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 is known
and 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 determinate the variability in 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”. Include 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 were wide, with minimum values of 77 IU/dl
and maximum values of 245 IU/dl and a mean average of 146 IU/dl; Age of
patients ranged between 54 and 78 years, and the percentage of males ranged
between 23% and 80%. 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.
Credits: Gerardo Muñoz Cortés; Martha Eva Viveros Sandoval; Carlos Arturo Areán Martínez; Helios Eduardo Vega Gómez; Sandra Edith López Castañeda; Anel Gómez García