication-based treatment, as it demonstrates a lower relapse rate and longer maintenance of remission.

Background/Aims: The association between inflammatory bowel disease (IBD) and gallstone and renal stone formation has been established. However, few studies have investigated this association in patients with intestinal Behçet's disease (BD). We aimed to examine the prevalence of gallstones and renal stones in patients with intestinal BD and identify potential risk factors. Methods: We analyzed gallstone and renal stone occurrences in 553 patients diagnosed with intestinal BD who had undergone cross-sectional imaging examinations between March 2005 and April 2021 at the IBD Center, Severance Hospital, Seoul, South Korea. Logistic regression models were used to identify risk factors for gallstone and renal stone formation. Results: Of 553 patients over a mean 12.1-year duration, 141 (25.4%) patients had gallstones and 35 (6.3%) had renal stones. In multivariate logistic regression analysis, disease duration > 19 years (OR 2.91, 95% CI 1.56-5.44, p < 0.001), prior intestinal BD-related surgery (OR 2.29, 95% CI 1.42-3.68, p < 0.001), and disease activity index for intestinal BD scores ≥ 75 (OR 2.23, 95% CI 1.12-4.45, p = 0.022) were associated with increased gallstone occurrence. A positive correlation was observed between renal stones, disease duration > 19 years (OR 5.61, 95% CI 1.98-15.90, p = 0.001) and frequent hospitalization (> 3 times) (OR 3.29, 95% CI 1.52-7.13, p = 0.002). No significant correlation was observed between gallstone and renal stone occurrence. Conclusions: These findings contribute to greater understanding concerning gallstone and renal stone prevalence and associated risk factors in patients with intestinal BD.

Background/Aims: Fecal microbiota transplantation (FMT) is a promising therapy for inducing and maintaining remission in patients with ulcerative colitis (UC). However, FMT has not been approved for UC treatment in Korea. Our study aimed to investigate patient perceptions of FMT under the national medical policy. Methods: This was a prospective, multicenter study. Patients with UC ≥ 19 years of age were included. Patients were surveyed using 22 questions on FMT. Changes in perceptions of FMT before and after education were also compared. Results: A total of 210 patients with UC were enrolled. We found that 51.4% of the patients were unaware that FMT was an alternative treatment option for UC. After reading the educational materials on FMT, more patients were willing to undergo this procedure (27.1% vs. 46.7%; p < 0.001). The preferred fecal donor was the one recommended by a physician (41.0%), and the preferred transplantation method was the oral capsule (30.4%). A large proportion of patients (50.0%) reported that the national medical policy influenced their choice of FMT treatment. When patients felt severe disease activity, their willingness to undergo FMT increased (92.3% vs. 43.1%; p = 0.001). Conclusions: Education can increase preference for FMT in patients with UC. When patients have severe disease symptoms or their quality of life decreases their willingness to undergo FMT increases. Moreover, national medical policies may influence patient choices regarding FMT.

Background/Aims: Achieving rapid reduction of low-density lipoprotein cholesterol (LDL-C) levels below 55 mg/dL in patients with acute myocardial infarction (AMI) can be challenging with statins alone. This single-center, retrospective study aimed to assess the impact of single-dose injection of evolocumab 140 mg on LDL-C levels during the peri-percutaneous coronary intervention (PCI) period in patients with AMI. Methods: A total of 95 patients with AMI who underwent PCI were divided into the evolocumab (n = 50) and non-evolocumab (n = 45) groups. Results: The percentage change of LDL-C level at 1-3 weeks from baseline was 78.4 ± 13.4% reduction in the evolocumab group versus 45.6 ± 22.6% in the non-evolocumab group, with a mean difference of -33.5% between the groups (95% CI: -42.6 to -24.5%; p < 0.001). The achievement rate of LDL-C levels below 55 mg/dL at 1-3 weeks was significantly higher in the evolocumab group than in the non-evolocumab group (97.7% vs. 60.0%, p < 0.001). Conclusions: Patients with AMI who received single-dose injection of evolocumab 140 mg during the peri-PCI period had a significantly greater LDL-C reduction and higher proportion of patients achieved the target LDL-C level in the early phase AMI than those who did not receive evolocumab.

