21 Nov Fat Around the Heart Increases Risk of Atrial Fibrillation
MedicalResearch.com: What are the main findings of this study?
Dr. Rabbat : Atrial fibrillation (AF) is the most common sustained arrhythmia in clinical practice and is responsible for significant morbidity and mortality. Epidemiologic data suggest that obesity as measured by one’s BMI is a risk factor for Atrial fibrillation. But there is more to the story. What may be even more important than overall BMI is how much fat you have around the heart. There are many individuals who, as measured by their BMI, are not considered obese, but they have high volumes of fat around their heart, which may have been a major cause for their atrial fibrillation. Therefore, simple measures such as BMI may fail to completely inform us of a patient’s true CV risk.
In a previous study we found that epicardial adipose tissue (EAT), or the fat around the heart, has been associated with the presence and severity of AF independent of known risk factors and body mass index (BMI). The inflammatory mediators released from the fat are metabolically active, and may promote fibrosis in adjacent heart muscle. Fibrosis of the left atrium appears to be a hallmark feature of atrial fibrillation and higher amounts of fibrosis are linked to recurrence of atrial fibrillation. New innovations in cardiac magnetic resonance imaging (CMR) allow LA fibrosis and EAT to be precisely quantified. Our current study is the first of its kind to demonstrate the association of EAT volume and extent of LA fibrosis in human AF independent of LA size, BMI, and other AF risk factors.
MedicalResearch.com: What should patients and health care providers take away from this report?
Dr. Rabbat For many years, EAT was felt to be inert. However, this is not the case as epicardial adipose tissue is a metabolically active organ and by means of various adipokines and inflammatory mediators likely contributes to both the initiation (trigger) and maintenance (substrate) of AF.
Assessment of EAT in future large follow-up studies are needed to further clarify the pathophysiology behind these intriguing findings and to further investigate its role in AF and other cardiovascular disease states (CAD and CHF).
Weight loss either through healthy lifestyle, diet and exercise or via bariatric surgery has demonstrated reduction in EAT. Our current CV therapeutic armamentarium fails to target the adipose tissue. EAT may be a novel target to reduce the risk of AF and its recurrence.
Abstract Presented at American Heart Association 2014
Epicardial adipose tissue volume predicts extent of left atrial fibrosis in patients with atrial fibrillation.”
Other co-authors of the study, all at Loyola, are Bassel Sayegh, MD; Andrew Stiff, MD; Brian Vetter, MS; Kim Chan, MBBS; Tonye Teme, MD; and senior author David Wilber, MD.