Background/Aims: Various expanded criteria (EC) for liver transplantation (LT) in patients with hepatocellular carcinoma (HCC) have been proposed to avoid the narrow nature of the Milan criteria (MC). To investigate which EC predicts more favorable outcomes in terms of overall survival (OS) and recurrence-free survival (RFS), we conducted a network meta-analysis (NMA). Methods: A database search was conducted on PubMed, Embase, and the Cochrane Library, to identify studies comparing OS and RFS between patients within the MC and those exceeding the MC but within the EC. Hazard ratios (HRs) were pooled using a random-effects NMA and validated in an in-house cohort of 1,008 LT recipients. Results: Among 22,466 articles identified, 35 studies with 45 pairwise comparisons were included in the NMA along with 8 different EC. The University of California San Francisco (HR, 1.43; 95% CI, 1.19–1.71), Up-to-Seven (HR, 1.50; 95% CI, 1.15–1.97), and Hangzhou criteria (HR, 1.69; 95% CI, 1.11–2.57) showed inferior OS to the MC. The MC ranked highest for both OS and RFS, followed by Metroticket 2.0 for OS and the Asan criteria for RFS. In the validation cohort, both Metroticket 2.0 and AFP model yielded more favorable HCC-specific mortality than other EC. Conclusions Several EC, of which those of Metroticket 2.0 were the best, yielded comparable outcomes to the MC. AFP-based EC such as Metroticket 2.0 and AFP model appeared to be useful in both the NMA and the validation cohort, suggesting a potential role in identifying selected low-risk patients beyond the MC.

Background and Objectives: Clinical characteristics and outcomes in acute heart failure (AHF) vary by phenotype. We assessed phenotype-specific features, treatment patterns, and outcomes in a nationwide Korean cohort. Methods: The Korean Heart Failure III registry prospectively enrolled 7,351 AHF admissions at 47 hospitals. Among 6,777 patients with available left ventricular ejection fraction (EF), phenotypes were defined as heart failure with reduced EF (HFrEF, ≤40%), mildly reduced EF (HFmrEF,41–49%), or preserved EF (HFpEF, ≥50%). The primary endpoint was a 12-month composite of all-cause death or heart transplantation, evaluated from index admission and, among hospital survivors, from discharge. We used inverse probability weighting (multinomial generalized boosted models with stabilized, trimmed weights) and weighted Cox proportional-hazards models to estimate hazard ratios (HRs). Results: Phenotype distribution was 58.9% HFrEF, 13.6% HFmrEF, and 27.5% HFpEF. Crude 12-month composite rates from index admission were 13.4% (HFrEF), 12.7% (HFmrEF), and 16.8% (HFpEF). After weighting, from index admission, HFmrEF (HR, 0.892; 95% confidence interval [CI], 0.731–1.088) and HFpEF (HR, 1.101; 95% CI, 0.939–1.291) did not differ from HFrEF; from discharge, HFpEF had modestly higher risk (HR, 1.207; 95% CI, 1.008–1.445) whereas HFmrEF did not (HR, 1.039; 95% CI, 0.844–1.279). Hyponatremia and chronic kidney disease were consistent adverse markers, while angiotensin-converting enzyme inhibitor/ angiotensin II receptor blocker use at discharge was protective. Conclusions Across the EF spectrum, phenotypes showed distinct profiles and risk. Postdischarge risk was modestly higher in HFpEF, supporting phenotype-tailored care and systematic discharge optimization in Korean patients with AHF.

