In the 2023–2024 season, the influenza epidemic in South Korea peaked earlier than in recent years. In this study, we aimed to estimate the interim vaccine effectiveness (VE) of the influenza vaccination to prevent influenza during the early season. From November 1, 2023, to December 31, 2023, we enrolled 2,632 subjects with influenza-like illness from eight hospitals participating in hospital-based influenza morbidity and mortality surveillance. A retrospective test-negative case-control study was conducted to estimate the VE. The results showed an adjusted VE of 22.5% (95% confidence interval [CI], 6.6 to 35.8) for the total population. The adjusted VE was 22.3% (95% CI, 6.1 to 35.7) for influenza A and 9.4% (95% CI, −51.3 to 45.7) for influenza A/H1N1. Full results of the analysis will be reported.

Background: Bivalent booster mRNA vaccines containing the omicron-variant strains have been introduced worldwide in the autumn of 2022. Nevertheless, the omicron subvariants evoked another large coronavirus disease 2019 (COVID-19) pandemic wave in late 2022 and early 2023. Methods: A retrospective, test-negative, case-control study was conducted to estimate the vaccine effectiveness (VE) of bivalent COVID-19 vaccines in 8 university hospitals between January and February 2023. The case and control groups were divided based on nasopharyngeal COVID-19 real-time polymerase chain reaction results and matched based on age, sex, hospital, and date (week) of the test performed. The VE of the BA.1- or BA.4/BA.5-based mRNA vaccines were estimated. VE was calculated using the 1−adjusted odds ratio from multivariable logistic regression. Results: In total, 949 patients and 947 controls were enrolled in this study. VE for the BA.4/ BA.5-based bivalent mRNA vaccine was 43% (95% confidence interval [CI], 17, 61%). In subgroup analysis based on age and underlying medical conditions, BA.4/BA.5-based bivalent mRNA vaccine was effective against old adults aged ≥ 65-years (VE, 55%; 95% CI, 23, 73%) and individuals with comorbidities (VE, 54%; 95% CI, 23, 73%). In comparison, the BA.1-based bivalent mRNA vaccine did not demonstrate statistically significant effectiveness (VE, 25%; 95% CI, −8, 49%). Conclusion The BA.4/BA.5-based bivalent mRNA booster vaccine provided significant protection against COVID-19 in the Korean adults, especially in the older adults aged ≥ 65 years and in individuals with underlying medical conditions.

Background: For acute ischemic stroke (AIS) patients with history of prior stroke (PS) and diabetes mellitus (DM), intravenous recombinant tissue plasminogen activator (IV-tPA) therapy in the 3- to 4.5-hour window is off-label in Korea. This study aimed to assess the safety and efficacy of IV-tPA in these patients. Methods: Using data from a prospective multicenter stroke registry between January 2009 and March 2021, we identified AIS patients who received IV-tPA in the 3- to 4.5-hour window, and compared the outcomes of symptomatic intracranial hemorrhage (SICH), 3-month mortality, 3-month modified Rankin Scale (mRS) score 0-1 and 3-month mRS distribution between patients with both PS and DM (PS/DM, n=56) versus those with neither PS nor DM, or with only one (non-PS/DM, n=927). Results: The PS/DM group versus the non-PS/DM group was more likely to have a prior disability, hypertension, hyperlipidemia, coronary heart disease and less likely to have atrial fibrillation. The PS/DM and the non-PS/DM groups had comparable rates of SICH (0% vs. 1.7%; p>0.999) and 3-month mortality (10.7% vs. 10.2%; p=0.9112). The rate of 3-month mRS 0-1 was non-significantly lower in the PS/DM group than in the non-PS/DM group (30.4% vs. 40.7%; adjusted odds ratio [95% confidence interval], 0.81 [0.41-1.59]). Conclusions In the 3- to 4.5-hour window, AIS patients with PS/DM, as compared to those with non-PS/DM, might benefit less from IV-tPA. However, given the similar risks of SICH and mortality, IV-tPA in the late time window could be considered in patients with both PS and DM.

