Yoshiharu Kinugasa

Bartter syndrome (BS) type 3 typically presents in childhood and is caused by defects in NaCl transporters of the thick ascending limb of the loop of Henle. We report a 66‐year‐old woman with asymptomatic but severe hypokalemia (2.0 mmol/L), metabolic alkalosis, and hyperreninemic hyperaldosteronism. Initial clinic blood pressure was 157/88 mmHg, but repeated office and home measurements were ~120/70 mmHg, consistent with white‐coat hypertension. Imaging excluded renovascular disease. Sequential diuretic testing supported BS physiology: a thiazide loading test increased fractional excretion of chloride (FECl) from 0.46% to 3.88% (ΔFECl 3.4%), exceeding the 2.3% cutoff that argues against Gitelman syndrome; a furosemide test showed chloride reabsorption of 10.1%, indicating a profound loop‐segment defect, even lower than values commonly reported in BS3. Targeted next‐generation sequencing identified a homozygous CLCNKB stop‐gain variant (c.1830G >A; p.Trp610Ter), confirming BS type 3. High‐dose potassium chloride (9.9 g/day) failed to correct hypokalemia, whereas low‐dose enalapril plus spironolactone normalized serum potassium (4.0 mmol/L) without persistent hypotension. The urine calcium/creatinine ratio was borderline‐normal (0.65 mmol/mmol), rather than hypocalciuric. This case suggests that BS3 should remain in the differential diagnosis of refractory hypokalemia in older adults and highlights the diagnostic value of physiology‐guided diuretic testing combined with genetic analysis, as well as the potential efficacy of low‐dose ACE inhibitor plus mineralocorticoid receptor antagonist therapy when potassium supplementation alone is insufficient.

Objective: Guidelines worldwide recommend specialist outpatient clinics staffed by a multidisciplinary team for management of patients with heart failure (HF). However, there is limited information on how best to select these patients for efficient use of resources. This study aimed to determine the effectiveness of team-based care for patients with HF after discharge from hospital according to duration of intervention and stratification of patients according to risk. Methods: We retrospectively identified 185 eligible patients who were hospitalised with acute decompensated HF at our institution between January 2021 and June 2023. Multidisciplinary team care was defined as outpatient follow-up by both cardiologists and nurses postdischarge. The primary outcome was a composite of cardiovascular-related death and readmission with HF within 1 year, which was compared between patients receiving HF team care and those receiving standard follow-up. Results: HF team care was provided for 53.0% of patients, who were younger than those receiving standard follow-up and required more oral inotropes, tolvaptan and amiodarone. Among those receiving HF team care, the majority (58.2%) had an intervention duration of 30 days or less after discharge. After adjusting for background differences by inverse probability of treatment weighting, HF team care was associated with favourable 180-day outcomes, but there was no significant between-group difference in the 1-year primary outcomes. In subgroup analysis, patients with a higher Meta-Analysis Global Group in Chronic Heart Failure score (≥28), indicating a higher risk of exacerbation of HF, had significantly lower 1-year event rates with HF team care (p value for interaction <0.05). Conclusions: Multidisciplinary HF team care is most effective for patients at higher risk of exacerbation of HF. A risk score model may optimise patient selection for specialised care.

Background: Heart failure (HF) patients with complex care needs often experience exacerbations during the transitional phase as care providers and settings change. Regional collaboration aims to ensure continuity of care; however, its impact on vulnerable patients certified as needing support or care under the Japanese long-term care insurance (LTCI) system remains unclear.Methods and Results: We implemented a regional collaborative program for HF patients involving 3 pillars of transitional care with general practitioners and nursing care facilities: (1) standardized health monitoring using a patient diary and identification of exacerbation warning signs; (2) standardized information sharing among care providers; and (3) standardized HF management manuals. We evaluated outcomes within 1 year of discharge for patients hospitalized with HF and referred to other facilities for outpatient follow-up in 2017–2018 before program implementation (n=110) and in 2019–2020 after implementation (n=126). Patients with LTCI frequently received non-cardiologist follow up and care services and had a higher risk of all-cause mortality and HF readmission compared with those without LTCI (P<0.05). Program implementation was significantly associated with a greater reduction in HF readmissions among patients with LTCI compared with those without (P<0.05 for interaction), although mortality rates remained unchanged.Conclusions: A regional collaborative program significantly reduces HF readmissions in HF patients with LTCI who are at high risk of worsening HF.

