Role of 3D echocardiography-determined atrial volumes in predicting elevated left ventricular filling pressure

Abstract

Funding Acknowledgements Type of funding sources: Public grant(s) – National budget only. Main funding source(s): Hungarian Government Research Fund, Szív- és érkutatási kiválóságközpont (IRONHEART) Aims Atrial sizes are considered markers of ventricular filling pressures. The studies focused on left atrial (LA) maximum volume (LAV max), however during diastole the left ventricular (LV) diastolic pressure affects the LA minimum volume (LAV min) instead. Therefore, we aimed to test the clinical applicability of atrial volumes measured by transthoracic three-dimensional echocardiography (3DE) in predicting elevated LV filling pressure. Methods Eighty-eight consecutive patients with and without left-sided heart disease were prospectively examined with transthoracic 3DE who underwent right heart catheterization because of clinical indication. Elevated LV filling pressure was determined as the pulmonary artery wedge pressure was higher than 15 mm Hg. The atrial volumes were measured offline with dedicated commercial software. Results Thirty-eight patients (24 males, age 62 ± 8 y) had left-sided heart disease (group A) and 50 (20 males, age 62 ± 15 y) had pulmonary hypertension because of lung disease (Group B). The left atrial indexed maximum (LAVi max) and minimum (LAVi min) volumes were significantly larger in group A than in group B (LAVi max: 64 ± 31 ml/m² vs. 40 ± 22 ml/m², p = 0.001; LAVi min: 51 ± 22 ml/m² vs. 25 ± 21 ml/m², p < 0.0001). The LA minimum volume correlated with the pulmonary artery wedge pressure [r = 0.6 (p < 0.0001) for LAV min vs. r = 0.47 (p < 0.0001) for LAV max]. In the receiver operating characteristic (ROC) curves of parameters predicting the elevated LV filling pressure, the areas under the curve (AUC) for LAVi min and LAVi max were 0.86 (95% CI, 0.79-0.94), 0.79 (95% CI, 0.70-0.89), respectively. The ROC analysis indicated a possible cutoff value of 28 ml/m² for LAVi min to elevated LV filling pressure (AUC = 0.86; sensitivity = 87%, specificity = 74%). Conclusion The left atrial minimum volume measured by transthoracic 3DE is a useful parameter for predicting elevated left ventricular filling pressure.