1.Predictive value and optimal cut-off level of high-sensitivity troponin T in patients with acute pulmonary embolism
Moojun KIM ; Chang-Ok SEO ; Yong-Lee KIM ; Hangyul KIM ; Hye Ree KIM ; Yun Ho CHO ; Jeong Yoon JANG ; Jong-Hwa AHN ; Min Gyu KANG ; Kyehwan KIM ; Jin-Sin KOH ; Seok-Jae HWANG ; Jin Yong HWANG ; Jeong Rang PARK
The Korean Journal of Internal Medicine 2025;40(1):65-77
Background/Aims:
Elevated troponin levels predict in-hospital mortality and influence decisions regarding thrombolytic therapy in patients with acute pulmonary embolism (PE). However, the usefulness of high-sensitivity troponin T (hsTnT) regarding PE remains uncertain. We aimed to establish the optimal cut-off level and compare its performance for precise risk stratification.
Methods:
374 patients diagnosed with acute PE were reviewed. PE-related adverse outcomes, a composite of PE-related deaths, cardiopulmonary resuscitation incidents, systolic blood pressure < 90 mmHg, and all-cause mortality within 30 days were evaluated. The optimal hsTnT cut-off for all-cause mortality, and the net reclassification index (NRI) was used to assess the incremental value in risk stratification.
Results:
Among 343 normotensive patients, 17 (5.0%) experienced all-cause mortality, while 40 (10.7%) had PE-related adverse outcomes. An optimal hsTnT cut-off value of 60 ng/L for all-cause mortality (AUC 0.74, 95% CI 0.61–0.85, p < 0.001) was identified, which was significantly associated with PE-related adverse outcomes (OR 4.07, 95% CI 2.06–8.06, p < 0.001). Patients with hsTnT ≥ 60 ng/L were older, hypotensive, had higher creatinine levels, and right ventricular dysfunction signs. Combining hsTnT ≥ 60 ng/L with simplified pulmonary embolism severity index ≥1 provided additional prognostic information. Reclassification analysis showed a significant shift in risk categories, with an NRI of 1.016 ± 0.201 (p < 0.001).
Conclusions
We refined troponin’s predictive value in patients with acute PE, proposing a new cut-off value of hsTnT ≥ 60 ng/L. Validation through large-scale studies is essential to offer clinically useful guidance for managing patient population.
2.Initial and peak serum levels of Krebs von den Lungen-6 for predicting the prognosis of patients with COVID-19
Geonui KIM ; Hyeonwoo KWON ; Sang Hyun RA ; Euijin CHANG ; Seongman BAE ; Jiwon JUNG ; Min Jae KIM ; Yong Pil CHONG ; Sang-Oh LEE ; Sang-Ho CHOI ; Yang Soo KIM ; Sung-Han KIM
The Korean Journal of Internal Medicine 2025;40(2):321-329
Background/Aims:
Krebs von den Lungen-6 (KL-6) is associated with prognosis in patients with COVID-19. However, there is limited data on the correlation between the prognosis of COVID-19 and varying KL-6 levels at different time points. We investigated the optimal cutoff values of the initial and peak serum KL-6 levels to predict mortality and evaluated their correlation with mortality.
Methods:
This retrospective cohort study collected data on serially collected serum KL-6 levels in patients hospitalized with COVID-19 between October 2020 and January 2022 at a single tertiary hospital in South Korea. The area under the receiver operating characteristic curve and Youden index were used to determine the cutoff points for the initial and peak KL-6 levels that best predicted 30-day mortality. The association between the initial and peak KL-6 values was assessed by univariate and multivariate logistic regression models.
Results:
A total of 349 patients were included in this study. The mean initial and peak KL-6 levels were significantly higher in the non-survivor group than in the survivor group. The initial and peak KL-6 values that best predicted 30-day mortality were 491.85 U/mL and 660.05 U/mL, respectively. An initial KL-6 level greater than 491.85 U/mL and a peak KL-6 level greater than 660.05 U/mL were significantly associated with 30-day mortality.
Conclusions
The initial and peak levels of KL-6 were significantly associated with 30-day mortality in hospitalized patients with COVID-19. These findings suggest that serially monitoring blood KL-6 levels could be a valuable prognostic indicator for COVID-19.
3.Explainable paroxysmal atrial fibrillation diagnosis using an artificial intelligence-enabled electrocardiogram
Yeongbong JIN ; Bonggyun KO ; Woojin CHANG ; Kang-Ho CHOI ; Ki Hong LEE
The Korean Journal of Internal Medicine 2025;40(2):251-261
Background/Aims:
Atrial fibrillation (AF) significantly contributes to global morbidity and mortality. Paroxysmal atrial fibrillation (PAF) is particularly common among patients with cryptogenic strokes or transient ischemic attacks and has a silent nature. This study aims to develop reliable artificial intelligence (AI) algorithms to detect early signs of AF in patients with normal sinus rhythm (NSR) using a 12-lead electrocardiogram (ECG).