Background: Frailty increases the risk of needing nursing care and significantly affects the life and functional prognosis of older individuals. Early detection and tailored interventions are crucial for maintaining and enhancing their life functions. Recognizing distinct clinical phenotypes is essential for devising appropriate interventions. This study aimed to explore diverse frailty phenotypes, focusing on poor nutrition in older Japanese individuals through observational research. Methods: Twenty-one nursing home residents underwent a comprehensive survey covering physical, blood, dietary, cardiac, cognitive, nutritional, nursing care, frailty, agitated behavior, and gut microbiome assessments (high-throughput 16S rRNA gene sequencing). Using clustering analysis with 239 survey items (excluding gut microbiome), participants were classified into subgroups based on clinical phenotypes, and group characteristics were compared through analysis. Results: Individuals with moderate or severe frailty and suspected dementia formed subgroups with distinct clinical phenotypes based on nutritional, defecation, and nursing care statuses. The gut microbiome significantly varied among these groups (p = 0.007), indicating its correlation with changes in clinical phenotype. Nutritional status differences suggested poor nutrition as a differentiating factor in the core clinical phenotype. Conclusions: This study proposes that the gut microbiome differs based on the clinical phenotype of Japanese older individuals with frailty, and targeted interventions addressing the gut microbiome may contribute to preventing frailty in this population.

Aims: A high extracellular water (ECW) to intracellular water (ICW) ratio of skeletal muscle as assessed by bioelectrical impedance analysis is reportedly associated with loss of muscle strength. However, the validity of this index for heart failure (HF), which is likely associated with changes in the water distribution, is unclear. Methods and results: This study involved 190 patients with HF. The total ECW and ICW of both upper and lower extremities were measured, and a high ECW/ICW ratio was defined as an ECW/ICW ratio higher than the median (≥0.636 for men, ≥0.652 for women). Low muscle strength was defined as reduced handgrip strength according to the criteria established by the Asian Working Group for Sarcopenia. Patients with a high ECW/ICW ratio had a lower handgrip strength (21.1 ± 8.1 kg vs. 27.6 ± 9.3 kg, P ≤ 0.05) and 6 min walk distance (329 ± 116 m vs. 440 ± 114 m) than those with a low ECW/ICW ratio. An increasing ECW and/or decreasing ICW was associated with a higher ECW/ICW ratio and a lower handgrip strength (P < 0.05). In the multivariate logistic regression analysis, a high ECW/ICW ratio and low skeletal muscle mass were independently associated with low muscle strength (P < 0.05). Conclusions: A high ECW/ICW ratio in limb muscles, that is, the water imbalance of increasing ECW and/or decreasing ICW, is useful in assessing muscle quality in patients with HF.

Background: Evidence on transitional care for heart failure (HF) in Japan is limited.Methods and Results: We implemented a transitional HF management program in rural Japan in 2019. This involved collaboration with general practitioners or nursing care facilities and included symptom monitoring by medical/nursing staff using a handbook; standardized discharge care planning and information sharing on self-care and advance care planning using a collaborative sheet; and sharing expertise on HF management via manuals. We compared the outcomes within 1 year of discharge among patients hospitalized with HF in the 2 years before program implementation (2017–2018; historical control, n=198), in the first 2 years after program implementation (2019–2020; Intervention Phase 1, n=205), and in the second 2 years, following program revision and regional dissemination (2021–2022; Intervention Phase 2, n=195). HF readmission rates gradually decreased over Phases 1 and 2 (P0.1 for interaction). Mortality rates remained unchanged, but significantly more patients received end-of-life care at home in Phase 2 than before (P<0.05).Conclusions: The implementation of a transitional care program was associated with decreased HF readmissions and increased end-of-life care at home for HF patients in rural Japan.