PURPOSE: Emergent intracranial occlusions causing acute ischemic stroke are often related to extracranial atherosclerotic stenosis. This study aimed to investigate the association between post-procedure intracerebral hemorrhage (ICH) and emergent extracranial artery stenting and assess their effects on clinical outcomes in patients with acute ischemic stroke. MATERIALS AND METHODS: We retrospectively analyzed patients undergoing hyperacute endovascular treatment for cervicocephalic vascular occlusion in three Korean hospitals between January 2011 and February 2016. Patients who had extracranial artery involvement and were treated from 24 hours of symptom onset to puncture were included in this study, and they were divided into the extracranial stenting (ES) and non-ES groups. Any type of petechial hemorrhages and parenchymal hematoma was defined as ICH for the current study. RESULTS: In total, 76 patients were included in this study. Among them, 56 patients underwent ES, and 20 patients did not. Baseline characteristics, risk factors, laboratory data, treatment methods, successful reperfusion rates, and baseline stenotic degrees of extracranial internal carotid artery did not differ between these two groups. However, atrial fibrillation was more frequent in patients without than with ES (P=0.002), and post-procedure ICH was more frequent in patients with than without ES (P=0.035). Logistic regression models revealed that ES was independently associated with post-procedure ICH (odds ratio [OR], 7.807; 95% confidence interval [CI], 1.213–50.248; P=0.031), and ICH was independently associated with poor clinical outcomes (OR, 0.202; 95% CI, 0.054–0.759; P=0.018); however, ES itself was not associated with clinical outcomes (OR, 0.530; 95% CI, 0.117–2.395; P=0.409). Notably, ICH and ES had interaction for predicting good outcomes (P=0.041). CONCLUSION: Post-procedure ICH was associated with ES and poor clinical outcomes. Therefore, ES should be cautiously considered in patients with hyperacute stroke.
Arteries ; Atrial Fibrillation ; Carotid Artery, Internal ; Carotid Stenosis ; Cerebral Hemorrhage ; Cerebral Infarction ; Constriction, Pathologic ; Endovascular Procedures ; Hematoma ; Hemorrhage ; Humans ; Logistic Models ; Punctures ; Reperfusion ; Retrospective Studies ; Risk Factors ; Stents ; Stroke

BACKGROUND AND PURPOSE: The purpose of the current study is to evaluate the influence of temporal patterns related to the availability of new endovascular treatment (EVT) devices on care processes and outcomes among patients with AIS. MATERIALS AND METHODS: We enrolled 720 consecutive patients (January 2011 to May 2016) in a retrospective registry, ASIAN KR, from three Korean hospitals, who received EVT for acute ischemic stroke (AIS) caused by cervicocephalic arterial occlusions. We performed period-to-period analyses based on stent retriever reimbursement and the availability of second-generation direct-aspiration devices (Period 1: January 2011–July 2014 vs. Period 2: August 2014–May 2016); time metrics and outcomes were compared when the onset-to-puncture time was <720 min among patients with EVT for intracranial occlusion. RESULTS: Period 2 had better post-EVT outcomes (3-month modified Rankin Scale 0–2 or equal to prestroke score, 48.3% vs. 60.2%, P=0.004), more successful reperfusion rates (modified Treatment In Cerebral Ischemia 2b–3, 74.2% vs. 82.2%, P=0.019), fewer subarachnoid hemorrhages (modified Fisher grade 3–4, 5.5% vs. 2.0%, P=0.034) and lower hemorrhagic transformation rates (any intracerebral hemorrhage, 35.3 vs. 22.7%, P=0.001) than Period 1. Compared to Period 1, Period 2 had a shorter door-to-puncture time (median 109 vs. 90 min, P<0.001), but longer onset-to-door time (129 vs. 143 min, P=0.057). CONCLUSION: Recent temporal improvements in post-EVT AIS outcomes in Korea are likely due to a combination of enhanced hospital care processes and administration of newer thrombectomy devices.
Asian Continental Ancestry Group ; Brain Ischemia ; Cerebral Hemorrhage ; Cerebral Infarction ; Humans ; Korea ; Learning Curve ; Reperfusion ; Retrospective Studies* ; Stents ; Stroke* ; Subarachnoid Hemorrhage ; Thrombectomy ; Treatment Outcome

BackgroundUntil now, various types of combined therapy with nucleotide analogs and pegylated interferon (Peg-INF) in patients with hepatitis B patients have been tried. However, studies regarding the benefits of de novo combination, late-add on, and sequential treatment are very limited. The objective of the current study was to identify the efficacy of sequential treatment of Peg-INF after short-term antiviral treatment.

MethodsBetween June 2010 and June 2015, hepatitis B e antigen (HBeAg)-positive patients (n = 162) received Peg-IFN for 48 weeks (mono-treatment group, n = 81) and entecavir (ETV) for 12 weeks with a 48-week course of Peg-IFN starting at week 5 of ETV therapy (sequential treatment group, n = 81). The primary endpoint was HBeAg seroconversion at the end of follow-up period after the 24-week treatment. The primary endpoint was analyzed using Chi-square test, Fisher's exact test, and regression analysis.

