Background: Although respiratory tract infection is one of the most important factors triggering acute exacerbation of chronic obstructive pulmonary disease (AE-COPD), limited data are available to suggest an epidemiologic pattern of microbiology in South Korea. Methods: A multicenter observational study was conducted between January 2015 and December 2018 across 28 hospitals in South Korea. Adult patients with moderate-to-severe acute exacerbations of COPD were eligible to participate in the present study. The participants underwent all conventional tests to identify etiology of microbial pathogenesis. The primary outcome was the percentage of different microbiological pathogens causing AE-COPD. A comparative microbiological analysis of the patients with overlapping asthma–COPD (ACO) and pure COPD was performed. Results: We included 1,186 patients with AE-COPD. Patients with pure COPD constituted 87.9% and those with ACO accounted for 12.1%. Nearly half of the patients used an inhaled corticosteroid-containing regimen and one-fifth used systemic corticosteroids. Respiratory pathogens were found in 55.3% of all such patients. Bacteria and viruses were detected in 33% and 33.2%, respectively. Bacterial and viral coinfections were found in 10.9%. The most frequently detected bacteria were Pseudomonas aeruginosa (9.8%), and the most frequently detected virus was influenza A (10.4%). Multiple bacterial infections were more likely to appear in ACO than in pure COPD (8.3% vs. 3.6%, p=0.016). Conclusion Distinct microbiological patterns were identified in patients with moderate-to-severe AE-COPD in South Korea. These findings may improve evidence-based management of patients with AE-COPD and represent the basis for further studies investigating infectious pathogens in patients with COPD.

Objective: This study evaluated the anxiety, work, and socioeconomic burden of emergency physicians (EP) during the coronavirus disease 2019 (COVID-19) pandemic in South Korea. Methods: A cross-sectional observational study was conducted using data from the 2020 Korean Emergency Physician Survey that included the following domains: hospital resources of suspected COVID-19 patients, availability of personal protective equipment, levels of home and workplace anxiety, the severity of work burnout, identification of stressors, changes in personal environments, and measures to decrease stress/anxiety. Results: Totally, 855 eligible participants were enrolled in the study. A statistically significant deterioration was observed in response to decreased working income or an unstable employment situation (0.46±0.88 points). The median number of patients with confirmed COVID-19 was 2.72. The risk of infection during emergency department (ED) work was found to be significantly increased (P<0.01). Of the 751 respondents (91.4%) who reported patient contact during their survey phase, 516 (62.8%) reported having taken the COVID-19 reverse transcription polymerase chain reaction test. The major factors that affected worsening of the work burden were determined to be unsuitable inter-hospital transfer arrangements for febrile patients (3.46±1.06 before vs. 1.99±1.16 after the pandemic, P<0.01) and delayed consultation for patients with fever or respiratory symptoms in the ED (3.20±1.06 before vs. 2.66±1.10 after the pandemic, P<0.01). Conclusion During the peak phase, the COVID-19 pandemic induced substantial workplace and socioeconomic burdens for Korean EPs. The sustained impact of the pandemic on the wellness of EPs deserves further investigation to guide targeted interventions.

Background/Aims: Left ventricular hypertrophy (LVH) on clinical outcomes in patients with acute myocardial infarction (AMI) is not clear. This study was performed to investigate the effect of abnormal left ventricular geometry on clinical outcomes in Korean patients with AMI. Methods: A total of 852 consecutive patients with AMI were divided into two groups: normal left ventricular geometry (n = 470; 389 males) and LVH (n = 382; 214 males) groups. Major adverse cardiac events (MACEs) were defined as cardiac death, recurrent myocardial infarction, and rehospitalization. Results: During the clinical follow-up period of 21 ± 7.8 months, MACEs developed in 173 patients (20.0%), and the rate was higher in the LVH than normal left ventricular geometry groups (25.5% vs. 16.0%, respectively, p = 0.001). According to Kaplan-Meier survival curves, the MACE-free survival rate was significantly lower in the LVH group than in the left ventricular geometry group (p = 0.008). The rates of MACEs and all-cause mortality differed among the AMI with concentric remodeling, concentric hypertrophy, and eccentric hypertrophy subgroups (11.2% vs. 15.5% vs. 22.1%, respectively, p = 0.046). Eccentric hypertrophy was a predictive factor of MACE according to Cox proportional hazards analysis (hazard ratio 1.804, confidence interval 1.034-3.148, p = 0.038). Conclusions LVH is a predictor of poor outcomes in patients with AMI, and eccentric hypertrophy is associated with a worse prognosis compared with concentric remodeling and concentric hypertrophy. Therefore, Korean patients with AMI and LVH, especially eccentric hypertrophy, require more careful observation and intensive treatment.