Background: With the aging of heart failure (HF) patients, collaboration between medical and nursing care facilities is essential for HF care. The aims of this study were: (1) to identify the factors that affect willingness of nursing care staffs to cooperate with HF care; (2) to test whether the internet video education is useful in improving their willingness to collaborate.Methods: A web‐based questionnaire was e‐mailed to 417 registered medical corporations that operated nursing care facilities in the prefecture where the authors work. Medical and care staff working at each facility were asked their willingness to cooperate with HF care and their problems about collaboration. Machine learning analysis was used to assess the factors associated with unwillingness to cooperate. After watching a 6‐min YouTube video explaining HF and community collaboration, we reaffirmed their willingness to cooperate.Results: We received responses from 76 medical and care staff members. Before watching the video, 32.9% of participants stated that they were unwilling to cooperate with HF care. Machine learning analysis showed that job types, perceived problems of collaboration, and low opportunities to learn about HF were associated with unwillingness to cooperation. After watching the video, we observed an increase from 67.1% to 80.3% (p < 0.05) of participants willing to cooperate with HF care.Conclusions: Job types, perceived problems of collaboration, and low opportunities to learn about HF are associated with unwillingness of nursing care staff for HF care. Internet videos are potential learning tool that can easily promote community collaboration for HF.

Background A high extracellular water (ECW) to intracellular water (ICW) ratio of skeletal muscle as assessed by bioelectrical impedance analysis is reportedly associated with loss of muscle strength. However, the validity of this index for heart failure (HF), which is likely associated with changes in the water distribution, is unclear. Methods This study involved 190 patients with HF. The total ECW and ICW of both upper and lower extremities were measured, and a high ECW/ICW ratio was defined as an ECW/ICW ratio higher than the median (≥0.636 for men, ≥0.652 for women). Low muscle strength was defined as reduced handgrip strength according to the criteria established by the Asian Working Group for Sarcopenia. Results Patients with a high ECW/ICW ratio were older, had a higher left ventricular ejection fraction and B-type natriuretic peptide level, and had a lower body mass index, hemoglobin level, albumin level, estimated glomerular filtration rate, handgrip strength, and 6-minute walk distance than patients with a low ECW/ICW ratio (p < 0.05). An increasing ECW and/or decreasing ICW was associated with a higher ECW/ICW ratio (p < 0.05). In the multivariate logistic regression analysis, a high ECW/ICW ratio and low skeletal muscle mass were independently associated with low muscle strength (p < 0.05). Conclusion A high ECW/ICW ratio in limb muscles (i.e., an increasing ECW and/or decreasing ICW) is independently associated with muscle weakness regardless of skeletal muscle mass in patients with HF. What Is New? ◆ A high extracellular water (ECW) to intracellular water (ICW) ratio of skeletal muscle as assessed by bioelectrical impedance analysis was independently associated with low muscle strength regardless of skeletal muscle mass in patients with heart failure (HF). ◆ Both an increasing ECW and decreasing ICW were independently associated with low muscle strength in patients with HF. What Are the Clinical Implications? ◆ The ECW/ICW ratio in limb muscles is a new index that can be used to assess muscle function apart from muscle mass in patients with HF.

Aim: L‐carnitine transports fatty acids into mitochondria and contributes to energy metabolism in skeletal muscles. However, the association between carnitine insufficiency and skeletal muscle weakness, namely sarcopenia and dynapenia, in patients with heart failure (HF) remains unclear.Methods: In total, 124 patients with HF were enrolled in this study. Carnitine insufficiency was indicated by a decrease in serum free carnitine (FC) levels of less than 36 μmol/L or an elevated serum acylcarnitine (AC) to free carnitine (FC) ratio (AC/FC ratio) of 0.27 or higher. Skeletal muscle weakness was defined as reduced handgrip strength and classified into two phenotypes: sarcopenia (low muscle strength with low skeletal muscle mass) and dynapenia (low muscle strength with normal skeletal muscle mass).Results: Patients with carnitine insufficiency had a significantly higher prevalence of muscle weakness and a lower 6‐min walk distance than those without carnitine insufficiency (P < 0.05). A machine learning model showed that older age (≥77 years) and, in patients aged 64–76 years, a higher AC/FC ratio (≥0.31) were associated with sarcopenia. However, there was only a week association between carnitine levels and dynapenia. The effect of carnitine insufficiency on skeletal muscle weakness was greater in patients with low skeletal muscle mass than in those with normal skeletal muscle mass (P < 0.05 for interaction).Conclusions: Carnitine insufficiency is more closely associated with sarcopenia than with dynapenia in patients with HF, suggesting carnitine insufficiency as a potential therapeutic target for sarcopenia in these patients. Geriatr Gerontol Int 2023; 23: 524–530.