Prophylactic Statin Administration May Prevent Shortening of the Fibrillation Cycle Length in Patients With New-Onset Atrial Fibrillation

Abstract

SummaryPatients with recently diagnosed atrial fi brillation (AF) tend to exhibit a longer fi brillation cycle length (FCL) than those having a longer clinical history. However, the electrophysiological properties of new-onset AF may vary because of the clinical background of patients. In this study, we evaluated clinical factors to identify the determinants of FCL in new-onset AF. Electrocardiograms (ECGs) recorded from 2008 through 2011 were analyzed using our digital ECG-profi ling system. In the 1,578 AF episodes recorded, 466 new-onset AF episodes were identifi ed using clinical referral history and previous ECGs. After evaluating FCL in these new-onset AF episodes, using a customized fi brillation wave analyzer with fast Fourier transform analysis, we divided the patients into a longer-FCL group and a shorter-FCL group using the median FCL (158 ms). Propensity score matching yielded 135 matched pairs of patients with comparable mean ages between the two groups. Four factors (brain natriuretic peptide levels, and use of angiotensin receptor blockers, calcium channel blockers or statins) exhibited a signifi cant difference between the two groups. Multivariate analysis revealed that statin use was the only signifi cant independent predictor of longer FCL (Odds ratio, 3.86; 95% CI, 1.65-9.63; P = 0. and it is a major cause of morbidity and mortality in the general population.2) The prevalence of AF is related to aging, and there are approximately 716,000 people with AF in Japan, an overall prevalence of 0.56% in the Japanese population.3) The arrhythmogenic substrate of AF is known to be constructed progressively under various pathological conditions, including AF itself. This process is understood as atrial remodeling. Therapies designed to suppress this remodeling are termed "upstream therapy." Although the suppressive effects of some medicines, such as angiotensin receptor blockers (ARBs) 4,5) or statins, 6,7) as upstream therapy have been experimentally documented in animal models of AF, the clinical effect of this therapy is still controversial. [8][9][10] The reason for this discrepancy between experimental and clinical results remains unclear, but the atrial structural changes may have already progressed further in clinical cases than in experimental models, even in cases with paroxysmal AF, because of the infl uence of various clinical factors. We evaluated the atrial electrophysiological properties through analysis of the fi brillation cycle length (FCL).11) This method enables us to evaluate the degree of refractory shortening or the complexity of the AF substrate noninvasively and repeatedly, and then gives us indirect but important information about the degree of atrial remodeling.12) In the present study, we hypothesized that various clinical factors including those related to the disease underlying AF and/or the use of various prescribed medicines, may infl uence atrial electrophysiological properties even before the clinical appearance of AF. These clinical factors were compared between patients...