elastin and Atrial-Fibrillation

The Utah Project on Exfoliation Syndrome (UPEXS) study was created to investigate the association between exfoliation syndrome (XFS) and systemic disorders or pathologies. The study utilizes the resources of the Utah Population Database, which is linked to the Utah genealogy, a compilation of large pedigrees extending back 3 to ≥11 generations, representing most families in the state. These family members medical and health records are linked to vital records and can be used effectively to identify familial clustering of disorders, like XFS, with comorbid diseases or health-related data. There is growing evidence that XFS patients have an increased risk for systemic disorders that may reflect the systemic tissue involvement of this disease. Epidemiologic studies of individuals with XFS have reported an increased risk of various pathologies that have abnormalities in extracellular matrix metabolism and repair. For this reason, the UPEXS has focused on disorders that involve the extracellular matrix in general and elastin specifically, such as pelvic organ prolapse, atrial fibrillation, inguinal hernias, and chronic obstructive pulmonary disease. In this paper we present our results from the analysis of pelvic organ prolapse, as well as, preliminary data for atrial fibrillation.

Topics: Atrial Fibrillation; Databases, Factual; Elastin; Exfoliation Syndrome; Extracellular Matrix; Humans; Intraocular Pressure; Pelvic Organ Prolapse; Utah

One of the generally recognized factors contributing to the initiation and maintenance of atrial fibrillation (AF) is structural remodeling of the myocardium that affects both atrial cardiomyocytes as well as interstitium. The goal of this study was to characterize morphologically and functionally interstitium of atria in patients with AF or in sinus rhythm (SR) who were indicated to heart surgery. Patient population consisted of 46 subjects (19 with long-term persistent AF, and 27 in SR) undergoing coronary bypass or valve surgery. Peroperative bioptic samples of the left and the right atria were examined using immunohistochemistry to visualize and quantify collagen I, collagen III, elastin, desmin, smooth muscle actin, endothelium and Vascular Endothelial Growth Factor (VEGF). The content of interstitial elastin, collagen I, and collagen III in atrial tissue was similar in AF and SR groups. However, the right atrium was more than twofold more abundant in elastin as compared with the left atrium and similar difference was found for collagen I and III. The right atrium showed also higher VEGF expression and lower microvascular density as compared to the left atrium. No significant changes in atrial extracellular matrix fiber content, microvascular density and angiogenic signaling, attributable to AF, were found in this cohort of patients with structural heart disease. This finding suggests that interstitial fibrosis and other morphological changes in atrial tissue are rather linked to structural heart disease than to AF per se. Significant regional differences in interstitial structure between right and left atrium is a novel observation that deserves further investigation.

Topics: Aged; Atrial Fibrillation; Atrial Function; Case-Control Studies; Collagen Type I; Collagen Type III; Elastin; Extracellular Matrix; Female; Heart Atria; Heart Rate; Humans; Male; Middle Aged; Organ Specificity