Background and Objectives: The number of people with heart failure (HF) is increasing worldwide, and the social burden is increasing as HF has high mortality and morbidity. We aimed to provide updated trends on the epidemiology of HF in Korea to shape future social measures against HF. Methods: We used the National Health Information Database of the National Health Insurance Service to determine the prevalence, incidence, hospitalization rate, mortality rate, comorbidities, in-hospital mortality, and healthcare cost of patients with HF from 2002 to 2020 in Korea. Results: The prevalence of HF in the total Korean population rose from 0.77% in 2002 to 2.58% (1,326,886 people) in 2020. Although the age-standardized incidence of HF decreased over the past 18 years, the age-standardized prevalence increased. In 2020, the hospitalization rate for any cause in patients with HF was 1,166 per 100,000 persons, with a steady increase from 2002. In 2002, the HF mortality was 3.0 per 100,000 persons, which rose to 15.6 per 100,000 persons in 2020. While hospitalization rates and in-hospital mortality for patients with HF increased, the mortality rate for patients with HF did not (5.8% in 2020), and the one-year survival rate from the first diagnosis of HF improved. The total healthcare costs for patients with HF were approximately $2.4 billion in 2020, a 16-fold increase over the $0.15 billion in 2002. Conclusions The study’s results underscore the growing socioeconomic burden of HF in Korea, driven by an aging population and increasing HF prevalence.

Purpose: This study aims to analyze the learning curve of hand-assisted laparoscopic living donor nephrectomy (HLDN) conducted by a trained gastrointestinal surgeon. Methods: A retrospective analysis was performed on the perioperative clinical data of 96 consecutive patients who underwent HLDN from May 2013 to March 2023. The learning curve was evaluated using the cumulative sum (CUSUM) test based on operation time and risk-adjusted CUSUM for postoperative complications. Patients were divided into three groups (novice, development, and competency phases) based on changes in operation time. Patient demographics and perioperative outcomes were compared between each group. Results: Among the patients, 35 were male, with a mean age of 48.9 ± 11.3 years and a mean body mass index (BMI) of 24.5 ± 3.2 kg/m 2 . The novice phase (phase 1) included the first 30 cases, with the development phase (phase 2) up to the 65th case. Operation times were significantly different across phases, averaging 263.2 ± 33.4, 211.1 ± 34.4, and 161.1 ± 31.3 minutes for phases 1, 2, and 3, respectively (P < 0.001). Blood loss decreased gradually across phases (phase 1, 264.7 ± 144.4 mL; phase 2, 239.7 ± 166.3 mL; phase 3, 198.8 ± 103.5 mL), though not statistically significant. BMI impacted operation time only in phase 1. Overall postoperative complications occurred in 13 cases (Clavien-Dindo grade I, 4 cases;grade II, 9 cases), with no significant differences across phases. Conclusion HLDN can be safely performed by a trained gastrointestinal surgeon, with approximately 30 cases needed to achieve proficiency.

Purpose: Despite the increasing use of immediate breast reconstruction (IBR), its oncologic safety in the setting of neoadjuvant chemotherapy (NACT) needs to be comprehensively clarified in breast cancer management. The objective of the present study was to analyze the oncologic safety of IBR following NACT. Methods: In total, 587 patients with breast cancer who underwent a total mastectomy (TM) with IBR after NACT between 2008 and 2017 at a single institution were retrospectively reviewed. The reviewed patients with IBR following skin-sparing mastectomy (SSM) or nipple-sparing mastectomy (NSM) were matched 1:3 to patients who underwent TM alone after NACT. Matching variables included age, clinical T and N stages before NACT, response to NACT, pathologic T and N stages, and molecular subtypes. Results: After propensity score matching, 95 patients who underwent IBR following SSM/ NSM after NACT (IBR group) and 228 patients who underwent TM alone after NACT (TM group) were selected. The median follow-up period was 73 (range, 5–181) months after matching. After matching, there were no significant differences between the two groups in 5-year locoregional recurrence-free survival (88.8% vs. 91.2%, p = 0.516), disease-free survival (67.3% vs. 76.6%, p = 0.099), distant metastasis-free survival (71.9% vs. 81.9%, p = 0.057), or overall survival (84.1% vs. 91.5, p = 0.061) rates. In multivariate analyses, conducting IBR was not associated with increased risks for locoregional recurrence, any recurrence, distant metastasis, or overall death. Conclusion Our findings suggest that IBR following SSM/NSM elicits comparable long-term oncologic outcomes to those of TM alone in the setting of NACT.

