Determinants of left atrioventricular coupling index: The Multi-Ethnic Study of Atherosclerosis (MESA)

International audienceBackground: Recent studies have described a novel left atrioventricular coupling index (LACI), which had a better prognostic value in predicting cardiovascular events than individual left atrial (LA) or left ventricular (LV) variables.Aims: To identify determinants of LACI and its 10-year annual change (ΔLACI), measured by cardiac magnetic resonance (CMR), and to better understand the variables governing this left atrioventricular coupling.Methods: In the Multi-Ethnic Study of Atherosclerosis, 2112 study participants, free from cardiovascular disease at baseline, had LACI assessed by CMR imaging at baseline (LACIBaseline; 2000-2002) and 10 years later (2010-2012). The LACI was defined as the ratio of LA to LV end-diastolic volumes. Linear regression analyses were performed to identify independent determinants of LACIBaseline and ΔLACI.Results: In the 2112 participants (mean age 58.8±9.1 years; 46.6% male), after adjustment for all covariates, age was independently associated with LACIBaseline (R2=0.10, slope=0.16) and ΔLACI (R2=0.15, slope=0.008; both P<0.001). African Americans had the highest LACIBaseline value (18.0±7.7%). Although there was no difference in LACIBaseline between women and men (P=0.19), ΔLACI was higher in women (1.0±1.1 vs 0.8±1.1%/year; P<0.001). Diabetes and higher body mass index (BMI) were independently associated with LACIBaseline (both P<0.001). LACIBaseline was independently associated with LV myocardial fibrosis markers (native T1: R2=0.11, slope=0.09 [P=0.038]; extracellular volume: R2=0.08, slope=0.28 [P=0.035]) and N-terminal prohormone of B-type natriuretic peptide (NT-proBNP) concentration (R2=0.10, slope=-1.11; P