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.

Objective: To identify the asymmetric spinal stabilizing exercise (ASSE) postures that selectively activate the multifidus (Mu) relative to the erector spinae (ES) in patients with adolescent idiopathic scoliosis (AIS), thereby supporting the development of curve-specific exercise programs for three-dimensional spinal deformities. Methods: Surface electromyography recordings were obtained bilaterally from the ES and Mu muscles during ASSE postures. Signals were normalized to the maximal voluntary isometric contraction. The asymmetry ratio, Mu/ES ratio, and additional asymmetric contraction of the Mu were analyzed. Results: The study included 40 patients with AIS. The Mu demonstrated greater ipsilateral activation in the side-lying posture, whereas greater contralateral activation was observed during unilateral lower extremity lifting and combined upper–lower extremity lifting in the prone posture, as well as during combined upper–lower extremity lifting in the bird-dog posture. In the prone and bird-dog postures, the Mu/ES ratio exceeded 1.0, indicating relatively stronger Mu recruitment under rotational loading. Additional asymmetric contraction of the Mu was greatest in the side-lying posture (47%), with differences<15% in all other postures. Conclusion ASSE induces posture-specific asymmetric activation of the paraspinal muscles in patients with AIS. Although the side-lying posture produced the largest asymmetry, this reflected increased ES activity for trunk elevation rather than true selective Mu contraction. In contrast, the prone and bird-dog postures demonstrated a greater Mu contribution relative to the ES under rotational loading. These findings suggest that ASSE can be adapted to target specific paraspinal muscle components: side lying for lateral bending and bird-dog variations to enhance rotational stability.

This study aimed to analyze the 3D morphology of the condylar part of the occiput in a Korean population and evaluate its applicability for sex estimation. A total of 87 individuals (44 males and 43 females) were included, and measurements of the occipital condyle and foramen magnum were obtained using computed tomography–based 3D reconstructions. Intra-observer reliability was assessed, and univariate and multivariate discriminant analyses were performed to evaluate the discriminative power of each variable. Most measurements showed significant sexual dimorphism, with males generally exhibiting higher values than females. Particularly, variables related to the occipital condyle, including length, width, and area, demonstrated relatively high discriminative performance, whereas those related to the foramen magnum showed comparatively lower discriminative ability. Multivariate analysis further improved the classification accuracy, indicating that the combined use of multiple variables enhanced the ability to distinguish between sexes. These findings suggest that this approach may be particularly valuable in forensic contexts where skeletal remains are incomplete and offer a reliable alternative when more commonly used elements are unavailable.

Purpose: Alectinib has been approved for anaplastic lymphoma kinase (ALK)–positive non–small cell lung cancer (NSCLC) at 300 mg twice daily in Japan, lower than global standard of 600 mg twice daily. This study evaluated the clinical relevance of the reduced dose by comparing outcomes between the two doses. Materials and Methods: This study included patients with advanced ALK-positive NSCLC who received alectinib at Samsung Medical Center, Korea. The progression-free survival (PFS), overall survival, cumulative incidence of central nervous system (CNS) progression, and safety profiles were retrospectively reviewed and compared. Results: Among 306 patients, 32 and 274 received alectinib at either 300 or 600 mg twice daily, respectively. The 300 mg group showed a slight but not significant advantage in PFS (hazard ratio [HR], 0.82; 95% confidence interval [CI], 0.44 to 1.51; p=0.51) and overall survival (HR, 0.51; 95% CI, 0.20 to 1.21; p=0.13). Superior outcome with 300 mg was remarkable in patients with lower body weight (≤ 60 kg), but diminished in patients with higher body weights. Patients with baseline brain metastasis in the 300 mg group exhibited a slight increase in incidence of CNS failure (HR, 1.76; 95% CI, 0.53 to 5.8; p=0.36). Although the safety profiles were mostly mild, adverse events were more frequent in the 600 mg group, 50% of which requiring dose reduction. Conclusion Alectinib at 300 mg twice daily seems an acceptable dose in East Asians with ALK-positive NSCLC. Notably, our data favor 300 mg twice daily in patients with lower body weight and no baseline brain metastasis, considering the more tolerable safety profiles and the potential to reduce medical costs.

Limited data exist regarding the real-world practices and clinical outcomes in patients with ischemic heart failure with reduced left ventricular ejection fractions (LVEFs).Using nationwide registry data from South Korea, we aimed to investigate long-term outcomes and clinical practices, especially implantable cardioverter defibrillators (ICDs) implantation, in patients with reduced LVEFs at least 40 days after acute myocardial infarction (AMI). Of 13,056 patients with AMI between 2011 and 2015, we analyzed 350 (median age, 66 years [interquartile range, 56-75]) who had LVEFs <40% on follow-up transthoracic echocardiogram 40 days after the index event. The primary outcome was cardiac-cause mortality at 3 years. Secondary outcomes comprised major cardiovascular events as well as outcomes defined by the use of ICDs, cardiac resynchronization therapy defibrillators (CRT-Ds), and electrophysiology studies. Among 350 patients, 39 (11.1%) died from cardiac causes during 3 years of follow-up. Eleven (3.1%) were hospitalized for ventricular tachycardia. The rate of ICD or CRT-D implantation up to 3 years was 5.7% (20/350). Cox time-to-event analysis revealed older age, LVEF <30%, diabetes mellitus, and previous MI or revascularization as positively associated with cardiac death, whereas the use of statins and body weight <67 kg were negatively associated. This nationwide Korean registry demonstrated that only 5.7% of patients who had reduced LVEFs after 40 days of AMI underwent ICD implantations over 3 years. Considering the high mortality, concerted efforts are needed to improve clinical outcomes for patients who may have been candidates for ICD implantation.