BACKGROUND AND OBJECTIVES: Although anticoagulation with warfarin is recommended as an international normalized ratio (INR) of prothrombin time between 2.0 and 3.0 and mean time in the therapeutic range (TTR) ≥70%, little has been proven that universal criteria might be suitable in Korean atrial fibrillation (AF) patients.METHODS: We analyzed 710 patients with non-valvular AF who took warfarin. INR value and clinical outcomes were assessed during 2-year follow-up. Intensity of anticoagulation was assessed as mean INR value and TTR according to target INR range. Primary net-clinical outcome was defined as the composite of new-onset stroke and major bleeding. Secondary net-clinical outcome was defined as the composite of new-onset stroke, major bleeding and death.RESULTS: Thromboembolism was significantly decreased when mean INR was over 1.6. Major bleeding was significantly decreased when TTR was over 70% and mean INR was less than 2.6. Mean INR 1.6–2.6 significantly reduced thromboembolism (adjusted hazard ratio [HR], 0.40; 95% confidence interval [CI], 0.19–0.85), major bleeding (HR, 0.43; 95% CI, 0.23–0.81), primary (HR, 0.50; 95% CI, 0.29–0.84) and secondary (HR, 0.45; 95% CI, 0.28–0.74) net-clinical outcomes, whereas mean INR 2.0–3.0 did not. Simultaneous satisfaction of mean INR 1.6–2.6 and TTR ≥70% was associated with significant risk reduction of major bleeding, primary and secondary net-clinical outcomes.CONCLUSIONS: Mean INR 1.6–2.6 was better than mean INR 2.0–3.0 for the prevention of thromboembolism and major bleeding. However, INR 1.6–2.6 and TTR ≥70% had similar clinical outcomes to INR 2.0–3.0 and TTR ≥70% in Korean patients with non-valvular AF.
Atrial Fibrillation ; Follow-Up Studies ; Hemorrhage ; Humans ; International Normalized Ratio ; Prothrombin Time ; Risk Reduction Behavior ; Stroke ; Thromboembolism ; Warfarin

Background/Aims: Left ventricular hypertrophy (LVH) on clinical outcomes in patients with acute myocardial infarction (AMI) is not clear. This study was performed to investigate the effect of abnormal left ventricular geometry on clinical outcomes in Korean patients with AMI. Methods: A total of 852 consecutive patients with AMI were divided into two groups: normal left ventricular geometry (n = 470; 389 males) and LVH (n = 382; 214 males) groups. Major adverse cardiac events (MACEs) were defined as cardiac death, recurrent myocardial infarction, and rehospitalization. Results: During the clinical follow-up period of 21 ± 7.8 months, MACEs developed in 173 patients (20.0%), and the rate was higher in the LVH than normal left ventricular geometry groups (25.5% vs. 16.0%, respectively, p = 0.001). According to Kaplan-Meier survival curves, the MACE-free survival rate was significantly lower in the LVH group than in the left ventricular geometry group (p = 0.008). The rates of MACEs and all-cause mortality differed among the AMI with concentric remodeling, concentric hypertrophy, and eccentric hypertrophy subgroups (11.2% vs. 15.5% vs. 22.1%, respectively, p = 0.046). Eccentric hypertrophy was a predictive factor of MACE according to Cox proportional hazards analysis (hazard ratio 1.804, confidence interval 1.034-3.148, p = 0.038). Conclusions LVH is a predictor of poor outcomes in patients with AMI, and eccentric hypertrophy is associated with a worse prognosis compared with concentric remodeling and concentric hypertrophy. Therefore, Korean patients with AMI and LVH, especially eccentric hypertrophy, require more careful observation and intensive treatment.

