Resumo Fundamento: A fração de ejeção (FE) tem sido utilizada em análises fenotípicas e na tomada de decisões sobre o tratamento de insuficiência cardíaca (IC). Assim, a FE tornou-se parte fundamental da prática clínica diária. Objetivo: Este estudo tem como objetivo investigar características, preditores e desfechos associados a alterações da FE em pacientes com diferentes tipos de IC grave. Métodos: Foram incluídos neste estudo 626 pacientes com IC grave e classe III–IV da New York Heart Association (NYHA). Os pacientes foram classificados em três grupos de acordo com as alterações da FE, ou seja, FE aumentada (FE-A), definida como aumento da FE ≥10%, FE diminuída (FE-D), definida como diminuição da FE ≥10%, e FE estável (FE-E), definida como alteração da FE <10%. Valores p inferiores a 0,05 foram considerados significativos. Resultados: Dos 377 pacientes com IC grave, 23,3% apresentaram FE-A, 59,5% apresentaram FE-E e 17,2% apresentaram FE-D. Os resultados mostraram ainda 68,2% de insuficiência cardíaca com fração de ejeção reduzida (ICFEr) no grupo FE-A e 64,6% de insuficiência cardíaca com fração de ejeção preservada (ICFEp) no grupo FE-D. Os preditores de FE-A identificados foram faixa etária mais jovem, ausência de diabetes e fração de ejeção do ventrículo esquerdo (FEVE) menor. Já os preditores de FE-D encontrados foram ausência de fibrilação atrial, baixos níveis de ácido úrico e maior FEVE. Em um seguimento mediano de 40 meses, 44,8% dos pacientes foram vítimas de morte por todas as causas. Conclusão: Na IC grave, a ICFEr apresentou maior percentual no grupo FE-A e a ICFEp foi mais comum no grupo FE-D.

Abstract Background: Ejection fraction (EF) has been used in phenotype analyses and to make treatment decisions regarding heart failure (HF). Thus, EF has become a fundamental part of daily clinical practice. Objective: This study aims to investigate the characteristics, predictors, and outcomes associated with EF changes in patients with different types of severe HF. Methods: A total of 626 severe HF patients with New York Heart Association (NYHA) class III–IV were enrolled in this study. The patients were classified into three groups according to EF changes, namely, increased EF (EF-I), defined as an EF increase ≥10%, decreased EF (EF-D), defined as an EF decrease ≥10%, and stable EF (EF-S), defined as an EF change <10%. A p-value lower than 0.05 was considered significant. Results: Out of 377 severe HF patients, 23.3% presented EF-I, 59.5% presented EF-S, and 17.2% presented EF-D. The results further showed 68.2% of heart failure with reduced ejection fraction (HFrEF) in the EF-I group and 64.6% of heart failure with preserved ejection fraction (HFpEF) in the EF-D group. The predictors of EF-I included younger age, absence of diabetes, and lower left ventricular ejection fraction (LVEF). The predictors of EF-D were absence of atrial fibrillation, lower uric acid level, and higher LVEF. Within a median follow-up of 40 months, 44.8% of patients suffered from all-cause death. Conclusion: In severe HF, HFrEF presented the highest percentage in the EF-I group, and HFpEF was most common in the EF-D group.

Following radiotherapy, patients have decreased bone mass and increased risk of fragility fractures. Diabetes mellitus (DM) is also reported to have detrimental effects on bone architecture and quality. However, no clinical or experimental study has systematically characterized the bone phenotype of the diabetic patients following radiotherapy. After one month of streptozotocin injection, three-month-old male rats were subjected to focal radiotherapy (8 Gy, twice, at days 1 and 3), and then bone mass, microarchitecture, and turnover as well as bone cell activities were evaluated at 2 months post-irradiation. Micro-computed tomography results demonstrated that DM rats exhibited greater deterioration in trabecular bone mass and microarchitecture following irradiation compared with the damage to bone structure induced by DM or radiotherapy. The serum biochemical, bone histomorphometric, and gene expression assays revealed that DM combined with radiotherapy showed lower bone formation rate, osteoblast number on bone surface, and expression of osteoblast-related markers (ALP, Runx2, Osx, and Col-1) compared with DM or irradiation alone. DM plus irradiation also caused higher bone resorption rate, osteoclast number on bone surface, and expression of osteoclast-specific markers (TRAP, cathepsin K, and calcitonin receptor) than DM or irradiation treatment alone. Moreover, lower osteocyte survival and higher expression of Sost and DKK1 genes (two negative modulators of Wnt signaling) were observed in rats with combined DM and radiotherapy. Together, these findings revealed a higher deterioration of the diabetic skeleton following radiotherapy, and emphasized the clinical importance of health maintenance.

In this paper, an iterative method is constructed to solve the following constrained linear matrix equations system: [A1(X),A2(X),... ,Ar(X)]=[E1,E2, ... ,Er ], X ∈ I={X |X= U(X)}, where Ai is a linear operator from Cmxn onto Cpixqi, Ei ∈ Cpixqi, i=1 , 2,..., r , and U is a linear self-conjugate involution operator. When the above constrained matrix equations system is consistent, for any initial matrix X0 ∈ I, a solution can be obtained by the proposed iterative method in finite iteration steps in the absence of roundoff errors, and the least Frobenius norm solution can be derived when a special kind of initial matrix is chosen. Furthermore, the optimal approximation solution to a given matrix can be derived. Several numerical examples are given to show the efficiency of the presented iterative method. Mathematical subject classification: 15A24, 65D99,65F30.