Purpose: Radiotherapy (RT) remains a cornerstone of curative treatment for localized and locally advanced prostate cancer. However, dose escalation to improve tumor control is often constrained by the proximity of the rectum, which increases the risk of gastrointestinal (GI) and genitourinary toxicities. Biodegradable rectal spacers inserted between the prostate and rectum have emerged as an effective approach to reduce rectal radiation exposure. This guideline provides evidence-based recommendations on indications, contraindications, procedural standards, and clinical management for biodegradable rectal spacer insertion during prostate cancer RT. Materials and Methods: This guideline was developed by a multidisciplinary expert panel through a systematic review of the literature, analysis of international guidelines (National Comprehensive Cancer Network, European Association of Urology, American Society for Radiation Oncology), and expert consensus among radiation oncologists, radiologists, and urologists with clinical experience in spacer insertion. The strength of each recommendation and the level of evidence were classified according to the modified GRADE (Grading of Recommendations, Assessment, Development, and Evaluation) system. Results: Spacer insertion is conditionally recommended (Grade C, Level I) for patients receiving definitive external-beam RT without rectal invasion. It reduces the high-dose rectal irradiation volume (V70–75) by >50%, decreases acute GI toxicity, and helps maintain bowel-related quality of life. However, the benefit for late severe toxicity (grade 2 or higher) remains debated in recent meta-analyses. Contraindications include rectal invasion, anatomical inaccessibility, infection, and material hypersensitivity. Procedures should be performed under local anesthesia in a sterile environment by trained physicians. Short-course antibiotics and simulator-based training, including completion of multiple supervised cases, are advised. Conclusion Biodegradable rectal spacer insertion is clinically validated and effective in reducing acute rectal toxicity. Although pivotal trials demonstrated a favorable procedural safety profile, real-world postmarket data include reports of rare but severe procedural complications. This guideline provides standardized recommendations tailored to Korean clinical practice while remaining consistent with international standards, emphasizing the importance of operator training and careful patient selection.

This systematic review and meta-analysis examined the potential causal link between coffee consumption and hepatocellular carcinoma (HCC) risk via Mendelian randomization (MR) studies.Five eligible MR studies that involved the use of analytical approaches such as inverse variance weighted (IVW), MR-Egger, and weighted median methods were included. While previous observational studies suggested a protective role of coffee, the MR-based analyses in this study did not demonstrate a statistically significant association across all methods. IVW analysis yielded an odds ratio of 0.92 (95% confidence interval, 0.58 to 1.47), indicating no significant effect. Moderate to substantial heterogeneity was observed, but no publication bias was detected. These findings suggest that the previously reported inverse association may have been overestimated due to methodological limitations in observational research. Our results emphasize the importance of using genetically informed methods to infer causality, and the results indicate that coffee consumption may not causally reduce the risk of HCC.

Direct-acting antiviral (DAA) therapy has brought a revolution to the management of chronic hepatitis C virus infection, but its role in patients with active hepatocellular carcinoma (HCC) remains controversial. Early observations suggested a high rate of HCC recurrence following DAA treatment, raising concerns about a potential oncogenic effect regarding rapid viral clearance. However, subsequent large-scale cohort studies and meta-analyses have not consistently confirmed this finding, leading to an overall neutral conclusion regarding the impact of DAA on HCC recurrence. International guidelines from organizations such as the American Gastroenterological Association, American Association for the Study of Liver Diseases, European Association for the Study of the Liver, and Korean Association for the Study of the Liver offer conflicting recommendations, underscoring the absence of a universal framework for this patient population. While the available evidence is largely heterogeneous and retrospective, current data indicate that DAA therapy can be safely integrated into HCC management without clear evidence of harm. Oncologic outcomes, particularly overall and recurrence-free survival, are most favorable when DAAs are administered in close proximity to curative procedures or in non-transplant therapeutic settings. In contrast, studies in liver transplant candidates often show a neutral effect on oncologic outcomes after adjusting for confounding variables. These findings underscore the necessity of individualized, multidisciplinary decisions based on tumor biology, hepatic reserve, and treatment intent. Prospective studies and validated biomarkers are essential to establish a more definitive framework for optimizing DAA therapy in this complex clinical context.

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.

Abrupt vessel closure (AVC) is a complication of percutaneous coronary intervention (PCI) and is defined as the sudden cessation of forward coronary blood flow due to a variety of mechanisms. The incidence of AVC has markedly decreased from approximately 3.0% in the early era to about 0.3% today. Nevertheless, cardiovascular interventionists must remain prepared to manage AVC effectively, given its significant impact on clinical outcomes.AVC can arise from several mechanisms, including dissection, intramural hematoma, intracoronary thrombosis, air embolism, vasospasm, and no-reflow. The clinical impact of AVC varies depending on the extent of myocardium affected, ranging from asymptomatic events or transient ischemic chest pain to cardiogenic shock or cardiac arrest. Both a general approach for stabilizing hemodynamic consequences and an etiology-specific management strategy are essential. Hasty decision-making may worsen the situation, whereas a structured approach—focused on hemodynamic stabilization, logical diagnostic processes, and targeted interventions—can improve outcomes. In this narrative review, we describe the mechanisms underlying each etiology, outline mechanism-specific management strategies, and discuss general approaches to managing patients with AVC through logical diagnostic and treatment processes. We hope this review offers valuable insights into this uncommon but significant complication and enhances readers’ skills in managing AVC more effectively during PCI.