P558Left atrial strain as a predictor of functional capacity in preserved left ventricular function patients

Introduction: Left atrial function plays an important role in diastolic filling and cardiovascular performance. New imaging tools such as left atrial strain are promising markers of diastolic function. Purpose: Our aim was to determine the contribution of left atrial dynamics in a functional capacity assessed by treadmill stress testing. Methods: A total of 89 patients with preserved left ventricular ejection fraction were studied. Two dimensional echocardiography images were taken before the stress test and patients with inducible ischemia in the stress test were excluded (11 patients). The left atrial longitudinal strain and left atrial strain rate were measured using 2D speckle tracking. Functional capacity was assessed with a treadmill stress test and expressed as metabolic equivalents (METs). We analyzed left atrial strain values with functional capacity through linear correlations (Bonferroni type adjustment). Results: In our group of patients, the relationship between left atrial ejection fraction and METs were not shown to be significant (r=0.11, p=0.34), but atrial strain values were significant predictors of functional capacity. Left atrial strain was significantly related to the diastolic patron, assessed by E/E' valor (r= -0.26, p=0.0269). We found a direct proportional relationship between peak atrial strain measured during the left atrial reservoir phase and METs (r=0.55, p<0.001) and an inverse relationship between the strain rate measured during the conduit phase and METs (r= -0.55, p<0.001). In our sample, we did not find any statistically significant association between E/E' rest with exercise capacity (r= -0.17, p=0.146).