Association between left atrial function using multimodality tissue tracking from cine MRI and myocardial scar in the multi-ethnic study of atherosclerosis (MESA)

Background Left atrial (LA) function is strongly related to left ventricular (LV) filling pressures and has shown association to cardiovascular outcomes. A recently developed speckle tracking technique can assess LA deformation using CMR cine sequences. Myocardial scar assessed by late gadolinium enhancement (LGE-CMR) relates to cardiac remodeling, but its association to LA function is unknown. We explored the relationship of LA function with the amount of myocardial scar. Methods A total of 1666 participants from the MESA, age range 55-94 yrs, underwent LGE-CMR using 1.5T scanners at six field centers. Myocardial scar was visually detected, classified (ischemic/non-ischemic), and quantified using semi-automated methods in 136 participants. The amount of scar was quantified as the ratio of scar mass over total LV mass and values greater than 5% were defined as clinically significant. LA function was evaluated using multimodality tissue tracking (MTT) from SSFP 2- and 4-chamber long-axis cine CMR images in all participants with myocardial scar and in an age and gender matched control group of 136 participants without scar. LA function was assessed using peak longitudinal strain (Smax), diastolic longitudinal strain rate (SRdia), ejection fraction (LAEF), emptying fraction (LAEmF), and LA maximum volume (Vmax). Wilcoxon rank-sum test was used to evaluate differences between groups: control, scar>5%, and scar<5%. Pearson’s correlation assessed the relationship between the amount of scar and LA function parameters. Results