Background: Complete revascularization has demonstrated better outcomes in patients with acute myocardial infarction (AMI) and multivessel disease. However, in the case of left main (LM) culprit lesion AMI with multivessel disease, there is limited evidence to suggest that complete revascularization is better. Methods: We reviewed 16,831 patients in the Korea Acute Myocardial Infarction Registry who were treated from July 2016 to June 2020, and 399 patients were enrolled with LM culprit lesion AMI treated with percutaneous coronary intervention. We categorized the patients as those treated with complete revascularization (n=295) or incomplete revascularization (n=104). The study endpoint was major adverse cardiac and cerebrovascular events (MACCE), a composite of all-cause death, myocardial infarction, ischemia-driven revascularization, stent thrombosis, and stroke. We performed propensity score matching (PSM) and analyzed the incidence of MACCE at 1 year. Results: After PSM, the two groups were well balanced. There was no significant difference between the two groups in MACCE at 1 year (12.1% vs. 15.2%; hazard ratio, 1.28; 95% confidence interval, 0.60–2.74; p=0.524) after PSM. The components of MACCE and major bleeding were also not significantly different. Conclusion There was no significant difference in clinical outcomes between the groups treated with complete or incomplete revascularization for LM culprit lesion AMI with multivessel disease.

Background: Complete revascularization has demonstrated better outcomes in patients with acute myocardial infarction (AMI) and multivessel disease. However, in the case of left main (LM) culprit lesion AMI with multivessel disease, there is limited evidence to suggest that complete revascularization is better. Methods: We reviewed 16,831 patients in the Korea Acute Myocardial Infarction Registry who were treated from July 2016 to June 2020, and 399 patients were enrolled with LM culprit lesion AMI treated with percutaneous coronary intervention. We categorized the patients as those treated with complete revascularization (n=295) or incomplete revascularization (n=104). The study endpoint was major adverse cardiac and cerebrovascular events (MACCE), a composite of all-cause death, myocardial infarction, ischemia-driven revascularization, stent thrombosis, and stroke. We performed propensity score matching (PSM) and analyzed the incidence of MACCE at 1 year. Results: After PSM, the two groups were well balanced. There was no significant difference between the two groups in MACCE at 1 year (12.1% vs. 15.2%; hazard ratio, 1.28; 95% confidence interval, 0.60–2.74; p=0.524) after PSM. The components of MACCE and major bleeding were also not significantly different. Conclusion There was no significant difference in clinical outcomes between the groups treated with complete or incomplete revascularization for LM culprit lesion AMI with multivessel disease.

Background: Complete revascularization has demonstrated better outcomes in patients with acute myocardial infarction (AMI) and multivessel disease. However, in the case of left main (LM) culprit lesion AMI with multivessel disease, there is limited evidence to suggest that complete revascularization is better. Methods: We reviewed 16,831 patients in the Korea Acute Myocardial Infarction Registry who were treated from July 2016 to June 2020, and 399 patients were enrolled with LM culprit lesion AMI treated with percutaneous coronary intervention. We categorized the patients as those treated with complete revascularization (n=295) or incomplete revascularization (n=104). The study endpoint was major adverse cardiac and cerebrovascular events (MACCE), a composite of all-cause death, myocardial infarction, ischemia-driven revascularization, stent thrombosis, and stroke. We performed propensity score matching (PSM) and analyzed the incidence of MACCE at 1 year. Results: After PSM, the two groups were well balanced. There was no significant difference between the two groups in MACCE at 1 year (12.1% vs. 15.2%; hazard ratio, 1.28; 95% confidence interval, 0.60–2.74; p=0.524) after PSM. The components of MACCE and major bleeding were also not significantly different. Conclusion There was no significant difference in clinical outcomes between the groups treated with complete or incomplete revascularization for LM culprit lesion AMI with multivessel disease.

