Impact of BMI on Left Atrial Strain and Abnormal Atrioventricular Interaction in Patients With Type 2 Diabetes Mellitus: A Cardiac Magnetic Resonance Feature Tracking Study

BACKGROUND Type 2 diabetes mellitus (T2DM) and obesity often coexist and together contribute to left atrial (LA) functional abnormalities. However, little is known about the impact of body mass index (BMI) on LA strains measured using cardiac magnetic resonance feature tracking (MR-FT). PURPOSE To investigate the additive effect of BMI on LA functional remodeling using MR-FT as well as to explore abnormal atrioventricular interaction in T2DM patients. STUDY TYPE Retrospective. POPULATION One hundred and fifty-nine T2DM patients (53, 34, and 72 normal-weight, overweight, and obese individuals) and 105 non-diabetic controls (46, 32, and 27 normal-weight, overweight, and obese individuals). FIELD STRENGTH/SEQUENCE 3.0 T/balanced steady-state free precession. ASSESSMENT LA reservoir strain (es ), conduit strain (ee ), and active strain (ea ) and their corresponding strain rates (SRs, SRe, SRa) were measured together with left ventricular (LV) radial, circumferential, and longitudinal peak strain, peak systolic strain rate, and peak diastolic strain rate. STATISTICAL TESTS Student's t-test or Mann-Whitney U test, one-way ANOVA, univariate and multivariate linear regression. A P value <0.05 was considered statistically significant. RESULTS Compared to controls in the same BMI category, T2DM patients had significantly decreased reservoir and conduit function, while pump function was not significantly different (ea and SRa: P = 0.757 and 0.583 for normal-weight, P = 0.171 and 0.426 for overweight, P = 0.067 and 0.330 for obese). LA strains were significantly correlated with BMI (r = -0.346 for es , -0.345 for ee ) in T2DM patients. Multivariable linear regression analysis indicated that BMI was independently associated with LA es and ee , LV global longitudinal strain was independently associated with LA es and ea , and LV circumferential peak diastolic strain rate was independently associated with LA ee . DATA CONCLUSION These findings suggest that the coexistence of increased body weight and T2DM patients can exacerbate the impairment of LA strains and indicate abnormal atrioventricular interactions. LEVEL OF EVIDENCE 3 TECHNICAL EFFICACY: Stage 3.