Search

Background: A methodology to identify patients with ascending aortic aneurysm (AsAA) under high risk for aortic growth is not completely defined., Objetive: This research seeks to numerically characterize the aortic blood flow by relating the resulting mechanical stress distribution with AsAA growth., Methods: Analytical, observational, single-center study in which a computational fluid dynamics (CFD) protocol was applied to aortic computed tomography angiogram (CTA) images of patients with AsAA. Two CTA exams taken at a minimum interval of one year were obtained. From the CTA-gathered images, three-dimensional models were built, and clinical data were registered. Study of velocity field and coherent structures (vortices) was performed aiming to relate them to the presence or absence of aneurysm growth, as well as comparing them to the patients' clinical data. The Kolmogorov-Smirnov test was used to evaluate the normality of the distribution, and the non-parametric Wilcoxon signed-rank test, for non-normal distribution, was used to compare the paired data of the aortic angles. Statistical significance was set at 5%., Results: The incident jet in the aortic wall generated recirculation areas in the posterior region of the jet, inducing complex vortices formation in the group with aneurysm growth, leading to an average pressure increase in the ascending aortic wall between exams. In the group without aneurysm growth, the average pressure decreased., Conclusion: This pilot study showed that CFD based on CTA may in the near future be a tool to help identify flow patterns associated with AsAA remodeling process.

Backgroud: Transcatheter aortic valve replacement (TAVR) can reduce mortality among patients with aortic stenosis. Knowledge of pressure distribution and shear stress at the aortic wall may help identify critical regions, where aortic remodeling process may occur. Here a numerical simulation study of the influence of positioning of the prosthetic valve orifice on the flow field is presented., Objective: The present analysis provides a perspective of great variance on flow behavior due only to angle changes., Methods: A 3D model was generated from computed tomography angiography of a patient who had undergone a TAVR. Different mass flow rates were imposed at the inlet valve., Results: Small variations of the tilt angle could modify the nature of the flow, displacing the position of the vortices, and altering the prerssure distribution and the location of high wall shear stress., Conclusion: These hemodynamic features may be relevant in the aortic remodeling process and distribution of the stress mapping and could help, in the near future, the optimization of the percutaneous prosthesis implantation. (Arq Bras Cardiol. 2020; [online].ahead print, PP.0-0).

Background: Anemia is common in patients with heart failure (HF). Its prevalence in patients with HF from a community-based cohort is unknown in our country., Objective: evaluate the prevalence and characteristics of patients with anemia in a non-selected population with HF from a community-based cohort, comparing it with that of a HF population treated at a specialized outpatient clinic., Methods: This was a transversal, prospective, observational study, carried out from January 2006 to March 2007. The patients with HF met the Boston criteria, with a score > 8. Anemia was defined through the criteria of the World Health Organization as hemoglobin levels < 13 g/dL for men and <12 g/dl for women. Patients treated at a primary care program in the community were randomly selected, as well as patients treated at a Heart Failure Outpatient Clinic in a university hospital., Results: A total of 206 patients were assessed, with a mean age of 61.3+/-13.1 years, of which 53.4% were females. The prevalence of anemia in the community-based cohort (n=114) was 21% and at the outpatient clinic (n=92), of 25% (p=0.50). The patients from the community-based cohort presented a lower rate of kidney dysfunction (GFR<60 ml/min/1,73-5), predominance of HF with normal ejection fraction and female sex. Kidney function parameters (urea or creatinine) independently correlated with anemia in both populations., Conclusion: The prevalence of anemia was similar in the studied populations. Kidney function was the only factor that independently correlated with anemia in both populations.