The impact of different fat depots in the body on the progression of atrial fibrillation - data from RACE V

Abstract

Abstract Funding Acknowledgements Type of funding sources: Foundation. Main funding source(s): Dutch Heart Foundation, Medtronic Background Paroxysmal atrial fibrillation (PAF) progression is associated with cardiovascular complications and worse outcome. Obesity is independently associated with AF prevalence and progression. The association between different fat depots in the body with AF is unclear. Aim We aim to systematically investigate the association of different fat depots in the body with AF. Methods 417 patients with PAF and continuous rhythm monitoring (implantable loop recorder or pacemaker) were included in the prospective RACE V study. In addition to extensive phenotyping at baseline including calculating BMI and measuring waist circumference (WC) epicardial and pericardial fat were measured on non-contrast enhanced cardiac CT scans by tracing the pericardium manually on every slice and afterwards fat automatically summed between -50 and -150 HU. Epicardial fat was defined as fat within the pericardium, pericardial fat as fat inside the pericardium and adjacent to the pericardium and thoracic fat as adjacent fat outside the pericardium. AF progression was defined as (1) progression to persistent or permanent AF, or (2) progression of PAF with >3% burden increase within 2.2years of follow-up. Multivariable logistic regression analysis was used to analyse the association of different fat pads with AF progression. Results Six percent of patients per year showed AF progression (51/417) after a median follow-up of 2.2 (1.6-2.8) years. Multivariate analysis identified WC (odds ratio [OR] 1.03, 95% confidence intervals [CI] 1.01-1.06, p=.014) to be associated with AF progression. Epicardial fat (OR 1.00, 95%CI .99-1.01, p=.407), pericardial fat (OR 1.00, 95%CI .99-1.01, p=.311), thoracic fat (OR 1.00, 95%CI .99-1.01, p=.372), and BMI (OR 1.03, 95%CI .97-1.10, p=.328) showed no relation with AF progression. Conclusion AF progression occurred in 6% per year in patients with PAF. In contrast to epicardial, pericardial and thoracic fat measured in a semiautomatic way, WC was the only fat depot associated with AF progression. Whether a more different assessment of obesity and epicardial fat may demonstrate an association with AF progression warrants further study.