Methods:
Between 2013 and 2020, 552,372 ECG traces from 318,321 patients were collected and split into training (n = 331,422), validation (n = 110,475), and test sets (n = 110,475). Deep neural networks were then trained to predict AF onset within one month of NSR. Model performance was evaluated using the area under the receiver operating characteristic curve (AUROC). An explainable AI technique was employed to identify the inference evidence underlying the predictions of deep learning models.
Results:
The AUROC for early diagnosis of PAF was 0.905 ± 0.007. The findings reveal that the vicinity of the T wave, including the ST segment and S-peak, significantly influences the ability of the trained neural network to diagnose PAF. Additionally, comparing the summarized ECG in NSR with those in PAF revealed that nonspecific ST-T abnormalities and inverted T waves were associated with PAF.
Conclusions
Deep learning can predict AF onset from NSR while detecting key features that influence decisions. This suggests that identifying undetected AF may serve as a predictive tool for PAF screening, offering valuable insights into cardiac dysfunction and stroke risk.
4.Characteristics and outcomes of portal vein thrombosis in patients with inflammatory bowel disease in Korea
Ki Jin KIM ; Su-Bin SONG ; Jung-Bin PARK ; June Hwa BAE ; Ji Eun BAEK ; Ga Hee KIM ; Min-Jun KIM ; Seung Wook HONG ; Sung Wook HWANG ; Dong-Hoon YANG ; Byong Duk YE ; Jeong-Sik BYEON ; Seung-Jae MYUNG ; Suk-Kyun YANG ; Chang Sik YU ; Yong-Sik YOON ; Jong-Lyul LEE ; Min Hyun KIM ; Ho-Su LEE ; Sang Hyoung PARK
The Korean Journal of Internal Medicine 2025;40(2):243-250
Background/Aims:
Portal vein thrombosis (PVT) frequently occurs in patients with inflammatory bowel disease (IBD), particularly when influenced by factors such as abdominal infections, IBD flare-ups, or surgical procedures. The implications of PVT range from immediate issues such as intestinal ischemia to long-term concerns including portal hypertension and its complications. However, there is a notable gap in comprehensive studies on PVT in IBD, especially with the increasing incidence of IBD in Asia. This research aimed to evaluate the clinical features and outcomes of PVT in patients with IBD at a leading hospital in South Korea.
Methods:
This retrospective analysis reviewed adult patients diagnosed with both IBD and PVT from 1989 to 2021 at a renowned South Korean medical center. The study focused on patient characteristics, specifics of PVT, administered treatments, and outcomes, all confirmed through enhanced CT scans.
Results:
A total of 78 patients met the study’s criteria. Notably, only 20.5% (16/78) were treated with oral anticoagulants; however, a vast majority (96.2%; 75/78) achieved complete radiographic resolution (CRR). When comparing patients receiving anticoagulants to those who did not, a significant preference for anticoagulant use was observed in cases where the main portal vein was affected, as opposed to just the left or right veins (p = 0.006). However, multivariable analysis indicated that neither anticoagulant use nor previous surgeries significantly impacted CRR.
Conclusions
Patients with IBD and PVT generally had favorable outcomes, regardless of anticoagulant use.
5.Predicting Clinically Significant Prostate Cancer Using Urine Metabolomics via Liquid Chromatography Mass Spectrometry
Chung-Hsin CHEN ; Hsiang-Po HUANG ; Kai-Hsiung CHANG ; Ming-Shyue LEE ; Cheng-Fan LEE ; Chih-Yu LIN ; Yuan Chi LIN ; William J. HUANG ; Chun-Hou LIAO ; Chih-Chin YU ; Shiu-Dong CHUNG ; Yao-Chou TSAI ; Chia-Chang WU ; Chen-Hsun HO ; Pei-Wen HSIAO ; Yeong-Shiau PU ;
The World Journal of Men's Health 2025;43(2):376-386
Purpose:
Biomarkers predicting clinically significant prostate cancer (sPC) before biopsy are currently lacking. This study aimed to develop a non-invasive urine test to predict sPC in at-risk men using urinary metabolomic profiles.