Background and Objectives: Heart failure (HF) imposes a significant global burden, yet awareness and implementation of guideline-directed management remain suboptimal. This study evaluated HF awareness, diagnostic patterns, and therapeutic strategies among physicians in Korea. Methods: A nationwide online survey was conducted from July to August 2019, targeting primary care physicians (PCPs; n=8,000) and hospital-based cardiology specialists (n=1,339) across Korea. The questionnaire comprised 23 items covering baseline characteristics, perceptions of HF prognosis, diagnostic approaches, and treatment practices. Results: A total of 543 physicians responded (209 PCPs and 334 cardiology specialists). While the majority correctly defined HF, a substantial proportion underestimated the lifetime risk and poor prognosis. Cardiology specialists were more likely than PCPs to use objective diagnostic tools, including echocardiography (97% vs. 61%, p<0.001) and natriuretic peptide testing (90% vs. 57%, p<0.001). Among PCPs, 29% reported diagnosing HF based on symptoms and physical findings without objective testing, and 27% reported referring patients to general hospitals for diagnostic evaluation. Prescription rates for guideline-directed medical therapies, including renin-angiotensin system blockers and beta-blockers, were consistently higher among cardiology specialists.PCPs more frequently cited advanced age as a barrier to prescribing evidence-based medications. Conclusions Physicians’ awareness and clinical practices regarding HF in Korea remain suboptimal. Given the growing burden, high mortality, and substantial costs of HF, early detection, appropriate diagnostic evaluation, and timely referral are essential. Targeted education and system-level strategies to improve guideline implementation, particularly in primary care settings, are warranted.

Background: There are limited long-term clinical outcome data comparing first-generation (1G) versus second-generation (2G) drug-eluting stents (DES) in patients with single-vessel disease (SVD). We sought to compare the efficacy and safety of 1G- and 2G-DES in SVD patients who underwent successful percutaneous coronary intervention (PCI) over 10 years of clinical follow-up. Methods: A total of 2,312 consecutive patients with SVD who underwent PCI with 1G-DES (paclitaxel- or sirolimus-eluting stents, n = 811) or 2G-DES (zotarolimus [Endeavor, Endeavor Resolute]- or everolimus-eluting stents [Promus Element, Xience], n = 1,082) were enrolled.After propensity score matching, 2 matched groups (538 pairs) were generated. Study endpoints included individual and composite clinical outcomes through 10 years. Results: During the 10-year follow-up, the 2G-DES group had lower incidences of myocardial infarction (MI; hazard ratio [HR], 0.44; 95% confidence interval [CI], 0.22–0.92; P = 0.028) and target lesion revascularization (TLR; HR, 0.54; 95% CI, 0.32–0.91; P = 0.021) than the 1G-DES group. Rates of total death, cardiac death, non-target vessel revascularization, stroke, major adverse cardiac events, and major adverse cardiac and cerebrovascular events were similar between groups. Conclusions In our single-center, all-comer registry, 2G-DES were associated with lower incidence rates of MI and TLR compared to 1G-DES in SVD patients over 10 years of followup, indicating a safer and more durable effect than 1G-DES.

Vaccines are highly effective, but rare or delayed adverse events following immunization (AEFIs) require post-licensure surveillance beyond clinical trials. Korea lacks a comprehensive, active, database-based framework, yet key assets exist: nationwide claims databases (National Health Insurance Service/Health Insurance Review and Assessment Service), the national immunization registry (Korea Disease Control and Prevention Agency’s Immunization Registry Information System) for National Immunization Program (NIP) and non-NIP vaccines, and increasingly standardized hospital electronic health records.We propose a federated, code to data architecture with data linkages between these data.Implementation should adopt a common data model (CDM), standardized case definitions, latency accounting, and transparent public reporting under strong privacy governance. Major challenges include multi step administrative approvals for data linkage, incomplete capture of adult non-NIP vaccinations, heterogeneous hospital data structures, and strict data protection constraints. Strategic priorities are to streamline statutory and administrative processes for public health use, mandate or enable claims-based capture of adult vaccinations, enhance CDM based interoperability, and develop secure hubs for aggregated outputs. With these measures, Korea will be well positioned to establish a scalable active surveillance system capable of detecting rare AEFIs, supporting transparent and evidence-based communication, and ensuring equitable injury compensation grounded in domestic data.

