Performance of 3-dimensional echocardiography in measuring left ventricular volumes and ejection fraction: a systematic review and meta-analysis

Abstract

Objectives: The primary aim of this systematic review is to objectively evaluate the test performance characteristics of three-dimensional echocardiography (3DE) in measuring left ventricular (LV) volumes and ejection fraction (EF).

Background: Despite its growing use in clinical laboratories, the accuracy of 3DE has not been studied on a large scale. It is unclear if this technology offers an advantage over traditional two-dimensional (2D) methods.

Methods: We searched for studies that compared LV volumes and EF measured by 3DE and cardiac magnetic resonance (CMR) imaging. A subset of those also compared standard 2D methods with CMR. We used meta-analyses to determine the overall bias and limits of agreement of LV end-diastolic volume (EDV), end-systolic volume (ESV), and EF measured by 3DE and 2D echocardiography (2DE).

Results: Twenty-three studies (1,638 echocardiograms) were included. The pooled biases ± 2 SDs for 3DE were -19.1 ± 34.2 ml, -10.1 ± 29.7 ml, and - 0.6 ± 11.8% for EDV, ESV, and EF, respectively. Nine studies also included data from 2DE, where the pooled biases were -48.2 ± 55.9 ml, -27.7 ± 45.7 ml, and 0.1 ± 13.9% for EDV, ESV, and EF, respectively. In this subset, the difference in bias between 3DE and 2D volumes was statistically significant (p = 0.01 for both EDV and ESV). The difference in variance was statistically significant (p < 0.001) for all 3 measurements.

Conclusions: Three-dimensional echocardiography underestimates volumes and has wide limits of agreement, but compared with traditional 2D methods in these carefully performed studies, 3DE is more accurate for volumes and more precise in all 3 measurements.

Figure 1. Published Report Selection

This flow sheet describes how the 23 included studies were selected for the meta-analysis. 2D= two-dimensional; 3D = three-dimensional; CMR = cardiac magnetic resonance.

Figure 2. Examples of Three-Dimensional Echocardiographic Analysis Using Mesh and Slices

Volumes can be obtained from three-dimensional echocardiographic (3DE) datasets by 1 of 2 methods. With the first, equally spaced slices are traced in end-systole and end-diastole and combined to obtain volumes (3 traced slices are shown in A to D). The second method uses automated software to generate a 3D mesh from points identified on the 4- and 2-chamber views (E to H).

Figure 3. Three-Dimensional Echocardiography Versus Cardiac Magnetic Resonance

The absolute Bland-Altman difference between 3DE and CMR, expressed as bias ±2 SDs for each substudy. The overall pooled results are shown at the bottom. End-diastolic volume (EDV), end-systolic volume (ESV), and ejection fraction (EF) are shown in A, B, and C, respectively. Abbreviations as in Figures 1 and 2.

Figure 4. 3-Versus 2-Dimensional Echocardiography

Comparison of the Bland-Altman differences (bias ±2 SDs) of 3DE compared with CMR versus that of 2D echocardiography in the 12 substudies that reported on both methods. The overall pooled results are shown at the bottom. EDV, ESV, and EF are shown in A, B, and C, respectively. Abbreviations as in Figures 1 and 3.

Figure 5. Interobserver and Intraobserver Variability

The interobserver and intraobserver reproducibility for 3DE-derived EDV (expressed as mean difference between observations and/or average) are shown for 20 substudies (5 also reported results for 2D echo). Interobserver and intraobserver reproducibilities are shown in A and B, respectively. Abbreviations as in Figure 3.