Materials and Methods:
Urine samples from 934 at-risk subjects and 268 treatment-naïve PC patients were subjected to liquid chromatography/mass spectrophotometry (LC-MS)-based metabolomics profiling using both C18 and hydrophilic interaction liquid chromatography (HILIC) column analyses. Four models were constructed (training cohort [n=647]) and validated (validation cohort [n=344]) for different purposes. Model I differentiates PC from benign cases. Models II, III, and a Gleason score model (model GS) predict sPC that is defined as National Comprehensive Cancer Network (NCCN)-categorized favorable-intermediate risk group or higher (Model II), unfavorable-intermediate risk group or higher (Model III), and GS ≥7 PC (model GS), respectively. The metabolomic panels and predicting models were constructed using logistic regression and Akaike information criterion.
Results:
The best metabolomic panels from the HILIC column include 25, 27, 28 and 26 metabolites in Models I, II, III, and GS, respectively, with area under the curve (AUC) values ranging between 0.82 and 0.91 in the training cohort and between 0.77 and 0.86 in the validation cohort. The combination of the metabolomic panels and five baseline clinical factors that include serum prostate-specific antigen, age, family history of PC, previously negative biopsy, and abnormal digital rectal examination results significantly increased AUCs (range 0.88–0.91). At 90% sensitivity (validation cohort), 33%, 34%, 41%, and 36% of unnecessary biopsies were avoided in Models I, II, III, and GS, respectively. The above results were successfully validated using LC-MS with the C18 column.
Conclusions
Urinary metabolomic profiles with baseline clinical factors may accurately predict sPC in men with elevated risk before biopsy.
6.Human Understanding is Expected of the Physician: Proposing a Model of Disease Development
Sang-Heum PARK ; Samel PARK ; Jin Young KIM ; Hyeon Ah LEE ; Sang Mi LEE ; Tae Hoon LEE ; Sang Byung BAE ; Sung Hae CHANG ; Si Hyong JANG ; Sung Wan CHUN ; Jong Ho MOON
Korean Journal of Medicine 2025;100(1):44-
7.Clinical Characteristics and Visual Prognostic Biomarkers in Pericentral Retinitis Pigmentosa: A Study in a South Korean Cohort
Su Ho BAE ; Seung Woo CHOI ; Chang Ki YOON ; Un Chul PARK ; Kyu Hyung PARK ; Eun Kyoung LEE
Korean Journal of Ophthalmology 2025;39(2):157-169
Purpose:
To investigate the clinical characteristics of South Korean patients with pericentral retinitis pigmentosa (RP) and to identify clinical biomarkers associated with rapid visual acuity decline based on baseline factors.
Methods:
This retrospective study included 59 eyes of 31 patients diagnosed with pericentral RP. Comprehensive ophthalmological examinations and genetic sequencing were conducted to assess the baseline characteristics. For biomarker analysis, eyes were categorized into two groups based on the annual rate of change in visual acuity. The clinical findings of the two groups were evaluated to identify the biomarkers associated with rapid loss of visual acuity.
Results:
Patients with pericentral RP in this study exhibited a mean best-corrected visual acuity of 0.17 ± 0.23 in logarithm of the minimum angle of resolution. The visual field test showed annular or semicircular scotoma with relatively preserved periphery and 27 eyes (45.8%) exhibited no macular complications in optical coherence tomography. Genetic analysis identified genes associated with previous typical and pericentral RP studies but also highlighted that many genetic causes of pericentral RP remain unidentified. Of the 55 eyes for which the rate of visual acuity change could be estimated, 18 exhibited an annual decline of ≥10%, whereas 37 showed an annual decline of <10%. Male sex and prolonged b-wave latency on dark-adapted 0.01 electroretinogram correlated with rapid visual acuity decline in the multivariate analysis.
Conclusions
South Korean patients with pericentral RP exhibited a milder phenotype compared to typical RP patients reported in previous studies. Genetic analysis revealed heterogeneity, with mutations in some genes commonly associated with milder forms of RP. Male sex and prolonged b-wave latency on dark-adapted 0.01 electroretinogram were significant biomarkers for predicting rapid visual acuity decline. Monitoring initial b-wave latency is important for predicting visual decline, particularly in male patients with pericentral RP.
8.Long-term Effects and Prognostic Factors of Accelerated Cross-Linking with Retention Ring-assisted Riboflavin Application on Keratoconus Progression
Seonghwan KIM ; Won Jong CHOI ; Chang Ho YOON ; Mee Kum KIM
Korean Journal of Ophthalmology 2025;39(2):145-156
Purpose:
To evaluate the long-term efficacy, safety, and prognostic factors of pulsed-light accelerated corneal collagen cross-linking (A-CXL) with continuous riboflavin application to halt keratoconus progression
Methods:
A-CXL with retention ring-assisted continuous riboflavin application for either 10 or 5 minutes was performed in 37 eyes of 33 patients with progressive keratoconus between 2016 and 2020. Successful halting rates and prognostic factors of time-dependent changes in keratometric values, visual acuity, refractive errors, topographic indices, central corneal thickness, thinnest corneal thickness, irregularity at 3- and 5-mm zone, and endothelial cell density were evaluated.