BACKGROUND AND OBJECTIVES: Although anticoagulation with warfarin is recommended as an international normalized ratio (INR) of prothrombin time between 2.0 and 3.0 and mean time in the therapeutic range (TTR) ≥70%, little has been proven that universal criteria might be suitable in Korean atrial fibrillation (AF) patients. METHODS: We analyzed 710 patients with non-valvular AF who took warfarin. INR value and clinical outcomes were assessed during 2-year follow-up. Intensity of anticoagulation was assessed as mean INR value and TTR according to target INR range. Primary net-clinical outcome was defined as the composite of new-onset stroke and major bleeding. Secondary net-clinical outcome was defined as the composite of new-onset stroke, major bleeding and death. RESULTS: Thromboembolism was significantly decreased when mean INR was over 1.6. Major bleeding was significantly decreased when TTR was over 70% and mean INR was less than 2.6. Mean INR 1.6–2.6 significantly reduced thromboembolism (adjusted hazard ratio [HR], 0.40; 95% confidence interval [CI], 0.19–0.85), major bleeding (HR, 0.43; 95% CI, 0.23–0.81), primary (HR, 0.50; 95% CI, 0.29–0.84) and secondary (HR, 0.45; 95% CI, 0.28–0.74) net-clinical outcomes, whereas mean INR 2.0–3.0 did not. Simultaneous satisfaction of mean INR 1.6–2.6 and TTR ≥70% was associated with significant risk reduction of major bleeding, primary and secondary net-clinical outcomes. CONCLUSIONS Mean INR 1.6–2.6 was better than mean INR 2.0–3.0 for the prevention of thromboembolism and major bleeding. However, INR 1.6–2.6 and TTR ≥70% had similar clinical outcomes to INR 2.0–3.0 and TTR ≥70% in Korean patients with non-valvular AF.

Background/Aims: Many patients with acute myocardial infarction (AMI) suffer from heart failure due to progressive ischemic left ventricular (LV) remodeling. This study investigated the predictors of ischemic cardiomyopathy (ICMP) in patients with AMI who underwent successful percutaneous intervention. Methods: A total of 547 patients with AMI were divided into two groups: ICMP (n = 66, 67.1 ± 11.9 years, 78.8% males) and non-ICMP (n = 481, 62.5 ± 12.2 years, 70.1% males). Results: On echocardiography, the LVEF was significantly decreased (41.7 ± 10.5 vs. 55.4 ± 10.3%, p < 0.001) but the LV end-diastolic (54.1 ± 7.2 vs. 49.3 ± 5.3 mm, p < 0.001) and systolic (42.1 ± 8.0 vs. 33.5 ± 6.0 mm, p < 0.001) dimensions significantly increased in the ICMP group compared with the non-ICMP group. According to multivariate logistic regression analysis, LVEF < 50% (odds ratio [OR] 8.722, 95% confidence interval [CI] 2.986–25.478, p < 0.001), LV end-diastolic dimension > 55 mm (OR 4.511, 95% CI 1.561–13.038, p = 0.005), and ratio of early mitral inflow velocity to mitral annular early diastolic velocity (E/e’) ≥ 15 (OR 3.270, 95% CI 1.168–9.155, p = 0.024) were independent predictors of ICMP development. Conclusions The present study demonstrates that a larger LV size, lower LV function, and increased E/e’ (≥ 15) were independent predictors of ICMP. Therefore, the development of ICMP should be carefully monitored in AMI patients with these features.

