Background: The coronavirus disease 2019 (COVID-19) pandemic has caused the death of thousands of patients worldwide. Although age is known to be a risk factor for morbidity and mortality in COVID-19 patients, critical illness or death is occurring even in the younger age group as the epidemic spreads. In early 2022, omicron became the dominant variant of the COVID-19 virus in South Korea, and the epidemic proceeded on a large scale. Accordingly, this study aimed to determine whether young adults (aged ≤ 50 years) with critical COVID-19 infection during the omicron period had different characteristics from older patients and to determine the risk factors for mortality in this specific age group. Methods: We evaluated 213 critical adult patients (high flow nasal cannula or higher respiratory support) hospitalized for polymerase chain reaction-confirmed COVID-19 in nine hospitals in South Korea between February 1, 2022 and April 30, 2022. Demographic characteristics, including body mass index (BMI) and vaccination status; underlying diseases; clinical features and laboratory findings; clinical course; treatment received; and outcomes were collected from electronic medical records (EMRs) and analyzed according to age and mortality. Results: Overall, 71 critically ill patients aged ≤ 50 years were enrolled, and 142 critically ill patients aged over 50 years were selected through 1:2 matching based on the date of diagnosis. The most frequent underlying diseases among those aged ≤ 50 years were diabetes and hypertension, and all 14 patients who died had either a BMI ≥ 25 kg/m 2 or an underlying disease. The total case fatality rate among severe patients (S-CFR) was 31.0%, and the S-CFR differed according to age and was higher than that during the delta period. The S-CFR was 19.7% for those aged ≤ 50 years, 36.6% for those aged > 50 years, and 38.1% for those aged ≥ 65 years. In multivariate analysis, age (odds ratio [OR], 1.084; 95% confidence interval [CI], 1.043–1.127), initial low-density lipoprotein > 600 IU/L (OR, 4.782; 95% CI, 1.584–14.434), initial C-reactive protein > 8 mg/dL (OR, 2.940; 95% CI, 1.042–8.293), highest aspartate aminotransferase > 200 IU/L (OR, 12.931; 95% CI, 1.691–98.908), and mechanical ventilation implementation (OR, 3.671; 95% CI, 1.294–10.420) were significant independent predictors of mortality in critical COVID-19 patients during the omicron wave. A similar pattern was shown when analyzing the data by age group, but most had no statistical significance owing to the small number of deaths in the young critical group. Although the vaccination completion rate of all the patients (31.0%) was higher than that in the delta wave period (13.6%), it was still lower than that of the general population. Further, only 15 (21.1%) critically ill patients aged ≤ 50 years were fully vaccinated. Overall, the severity of hospitalized critical patients was significantly higher than that in the delta period, indicating that it was difficult to find common risk factors in the two periods only with a simple comparison. Conclusion Overall, the S-CFR of critically ill COVID-19 patients in the omicron period was higher than that in the delta period, especially in those aged ≤ 50 years. All of the patients who died had an underlying disease or obesity. In the same population, the vaccination rate was very low compared to that in the delta wave, indicating that non-vaccination significantly affected the progression to critical illness. Notably, there was a lack of prescription for Paxlovid for these patients although they satisfied the prescription criteria. Early diagnosis and active initial treatment was necessary, along with the proven methods of vaccination and personal hygiene. Further studies are needed to determine how each variant affects critically ill patients.

Background and Objectives: Smoking is well-established as a risk factor for coronary artery disease. However, recent studies demonstrated favorable results, including reduced mortality, among smokers, which are referred to as the “smoker's paradox”. This study examined the impact of smoking on clinical outcomes in patients with acute myocardial infarction (AMI) undergoing percutaneous coronary intervention (PCI). Methods: Patients with AMI undergoing PCI between 2004 and 2014 were enrolled and classified according to smoking status. The primary endpoint was a composite of major adverse cardiovascular events (MACE) including cardiac death, myocardial infarction, stroke, and revascularization. Results: Among the 10,683 patients, 4,352 (40.7%) were current smokers. Smokers were 10.7 years younger and less likely to have comorbidities such as hypertension, diabetes mellitus, chronic kidney disease, stroke, and prior PCI. Smokers had less MACE (hazard ratio [HR], 0.644; 95% confidence interval [CI], 0.594–0.698; p<0.001) and cardiac death (HR, 0.494; 95% CI, 0.443–0.551; p<0.001) compared to nonsmokers during the 5 years in an unadjusted model. However, after propensity-score matching, smokers showed higher risk of MACE (HR, 1.125; 95% CI, 1.009–1.254; p=0.034) and cardiac death (HR, 1.190; 95% CI, 1.026–1.381; p=0.022). Smoking was a strong independent predictor of lung cancer (propensityscore matched HR, 2.749; 95% CI, 1.416–5.338; p=0.003). Conclusions In contrast to the unadjusted model, smoking is associated with worse cardiovascular outcome and higher incidence of lung cancer after adjustment of various confounding factors. This result can be explained by the characteristics of smokers, which were young and had fewer comorbidities.

