Left atrial function in patients with heart failure with mid-range and preserved ejection fraction

Abstract

Abstract Funding Acknowledgements Type of funding sources: None. Introduction Little is known about the left atrial (LA) function in patients with heart failure with mid-range and preserved ejection fraction (EF). We explored LA function in patients with heart failure with mid-range ejection fraction (HFmrEF) and compared to that in patients heart failure with preserved ejection fraction (HFpEF). Methods A total of 66 HF patients (35 HFpEF and 31 HFmrEF) were included in the study. Left venticular EF, global longitudinal strain (GLS) and the mitral E/e" ratio were measured in all patients. LA function was assesed by measuring phasic changes in LA volume - maximal LA volume, pre-atrial contraction volume and minimal LA volume. All volumes were indexed to body surface area before calculating the indices of LA function: LA total emtying fraction (reservoir function), LA passive emptying fraction (conduit function) and LA active emptying fraction (pump function). Peak LA strain during ventricular systole (S-LAs) and peak LA strain during atrial systole (S-LAa) were measured also as LA functional parameters (reservoir and pump function). Conduit function of LA was derived as difference of S-LAs and S-LAa. LA deformation was also assessed by strain rate at different phases of the cardiac cycle. Strain rate analysis was used to measure peak LA strain rate during ventricular systole (SR-LAs), during early LV filling (SR-LAe) and during atrial contraction (SR-LAa). Results There were no significant differences in GLS and the mitral E/e’ between patients with HFmrEF and HFpEF (p > 0.05 for all). Significantly lower values of LA total emptyng fraction (47.6 ± 13.0 vs 38.9 ± 11.8, p = 0.006), LA passive emptyng fraction (26.6 ± 13,2 vs 20.9 ± 9.4, p = 0.049) and LA active emptyng fraction (33.0 ± 10.0  vs. 26.0 ± 9.7, p = 0.005) were observed  in HFmrEF tham HFpEF patients, respectively. Significantly lower values of S-LAs (27,3 ± 5,8 vs 22,3 ± 8,0, p = 0,004), S-LAa (12,8 ± 4,0 vs  10,3 ± 3,7, p = 0,01) (Figure 1), SR-LAs (1,40 ± 0,42 vs 1,18 ± 0,43, p = 0,045), SR-Lae (-1,47 ± 0,56 vs -1,13 ± 0,51, p = 0,012) and SR-LAa (-1,90 ± 0,50 vs -1,64 ± 0,55, p = 0,044) were obtained in group of HFmrEF patients. Conclusions All components of left atrial function were worse in patients with HFmrEF than in those with HFpEF, despite similar GLS and mitral E/e" ratio. Clinical and prognostic implications of these observations warrant futher research. Abstract Figure.