Background: Sutureless valves are widely used in aortic valve replacement surgery, with Perceval valves and Intuity valves being particularly prominent. However, concerns have been raised about postoperative thrombocytopenia with Perceval valves (Corcym, UK). We conducted a comparative analysis with the Intuity valve (Edwards Lifesciences, USA), and assessed how thrombocytopenia affected patient and transfusion outcomes. Methods: Among 595 patients who underwent aortic valve replacement from June 2016 to March 2023, sutureless valves were used in 53 (Perceval: n=23; Intuity: n=30). Platelet counts were monitored during hospitalization and outpatient visits. Daily platelet count changes were compared between groups, and the results from patients who underwent procedures using Carpentier Edwards Perimount Magna valves were used as a reference group. Results: Compared to the Intuity group, the Perceval group showed a significantly higher amount of platelet transfusion (5.48±1.64 packs vs. 0.60±0.44 packs, p=0.008). During the postoperative period, severe thrombocytopenia (<50,000/μL) was significantly more prevalent in the Perceval group (56.5%, n=13) than in the Intuity group (6.7%, n=2). After initial postoperative depletion, daily platelet counts increased, with significant differences observed in the extent of improvement between the Perceval and Intuity groups (p<0.001).However, there was no significant difference in early mortality or the incidence of neurological complications between the 2 groups. Conclusion The severity of postoperative thrombocytopenia differed significantly between the Perceval and Intuity valves. The Perceval group showed a significantly higher prevalence of severe thrombocytopenia and higher platelet transfusion volumes. However, thrombocytopenia gradually recovered during the postoperative period in both groups, and the early outcomes were similar in both groups.

Background: The US Food and Drug Administration (FDA) and European Medicines Agency (EMA) approved empagliflozin for reducing cardiovascular mortality and heart failure (HF) hospitalization in patients with both HF with reduced ejection fraction (HFrEF) and HF with preserved ejection fraction (HFpEF). However, limited data are available on the generalizability of empagliflozin to clinical practice. Therefore, we evaluated real-world eligibility and potential cost-effectiveness based on a nationwide prospective HF registry. Methods: A total of 3,108 HFrEF and 2,070 HFpEF patients from the Korean Acute Heart Failure (KorAHF) registry were analyzed. Eligibility was estimated by inclusion and exclusion criteria of EMPagliflozin outcomE tRial in Patients With chrOnic heaRt Failure With Reduced Ejection Fraction (EMPEROR-Reduced) and EMPagliflozin outcomE tRial in Patients With chrOnic heaRt Failure With Preserved Ejection Fraction (EMPEROR-Preserved) trials and by FDA & EMA label criteria. The cost-utility analysis was done using a Markov model to project the lifetime medical cost and quality-adjusted life year (QALY). Results: Among the KorAHF patients, 91.4% met FDA & EMA label criteria, while 44.7% met the clinical trial criteria. The incremental cost-effectiveness ratio of empagliflozin was calculated at US$6,764 per QALY in the overall population, which is far below a threshold of US$18,182 per QALY. The cost-effectiveness benefit was more evident in patients with HFrEF (US$5,012 per QALY) than HFpEF (US$8,971 per QALY). Conclusion There is a large discrepancy in real-world eligibility for empagliflozin between FDA & EMA labels and clinical trial criteria. Empagliflozin is cost-effective in HF patients regardless of ejection fraction in South Korea health care setting. The efficacy and safety of empagliflozin in real-world HF patients should be further investigated for a broader range of clinical applications.

Subclinical hypothyroidism (SCH), characterized by elevated serum thyroid-stimulating hormone (TSH) levels and normal free thyroxine levels, usually presents without symptoms, and is often discovered incidentally during routine blood test. The Task Force of the Korean Thyroid Association Committee of Clinical Practice Guidelines has established a guideline to evaluate and manage SCH; the guideline emphasizes the implementation of diagnostic criteria based on the TSH reference range for Koreans and focuses on the proven health benefits of levothyroxine (LT4) treatment. Based on the Korea National Health and Nutrition Examination Survey (2013-2015), serum TSH level of 6.8 mIU/L is considered the reference value for SCH. SCH can be categorized as mild (TSH 6.8-10.0 mIU/L) or severe (TSH ＞10.0 mIU/L), and patients are classified as adults (age ＜70 years) or elderly patients (age ≥70years) depending on the health effects of LT4 treatment. An initial increase in serum TSH levels should be reassessed with a subsequent measurement, along with the thyroid peroxidase antibody test, preferably 2-3 months after the initial evaluation. Usually, LT4 treatment is not recommended for mild SCH in adults; however, treatment is necessary for severe SCH in patients with underlying coronary artery disease or heart failure and can be considered for coexisting dyslipidemia. LT4 treatment is not recommended for mild or even severe SCH in elderly patients, in general. Patients with SCH who receive LT4 treatment, the LT4 dosage should be personalized, and serum TSH levels should be monitored to ensure optimal LT4 dosage (dosage that is neither excessive nor insufficient). Patients with SCH who do not receive LT4 treatment require periodic follow-up at appropriate testing intervals determined by disease severity. The guideline also provides several educational points applicable in clinical settings.