Background and Objectives: Smoking is well-established as a risk factor for coronary artery disease. However, recent studies demonstrated favorable results, including reduced mortality, among smokers, which are referred to as the “smoker's paradox”. This study examined the impact of smoking on clinical outcomes in patients with acute myocardial infarction (AMI) undergoing percutaneous coronary intervention (PCI). Methods: Patients with AMI undergoing PCI between 2004 and 2014 were enrolled and classified according to smoking status. The primary endpoint was a composite of major adverse cardiovascular events (MACE) including cardiac death, myocardial infarction, stroke, and revascularization. Results: Among the 10,683 patients, 4,352 (40.7%) were current smokers. Smokers were 10.7 years younger and less likely to have comorbidities such as hypertension, diabetes mellitus, chronic kidney disease, stroke, and prior PCI. Smokers had less MACE (hazard ratio [HR], 0.644; 95% confidence interval [CI], 0.594–0.698; p<0.001) and cardiac death (HR, 0.494; 95% CI, 0.443–0.551; p<0.001) compared to nonsmokers during the 5 years in an unadjusted model. However, after propensity-score matching, smokers showed higher risk of MACE (HR, 1.125; 95% CI, 1.009–1.254; p=0.034) and cardiac death (HR, 1.190; 95% CI, 1.026–1.381; p=0.022). Smoking was a strong independent predictor of lung cancer (propensityscore matched HR, 2.749; 95% CI, 1.416–5.338; p=0.003). Conclusions In contrast to the unadjusted model, smoking is associated with worse cardiovascular outcome and higher incidence of lung cancer after adjustment of various confounding factors. This result can be explained by the characteristics of smokers, which were young and had fewer comorbidities.

Purpose: The purpose of this study was to evaluate the usefulness of multiphasic CT and 18 F-fluorodeoxyglucose (FDG) PET/CT for the differentiation of combined hepatocellular carcinomacholangiocarcinoma (cHCC-CCA) from hepatocellular carcinoma (HCC). Materials and Methods: From January 2007 to April 2016, 93 patients with pathologically confirmed HCC (n = 84) or cHCC-CCA (n = 9) underwent CT and PET/CT imaging. Contrast enhancement patterns were divided into three types based on the attenuation of the surrounding liver parenchyma: type I (early arterial enhancement with delayed washout), type II (early arterial enhancement without delayed washout), and type III (early hypovascular, infiltrative appearance, or peripheral rim enhancement). Results: cHCC-CCAs (89%) had a higher PET/CT positive rate than did HCCs (61%), but the PET/ CT positive rate did not differ significantly (p = 0.095). Among the 19 cases of the type II enhancement pattern, 3 (21%) of 14 HCCs and 4 (80%) of 5 cHCC-CCAs were PET/CT positive. cHCC-CCAs had a significantly higher PET/CT positive rate (p = 0.020) in the type II enhancement pattern. Conclusion The PET/CT positive rate of cHCC-CCA was significantly higher than that of HCC in lesions with a type II enhancement pattern. The 18 F-FDG PET/CT can be useful for the differentiation of cHCCCCA from HCC in lesions with a type II enhancement pattern on multiphasic CT.