Purpose: This study evaluated the clinical outcomes and prognostic factors in patients with borderline resectable pancreatic cancer (BRPC) and locally advanced pancreatic cancer (LAPC) treated with upfront FOLFIRINOX followed by local-regional therapy (LRT), surgical resection (SR), and radiotherapy (RT). We aimed to identify specific patient subgroups for which RT may serve as a reasonable alternative to SR for local tumor control. Methods: We retrospectively analyzed 116 patients (SR group, n= 70; RT group, n= 46) at a single center between 2015 and 2020. Survival outcomes were compared based on LRT modalities, focusing on identifying subgroups in which RT provided an efficacy comparable to that of SR. Results: Among 116 patients, the SR group achieved a significantly higher 5-year overall survival (OS) than the RT group (27.1% vs. 8.7%, P< 0.0001), despite similar progression-free survival (P= 0.23). Significant prognostic factors for OS included carbohydrate antigen 19-9 (CA19-9) response in BRPC (P= 0.02) and radiologic partial response in LAPC (P= 0.05). Subgroup analysis revealed that, while SR provided a survival advantage in CA19-9 responders, no significant difference in OS was observed between SR and RT in CA19-9 non-responders (P= 0.37). Conclusion Although surgery remains the gold standard, RT may be considered a justifiable local alternative for CA19-9 non-responders and surgically ineligible patients with LAPC, yielding comparable outcomes in these specific, biologically unfavorable subgroups.

Objectives: Endoscopic submucosal dissection (ESD) has become a standard minimally invasive treatment for selected patients with early gastric cancer (EGC). This study presents the first nationwide survey of patients with EGC treated with ESD in 2023, conducted by the Korean College of Helicobacter and Upper Gastrointestinal Research. Methods: Data were retrospectively collected from participating referral centers across Korea using a standardized case report form covering patient characteristics, tumor features, procedural details, histopathological findings, and clinical outcomes. Descriptive and comparative analyses were conducted to summarize nationwide ESD practice patterns and outcomes. Results: Data from 5460 ESD cases from 5250 patients across 27 institutions were analyzed. The mean age was 67.4 years, with 74.1% males. Multiple synchronous lesions were identified in 3.7%. Most lesions were located in the lower third of the stomach (64.0%), and differentiated-type adenocarcinomas accounted for 87.8%. The en bloc and complete resection rates were 99.2% and 91.4%, respectively. Curative resection was achieved in 80.5%, whereas local non-curative resection (L-NCR) and surgical non-curative resection (S-NCR) were identified in 2.8% and 16.7%, respectively. Additional surgery was performed more frequently in patients with S-NCR than in those with L-NCR (59.3% vs. 24.7%). The bleeding and perforation rates were 3.6% and 0.9%, respectively, and were mostly managed conservatively or endoscopically. The median length of hospitalization was 4.0 days. Conclusions This first nationwide survey provides a comprehensive overview of the current practice of EGC treatment using ESD in Korea, demonstrating high technical success and safety, and establishing a baseline dataset for future longitudinal research.

Background: The Act on Decisions on Life-Sustaining Treatment (LST) has been implemented in Korea since 2018, yet data on its application in neurocritical care units remain scarce. This study aimed to evaluate the clinical characteristics and outcomes of LST withdrawal or withholding in the neurocritical care unit. Methods: This study was a retrospective analysis conducted at a tertiary university hospital in Busan, South Korea. Among patients admitted to the neurocritical care unit between February 2018 and August 2023, those with documented decisions for LST withdrawal or withholding were enrolled. Demographic and clinical characteristics, underlying and combined conditions, reasons for LST decisions, measures taken, and time from LST withdrawal to death were extracted from medical records. Results: A total of 69 patients were included, with a median age of 67 years, and 38 (55%) were male. Cerebrovascular disease (62%) and traumatic brain injury (22%) were the most common underlying diagnoses. The primary reason for LST decisions was irreversible neurological damage (71%), followed by systemic complications (19%). Mechanical ventilation cessation (91%) and extubation (86%) were most frequently used measures for LST withdrawal. The median time from LST withdrawal to death was 22 minutes. Conclusions Our study demonstrates that LST decisions in the neurocritical care unit predominantly occur among patients with cerebrovascular disease or traumatic brain injury, mostly triggered by neurological deterioration. Most patients died shortly after withdrawal. These findings provide important insight into current LST withdrawal practices in neurocritical care and may assist clinical and ethical decision making in similar settings.