BACKGROUND/AIMS: The impact of the timing of anemia during hospitalization on future clinical outcomes after surviving discharge from an index heart failure (HF) has been poorly studied in patients with acute decompensated heart failure (ADHF). METHODS: A total of 384 surviving patients with acute ADHF were divided into two groups: an anemia group (n = 270, 199 anemia at admission and 71 pre-discharge anemia) and a no anemia group (n = 114). All-cause mortality and HF re-hospitalization were compared between groups. RESULTS: During the follow-up period (median, 528 days), death occurred in 60 patients (15.6%) and HF re-hospitalization occurred in 131 patients (34.1%). Overall anemia was associated with increased mortality (hazard ratio [HR], 1.74; 95% confidence interval [CI], 1.03 to 3.01; p = 0.039), but not HF re-hospitalization (HR, 0.92; 95% CI, 0.59 to 1.42; p = 0.707). Pre-discharge anemia was significantly associated with increased mortality (HR, 1.68; 95% CI, 1.01 to 2.82; p = 0.048), but anemia at admission did not predict increased mortality or re-hospitalization. CONCLUSIONS Pre-discharge anemia, rather than anemia at admission, was identified as an independent predictor of mortality in patients with ADHF after surviving discharge. The results of the present study suggest that the identification and optimal management of anemia during hospitalization are important in patients with ADHF.

BACKGROUND/AIMS: The aim of this study was to investigate useful cardiac biomarkers in the differential diagnosis of acute pulmonary embolism (APE) with troponin elevation from acute non-ST elevation myocardial infarction (NSTEMI). METHODS: A total of 771 consecutive NSTEMI patients with D-dimer measurements and 90 patients with troponin-I (TnI) elevation out of 233 APE patients were enrolled, and cardiac biomarkers were compared. RESULTS: D-dimer elevation was noted in 382 patients with NSTEMI (49.5%), and TnI elevation was noted 90 out of 233 APE patients (38.6%). Unnecessary coronary angiography was performed in 10 patients (11.1%) among 90 APE patients with TnI elevation. D-dimer was significantly elevated in APE than in NSTEMI (9.9 ± 11.6 mg/L vs. 1.8 ± 4.3 mg/L, p < 0.001), whereas TnI was significantly elevated in NSTEMI (22.4 ± 41.5 ng/mL vs. 0.7 ± 1.4 ng/mL, p < 0.001). D-dimer/TnI ratio was significantly higher in APE than in NSTEMI (50.6 ± 85.3 vs. 1.6 ± 5.7, p < 0.001). On receiver operation characteristic curve analysis, the optimal cut-off value for differentiating APE from NSTEMI was 1.12 mg/L for D-dimer (sensitivity 81.1%, specificity 70.2%), 0.72 ng/mL for TnI (sensitivity 80.6%, specificity 78.9%), and 1.82 for D-dimer/TnI ratio (sensitivity 93.3%, specificity 86.6%). CONCLUSIONS D-dimer/TnI ratio would be a simple and useful parameter for differentiating APE with cardiac troponin elevation from NSTEMI. Optimal cardiovascular imaging to identify APE should be considered in patients with D-dimer/TnI ratio > 1.82 before performing coronary angiography to avoid unnecessary invasive procedure.

BACKGROUND/AIMS: It is well known that gender differences are associated with clinical outcomes in patients with acute myocardial infarction (AMI). However, it is not clear whether gender differences affect the prognosis of elderly patients with AMI. METHODS: We analyzed the incidence of in-hospital complications and mortality in the Korea Acute Myocardial Infarction Registry-National Institutes of Health from November 2011 to June 2015. This study included elderly patients (≥ 75 years) diagnosed with AMI. RESULTS: A total of 2,953 patients were eligible for this study. Among them, 1,529 (51.8%) patients were female, and the mean age of the female group was older than that of the male group (80.7 ± 4.4 vs. 79.6 ± 4.0 years, respectively, p < 0.001). Elderly females utilized emergency medical services less frequently compared with elderly males (11.5 vs. 15.4%, respectively, p < 0.001). Elderly female AMI patients had a similar rate of in-hospital mortality compared with elderly males (7.1 vs. 8.4%, respectively, p = 0.196). The rate of major cardiac adverse events (MACEs) was lower in elderly females than males during a 12-month follow-up (hazard ratio [HR] 1.19, 95% confidence interval [CI] 1.00-1.41, p = 0.045). According to multivariate analysis, the male gender is an independent factor for predicting 1-year MACEs (HR 1.37, 95% CI 1.14-1.65, p < 0.001). CONCLUSIONS No significant differences in peri-procedural complications or in-hospital mortality were observed between male and female elderly patients with AMI. However, elderly female patients had a more favorable prognosis than male patients during a 1-year clinical follow-up.