title: Von Willebrand Factor Plasma Levels Variability In Nonvalvular Atrial Fibrillation.
abstract: Atrial Fibrillation (AF) is the most common cardiac arrhythmia of clinical significance; it increases the risk of mortality due to stroke. The mechanisms behind cerebral thromboembolism in AF are associated with a prothrombotic state, demonstrated by higher levels of von Willebrand Factor (vWF), a multimeric glycoprotein that plays a crucial role in platelet adhesion and aggregation and it has been proposed as a biomarker of endothelial dysfunction. Plasma vWF levels are elevated in patients with nonvalvular Atrial Fibrillation (NVAF) associated to the presence of cardiovascular risk factors. The variability in vWF plasma levels in healthy subjects has a wide distribution, but there is no description available of the variability in AF patients and among types of AF. The aim of this study was to determine the variability of vWF plasma concentrations in patients with NVAF, associated to cardiovascular risk factors. Search strategy included PubMed and Ovid. Keywords used were "Atrial Fibrillation" and "von Willebrand Factor". It includes original articles, with analysis of plasma vWF levels by ELISA, without acute stroke. Review articles and meta-analysis were excluded. Reviewed studies include 22 trials and 6542 patients with nonvalvular AF associated to cardiovascular disease risk factors: age, sex, hypertension, heart failure, diabetes mellitus, prior stroke, coronary artery disease. Variability in vWF plasma levels was wide, with minimum values of 77 IU/dl and maximum values of 245 IU/dl and a mean of 146 IU/dl. Age of patients ranged between 54 and 78 years, and the percentage of males ranged between 23% and 80%. According to type of AF vWF levels were as follows, in paroxysmal AF: 92-264 IU/dl; persistent AF: 76-234 IU/dl; permanent AF: 91-247 IU/dl. The variability in vWF plasma levels is affected by risk factors and the AF type, however vWF levels in AF patients are higher when compared with healthy subjects.
authors.affiliation: Laboratory of Haemostasis and Vascular Biology. Faculty of Medical and Biological Sciences "Dr. Ignacio Chavez". Michoacan University of San Nicolas de Hidalgo. Biomedical Research Center of Michoacán. Mexican Social Security Institute. Morelia, Michoacán, México.
authors.forename: Gerardo Muñoz
authors.initials: GM
authors.lastname: Cortés
authors.affiliation: Laboratory of Haemostasis and Vascular Biology. Faculty of Medical and Biological Sciences "Dr. Ignacio Chavez". Michoacan University of San Nicolas de Hidalgo. Morelia, Michoacán, México.
authors.forename: Martha Eva
authors.initials: ME
authors.lastname: Viveros Sandoval
authors.affiliation: Department of Interventional Cardiology, General Hospital "Dr Miguel Silva". Morelia, Michoacán, México.
authors.forename: Carlos Arturo
authors.initials: CA
authors.lastname: Areán Martínez
authors.affiliation: Department of Cardiology, Regional General Hospital No. 1. Mexican Social Security Institute. Morelia, Michoacán, México.
authors.forename: Helios Eduardo
authors.initials: HE
authors.lastname: Vega Gómez
authors.affiliation: Laboratory of Haemostasis and Vascular Biology. Faculty of Medical and Biological Sciences "Dr. Ignacio Chavez". Michoacan University of San Nicolas de Hidalgo. Morelia, Michoacán, México.
authors.forename: Sandra Edith
authors.initials: SE
authors.lastname: López Castañeda
authors.affiliation: Biomedical Research Center of Michoacán, Mexican Social Security Institute. Morelia, Mich. México.
authors.forename: Anel Gómez
authors.initials: AG
authors.lastname: García
keywords: Atrial Fibrillation; Biomarker; von Willebrand Factor