Abstract 9874: Correlation of Left Ventricular Strain Derived From Rb-82 ECG-Gated PET Myocardial Perfusion Imaging vs 2D Echocardiography

Abstract

Introduction: Global longitudinal strain (GLS) by two-dimensional (2D) transthoracic echocardiography (TTE) is a robust index for identifying early left ventricular (LV) myocardial dysfunction. Positron emission tomography (PET) myocardial perfusion imaging (MPI) is widely used in the assessment of ischemic heart disease (IHD) but has not been used for strain analysis. Hypothesis: Longitudinal, radial, and circumferential myocardial strain measures at rest and at pharmacologic stress by Rb-82 ECG-gated PET MPI are correlated to those measured by resting 2D TTE. Methods: We developed a novel PET MPI method to track the LV myocardium throughout the cardiac cycle processed in the Emory Cardiac Toolbox, to measure LV strain from longitudinal, radial, and circumferential direction at regadenoson-stress and at rest. We retrospectively identified 80 patients who underwent Rb-82 PET MPI and also had TTE with strain analysis within 3 months. The agreement between LV strain and LVEF derived from PET MPI and resting TTE was assessed with Bland-Altman analysis, Pearson’s correlation, and the concordance correlation coefficient (CCC). Results: PET MPI derived measurements of longitudinal (Figure 1A-1B: Bland-Altman analysis; 1C-1D: Pearson’s correlations), circumferential (Figure 1E-1F: Pearson’s correlations) and radial (Figure 1G-1H: Pearson’s correlations) strain measures at rest and stress were strongly correlated to resting TTE derived GLS (p<.001). LVEF showed strong correlations at stress (0.83, p<.001) and rest (0.80, p<.001). Inter-observer agreements of PET MPI strain measures showed high correlation between 2 independent observers for all 3 directions (p<.001). Conclusions: LV strain measures by PET MPI using a novel automated technique correlated strongly with GLS by TTE. PET MPI measures are highly reproducible. Strain by PET MPI should be investigated further to establish its value in routine clinical practice.