Background: Complete revascularization has demonstrated better outcomes in patients with acute myocardial infarction (AMI) and multivessel disease. However, in the case of left main (LM) culprit lesion AMI with multivessel disease, there is limited evidence to suggest that complete revascularization is better. Methods: We reviewed 16,831 patients in the Korea Acute Myocardial Infarction Registry who were treated from July 2016 to June 2020, and 399 patients were enrolled with LM culprit lesion AMI treated with percutaneous coronary intervention. We categorized the patients as those treated with complete revascularization (n=295) or incomplete revascularization (n=104). The study endpoint was major adverse cardiac and cerebrovascular events (MACCE), a composite of all-cause death, myocardial infarction, ischemia-driven revascularization, stent thrombosis, and stroke. We performed propensity score matching (PSM) and analyzed the incidence of MACCE at 1 year. Results: After PSM, the two groups were well balanced. There was no significant difference between the two groups in MACCE at 1 year (12.1% vs. 15.2%; hazard ratio, 1.28; 95% confidence interval, 0.60–2.74; p=0.524) after PSM. The components of MACCE and major bleeding were also not significantly different. Conclusion There was no significant difference in clinical outcomes between the groups treated with complete or incomplete revascularization for LM culprit lesion AMI with multivessel disease.

Background: Heterotopic ossification (HO) is difficult to characterize and classify on simple radiographs. Therefore, we attempted to evaluate intraobserver and interobserver reliability of simple radiography and computed tomography (CT) for detecting and classifying HO after reverse shoulder arthroplasty (RSA). It was hypothesized that CT would provide more reliable results than simple radiography. Methods: This retrospective study reviewed 30 patients who underwent RSA performed by a single surgeon. Patients were included if they had both postoperative simple radiographs and CT images taken immediately after surgery and at 1 year after surgery and if they had completed clinical assessment at least 1 year after surgery. We first evaluated the intraobserver and interobserver reliability for the detection of the presence of HO and Modified Brooker’s classification both on simple radiographs and CT scans with the use of Kappa statistics. Then, we analyzed the correlation of HO observed in simple radiographs and CT scans with clinical outcomes. All radiographic evaluations were performed by 2 independent reviewers in random orders with 3 weeks of intervals. Results: The intraobserver reliability outcomes of both reviewers in simple radiography and CT were almost perfect or perfect for the detection of HO and classification. However, CT images improved the interobserver reliability for the detection of HO (kappa value for simple radiographs [KXR ] = 0.6018 and kappa value for CT [KCT ] = 0.8316) and classification (KXR = 0.5300 and KCT = 0.6964).At a mean follow-up of 25 months (range, 12–54 months), clinical scores were not significantly different according to the presence of HO based on simple radiographs. However, when CT images were used, the University of California, Los Angeles score and physical component score of short-form 36-item health survey were significantly lower in patients with HO than in patients without HO (27.0 vs. 30.4, p = 0.045 and 57.6 vs. 70.7, p = 0.034, respectively). Conclusions Both simple radiography and CT provided excellent intraobserver reliability for detecting and classifying HO after RSA. Compared to simple radiography, CT tended to improve interobserver reliability and defined the presence and severity of HO more clearly.