Background/Aims: Immune checkpoint inhibitors (ICIs) can induce immune-related adverse events, including endocrine dysfunctions, which can have serious consequences on patient health and quality of life. The clinical course and characteristics of immune-related hypophysitis (irH) are not well established. This study aimed to analyze the clinical course and characteristics of irH. Methods: This single-center, retrospective study analyzed data from electronic medical records of Asan Medical Center, spanning January 2017 through June 2021. It included adult patients with solid tumors who underwent thyroid and adrenal function tests, along with gonadotropin and/or growth hormone evaluations, following the initiation of ICI treatment within the same period. The study explored the clinical characteristics of ICI-treated patients with and without irH, the incidence of irH, the time to irH onset, and the associated hormonal changes. Results: Twenty-one patients were included in this analysis. Clinical characteristics did not differ significantly between the irH (n = 13) and non-irH (n = 8) groups. Deficiency rates in the irH group were 23.1% for thyroid-stimulating hormone (n = 3), 76.9% for adrenocorticotropic hormone (n = 10), 61.5% for gonadotropin (n = 8), and 15.4% for growth hormone (n = 2). The overall incidence was 0.9 per person-year, with 6-month and 1-year cumulative incidences of 38.8% and 57.1%, respectively. The median time from ICI initiation to irH diagnosis was 7.7 months. Time to levothyroxine replacement was shorter in the irH group. Conclusions: The findings provide evidence that could facilitate the prediction of ICI-induced irH based on clinical course and characteristics.

Background/Aims: Obesity has known to be a modifiable risk factor associated with worse outcomes in chronic kidney disease (CKD), but few studies have examined the impact of obesity on CKD incidence in the general population. The purpose of this study was to investigate the role of body mass index (BMI) and waist-to-hip ratio (WHR) as predictors of incident CKD and to evaluate the impact of weight reduction on CKD prevention. Methods: A total of 2,711 participants from a community-based cohort with normal renal function were prospectively analyzed. Among participants with obesity, we analyzed the change in WHR to evaluate the association of obesity reduction with CKD development. Results: During a mean follow-up of 11.03 ± 4.22 years, incident CKD occurred in 190 (7.0%) participants. In the fully adjusted multivariable Cox proportional hazard models, the risk of incident CKD increased with higher BMI (hazard ratio, 1.06; 95% confidence interval, 1.00-1.11; p = 0.033) and higher WHR (hazard ratio, 1.33; 95% confidence interval, 1.07-1.66; p = 0.009). In the Kaplan-Meier analysis, cumulative adverse renal events were significantly more common in the maintained obesity group than in the reduced obesity group (p = 0.001). Conclusions: Both higher BMI and WHR were associated with development of CKD, but the magnitude of the effect of WHR was higher than that of BMI. Moreover, reducing obesity would be beneficial for renal prognosis.

Background/Aims: This study aimed to assess the impact of non-pharmaceutical interventions (NPIs) implemented during the COVID-19 pandemic on nationally notifiable infectious diseases (NNIDs) in South Korea. Methods: Long-term data on seven NNIDs from 2018 to 2021 were analyzed to identify trends and change points using a change point detection technique. The timings of the NPI implementations were compared to the identified change points to determine their association. Results: Varicella, mumps, and scarlet fever showed a significant decrease in incidence following the implementation of NPIs during the COVID-19 pandemic. These diseases, which are primarily transmitted through respiratory droplets, demonstrated a clear response to NPIs. However, carbapenem-resistant Enterobacterales (CRE) showed an increasing trend unrelated to the timing of NPI implementation, suggesting the complex nature of controlling healthcare-associated infections. Hepatitis A, hepatitis C, and scrub typhus did not show significant changes associated with NPIs, likely due to their non-respiratory route of transmission. Conclusions: NPIs effectively controlled NNIDs, particularly those transmitted through respiratory infections. However, the impact varied depending on the disease. Understanding the effectiveness and limitations of NPIs is crucial for developing comprehensive public health strategies during infectious disease outbreaks.

