Three-dimensional Versus Two-dimensional Strain for the Assessment of Myocardial Function: A Case Series

Abstract

Introduction: Two-dimensional (2D) strain assessment is an important diagnostic and prognostic tool in various clinical conditions, particularly coronary artery disease (CAD). However, these measurements are limited in that the information is obtained in only a single plane (2D). Three-dimensional (3D) strain tracks the myocardium in all 3D, potentially overcoming the limitation of 2D strain. The objective of this study was to establish normal values for 3D strain in a population of healthy, normal controls and to compare these values with 2D strain values. In addition, we sought to evaluate the utility of 3D strain in patients with known or suspected CAD. Methods: We conducted a prospective study at a single major tertiary care center. Individuals were recruited for the study and divided into two groups: a normal control group and a CAD group. Global longitudinal strain (GLS) and global circumferential and global radial strain were calculated by both 2D and 3D strain methods. In addition, 3D was used to calculate area strain. Results: We enrolled a total of 43 individuals (20 normal control group, mean age 33 ± 2.7 years, and 23 CAD group, mean age 57 ± 2.8 years, 80% male). Values for 3D strain were consistently lower for GLS and global circumferential strain in both groups compared with 2D measurements. In the control group, the mean 2D GLS was −20 ± 1.6% versus −17.5 ± 1.5% for 3D GLS (P < 0.001). Similarly, the mean 2D circumferential strain was −17.7 ± 2.3% versus −15.6 ± 2.1% for 3D circumferential strain (P < 0.001). Combining both groups, the sensitivity of GLS for CAD was 80% for 2D versus 93% for 3D. Similar findings were seen for global circumferential strain (sensitivity 87% for 2D vs. 100% for 3D). However, the sensitivity of 3D global radial strain was lower (93% for 2D vs. 47% for 3D). 3D strain data were acquired in a shorter time span compared with 2D (2.2 ± 1 min vs. 3 ± 1 min). Conclusions: 3D strain assessment of longitudinal and circumferential strain is similar but mildly reduced compared with 2D techniques, with similar sensitivity for CAD. Radial strain measurements by 3D, however, are not accurate and correlate poorly with 2D.