Background: Heterotopic ossification (HO) is difficult to characterize and classify on simple radiographs. Therefore, we attempted to evaluate intraobserver and interobserver reliability of simple radiography and computed tomography (CT) for detecting and classifying HO after reverse shoulder arthroplasty (RSA). It was hypothesized that CT would provide more reliable results than simple radiography. Methods: This retrospective study reviewed 30 patients who underwent RSA performed by a single surgeon. Patients were included if they had both postoperative simple radiographs and CT images taken immediately after surgery and at 1 year after surgery and if they had completed clinical assessment at least 1 year after surgery. We first evaluated the intraobserver and interobserver reliability for the detection of the presence of HO and Modified Brooker’s classification both on simple radiographs and CT scans with the use of Kappa statistics. Then, we analyzed the correlation of HO observed in simple radiographs and CT scans with clinical outcomes. All radiographic evaluations were performed by 2 independent reviewers in random orders with 3 weeks of intervals. Results: The intraobserver reliability outcomes of both reviewers in simple radiography and CT were almost perfect or perfect for the detection of HO and classification. However, CT images improved the interobserver reliability for the detection of HO (kappa value for simple radiographs [KXR ] = 0.6018 and kappa value for CT [KCT ] = 0.8316) and classification (KXR = 0.5300 and KCT = 0.6964).At a mean follow-up of 25 months (range, 12–54 months), clinical scores were not significantly different according to the presence of HO based on simple radiographs. However, when CT images were used, the University of California, Los Angeles score and physical component score of short-form 36-item health survey were significantly lower in patients with HO than in patients without HO (27.0 vs. 30.4, p = 0.045 and 57.6 vs. 70.7, p = 0.034, respectively). Conclusions Both simple radiography and CT provided excellent intraobserver reliability for detecting and classifying HO after RSA. Compared to simple radiography, CT tended to improve interobserver reliability and defined the presence and severity of HO more clearly.

Background: Heterotopic ossification (HO) is difficult to characterize and classify on simple radiographs. Therefore, we attempted to evaluate intraobserver and interobserver reliability of simple radiography and computed tomography (CT) for detecting and classifying HO after reverse shoulder arthroplasty (RSA). It was hypothesized that CT would provide more reliable results than simple radiography. Methods: This retrospective study reviewed 30 patients who underwent RSA performed by a single surgeon. Patients were included if they had both postoperative simple radiographs and CT images taken immediately after surgery and at 1 year after surgery and if they had completed clinical assessment at least 1 year after surgery. We first evaluated the intraobserver and interobserver reliability for the detection of the presence of HO and Modified Brooker’s classification both on simple radiographs and CT scans with the use of Kappa statistics. Then, we analyzed the correlation of HO observed in simple radiographs and CT scans with clinical outcomes. All radiographic evaluations were performed by 2 independent reviewers in random orders with 3 weeks of intervals. Results: The intraobserver reliability outcomes of both reviewers in simple radiography and CT were almost perfect or perfect for the detection of HO and classification. However, CT images improved the interobserver reliability for the detection of HO (kappa value for simple radiographs [KXR ] = 0.6018 and kappa value for CT [KCT ] = 0.8316) and classification (KXR = 0.5300 and KCT = 0.6964).At a mean follow-up of 25 months (range, 12–54 months), clinical scores were not significantly different according to the presence of HO based on simple radiographs. However, when CT images were used, the University of California, Los Angeles score and physical component score of short-form 36-item health survey were significantly lower in patients with HO than in patients without HO (27.0 vs. 30.4, p = 0.045 and 57.6 vs. 70.7, p = 0.034, respectively). Conclusions Both simple radiography and CT provided excellent intraobserver reliability for detecting and classifying HO after RSA. Compared to simple radiography, CT tended to improve interobserver reliability and defined the presence and severity of HO more clearly.

Background: Since the emergence of hypervirulent strains of Clostridioides difficile, the incidence of C. difficile infections (CDI) has increased significantly. Methods: To assess the incidence of CDI in Korea, we conducted a prospective multicentre observational study from October 2020 to October 2021. Additionally, we calculated the incidence of CDI from mass data obtained from the Health Insurance Review and Assessment Service (HIRA) from 2008 to 2020. Results: In the prospective study with active surveillance, 30,212 patients had diarrhoea and 907 patients were diagnosed with CDI over 1,288,571 patient-days and 193,264 admissions in 18 participating hospitals during 3 months of study period; the CDI per 10,000 patientdays was 7.04 and the CDI per 1,000 admission was 4.69. The incidence of CDI was higher in general hospitals than in tertiary hospitals: 6.38 per 10,000 patient-days (range: 3.25–12.05) and 4.18 per 1,000 admissions (range: 1.92–8.59) in 11 tertiary hospitals, vs. 9.45 per 10,000 patient-days (range: 5.68–13.90) and 6.73 per 1,000 admissions (range: 3.18–15.85) in seven general hospitals. With regard to HIRA data, the incidence of CDI in all hospitals has been increasing over the 13-year-period: from 0.3 to 1.8 per 10,000 patient-days, 0.3 to 1.6 per 1,000 admissions, and 6.9 to 56.9 per 100,000 population, respectively. Conclusion The incidence of CDI in Korea has been gradually increasing, and its recent value is as high as that in the United State and Europe. CDI is underestimated, particularly in general hospitals in Korea.

