11 research outputs found

    Prognostic value of tissue Doppler E/e' ratio in hypertension patients with preserved left ventricular ejection fraction

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    Objectives: This study aims to investigate the association of tissue Doppler E/e' with cardiac events in hypertension patients, independent of and incremental to clinical and left ventricular geometric patterns. Methods: We retrospectively enrolled 222 asymptomatic nonischemic patients with hypertension who had echocardiogram in 2012 to evaluate tissue Doppler E/e'. Patients were followed up for cardiac events (cardiac events were defined as myocardial infarction, coronary revascularization procedures, new-onset angina (stable or unstable), heart failure). A cox regression was used to assess the association of the ratio of transmitral Doppler early filling velocity to tissue Doppler early diastolic mitral annular velocity (E/e') with cardiac events. Results: A total of 222 patients were included in analysis. There were 10 primary cardiac events during 3.2 ± 0.4 years follow-up. The E/e' ratio was the strongest predictor of cardiac events in Cox-proportional hazards models. Following adjustment for covariates, a unit rise in the E/e' ratio was associated with a 26% increment in risk of a cardiac event (HR 1.26, CI 1.06–1.50, p = 0.008). When E/e' 14 the hazard ratio of cardiac event was significantly increased compared with E/e' ≀ 14 in Kaplan–Meier analysis (log-rank ratio, 16.26; p  0.001). Conclusions: E/e', a non-invasive estimate of left ventricular filling pressure, predicts cardiac events in hypertensive population with preserved left ventricular ejection fraction, independent of and incremental to clinical and left ventricular geometric patterns. E/e' represents an early, effective tool for cardiovascular risk stratification in hypertension population

    Left atrial volume index is superior to left atrial diameter index in relation to coronary heart disease in hypertension patients with preserved left ventricular ejection fraction

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    Objective: Research hypothesis is that left atrial (LA) volume index is superior to LA diameter index for coronary heart disease and LA volume index is important to refine risk stratification. Methods: We retrospectively enrolled 222 asymptomatic non-ischemic patients with hypertension who had stored digital images in 2012. Patients were followed up for coronary heart disease over a median of 3.2 years. The Area under receiver operating characteristic curve for LA parameters with coronary heart disease was evaluated. Cox regression was used to assess the association between left atrial parameters and coronary heart disease. Results: The mean age of patients was 62 years, 45% were men, and mean left atrial diameter, mean left atrial volume, mean LA diameter index, mean LA volume index was 32 mm, 43 ml, 21 mm/m2, 27 ml/m2, respectively. After 3.2 years follow up, 10 patients experienced coronary heart disease. Compared with patients without coronary heart disease, LA diameter index and LA volume index increased in coronary heart disease group (P < 0.05). Multivariate cox regression analysis showed, adjusted for age, sex, smoking, cholesterol, fasting plasma glucose, diabetes, systolic blood pressure, left ventricular mass index, and E/e’ ratio, a unit rise in LA volume index was associated with a 15% increase in the risk of coronary heart disease. (HR:1.155; 95% CI 1.002–1.332). Compared with LA diameter index, the area under receiver operating characteristic curve values for predicting coronary heart disease were higher for LA volume index (0.797). Conclusions: Our study showed that LA volume index was superior to LA diameter index. LA volume index had independent prognostic implications in terms of coronary heart disease prediction in hypertension patients with preserved left ventricular ejection fraction

    PTA-Welded Coatings with Saturation Magnetization above 1.3 T Using FeCrBSi Powders with Chemical Composition Similar to AISI 430 Ferrite Stainless Steel

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    Fe-Cr-based soft magnetic alloy (SMA) monolayer coatings with high saturation magnetization (Ms) above 1.3 T were deposited onto AISI 1010 substrate by co-axial powder feeding plasma transferred arc (PTA) welding, using FeCrBSi self-fluxing powders Fe313, which have a similar chemical composition to AISI 430 ferritic stainless steel (FSS). The effect of welding parameters on the phase assemblage, microstructure, hardness and magnetic performance of the coatings was investigated. The results show that the coating’s maximum width and the welding surplus height increased with the rise in welding heat input and powder distribution density, respectively. The coating’s Ms increased sharply, but its coercivity (Hc) decreased with the growth in the substrate dilution ratio. The coating’s Hc increased whereas its Ms decreased with the increment in welding heat input. The as-welded coating C3 with optimum magnetic performance had a dendrites–eutectics composite structure, where the columnar or equiaxed sorbitic pearlite dendritic cores surrounded by network-like eutectics α(Fe,Cr) + (Fe1−xCrx)2B were the main contents. Moreover, (Fe,Cr)7C3 and CrB had also been detected, and they were mainly distributed in the interdendritic regions. The body-centered cubic (b.c.c.) α(Fe,Cr) multi-element solid solution contributes to a high Ms of 1.61 T, and the borides (Fe1−xCrx)2B and CrB as well as (Fe,Cr)7C3 and other carbides cause a high Hc of 58.6 Oe and hardness HV0.3 of 4.90 ± 0.06 GPa, much higher than that of AISI 430 FSS (HV < 1.8 GPa). The current work verifies the feasibility of fabricating Ni- and Co-free FeCrBSi SMA coatings with high Ms and high hardness via PTA welding, and since the feedstock powders have chemical composition similar to AISI 430 FSS, the work may bring about novel applications for AISI 430 FSS in particular cases where the considerable wear-resistant performance as well as superior soft magnetic and anti-corrosive properties are required
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