Purpose: The purpose of this study was to evaluate the usefulness of multiphasic CT and 18 F-fluorodeoxyglucose (FDG) PET/CT for the differentiation of combined hepatocellular carcinomacholangiocarcinoma (cHCC-CCA) from hepatocellular carcinoma (HCC). Materials and Methods: From January 2007 to April 2016, 93 patients with pathologically confirmed HCC (n = 84) or cHCC-CCA (n = 9) underwent CT and PET/CT imaging. Contrast enhancement patterns were divided into three types based on the attenuation of the surrounding liver parenchyma: type I (early arterial enhancement with delayed washout), type II (early arterial enhancement without delayed washout), and type III (early hypovascular, infiltrative appearance, or peripheral rim enhancement). Results: cHCC-CCAs (89%) had a higher PET/CT positive rate than did HCCs (61%), but the PET/ CT positive rate did not differ significantly (p = 0.095). Among the 19 cases of the type II enhancement pattern, 3 (21%) of 14 HCCs and 4 (80%) of 5 cHCC-CCAs were PET/CT positive. cHCC-CCAs had a significantly higher PET/CT positive rate (p = 0.020) in the type II enhancement pattern. Conclusion The PET/CT positive rate of cHCC-CCA was significantly higher than that of HCC in lesions with a type II enhancement pattern. The 18 F-FDG PET/CT can be useful for the differentiation of cHCCCCA from HCC in lesions with a type II enhancement pattern on multiphasic CT.

In 2019, a project designed to develop a system for measuring and comparing antibiotic usage in hospitals was launched in Korea. As part of this project, we developed a means to classify antibiotic usage in Korean hospitals using a modified Delphi method. In results, the following categories of antibiotic classification were accepted for use in Korean hospitals: 1) broad-spectrum antibacterial agents predominantly used for hospital-onset infections in adults, 2) broad-spectrum antibacterial agents predominantly used for community-acquired infections in adults, 3) antibacterial agents predominantly used for resistant gram-positive infections in adults, 4) narrow-spectrum beta-lactam agents in adults, 5) antibacterial agents predominantly used for extensive antibiotic resistant gram-negative bacteria in adults, and 6) total antibacterial agents.

BACKGROUND: Angiotensin-converting enzyme inhibitors (ACEIs) are the first choice for the treatment of acute myocardial infarction (AMI), and angiotensin receptor blockers (ARBs) should be considered in patients intolerant to ACEIs. Although previous studies support the use of ARBs as an alternative to ACEIs, these studies showed inconsistent results. The objective of this study was to demonstrate the clinical impact of ARBs as an alternative to ACEIs in patients with AMI undergoing percutaneous coronary intervention (PCI). METHODS: The CardiOvascular Risk and idEntificAtion of potential high-risk population in AMI (COREA-AMI) registry enrolled all consecutive patients with AMI undergoing PCI. The primary endpoint was the composite of cardiovascular death, myocardial infarction, stroke, or hospitalization due to heart failure. RESULTS: Of the 3,328 eligible patients, ARBs replaced ACEIs in 816 patients, while 824 patients continued to use ACEIs and 826 patients continued to use ARBs. The remaining 862 patients did not receive ACEIs/ARBs. After the adjustment with inverse probability weighting, the primary endpoints in the first groups were similar (7.5% vs. 8.0%, hazard ratio [HR], 0.89; 95% confidence interval [CI], 0.75–1.05; P = 0.164). Composite events were less frequent in the ACEI to ARB group than no ACEI/ARB group (7.5% vs. 11.8%, HR, 0.76; 95% CI, 0.64–0.90; P = 0.002). CONCLUSION: The alternative use of ARBs following initial treatment with ACEIs demonstrates comparable clinical outcomes to those with continued use of ACEIs and is associated with an improved rate of composite events compared to no ACEI/ARB use in patients with AMI undergoing PCI. TRIAL REGISTRATION: ClinicalTrials.gov Identifier: NCT02385682
Angiotensin Receptor Antagonists ; Angiotensin-Converting Enzyme Inhibitors ; Angiotensins ; Heart Failure ; Hospitalization ; Humans ; Myocardial Infarction ; Percutaneous Coronary Intervention ; Stroke

