Both minimal left atrial volume index (LAVImin) by 2-dimensional and 3-dimensional echocardiography (2DE and 3DE) can predict future cardiac outcomes, but 3D LAVImin seemed to be a stronger and more additive predictor than 3D maximal left atrial volume index (LAVImax). These findings were published online Sept. 4 in JACC: Cardiovascular Imaging.

“[T]he aims of this study were to establish a normal range of LAVImax and LAVImin and their cutoff values (mean +2 SD) in normal controls using 2DE and 3DE and to evaluate the utility of these cutoff criteria to predict future major cardiovascular events (MACE) and cardiac death in a larger number of patients,” explained the authors, led by Victor Chien-Chia Wu, MD, of the University of Occupational and Environmental Health in Kitakyushu, Japan.

The researchers randomly selected 556 patients with cardiovascular disease who underwent 2DE and 3DE from a 3DE database. As controls, they selected 124 healthy adults. In the control group, they evaluated age and sex dependency of LAVIs using 2DE and 3DE and determined cutoff values. In the cardiovascular disease group, they conducted 2DE and 3DE LAVImax/LAVImin. After eliminating some participants on the basis of age and certain heart conditions, they followed the remaining 439 and assessed for MACE.

In the control group, 2D and 3D LAVI were independent of age and sex. In the cardiovascular disease group, after an average of 2.5 follow-up years, MACE occurred in 88 patients with 32 cardiac deaths.

All four cutoff criteria (36 ml/m² for 2D LAVImax, 18 ml/m² for 2D LAVImin, 33 ml/m² for 3D LAVImax and 18 ml/m² LAVImin) were significantly and independently associated with MACE. However, 3D LAVImin yielded the highest risk ratio. 3D LAVImin was a slightly better predictor than 3D LAVImax.

“This is in agreement with previous studies that showed that LAVImin is more reflective of chronic LV [left ventricle] diastolic pressure/volume overload and is a better predictor of cardiac events than LAVImax,” the authors explained.

Overall, they found that 3D LAVImin tended to be the best predictor of MACE among high-risk patients.

“Thus, it should be useful to establish 3D LAVImin as the best predictor in larger, multicenter, prospective study,” they concluded.