ResultsHBeAg seroconversion rate (18.2% vs. 18.2%, t = 0.03, P = 1.000) and seroclearance rate (19.7% vs. 19.7%, t = 0.03, P = 1.000) were same in both mono-treatment and sequential treatment groups. The rate of alanine aminotransferase (ALT) normalization (45.5% vs. 54.5%, t = 1.12, P = 0.296) and serum hepatitis B virus (HBV)-DNA <2000 U/L (28.8% vs. 28.8%, t = 0.10, P = 1.000) was not different in sequential and mono-treatment groups at 24 weeks of Peg-INF. Viral response rate (HBeAg seroconversion and serum HBV-DNA <2000 U/L) was not different in the two groups (12.1% vs. 16.7%, t = 1.83, P = 0.457). Baseline HBV-DNA level (7 logU/ml vs. 7.5 logU/ml, t = 1.70, P = 0.019) and hepatitis B surface antigen titer (3.6 logU/ml vs. 4.0 logU/ml, t = 2.19, P = 0.020) were lower and predictors of responder in mono-treatment and sequential treatment groups, respectively.

ConclusionsThe current study shows no differences in HBeAg seroconversion rate, ALT normalization, and HBV-DNA levels between mono-therapy and sequential therapy regimens.

Trial RegistrationClinicalTrials.gov, NCT01220596; https://clinicaltrials.gov/ct2/show/NCT01220596?term=NCT01220596&rank=1.

BACKGROUND AND PURPOSE: Little is known about prognosis after endovascular therapy (EVT) for acute large artery occlusion (LAO) caused by underlying intracranial atherosclerotic stenosis (ICAS). Therefore, we investigated the prognosis following EVT according to the underlying etiology of LAO. METHODS: Patients from the Acute Stroke due to Intracranial Atherosclerotic occlusion and Neurointervention-Korean Retrospective (ASIAN KR) registry (n=720) were included if their occlusion was in the intracranial anterior circulation and their onset-to-puncture time was < 24 hours. Occlusion was classified according to etiology as follows: no significant stenosis after recanalization (Embolic group), and fixed significant focal stenosis in the occlusion site with flow impairment or re-occlusion observed during EVT (ICAS group). Patients were excluded when significant extracranial carotid lesions existed, and when the intracranial occlusion was intractable to EVT so that the etiology was undetermined. The effect of angiographic etiologic classification on outcomes was evaluated using multivariable analysis that was adjusted for potential confounders. RESULTS: Among eligible patients (n=520), 421 and 99 were classified in the Embolic and ICAS groups, respectively. Patients in the Embolic and ICAS groups had similar successful reperfusion rates with EVT (79.6% vs. 76.8%, P=0.537) and 3-month functional independence (54.5% vs. 45.5%, P=0.104). In multivariable analysis, ICAS-related occlusion (odds ratio, 0.495; 95% confidence interval, 0.269 to 0.913; P=0.024) showed poorer 3-month functional independence compared to embolic occlusion. CONCLUSIONS: After EVT, patients with acute ICAS-related occlusion have relatively poor functional outcomes compared to those with embolic occlusion. Novel strategies need to be developed to improve EVT outcomes for ICAS occlusion.
Arteries ; Atherosclerosis ; Cerebral Infarction ; Classification ; Constriction, Pathologic ; Embolism ; Humans ; Prognosis* ; Reperfusion ; Retrospective Studies ; Stroke ; Thrombectomy ; Treatment Outcome

BACKGROUND: Because conventional echocardiographic parameters have several limitations, strain echocardiography has often been introduced in clinical practice. However, there are also obstacles in using it in clinical practice. Therefore, we wanted to find the current status of awareness on using strain echocardiography in Korea. METHODS: We conducted a nationwide survey to evaluate current use and awareness of strain echocardiography from the members of the Korean Society of Echocardiography. RESULTS: We gathered total 321 questionnaires from 25 cardiology centers in Korea. All participants were able to perform or interpret echocardiographic examinations. All participating institutions performed strain echocardiography. Most of our study participants (97%) were aware of speckle tracking echocardiography and 185 (58%) performed it for clinical and research purposes. Two-dimensional strain echocardiography was the most commonly used modality and left ventricle (LV) was the most commonly used cardiac chamber (99%) for clinical purposes. Most of the participants (89%) did not think LV strain can replace LV ejection fraction (LVEF) in their clinical practice. The common reasons for not performing routine use of strain echocardiography was diversity of strain measurements and lack of normal reference value. Many participants had a favorable view of the future of strain echocardiography. CONCLUSION: Most of our study participants were aware of strain echocardiography, and all institutions performed strain echocardiography for clinical and research purposes. However, they did not think the LV strain values could replace LVEF. The diversity of strain measurements and lack of normal reference values were common reasons for not using strain echocardiography in clinical practice.
Cardiology ; Echocardiography* ; Heart Ventricles ; Korea* ; Reference Values

