Predictive value of left ventricular myocardial strain by four-dimensional speckle tracking echocardiography combined with red cell distribution width in heart failure with preserved ejection fraction.

OBJECTIVES: The diagnostic difficulty of heart failure with preserved ejection fraction (HFpEF) is differentiating it in patients with similar symptoms and signs. This study aimed to assess the potential predictive value of left ventricular global longitudinal strain (GLS), global radial strain (GRS), global circumferential strain (GCS), and global area strain (GAS) measured by four-dimensional speckle tracking echocardiography (4DSTE) combined with red cell distribution width (RDW) in patients with HFpEF. METHODS: One hundred and sixty-nine patients with symptoms or signs indicative of chronic heart failure and a left ventricular ejection fraction (LVEF) ≥ 50% and fifty controls with normal LVEF were recruited in this study. Standard echocardiography and 4DSTE examinations were performed. Laboratory examinations including RDW were performed on the same day as the echocardiographic study. RESULTS: GLS, GCS, GRS, and GAS in the patient cohort were significantly lower, and RDW was significantly higher than those in the control cohort (P < 0.01), and the strain parameters in definite HFpEF patients were also dramatically lower than the rest patients (P < 0.01). The associations of age, gender, NYHA classification, hypertension history, left ventricular end-diastolic volume index, interventricular septal thickness, and diastolic dysfunction with HFpEF were significantly improved by adding 4DSTE parameters (P < 0.01) and further improved by adding RDW (P < 0.01). CONCLUSIONS: In suspected HFpEF patients, who have symptoms or signs of heart failure, even without other conventional evidence of this diagnosis, GLS, GRS, and GCS have potential independent predictive value, while RDW has independent incremental predictive value for HFpEF.

Inhibition of MicroRNA-92 alleviates atherogenesis by regulation of macrophage polarization through targeting KLF4.

BACKGROUND: Atherosclerosis is a chronic inflammatory disease in which macrophage polarization plays an important role in contribution to atherosclerotic plaque formation and stability. Here we tested the effect of miR-92 regulation on the development of atherosclerosis beyond tumorigenesis and explored the potential mechanism. METHODS AND RESULTS: In the present study, bone marrow derived macrophages (BMDMs), mouse peritoneal macrophages (MPMs), and human macrophages were used to test the expression of miR-92. Here we noticed miR-92 levels were enhanced in classic M1 macrophage but decreased in alternative M2 macrophage, respectively. In vitro, we demonstrated that macrophages transfected with miR-92 inhibitor attenuated proinflammatory cytokine secretion represented by polarized M1 markers but promoted anti-inflammatory state that was indicative of an M2 phenotype. Mechanistically, miR-92 was found to directly interact with KLF4 and we further identified a requirement role of KLF4 in mediating the effect of miR-92 silencing macrophage polarization. Concomitantly, miR-92 inhibition treated ApoE-/- mice promoted macrophage polarization toward alternative M2 macrophage, thus protecting against atherosclerotic plaque formation and preventing a vulnerable phenotype. CONCLUSION: miR-92 inhibition promoted alternative macrophage activation and attenuated atherosclerosis regression partially regulated in a KLF4-dependent manner, which indicated that miR-92/KLF4 axis may serve as a promising strategy for prevention of atherosclerotic diseases.

Vertical distribution of ambient aerosol extinctive properties during haze and haze-free periods based on the Micro-Pulse Lidar observation in Shanghai.

Ambient aerosols make a significant contribution to the environment and climate through their optical properties. In this study, the aerosol extinction coefficient and Aerosol optical depth (AOD) retrieved using the Fernald Method from the ground-based Micro-Pulse Lidar (MPL) were used to investigate the characteristics of aerosols during haze and haze-free periods in Shanghai. There were 216 haze days including 145 dry haze days, 39 damp haze days and 32days of both dry and damp haze in Shanghai from March 2009 to February 2010. During the haze periods, aerosols were concentrated mainly below 600m resulting in the most severe pollution layer in Shanghai. In contrast to the aerosol optical properties during haze-free periods, aerosol extinction coefficients and AOD were larger in the lower altitude (below 1km) during haze periods. The lowest 1km contributed 53-72% of the Aerosol optical depth (AOD) below 6km for the haze periods and <41% of that for the haze-free periods except summer. According to the analysis of influencing factors, although atmospheric convection was strong in summer which led to reduce the extinction, the highest occurrence of haze with relatively low aerosol extinction most of time was in summer, which resulted from the factors such as higher relative humidity, temperature and more solar radiation causing hygroscopic growth of particles and formation of secondary aerosols; in spring and autumn, there was less haze occurrences because the boundary layer was relatively higher, which allowed pollutants to diffuse more easily, but spring was the second most frequency season of haze due to frequent dust transport from the north; in winter high concentrations of particles and low boundary layer height were not beneficial to the diffusion of pollutants near the surface and caused haze occurrence rather high with high aerosol extinction.

Evaluation of left atrial function in hypertensive patients with and without left ventricular hypertrophy using velocity vector imaging.

To study left atrial deformation characteristics using Velocity vector imaging (VVI) in hypertensive patients with and without left ventricular hypertrophy (LVH), and to explore its value for detection of left atrial dysfunction in these patients. Sixty-four patients with essential hypertension were divided into normal left ventricular geometry (LVN, 37 cases) and LVH (27 cases) groups, according to their left ventricular mass index. Twenty-five age-matched healthy participants were included as control group. Two-dimensional dynamic images of the apical four- and two-chamber echocardiographic views were obtained, and strain/strain rate (SR) curves of eight atrial segments were derived by VVI software. Peak systolic strain (ε(sys)), systolic SR (SRs), early and late diastolic SR (SRe, SRa) were measured and calculated. Peak early diastolic mitral inflow and annulus velocities were also measured and their ratio (E/E') calculated. Compared with the control group, SRe decreased and SRa increased significantly in LVH group (P < 0.05), while no significant difference was found between LVN and control groups with respect to SRe, SRa, SRs and ε(sys) (P > 0.05). Also, no significant difference was observed in SRe, SRa, SRs and ε(sys) between LVH and LVN groups (P > 0.05). SRe and SRa correlated significantly with E/E' (r = -0.634, r = 0.609; both P < 0.001). Strain/SR parameters derived from VVI may reflect decreased conduit, increased booster pump function of the left atrium in hypertensive patients with LVH and correlate with left ventricular diastolic function.