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Background The objectives of this study are to validate the Quality of Life in Cardiovascular Surgery (QLCS) questionnaire and to observe the evolution of quality of life in the first year of postoperative follow-up of patients who underwent coronary artery bypass grafting (CABG). Methods This was a prospective observational study of patients undergoing CABG from July 2016 to June 2017 who survived and answered the QLCS with 1, 6, and 12 months of follow-up. Validation was evaluated for internal consistency by Cronbach’s alpha, test–retest reproducibility by correlation coefficient of concordance, and accuracy for interrater reliability by the kappa statistic. The nonparametric analysis of variance test was used for analysis of repeated measures, during follow-up, of the QLCS was considered significant at p Results Included were 360 patients, with a mean age of 63 years; 72% were men. Cronbach's alpha was 0.82, demonstrating adequate internal consistency. The correlation coefficient of concordance was 0.93 and accuracy 0.99, showing good precision and accuracy. The kappa statistic for questions ranged from 0.58 to 0.78, which ensures a moderate reproducibility. Scores of the QLCS in patients undergoing CABG of 17.69, 18.82, and 19.52 were found at 1, 6, and 12 months, respectively. Thus there was a progressive improvement in quality of life over the first year of follow-up (p Conclusions The QLCS proved to be a good questionnaire in this population, with adequate internal consistency and moderate reproducibility. Its use revealed a progressive and significant improvement in the quality of life of patients undergoing CABG.

This paper aims to evaluate the heat transfer in a square cavity with an elliptical fin located in different positions on the cavity bottom and with different aspect ratios. The optimal geometry was analised using the Constructal Design principle. A two-dimensional, laminar, steady state and incompressible flow was considered. The thermophysics properties were defined for Pr = 0.71 and they are considered constant, except for the specific mass that was determined by the Boussinesq approximation. A Rayleigh number (RaH) of 104 was adopted to define the natural convection, while a Reynolds number (ReH) of 102 was adopted to define the forced convection. The fin position and its dimensions were varied, keeping the ratio of the fin area to cavity area constant (ϕ = 0.05). The optimal geometry that maximizes the heat transfer rate was obtained through the Constructal Law. A mesh was created to solve the problem and it was adequately refined to ensure the accuracy of the results. The governing equations of the problem were solved numerically using the software ANSYS/Fluent®. This study shows that the position of the fin which maximizes the average Nusselt number in these conditions is at the point X1 ≈ 0.3 of the lower surface. For the aspect ratio (r) of the fin, it was observed that the minimization of the average Nusselt number occurs for r between 15 and 25. Considering all studied geometries, the optimized one can reach a performance around 50% superior if compared with the worst one, proving the importance of geometric evaluation in this kind of engineering problem, as well as the effectiveness of the Constructal approach. Keywords: Heat transfer, Constructal Law, Nusselt number, elliptical fin, mixed convection