Visceral fat accumulation and left atrial phasic function in the general population

Abstract

Abstract Background Obesity carries independent risk for incident atrial fibrillation (AF), although the impact of abdominal fat distribution on LA morphological and functional remodeling is not fully elucidated. Speckle-tracking echocardiography is a novel and sensitive tool that allows quantification and detection of subtle alterations in left atrial (LA) phasic function. Purpose This study aimed to investigate whether increased visceral adiposity is independently associated with impaired LA phasic function in a community-based cohort. Methods We included 527 participants without overt cardiac disease who underwent laboratory testing, abdominal computed tomographic examination and speckle-tracking echocardiography. Abdominal adiposity was quantitatively assessed as visceral fat area (VFA) and subcutaneous fat area (SFA) at the level of the umbilicus. Speckle-tracking echocardiography was performed to assess LA phasic function including reservoir, conduit and pump strain as well as left ventricular global longitudinal strain (LVGLS). Results Mean age was 57±10 years and 362 of the participants (69%) were men. LA reservoir and conduit strain were decreased according to the VFA quartiles (both p<0.05), whereas there was no significant difference in LA volume index and LA pump strain. When stratified by SFA, there was no significant differences in LA volume index and all LA phasic strain across the quartiles. In multivariable analysis, VFA as continuous variable was significantly associated with LA conduit strain, independent of traditional cardiovascular risk factors, pertinent laboratory parameters and LV morphology and function including LVGLS (standardized b=−0.146, p=0.011). Representative cases are shown in the Figure. Conclusion In a sample of the general population, VFA accumulation was independently associated with worse LA conduit strain, which may be involved in the pathophysiological mechanism of obesity-related AF. Funding Acknowledgement Type of funding source: Foundation. Main funding source(s): Yamauchi Susumu Scholarship for Cardiovascular Research