Background: Atrial fibrillation (AF) is associated with increased risks of adverse events including stroke and all-cause death. Understanding the pattern of causes of death (COD) with the relative risks in patients with AF compared to the non-AF population is essential in planning optimal care for patients with AF. We aimed to analyze the COD and its relative risks in patients with AF, using a nationwide population-based cohort. Methods: Using the Korean nationwide claims database, people aged 40 or older who received health examinations in 2009 were included if they had no missing values (n = 6,877,929).In total the study included 40,585 people with AF and 6,837,344 without AF. COD was defined by International Classification of Diseases, Tenth Revision, Clinical Modification (ICD-10-CM) diagnostic codes. Comparison between the AF and non-AF groups was performed with Multivariate Cox proportional regression model. Results: In the AF group, cardiovascular diseases were the most common COD, causing 39.8% of all deaths, compared with 19.0% for non-AF subjects. The AF group was associated with a higher risk of death from cardiovascular and cerebrovascular diseases by almost 3-fold than the matched non-AF group (hazard ratios [HR], 3.082; 95% confidence intervals [CIs], 2.963–3.205 for cardiovascular diseases; HR, 2.981; 95% CI, 2.799–3.175 for cerebrovascular diseases, all P < 0.001). Among patients with AF, the risks of all-cause, cardiovascular, and cerebrovascular death were well-stratified by CHA2DS2 -VASc scores. The risk of cerebrovascular death was 11 times higher among patients with a CHA2DS2 -VASc score ≥ 7. Conclusion Compared to non-AF individuals, patients with AF had a higher risk of death from cardiovascular and cerebrovascular diseases, and the mortality risks were wellstratified by the CHA2DS2 -VASc score. Integrated care management of cardiovascular and cerebrovascular diseases for patients with AF might help mitigate mortality.

Background: Atrial fibrillation (AF) is associated with increased risks of adverse events including stroke and all-cause death. Understanding the pattern of causes of death (COD) with the relative risks in patients with AF compared to the non-AF population is essential in planning optimal care for patients with AF. We aimed to analyze the COD and its relative risks in patients with AF, using a nationwide population-based cohort. Methods: Using the Korean nationwide claims database, people aged 40 or older who received health examinations in 2009 were included if they had no missing values (n = 6,877,929).In total the study included 40,585 people with AF and 6,837,344 without AF. COD was defined by International Classification of Diseases, Tenth Revision, Clinical Modification (ICD-10-CM) diagnostic codes. Comparison between the AF and non-AF groups was performed with Multivariate Cox proportional regression model. Results: In the AF group, cardiovascular diseases were the most common COD, causing 39.8% of all deaths, compared with 19.0% for non-AF subjects. The AF group was associated with a higher risk of death from cardiovascular and cerebrovascular diseases by almost 3-fold than the matched non-AF group (hazard ratios [HR], 3.082; 95% confidence intervals [CIs], 2.963–3.205 for cardiovascular diseases; HR, 2.981; 95% CI, 2.799–3.175 for cerebrovascular diseases, all P < 0.001). Among patients with AF, the risks of all-cause, cardiovascular, and cerebrovascular death were well-stratified by CHA2DS2 -VASc scores. The risk of cerebrovascular death was 11 times higher among patients with a CHA2DS2 -VASc score ≥ 7. Conclusion Compared to non-AF individuals, patients with AF had a higher risk of death from cardiovascular and cerebrovascular diseases, and the mortality risks were wellstratified by the CHA2DS2 -VASc score. Integrated care management of cardiovascular and cerebrovascular diseases for patients with AF might help mitigate mortality.

Background: Atrial fibrillation (AF) is associated with increased risks of adverse events including stroke and all-cause death. Understanding the pattern of causes of death (COD) with the relative risks in patients with AF compared to the non-AF population is essential in planning optimal care for patients with AF. We aimed to analyze the COD and its relative risks in patients with AF, using a nationwide population-based cohort. Methods: Using the Korean nationwide claims database, people aged 40 or older who received health examinations in 2009 were included if they had no missing values (n = 6,877,929).In total the study included 40,585 people with AF and 6,837,344 without AF. COD was defined by International Classification of Diseases, Tenth Revision, Clinical Modification (ICD-10-CM) diagnostic codes. Comparison between the AF and non-AF groups was performed with Multivariate Cox proportional regression model. Results: In the AF group, cardiovascular diseases were the most common COD, causing 39.8% of all deaths, compared with 19.0% for non-AF subjects. The AF group was associated with a higher risk of death from cardiovascular and cerebrovascular diseases by almost 3-fold than the matched non-AF group (hazard ratios [HR], 3.082; 95% confidence intervals [CIs], 2.963–3.205 for cardiovascular diseases; HR, 2.981; 95% CI, 2.799–3.175 for cerebrovascular diseases, all P < 0.001). Among patients with AF, the risks of all-cause, cardiovascular, and cerebrovascular death were well-stratified by CHA2DS2 -VASc scores. The risk of cerebrovascular death was 11 times higher among patients with a CHA2DS2 -VASc score ≥ 7. Conclusion Compared to non-AF individuals, patients with AF had a higher risk of death from cardiovascular and cerebrovascular diseases, and the mortality risks were wellstratified by the CHA2DS2 -VASc score. Integrated care management of cardiovascular and cerebrovascular diseases for patients with AF might help mitigate mortality.