Background/Aims: The aim of this study was to compare the short- and long-term retention rates of biologic and targeted synthetic disease-modifying anti-rheumatic drugs (b/tsDMARDs) in Korean patients with seropositive rheumatoid arthritis. Methods: This study was conducted with 1,538 treatment courses of 1,063 patients, including adalimumab (n = 332), etanercept (n = 369), infliximab (n = 146), abatacept (n = 152), tocilizumab (n = 299), tofacitinib (n = 136), and baricitinib (n = 104), in patients with seropositive rheumatoid arthritis who started b/tsDMARD treatment between 2008 and 2020 at Seoul St. Mary's Hospital. Discontinuation 1 and 3 years after the first prescription of each drug was investigated. Kaplan-Meier estimates of time to discontinuation were calculated to compare the difference in drug retention rate for each drug. Patient-level predictors of drug discontinuation were evaluated using a Cox proportional hazards model. Results: The overall 1-year drug retention rate was from 60.1% for adalimumab to 90.0% for tofacitinib in the b/tsDMARD-naïve group, and from 55.2% for infliximab to 84.8% for tofacitinib in the b/tsDMARD-experienced group. The 3-year drug retention rate was from 36.9% for infliximab to 86.5% for tofacitinib in the b/tsDMARD-naïve group, and from 31.0% for infliximab to 65.4% for tocilizumab in the b/tsDMARD-experienced group. Drug discontinuation appeared to be affected by specific types of b/tsDMARDs. Conclusions: Tocilizumab and tofacitinib are less commonly discontinued compared to tumor necrosis factor-α inhibitors at 1 and 3 years. Specifically, tofacitinib in the b/tsDMARD-naïve group and tocilizumab in the b/tsDMARD-experienced group showed the highest 3-year retention rates.

Background/Aims: The Gout Impact Scale (GIS), a part of the Gout Assessment Questionnaire 2.0, is used to measure gout-specific health-related quality of life (HRQOL). Although several studies have been conducted on the factors affecting the HRQOL of patients with gout, few have focused on lifestyle factors. This study aimed to investigate the correlation between lifestyle habits and HRQOL using the GIS in patients with gout. Methods: We used data from the Urate-Lowering TheRApy in Gout (ULTRA) registry, a prospective cohort of Korean patients with gout treated at multiple centers nationwide. The patients were aged ≥18 years and met the 2015 American College of Rheumatology/European League Against Rheumatism gout classification criteria. They were asked to complete a GIS and questions regarding their lifestyle habits at enrollment. Results: The study included 232 patients. 'Gout concern overall' scores in the GIS were significantly lower in patients who exercised more frequently and consumed soft drinks and meat less, and 'well-being during attack' scores were significantly lower in patients who consumed vegetables and exercised more frequently. The frequency of vegetable consumption had a negative linear relationship with the 'well-being during attack' and 'gout concern during attack' scores (p = 0.01, p = 0.001, respectively). The frequency of exercise had a negative linear relationship with the 'gout concern overall' and 'gout concern during attack' scores (p = 0.04 and p = 0.002, respectively). Conclusions: Patients with gout who frequently consumed vegetables and exercised regularly experienced less impact of gout, exhibiting a better GIS that represented HRQOL.

Background/Aims: To compare the effects of abatacept and conventional synthetic disease modifying anti-rheumatic drugs (csDMARDs) on the progression and development of rheumatoid arthritis-associated interstitial lung disease (RA-ILD). Methods: This multi-center retrospective study included RA patients receiving abatacept or csDMARDs who underwent at least two pulmonary function tests and/or chest high-resolution computed tomography (HRCT). We compared the following outcomes between the groups: progression of RA-ILD, development of new ILD in RA patients without ILD at baseline, 28-joint Disease Activity Score with the erythrocyte sedimentation rate (DAS28-ESR), and safety. Longitudinal changes were compared between the groups by using a generalized estimating equation. Results: The study included 123 patients who were treated with abatacept (n = 59) or csDMARDs (n = 64). Nineteen (32.2%) and 38 (59.4%) patients treated with abatacept and csDMARDs, respectively, presented with RA-ILD at baseline. Newly developed ILD occurred in one patient receiving triple csDMARDs for 32 months. Among patients with RA-ILD at baseline, ILD progressed in 21.1% of cases treated with abatacept and 34.2% of cases treated with csDMARDs during a median 21-month follow-up. Longitudinal changes in forced vital capacity and diffusing capacity for carbon monoxide were comparable between the two groups. However, the abatacept group showed a more significant decrease in DAS28-ESR and glucocorticoid doses than csDMARDs group during the follow-up. The safety of both regimens was comparable. Conclusions: Abatacept and csDMARDs showed comparable effects on the development and stabilization of RA-ILD. Nevertheless, compared to csDMARDs, abatacept demonstrated a significant improvement in disease activity and led to reduced glucocorticoid use.