“Clinical Practice Guideline for Stroke Rehabilitation in Korea 2016” is the 3rd edition of clinical practice guideline (CPG) for stroke rehabilitation in Korea, which updates the 2nd edition published in 2014. Forty-two specialists in stroke rehabilitation from 21 universities and 4 rehabilitation hospitals and 4 consultants participated in this update. The purpose of this CPG is to provide optimum practical guidelines for stroke rehabilitation teams to make a decision when they manage stroke patients and ultimately, to help stroke patients obtain maximal functional recovery and return to the society. The recent two CPGs from Canada (2015) and USA (2016) and articles that were published following the 2nd edition were used to develop this 3rd edition of CPG for stroke rehabilitation in Korea. The chosen articles' level of evidence and grade of recommendation were decided by the criteria of Scotland (2010) and the formal consensus was derived by the nominal group technique. The levels of evidence range from 1++ to 4 and the grades of recommendation range from A to D. Good Practice Point was recommended as best practice based on the clinical experience of the guideline developmental group. The draft of the developed CPG was reviewed by the experts group in the public hearings and then revised. “Clinical Practice Guideline for Stroke Rehabilitation in Korea 2016” consists of ‘Chapter 1; Introduction of Stroke Rehabilitation’, ‘Chapter 2; Rehabilitation for Stroke Syndrome, ‘Chapter 3; Rehabilitation for Returning to the Society’, and ‘Chapter 4; Advanced Technique for Stroke Rehabilitation’. “Clinical Practice Guideline for Stroke Rehabilitation in Korea 2016” will provide direction and standardization for acute, subacute and chronic stroke rehabilitation in Korea.
Canada ; Consensus ; Consultants ; Humans ; Korea* ; Practice Guidelines as Topic ; Rehabilitation* ; Scotland ; Specialization ; Stroke*

PURPOSE: Differences in definitions of the condition, relevant triggers, and the geographical locations of study centers, cause estimates of the prevalence of anaphylaxis to vary. Recent epidemiological data indicate that the incidence of anaphylaxis is rising. METHODS: To investigate the causes and clinical features of anaphylaxis in Korean adults, factors associated with the severity of the condition, and serious outcomes, a retrospective medical record review was performed on adult patients diagnosed with anaphylaxis between 2007 and 2011 in 15 University Hospitals of South Korea. RESULTS: A total of 1,806 cases (52% male, age 16-86 years) were reported. Cutaneous symptoms (84.0%), combined with respiratory (53.9%) and/or cardiovascular (55.4%) symptoms, were the most frequent presentations. Using a recognized grading system, 1,776 cases could be classified as either mild, 340; moderate, 690; or severe, 746. Although eliciting factors varied significantly by age, gender, and regional and seasonal factors, drugs (46.5%; including nonsteroidal anti-inflammatory drugs, antibiotics, and radiocontrast media) were the most common cause of anaphylaxis, followed by foods (24.2%), insect stings (16.4%), exercise (5.9%), and unknown etiology (7.0%). All of age, multi-organ involvement, a history of allergic disease, and drug-induced anaphylaxis, were significant predictors of serious outcomes requiring hospital admission or prolongation of hospital stay. Epinephrine auto-injectors were prescribed for 7.4% of reported cases. CONCLUSIONS: The principal causes of anaphylaxis in Korean adults were drugs, food, and insect stings. Drug-associated anaphylaxis, a history of allergic disease, multi-organ involvement, and older age, were identified as predictors of serious outcomes.
Adult* ; Anaphylaxis* ; Anti-Bacterial Agents ; Epidemiology ; Epinephrine ; Hospitals, University ; Humans ; Incidence ; Insect Bites and Stings ; Korea ; Length of Stay ; Male ; Medical Records ; Prevalence ; Retrospective Studies* ; Seasons