Estado nutricional, obesidad y eventos en pacientes con fibrilación auricular / Nutrition status, obesity and outcomes in patients with atrial fibrillation

Introducción y objetivos Se ha descrito un efecto protector paradójico de la obesidad en pacientes con fibrilación auricular (FA) cuya mecanismo no está claro. El objetivo de este estudio fue determinar el impacto del estado nutricional y el índice de masa corporal (IMC) en el pronóstico de los pacientes con FA. Métodos Se realizó un estudio de cohortes retrospectivo de pacientes con FA entre 2014 y 2017 de una única área sanitaria en España. La escala CONUT se utilizó para evaluar el estado nutricional. La asociación del IMC y escala CONUT con la mortalidad se analizó por regresión de Cox. La asociación con eventos embólicos y hemorrágicos se evaluó mediante análisis de riesgos competitivos. Resultados Entre los 14.849 pacientes, se observó sobrepeso y obesidad en 42,6% y 46,0%, respectivamente, mientras que malnutrición en 34,3%. Durante un seguimiento medio de 4,4 años, 3.335 pacientes murieron, 984 pacientes sufrieron un evento embólico y 1.317 una hemorragia. El IMC se asoció inversamente con la mortalidad, embolias y hemorragias en el análisis univariado; sin embargo, esta asociación se perdió después del ajuste por edad, sexo, comorbilidades y escala CONUT (HR para el combinado de eventos 0,98; IC95%, 0,95-1,01; p=0,719). Por el contrario, la escala CONUT si se asoció con la mortalidad, la embolia y la hemorragia (HR = 1,15; IC95%, 1,14-1,17; p<0,001). Conclusiones El IMC no fue un predictor independiente de eventos en pacientes con FA, a diferencia del estado nutricional, que mostró una fuerte asociación con la mortalidad, la embolia y la hemorragia (AU)

Introduction and objectives A paradoxical protective effect of obesity has been previously reported in patients with atrial fibrillation (AF). The aim of this study was to determine the impact of nutritional status and body mass index (BMI) on the prognosis of AF patients. Methods We conducted a retrospective population-based cohort study of patients with AF from 2014 to 2017 from a single health area in Spain. The CONUT score was used to assess nutritional status. Cox regression models were used to estimate the association of BMI and CONUT score with mortality. The association with embolism and bleeding was assessed by a competing risk analysis. Results Among 14 849 AF patients, overweight and obesity were observed in 42.6% and 46.0%, respectively, while malnutrition was observed in 34.3%. During a mean follow-up of 4.4 years, 3335 patients died, 984 patients had a stroke or systemic embolism, and 1317 had a major bleeding event. On univariate analysis, BMI was inversely associated with mortality, embolism, and bleeding; however, this association was lost after adjustment by age, sex, comorbidities, and CONUT score (HR for composite endpoint, 0.98; 95%CI, 0.95-1.01; P=.719). Neither obesity nor overweight were predictors of mortality, embolism, and bleeding events. In contrast, nutritional status—assessed by the CONUT score—was associated with mortality, embolism and bleeding after multivariate analysis (HR for composite endpoint, 1.15; 95%CI, 1.14-1.17; P<.001). Conclusion BMI was not an independent predictor of events in patients with AF in contrast to nutritional status, which showed a strong association with mortality, embolism, and bleeding (AU)

Surface and intramural reentrant patterns during atrial fibrillation in the sheep.

INTRODUCTION: This article is part of the Focus Theme of Methods of Information in Medicine on "Biosignal Interpretation: Advanced Methods for Studying Cardiovascular and Respiratory Systems". BACKGROUND: Atrial fibrillation (AF) is the most common sustained cardiac arrhythmia in humans and is predicted to dramatically increase its prevalence in the future. High-resolution mapping data and Fourier power spectral analysis with its dominant frequency support the hypothesis that AF in the structurally normal sheep heart and in some patients often presents organized drivers in the form of periodic surface re-entries or breakthroughs. Nevertheless, the dynamics of those surface patterns of activity, as well as their intramural components are still poorly understood. OBJECTIVE: To present data on AF waves from the surface of isolated sheep hearts and discuss the interpretation of their intramural patterns. METHODS: We used a combination of endocardial-epicardial optical mapping with phase and spectral analysis as well as computer simulation of the re-entrant activity in the myocardial wall. RESULTS: Analysis of the surfaces' optical mapping data in the phase domain reveals that activation of the posterior left atrium (PLA) consisted of alternating patterns of breakthroughs and reentries. The patterns on the endocardial and epicardial PLA surface at any given moment of time of the AF could be either identical or not identical, and the activity in the thickness of the PLA wall is hypothesized to conform to either ectopic discharge or reentrant scroll waves, but a definite evidence for the presence of such mechanisms is currently lacking. A universal minimal-principle theory is shown in a computer model to result in a tendency of the axis of the scroll waves to align with the myocardial fibers inside the wall. CONCLUSION: The tendency of filaments of scroll waves to align with myocardial fibers may contribute to the variety and intermittency of surface rotors seen in AF.

Atrial fibrillation in young stroke patients: do we underestimate its prevalence?

BACKGROUND AND PURPOSE: The prevalence of atrial fibrillation (AF) in young stroke patients has rarely been reported and is considered an uncommon ischaemic stroke (IS) aetiology. Our objective was to analyse the prevalence of AF in IS patients up to 50 years of age and its relationship with stroke severity and outcomes. METHODS: This was an observational study of consecutive IS patients up to 50 years of age admitted to a stroke centre during a 5-year period (2007-2011). A complete cardiology study was performed with a daily electrocardiogram and cardiac monitoring for 72 h as well as echocardiography. In cases of stroke of unknown aetiology a 24-h Holter monitoring was performed. Baseline data, previously or newly diagnosed AF, structural heart disease (SHD) (valvulopathy/cardiomyopathy), stroke severity on admission as measured by the National Institutes of Health Stroke Scale (NIHSS) (moderate-severe stroke if NIHSS ≥ 8) and 3-month outcomes according to the modified Rankin Scale (mRS) (good outcome if mRS ≤ 2) were analysed. AF was classified as AF associated with SHD (AF-SHD) and AF not associated with SHD (AF-NSHD). RESULTS: One hundred and fifty-seven patients were included (mean age 43 years, 58.6% male). Fourteen subjects (8.9%) presented with AF, four with AF-NSHD and 10 with AF-SHD. AF was previously known in 10 patients (6.3%), two with AF-NSHD and eight with AF-SHD. A multivariate analysis showed an independent association between AF and moderate-severe IS (odds ratio 3.771, 95% CI 1.182-12.028), but AF was not an independent prognostic factor. CONCLUSION: AF may be more common than expected in young patients with IS and is associated with increased NIHSS scores.