Background and Objectives: Atrial fibrillation (AF) is associated with decreased cardiac resynchronization therapy (CRT) benefits compared to sinus rhythm (SR). Effective biventricular (BiV) pacing is a determinant of CRT success, but AF can interfere with adequate BiV pacing and affect clinical outcomes. We investigated the effect of device-detected AF on clinical outcomes and optimal BiV pacing in patients with heart failure (HF) treated with CRT. Methods: We retrospectively analyzed 174 patients who underwent CRT implantation between 2012 and 2019 at a tertiary center. The optimal BiV pacing percentage was defined as ≥98%. Device-detected AF was defined as an atrial high-rate episode ≥180 beats per minute lasting more than 6 minutes during the follow-up period. We stratified the patients without preexisting AF at pre-implantation into device-detected AF and no-AF groups. Results: A total of 120 patients did not show preexisting AF at pre-implantation, and 54 had AF. Among these 120 patients, 19 (15.8%) showed device-detected AF during a median follow-up of 25.1 months. The proportion of optimal BiV pacing was significantly lower in the device-detected AF group than in the no-AF group (42.1% vs. 75.2%, p=0.009). The devicedetected AF group had a higher incidence of HF hospitalization, cardiovascular death, and all-cause death than the no-AF group. The device-detected AF and previous AF groups showed no significant differences regarding the percentage of BiV pacing and clinical outcomes. Conclusions For HF patients implanted with CRT, device-detected AF was associated with lower optimal BiV pacing and worse clinical outcomes than no-AF.

Background and Objectives: Inherited arrhythmia (IA) is a more common cause of sudden cardiac death in Asian population, but little is known about the genetic background of Asian IA probands. We aimed to investigate the clinical characteristics and analyze the genetic underpinnings of IA in a Korean cohort. Methods: This study was conducted in a multicenter cohort of the Korean IA Registry from 2014 to 2017. Genetic testing was performed using a next-generation sequencing panel including 174 causative genes of cardiovascular disease. Results: Among the 265 IA probands, idiopathic ventricular fibrillation (IVF) and Brugada Syndrome (BrS) was the most prevalent diseases (96 and 95 cases respectively), followed by long QT syndrome (LQTS, n=54). Two-hundred-sixteen probands underwent genetic testing, and 69 probands (31.9%) were detected with genetic variant, with yield of pathogenic or likely pathogenic variant as 6.4%. Left ventricular ejection fraction was significantly lower in genotype positive probands (54.7±11.3 vs. 59.3±9.2%, p=0.005). IVF probands showed highest yield of positive genotype (54.0%), followed by LQTS (23.8%), and BrS (19.5%). Conclusions There were significant differences in clinical characteristics and genetic yields among BrS, LQTS, and IVF. Genetic testing did not provide better yield for BrS and LQTS. On the other hand, in IVF, genetic testing using multiple gene panel might enable the molecular diagnosis of concealed genotype, which may alter future clinical diagnosis and management strategies.

Objectives: We evaluated the effectiveness of coronavirus disease 2019 vaccination in high-risk facilities in the Republic of Korea during the period when the highly transmissible Delta variant was prevalent. Additionally, we aimed to explore any disparities in vaccine effectiveness (VE) across various types of institutions, specifically distinguishing between non-medical and medical establishments. Methods: We examined 8 outbreak clusters covering 243 cases and 895 contacts from 8 highrisk facilities divided into 2 groups: group A (4 non-medical institutions) and group B (4 medical institutions). These clusters were observed from July 27, 2021 to October 16, 2021 for the attack rate (AR) and VE with respect to disease severity. A generalized linear model with a binomial distribution was used to determine the odds ratio (OR) for disease severity and death. Results: AR was notably lower in group B (medical institutions). Furthermore, VE analysis revealed that group A exhibited higher effectivity for disease severity and death than group B. The OR for disease severity was 0.24 (95% confidence interval [CI], 0.03–2.16) for group A and 0.27 (95% CI, 0.12–0.64) for group B, with the OR for death at 0.12 (95% CI, 0.01–1.32) in group A and 0.34 (95% CI, 0.14–0.87) in group B. Conclusion Although VE may vary across institutions, our findings underscore the importance of implementing vaccinations in high-risk facilities. Customized vaccination programs, tailored response plans, and competent management personnel are essential for effectively addressing and mitigating public health challenges.