Background: Developmental trajectories of clinical skills in training physicians vary among tasks and show interindividual differences. This study examined the predictors of medical internship performance and residency entrance and found subtypes of performance trajectory in training physicians. Methods: This retrospective cohort study involved 888 training physicians who completed a medical internship between 2015 and 2019. After the internship, 627 physicians applied for residency training between 2016 and 2020. Finally, 160 of them completed their first-year residency in internal medicine, surgery, pediatrics, and psychiatry departments between 2016 and 2020. Pearson’s correlation coefficients of internship performance and first year-residency performance (n = 160) were calculated. Latent profile analysis identified performance trajectory subtypes according to medical school grade point average (GPA), internship performance, English proficiency, and residency selection procedures. Multivariate logistic regression models of residency acceptance (n = 627) and performance in the top 30%/lower 10% in the first year of residency were also constructed. Results: Medical internship performance showed a significant positive correlation with the medical school GPA (r = 0.194) and the written score for the medical licensing examination (r = 0.125). Higher scores in the interview (adjusted odds ratio [aOR], 2.57) and written examination (aOR, 1.45) of residency selection procedures and higher medical internship performance (aOR, 1.19) were associated with a higher chance of residency acceptance. The latent profile analyses identified three training physician subgroups: average performance, consistently high performance (top 30%), and adaptation to changes (lowest 10%). Higher scores in the interview for residency selection (aOR, 1.35) and lower scores for medical internship performance (aOR, 0.79) were associated with a higher chance of performing in the top 30% or lowest 10% in the first year of residency, respectively. Conclusion Performance in the interview and medical internship predicted being among the top 30% and lowest 10% of performers in the first year of residency training, respectively.Individualized educational programs to enhance the prospect of trainees becoming highfunctioning physicians are needed.

Background: The importance of digital technology is increasing among older adults. In this study, the digital health technology utilization status, purpose, and satisfaction of older adults were investigated according to frailty. Methods: A face-to-face survey was conducted among adults aged 65 years or older. Frailty was defined using the Korean version of the fatigue, resistance, ambulation, illnesses, and loss of weight scale. Results: A total of 505 participants completed the survey, with 153 (30.3%) identified as pre-frail or frail and 352 (69.7%) as healthy. All respondents used smartphones; 440 (87.1%) were application users, and 290 (57.4%) were healthcare application users. Wearable devices were used by only 36 patients (7.1%). Pre-frail or frail respondents used social media more frequently than healthy respondents (19.4% vs. 7.4%, P < 0.001). Among the respondents, 319 (63.2%) were not able to install or delete the application themselves, and 277 (54.9%) stated that the application was recommended by their children (or partner). Pre-frail and frail respondents used more healthcare applications to obtain health information (P = 0.002) and were less satisfied with wearable devices (P = 0.02). Conclusion The usage rate of digital devices, including mobile phones among older adults in Korea is high, whereas that of wearable devices is low. There was a notable difference in the services used by pre-frail and frail respondents compared to healthy respondents. Therefore, when developing digital devices for pre-frail and frail older adults, it is crucial to incorporate customized services that meet their unique needs, particularly those services that they frequently use.