Evidence for a Heritable Contribution to Atrial Fibrillation Associated With Fibrosis

Abstract Objectives The aim of this study was to define the population-based familial clustering of atrial fibrillation (AF) that is associated with fibrosis and describe evidence for a heritable predisposition. Background Although a heritable contribution to AF is well-established and the association of fibrosis with AF is well-recognized, no studies have analyzed the genetic contribution to AF co-occurring with fibrosis. Methods AF patients with magnetic resonance imaging–confirmed fibrosis were identified in a population-based health sciences center database linked to a Utah genealogy. Familial clustering of AF/fibrosis was defined by analysis of pairwise case relatedness, estimation of relative risk of AF/fibrosis in relatives, and identification of high-risk AF/fibrosis pedigrees. Results The 694 individuals identified with AF/fibrosis who had at least 3 generations of genealogy data were found to have significantly elevated pairwise relatedness (p  Conclusions There is a strong heritable contribution to predisposition to AF co-occurring with fibrosis. We suggest that this study provides a unique foundation for a search for predisposition genes, specifically for AF co-occurring with fibrosis.