Background: Atrial fibrillation (AF) is associated with increased risks of adverse events including stroke and all-cause death. Understanding the pattern of causes of death (COD) with the relative risks in patients with AF compared to the non-AF population is essential in planning optimal care for patients with AF. We aimed to analyze the COD and its relative risks in patients with AF, using a nationwide population-based cohort. Methods: Using the Korean nationwide claims database, people aged 40 or older who received health examinations in 2009 were included if they had no missing values (n = 6,877,929).In total the study included 40,585 people with AF and 6,837,344 without AF. COD was defined by International Classification of Diseases, Tenth Revision, Clinical Modification (ICD-10-CM) diagnostic codes. Comparison between the AF and non-AF groups was performed with Multivariate Cox proportional regression model. Results: In the AF group, cardiovascular diseases were the most common COD, causing 39.8% of all deaths, compared with 19.0% for non-AF subjects. The AF group was associated with a higher risk of death from cardiovascular and cerebrovascular diseases by almost 3-fold than the matched non-AF group (hazard ratios [HR], 3.082; 95% confidence intervals [CIs], 2.963–3.205 for cardiovascular diseases; HR, 2.981; 95% CI, 2.799–3.175 for cerebrovascular diseases, all P < 0.001). Among patients with AF, the risks of all-cause, cardiovascular, and cerebrovascular death were well-stratified by CHA2DS2 -VASc scores. The risk of cerebrovascular death was 11 times higher among patients with a CHA2DS2 -VASc score ≥ 7. Conclusion Compared to non-AF individuals, patients with AF had a higher risk of death from cardiovascular and cerebrovascular diseases, and the mortality risks were wellstratified by the CHA2DS2 -VASc score. Integrated care management of cardiovascular and cerebrovascular diseases for patients with AF might help mitigate mortality.

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.

Objectives: Limited information is available concerning the epidemiology of stroke and acute myocardial infarction (AMI) in the Republic of Korea. This study aimed to develop a national surveillance system to monitor the incidence of stroke and AMI using national claims data. Methods: We developed and validated identification algorithms for stroke and AMI using claims data. This validation involved a 2-stage stratified sampling method with a review of medical records for sampled cases. The weighted positive predictive value (PPV) and negative predictive value (NPV) were calculated based on the sampling structure and the correspondingsampling rates. Incident cases and the incidence rates of stroke and AMI in the Republic ofKorea were estimated by applying the algorithms and weighted PPV and NPV to the 2018National Health Insurance Service claims data. Results: In total, 2,200 cases (1,086 stroke cases and 1,114 AMI cases) were sampled from the 2018 claims database. The sensitivity and specificity of the algorithms were 94.3% and 88.6% for stroke and 97.9% and 90.1% for AMI, respectively. The estimated number of cases, including recurrent events, was 150,837 for stroke and 40,529 for AMI in 2018. The age- and sex-standardized incidence rate for stroke and AMI was 180.2 and 46.1 cases per 100,000 person-years, respectively, in 2018. Conclusion This study demonstrates the feasibility of developing a national surveillance system based on claims data and identification algorithms for stroke and AMI to monitor their incidence rates.

The aim of this study was to develop evidence-based recommendations for determining the surgical extent in patients with locally invasive differentiated thyroid cancer (DTC). Locally invasive DTC with gross extrathyroidal extension invading surrounding anatomical structures may lead to several functional deficits and poor oncological outcomes. At present, the optimal extent of surgery in locally invasive DTC remains a matter of debate, and there are no adequate guidelines. On October 8, 2021, four experts searched the PubMed, Embase, and Cochrane Library databases; the identified papers were reviewed by 39 experts in thyroid and head and neck surgery. The Grading of Recommendations Assessment, Development and Evaluation (GRADE) approach was used to assess the quality of evidence, and to develop and report recommendations. The strength of a recommendation reflects the confidence of a guideline panel that the desirable effects of an intervention outweigh any undesirable effects, across all patients for whom the recommendation is applicable. After completing the draft guidelines, Delphi questionnaires were completed by members of the Korean Society of Head and Neck Surgery. Twenty-seven evidence-based recommendations were made for several factors, including the preoperative workup; surgical extent of thyroidectomy; surgery for cancer invading the strap muscles, recurrent laryngeal nerve, laryngeal framework, trachea, or esophagus; and surgery for patients with central and lateral cervical lymph node involvement. Evidence-based guidelines were devised to help clinicians make safer and more efficient clinical decisions for the optimal surgical treatment of patients with locally invasive DTC.

