Comparisons of Left Atrial Functional Parameters with Left Ventricular Diastolic Dysfunction in a Large Taiwanese Population with Normal Left Ventricular Ejection Fraction According to Age

Background: Recent studies have shown that left atrial (LA) volume is a sensitive morphophysiological indicator of the severity of LV dysfunction and may also be a useful index of cardiovascular risk. In this study, we performed comparisons among left atrial (LA) functional parameters for predicting age-related diastolic dysfunction. Methods: Echocardiography was performed in 2248 healthy participants with a low possibility of heart disease according to the decennium of age, and reference values were established. Progressive diastolic dysfunction paralleled increasing age and could be well identified by traditional and advanced echocardiographic parameters, including mitral inflow pattern, tissue Doppler parameters, and LA volume. Results: Regarding LA functional parameters analyzed based on the decennium of age, left atrial ejection fraction (LAEF) and emptying fraction could not represent aging diastolic dysfunction well, but LA expansion index ((Vol(max)-Vol(min)) X 100%/Vol(min)) could. Vol max indicated maximal LA volume and Vol mm indicated minimal LA volume. In assessments of diastolic dysfunction with receiver operating characteristic curve analysis, the best cut-off value of LA expansion index was < 100%, with an area under the curve (AUC) of 0.86, sensitivity of 80%, and specificity of 74%. LAEF < 30% (AUC 0.76, sensitivity 67%, specificity 70%) and LA emptying fraction < 50% (AUC 0.80, sensitivity 72%, specificity 71%) were also useful but performed less well. Conclusions: Compared with other LA functional parameters, LA expansion index can well represent age-related diastolic dysfunction.