PURPOSE: We designed a modified technique to perform an advanced procedure using conventional instruments and did not employ specialized single-incision laparoscopic surgery (SILS) port equipment. We compared postoperative results for transumbilical, single-port laparoscopic appendectomy (TUSPLA) and single-incision, 2-port laparoscopic appendectomy (SITPLA). METHODS: This retrospective study enrolled 77 patients who underwent TUSPLA or SITPLA to provide more minimally invasive surgery between May 2017 and April 2018. TUSPLA was performed in 39 patients and 38 underwent SITPLA. In the SITPLA group, two 5-mm trocars were inserted through the umbilicus and an extra puncture site was used for a left-handed instrument. Demographic characteristics, operative data, and postoperative outcomes were collected and compared between the groups. RESULTS: The mean total operative time in the SITPLA group was shorter than in the TUSPLA group (p=0.003). The mean laparoscopic instrumental time was also shorter (p<0.001) in the SITPLA. The number of postoperative analgesics in the SITPLA group was less than in the TUSPLA group (p=0.002). The length of hospital day after surgery was shorter in the SITPLA group than in the TUSPLA group (p=0.008). There were no other significant differences between the groups. CONCLUSION: SITPLA had a shorter operative time, required less pain management, and had a similar cosmetic outcome when compared with TUSPLA.
Analgesics ; Appendectomy ; Humans ; Laparoscopy ; Minimally Invasive Surgical Procedures ; Operative Time ; Pain Management ; Punctures ; Retrospective Studies ; Surgical Instruments ; Umbilicus

Typhoid fever, showed a dramatic decrease in its incidence from 56 per 100,000 population just after Korea's independence to <1 per 100,000 population in 2000s. The clinical features of patients with typhoid fever in Korea were not too different from those reported in textbooks. Beyond cultures and Widal test, other diagnostic techniques such as string capsule culture and polymerase chain reaction have been tried in Korea. As chloramphenicol is not used anymore in Korea, ampicillin, cotrimoxazole, fluoroquinolones, and third-generation cephalosporins have been administered for therapy of typhoid fever. Especially, ciprofloxacin and ceftriaxone were successfully tried with shorter duration of treatment (1 week). However, cases of treatment failure and resistance in ciprofloxacin were reported in Korea, which requires a great caution. As preventive vaccines, parenteral Vi polysaccharide vaccine and oral live attenuated vaccine are mainly used in Korea. The decline in the number of chronic carriers of typhoid fever in Korea by the roles of doctors and patient management from the health care authorities such as Korea Centers for Diseases Control and Prevention, prescription of effective antimicrobial agents, and increased piped water supply ratio are considered to be the major contributing factors to the reduction in the outbreak of typhoid fever in Korea.

PURPOSE: Accurate human epidermal growth factor receptor 2 (HER2) status is important in predicting prognosis and providing treatment for HER2-positive breast cancer patients. However, performing in situ hybridization (ISH) can be an economic burden on developing countries. This study aimed to find an alternative to the ISH test by predicting the HER2 status in patients with equivocal immunohistochemistry (IHC) results. METHODS: We retrospectively reviewed the clinical data of 15,535 patients who underwent curative surgery for invasive breast cancer between February 2005 and April 2015 at the Samsung Medical Center. Equivocal HER2 IHC results were obtained for 461 patients. Logistic regression analysis using stepwise selection was performed to identify the clinicopathological factors related to silver in situ hybridization (SISH) status. We analyzed the data by dividing the estrogen receptor and progesterone receptor (PR) into three groups according to Allred score. RESULTS: Multivariable analysis identified poorly differentiated histological grade, lower PR score, higher expression of Ki-67 and p53, and lower expression of cytokeratin 5/6 and epidermal growth factor receptor as predictors of SISH-positive results. The area under the curve for the receiver-operating characteristic curve was 0.74. CONCLUSION: We identified factors related to a positive HER2 status by SISH. However, there was insufficient power in the prediction model for diagnosis and evaluation. Therefore, the SISH test is essential in determining the HER2 status of breast cancer patients when the IHC result is equivocal.
Breast Neoplasms* ; Breast* ; Developing Countries ; Diagnosis ; Epidermal Growth Factor* ; Estrogens ; Humans* ; Immunohistochemistry* ; In Situ Hybridization* ; Keratins ; Logistic Models ; Prognosis ; Receptor, Epidermal Growth Factor* ; Receptors, Progesterone ; Retrospective Studies ; Silver