Purpose: This single-arm phase II trial investigate the efficacy and safety of S-1 plus oxaliplatin (SOX) in patients with metastatic breast cancer. Materials and Methods: Patients with metastatic breast cancer previously treated with anthracyclines and taxanes were enrolled. Patients received S-1 (40-60 mg depending on patient’s body surface area, twice a day, day 1-14) and oxaliplatin (130 mg/m2, day 1) in 3 weeks cycle until disease progression or unacceptable toxicity. The primary endpoint was objective response rate (ORR) according to Response Evaluation Criteria in Solid Tumor 1.1. Secondary endpoints included time-to-progression (TTP), duration-of-response (DoR), overall survival (OS), and adverse events. Results: A total of 87 patients were enrolled from 11 institutions in Korea. Hormone receptor was positive in 54 (62.1%) patients and six (6.9%) had human epidermal growth factor receptor 2–positive disease. Forty-eight patients (85.1%) had visceral metastasis and 74 (55.2%) had more than three sites of metastases. The ORR of SOX regimen was 38.5% (95% confidence interval [CI], 26.9 to 50.0) with a median TTP of 6.0 months (95% CI, 5.1 to 6.9). Median DoR and OS were 10.3 months (95% CI, 5.5 to 15.1) and 19.4 (95% CI, not estimated) months, respectively. Grade 3 or 4 neutropenia was reported in 28 patients (32.1%) and thrombocytopenia was observed in 23 patients (26.6%). Conclusion This phase II study showed that SOX regimen is a reasonable option in metastatic breast cancer previously treated with anthracyclines and taxanes.

Purpose: Certain patient subgroups who do not respond to induction chemotherapy (IC) show inherent chemoresistance in locally advanced head and neck squamous cell carcinoma (LA-HNSCC). This study aimed to assess the prognostic value of IC, and role of IC in guiding the selection of a definitive locoregional therapy. Materials and Methods: Out of the 445 patients in multi-institutional LA-HNSCC cohort, 158 (36%) receiving IC were enrolled. The study outcome was to assess overall survival (OS) through IC responsiveness and its role to select subsequent treatments. Results: Among 135 patients who completed subsequent treatment following IC, 74% responded to IC (complete response in 17% and partial response in 58%). IC-non-responders showed 4.5 times higher risk of mortality than IC-responders (hazard ratio, 4.52; 95% confidence interval, 2.32 to 8.81; p < 0.001). Among IC-responders, 84% subsequently received definitive concurrent chemoradiotherapy (CCRT) and OS was not differed by surgery or CCRT (p=0.960). Regarding IC-non-responders, 54% received CCRT and 46% underwent surgery, and OS was poor in CCRT (24-month survival rate of 38%) or surgery (24-month survival rate of 63%). Conclusion Response to IC is a favorable prognostic factor. For IC-responders, either surgery or CCRT achieved similar survival probabilities. For IC-non-responder, multidisciplinary approach was warranted reflecting patients’ preference, morbidity, and prognosis.

Background/Aims: While switching strategies of P2Y12 receptor inhibitors (RIs) have sometimes been used in acute myocardial infarction (AMI) patients, the current status of in-hospital P2Y12RI switching remains unknown. Methods: Overall, 8,476 AMI patients who underwent successful revascularization from Korea Acute Myocardial Infarction Registry-National Institute of Health (KAMIR-NIH) were divided according to in-hospital P2Y12RI strategies, and net adverse cardiovascular events (NACEs), defined as a composite of cardiac death, non-fatal myocardial infarction (MI), stroke, or thrombolysis in myocardial infarction (TIMI) major bleeding during hospitalization were compared. Results: Patients with in-hospital P2Y12RI switching accounted for 16.5%, of which 867 patients were switched from clopidogrel to potent P2Y12RI (C-P) and 532 patients from potent P2Y12RI to clopidogrel (P-C). There were no differences in NACEs among the unchanged clopidogrel, the unchanged potent P2Y12RIs, and the P2Y12RI switching groups. However, compared to the unchanged clopidogrel group, the C-P group had a higher incidence of non-fatal MI, and the P-C group had a higher incidence of TIMI major bleeding. In clinical events of in-hospital P2Y12RI switching, 90.9% of non-fatal MI occurred during pre-switching clopidogrel administration, 60.7% of TIMI major bleeding was related to pre-switching P2Y12RIs, and 71.4% of TIMI major bleeding was related to potent P2Y12RIs. Only 21.6% of the P2Y12RI switching group switched to P2Y12RIs after a loading dose (LD); however, there were no differences in clinical events between patients with and without LD. Conclusions In-hospital P2Y12RI switching occurred occasionally, but had relatively similar clinical outcomes compared to unchanged P2Y12RIs in Korean AMI patients. Non-fatal MI and bleeding appeared to be mainly related to pre-switching P2Y12RIs.