Effect of Weight Loss on Early Left Atrial Myopathy in People With Obesity But No Established Cardiovascular Disease

Abstract

Background Obesity is associated with left atrial (LA) remodeling (ie, dilatation and dysfunction) which is an independent determinant of future cardiovascular events. We aimed to assess whether LA remodeling is present in obesity even in individuals without established cardiovascular disease and whether it can be improved by intentional weight loss. Methods and Results Forty‐five individuals with severe obesity without established cardiovascular disease (age, 45±11 years; body mass index; 39.1±6.7 kg/m2; excess body weight, 51±18 kg) underwent cardiac magnetic resonance for quantification of LA and left ventricular size and function before and at a median of 373 days following either a low glycemic index diet (n=28) or bariatric surgery (n=17). Results were compared with those obtained in 27 normal‐weight controls with similar age and sex. At baseline, individuals with obesity displayed reduced LA reservoir function (a marker of atrial distensibility), and a higher mass and LA maximum volume (all P0.05). Conclusions Obesity is linked to subtle LA myopathy in the absence of overt cardiovascular disease. Only larger volumes of weight loss can completely reverse the LA myopathic phenotype.

Keywords

• left atrial myopathy
• obesity
• reservoir strain
• weight loss