Increased serum oxidative stress in patients with severe mitral regurgitation: A new finding and potential mechanism for atrial enlargement

ObjectiveThe aim of this study was to examine the serum oxidative stress in patients with severe mitral regurgitation.Design and methodsThis study analyzed serum oxidative stress index in patients with severe mitral regurgitation [persistent atrial fibrillation (AF) or sinus rhythm], paroxysmal lone AF patients and healthy subjects.ResultsThe serum oxidative stress index was significantly higher in the mitral regurgitation AF group and sinus group than in the lone AF group and healthy subjects (p < 0.0001). Left atrial size was significantly larger in the mitral regurgitation AF group and sinus group than in the lone AF group and healthy subjects (p < 0.0001). The oxidative stress index significantly and positively correlated with left atrial size in the overall study population (r = 0.439, p = 0.0008).ConclusionsThis study provides new evidence of increased oxidative stress in human severe mitral regurgitation, probably contributing to atrial enlargement.