Results:
Survival analysis showed successful halting rates of 71% and 89% in A-CXL with 5- and 10-minute–applied riboflavin, respectively. Best-corrected visual acuity significantly improved after A-CXL in both groups. Maximum keratometry decreased significantly from 52.52 to 50.39 diopters (p < 0.001) in the 10-minute group, while there was no significant decrease in the 5-minute group (52.77–51.80 diopters, p = 0.146). irregularity in 3- and 5-mm zone decreased significantly in the 10-minute group, while there was no difference in 5-minute group. Central corneal thickness and thinnest corneal thickness did not differ, and endothelial cell density changes were within acceptable ranges in both groups before and after the surgery. Among keratometric values, keratometric astigmatism was significantly related to posttreatment corneal flattening effect in multivariate regression analysis.
Conclusions
A-CXL with continuous riboflavin application for 10 minutes is an effective and safe treatment for preventing keratoconus progression. In addition, higher corneal astigmatism showed greater posttreatment corneal flattening effect in successfully treated patients.
9.Long-term Outcome and Related Risk Factors in Implantable Collamer Lens Implantation of High Myopia
Yong Hee KIM ; Chang Ho YOON ; Mee Kum KIM
Korean Journal of Ophthalmology 2025;39(2):134-144
Purpose:
To investigate the long-term efficacy and safety of posterior chamber implantable collamer lens (ICL) implantation in high myopia, and the risk factors associated with endothelial cell loss (ECL) or cataract development.
Methods:
Medical records of 66 eyes of 37 patients who underwent ICL implantation for high myopia were retrospectively analyzed with a mean follow-up of 12 years. Changes in best-corrected visual acuity (logarithm of the minimum angle of resolution), intraocular pressure (IOP), refractive power, and endothelial cell density over time were analyzed with the incidence of cataract and IOP elevation. Risk factors were analyzed for their association with ECL or cataract development.
Results:
At 10 years after surgery, the mean uncorrected visual acuity was 0.06 and the spherical equivalent was –0.90 diopters. By year 10, cataract was present in 13 of 66 eyes (19.7%), whereas glaucoma was found in 1 of 66 eyes (1.5%). Although IOP continuously elevated over time (p < 0.05), it remained within normal limits. The cataract group had a lower vault of ICL and a higher mean age at surgery (p < 0.05). Endothelial cell density remained above 2,000/mm2 in 98.5% of cases, with an average annualized rate of decline of 1.13%. The high annualized rate group (>1.13% loss per year) had a lower mean age than in the low annualized rate group (<1.13% loss per year, p < 0.05).
Conclusions
This indicates that ICL implantation is effective for high myopia, and its main complication is cataract and ECL. It also suggests that ECL and cataract should be regularly monitored although ECL looks stable in long-term follow-up. Age may affect both ECL and cataract, while low-vault ICL may affect cataract.
10.Intralesional Triamcinolone Acetonide Injection as a Treatment for Granulomatous Tissue on Tracheocutaneous Stoma
Min Woo KIM ; Myung Ho JIN ; Jong Kwan KIM ; Dong Sik CHANG
Korean Journal of Otolaryngology - Head and Neck Surgery 2025;68(2):62-66
Background and Objectives:
The aim of this study was to confirm the effect of intralesional triamcinolone acetonide injections (TRIAM) to treat granulomatous tissue surrounding the tracheostomy stoma.Subjects and Method We reviewed and documented the medical charts of 20 patients who were administered with TRIAM to treat granulomatous tissue surrounding the tracheostomy stoma from January 2018 to June 2019 were. The surface area of the granulomatous tissue was measured using Image J. The differences between the area of the granulomatous tissue after conventional treatment and after TRIAM on the same patient were compared.
Results:
A total of 20 patients consisting of 12 males and 8 females were included, with the patients’ average age being 60.0±14.3 years. The initial surface area of granulation tissue was 1.266±0.449 cm2, and 1.243±0.432 cm2 after conventional treatment, showing no statistically significant difference in the tissue area (p=0.143). The pre-injection surface area of granulation tissue was 1.243±0.432 cm2, and the area on the 7th day after the third injection was 0.477±0.217 cm2, showing a significant difference (p<0.001).
Conclusion
Compared to the conventional treatment, the surface area of granulomatous tissue surrounding the tracheostomy stoma significantly decreased after being treating with TRIAM. This finding suggests the effectiveness of TRIAM as a treatment of granulomatous tissue surrounding the tracheostomy stoma without complications such as bleeding.

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