Correlation between Obesity and Left Atrial Enlargement in Patients Using Cardiac Magnetic Resonance

Objective: The correlation between left atrial (LA) enlargement and obesity has been previously reported. However, most studies primarily evaluated LA diameter using echocardiography, which is less accurate and reliable than assessing LA volume with cardiac magnetic resonance (CMR). This study aimed to explore the correlation between obesity and LA volume by using CMR imaging. Materials and Methods: We prospectively enrolled consecutive eligible patients aged 18 years or older who underwent CMR at a tertiary academic hospital. Clinical variables, including body mass index (BMI), were collected from the medical records. LA volume classification was based on the current guideline recommendations. Results: A total of 140 patients (41% men), with a mean age of 66.5 ± 10.5 years, were studied. The mean BMI was 25.7 ± 4.2 kg/m₂. CMR parameters revealed an LA volume of 75.7 ± 22.5 mL, a left ventricular (LV) ejection fraction of 71.1 ± 9.5%, and an LV mass index of 46.1 ± 27.4 g/m₂. Univariable analysis indicated that the factors affecting LA volume included BMI (r = 0.3, p < 0.001), LV mass index (r = 0.3, p = 0.001), waist circumference (r = 0.3, p < 0.001), male sex (p = 0.01), and hypertension (p = 0.01). In stepwise multivariable analysis, BMI (p < 0.001), LV mass index (p = 0.02), and male sex (p = 0.03) were independently associated with LA volume. Conclusion: Obesity, as represented by BMI, was independently associated with LA enlargement. Other independent factors correlated with LA volume included the LV mass index and male sex.