Abstract 16854: Left Atrial Dysfunction and Prediction of Atrial Fibrillation in LMNA Cardiomyopathy

Abstract

Introduction: LMNA cardiomyopathy is characterized by a high incidence of atrial fibrillation (AF) and an increased risk for AF-related stroke. AF commonly occurs before apparent cardiomyopathy, and the ability to predict its incidence in asymptomatic LMNA mutation carriers is limited. We sought to evaluate the presence of echocardiographic features specific to LMNA and whether they predict AF incidence. Methods: Patients harboring LMNA mutations (n=77) from two referrals centers between 2000 and 2017 were retrospectively included. Comparator groups included patients with TTN cardiomyopathy (n=35) and healthy subjects (n=36). Echocardiograms at first clinical contact were analyzed for routine metrics and LA strain and related to incident AF. Results: Patients with LMNA mutations were assessed at median age 47 years (IQR, 32-62) with median LVEF 51% (41-61). In LMNA patients with LVEF ≥55% (n=20) and healthy subjects matched for LVEF, LA contractile strain was lower in LMNA patients (-10% vs -16%, respectively; P = 0.047), whereas other parameters did not significantly differ (Figure, panel A). Comparison of LVEF-matched LMNA and TTN cardiomyopathy patients showed LA contractile strain as the only distinguishing feature (-5.8% vs -12.8%, respectively; P = 0.01) (Figure, panel B). LMNA patients without previous AF (n=35) were followed for a total of 133 patient-years during which 11 (31%) developed AF. In Cox regressions adjusted for clinical and echocardiographic variables, decreased LA contractile strain (<