Abstract 14081: Predictors of Left Atrial Ejection Fraction in Patients With Nonischemic Cardiomyopathy

Abstract

Background: The impact of cardiomyopathy on left atrial function is currently unclear. The aim of this study was to assess the predictors of left atrial function in patients with non-ischemic dilated cardiomyopathy (NICM) utilizing cardiovascular magnetic resonance (CMR) assessment. Methods: We evaluated 251 NICM patients who underwent CMR in our study, between 12/2008 - 1/2014. LA volumes were measured by the modified biplane method from 2- and 4-chamber long axis views at end-systole and end-diastole. Left atrial ejection fraction (LAEF) was calculated. Multivariable linear regression was performed to determine significant covariate associations with LA EF. Results: We studied 251consecutive patients (61 % male), mean age of 52.5 ± 15.5 years . The results of the multivariable linear regression are provided in Figure 1. Younger age, female sex, and less myocardial fibrosis were significantly associated with higher LAEF (p=0.008, p= 0.004, and p= 0.031, respectively). Additionally, increasing left ventricular end diastolic volume index (LVEDVi) and left ventricular ejection fraction (LVEF) was significantly associated with increasing LAEF (both with a significance of p<0.0001). Increased LA volume index (LAVi) was significantly associated with decreased LAEF (p<0.0001). Of note, there was a trend towards less mitral regurgitation fraction being significantly associated with higher LA EF, but did not demonstrate a significant effect on the LAEF (p=0.083). Similarly, right ventricular size and function were not significantly associated with LA EF. Conclusions: In patients with NICM, age, sex, LVEDVi, LVEF, myocardial fibrosis, and LAVi were independently associated with LAEF. Keywords: Nonischemic cardiomyopathy, left atrial ejection fraction, left atrial function, cardiovascular magnetic resonance