Background: Recent advancements in large language models (LLMs) have accelerated their integration into clinical domains, including laboratory medicine. The performance of LLMs in answering board-level laboratory medicine questions has not been comprehensively evaluated. Given the importance of diagnostic accuracy in this field, rigorous and objective evaluations of LLM capabilities are essential. Methods: We assessed 12 LLMs from OpenAI, Anthropic, and Google using 320 Korean Residency Examination questions (2021–2024) spanning six laboratory medicine subspecialties. Standardized prompts were provided via their application programming interfaces under deterministic settings (temperature = 0). Questions were administered thrice to assess response reproducibility. Outputs were compared with validated answers and analyzed for accuracy, reasoning quality, and error typology. Results: Google’s Gemini 2.0 Pro achieved the highest accuracy (80.0%), followed by OpenAI’s GPT-4.5 (77.2%) and Anthropic’s Claude 3.7 Sonnet (74.1%). Accuracy decreased as the difficulty of questions increased (78.0% for easy vs. 45.1% for challenging). Subspecialty performance varied. Al models underperformed on questions on transfusion medicine (mean accuracy: 38.8%), primarily because of limitations in domain-specific and regional knowledge representations. Incorrect answers primarily resulted from reasoning errors. Reproducibility exceeded 95% for most models; however, some residual non-determinism appeared even with greedy decoding (temperature = 0). Conclusions LLMs demonstrated substantial potential for integration into laboratory medicine, particularly in clinical chemistry and immunology. Performance inconsistencies (particularly for high-difficulty questions) and knowledge gaps (notably for transfusion medicine) highlight the necessity for further development—potentially including domain-specific fine-tuning and retrieval-augmented generation integration—and robust expert oversight before clinical application.

Background: Transthyretin amyloidosis, a protein-misfolding disorder characterized by systemic amyloid deposition, can be classified as wild-type transthyretin amyloidosis (ATTRwt) or hereditary transthyretin amyloidosis (ATTRv), depending on the presence of transthyretin (TTR) gene variants. We examined the genetic distribution of TTR variants in Korean patients diagnosed with ATTRv. Methods: We retrospectively reviewed 801 participants who underwent TTR analysis at Samsung Medical Center from 2012 to 2024. The participants were categorized into two groups: in-house probands or relatives, and externally referred probands or relatives. Results: Pathogenic or likely pathogenic TTR variants were detected in 36 of 165 in-house probands (21.8%), among which D38A was the most frequent variant (50.0%; 18/36), followed by M13dup and E89K (8.3% each). Among referred probands, D38A was predominant (54.5%; 12/22), followed by M13dup (22.7%; 5/22). Cardiac amyloid involvement was the most common manifestation, observed in 97.2% (35/36) of in-house probands with ATTRv, followed by peripheral nervous system (PNS; 94.4%) and autonomic nervous system (ANS; 88.9%) involvement. In contrast, ANS involvement was most prevalent among in-house relatives who underwent organ evaluation (61.5%; 24/39), followed by cardiac (52.1%; 25/48) and PNS (48.7%; 19/39) involvement. Five of the eight in-house relatives harboring M13dup (62.5%) showed organ involvement, primarily in the ANS, supporting the pathogenicity of this variant. Conclusions This study provides the largest single-institution dataset of Korean patients with ATTRv, incorporating systematic organ assessments. The predominance of the unique TTR variants D38A and M13dup delineates a distinct genetic landscape that may facilitate accurate and timely diagnosis of ATTRv in the Korean population.