1326025 - Ventricular-Atrial Coupling in Subjects with Normal, Preserved and Reduced Left Ventricular Ejection Fraction: Insights from Cardiac Magnetic Resonance Imaging

 Left atrial (LA) structure and function can be indicators for predicting adverse cardiac events and is determined by left ventricular (LV) function and volume ratio of the 2 cavities in subjects without pathology disturbed. Herein, we assess the correlation between LA and LV measurements in different clinical scenarios and evaluate what extent LA deformation contributes to prognosis compared to LV typical indicators.

Methods:

 A total of 297 consecutive participants including 75 healthy individuals, 75 hypertrophic cardiomyopathy (HCM) patients, 74 idiopathic dilated cardiomyopathy (DCM) and 73 chronic myocardial infarction (MI) patients were retrospectively enrolled in this study. Associations of LA-LV coupling with clinical status were statistically analyzed by correlation, multiple linear regression, logistic regression. Survival estimates were calculated by receiver operating characteristic analyses and Cox regression analyses.

Results: Overall, moderate correlations were found between LA and LV strain in every phase of the cardiac cycle (r: -0.598 to -0.580, all p< 0.001). In HCM group, LA strain was not significantly associated with LV strain in systole and early diastole (late diastole: r=-0.428, p< 0.001). Taking into account the clinical and LV correlates, LA strain in systole and late diastole were worse in HCM and DCM group compared to controls and MI group. The slope of the regression line of individual strain-strain curve had significant difference among 4 groups (-1.4±0.3 in controls, -1.1±0.6 in HCM, -1.8±0.8 in idiopathic DCM, -2.4±1.1, all p< 0.05). During a median follow-up of 4.7 years, LA reservoir strain and total LA emptying fraction showed both a good performance to predict primary endpoints with an area under the curve (AUC) of 0.724, respectively 0.720, which were higher than those of LV systolic strain (AUC=0.645) and LV ejection fraction (AUC=0.635).

Conclusion: The coupled correlations between left atria and ventricle in every phase and individual strain-strain curve varies with etiology. LA deformation in systole and late diastole provides prior and incremental information of cardiac dysfunction based on LV metrics. Total LA emptying fraction and reservoir strain are independently indicators for clinical outcome superior to LV typical predictors.