GMPI software packages show varied reference values for left ventricular function in low-risk CAD patients

BackgroundLeft ventricular function and synchronicity parameters are significant for the diagnosis, risk stratification, and prognosis evaluation of cardiovascular diseases. The purpose of this study was to determine the clinical reference values for left ventricular function and synchronicity parameters evaluated by gated myocardial perfusion imaging (GMPI) using three quantitative software packages.MethodsA cohort of 142 consecutive patients with low-risk coronary artery disease who underwent stress gated myocardial perfusion imaging was retrospectively collected. In our center, a portion of subjects were derived from the cadre department, who regularly participate in physical activity. The population was further grouped based on different physical activity levels, i.e., individuals who participated in regular physical activity vs. those who were sedentary. Data on left ventricular function and synchronicity parameters were collected by three quantitative software packages: Corridor 4-dimensional model (4D-M), quantitative gated single-photon emission computed tomography (QGS), and Emory Cardiac Toolbox (ECTb). The left ventricular function parameters included ejection fraction (EF), end-diastolic volume (EDV), and end-systolic volume (ESV). EDV and ESV were corrected for body surface area (BSA) as end-diastolic volume index (EDVI) and end-systolic volume index (ESVI). The clinical reference ranges for left ventricular function and synchronicity parameters in patients with low-risk coronary artery disease were based on 95% CIs.ResultsThere were significant differences in the left ventricular function (EF, EDV, and EDVI) and left ventricular synchronicity parameters obtained by the three quantitative software packages. There were no significant differences in ESV and ESVI. The multiple linear regression analysis showed that gender, age, and BMI were important variables for EDV and ESV. Age and gender were found to be the significant variables for EDVI, ESVI, and EF. For the men, the lower reference range for EF calculated by the three algorithms was 58%, 54%, and 58%, respectively; the upper range for EDV was 135, 116, and 131 mL, respectively; and the upper range of ESV was 51, 49, and 52 mL, respectively. For the women, the lower reference range for EF was 71%, 61%, and 65%, respectively; the upper range of EDV was 99, 86, and 96 mL, respectively; and the upper range for ESV was 28, 28, and 30 mL, respectively. The upper range for BW was 29.7∘, 53.1∘, and 50.9∘, respectively. The upper range for SD was 7.9∘, 17.8∘, and 19.0∘, respectively. The upper range for E obtained by QGS was 47∘. Compared to the women, the men had larger left ventricular volume values, lower mean EF values, and a lower prevalence of having a small heart. There were no differences in left ventricular synchronicity parameters between the men and women. After 1:1 propensity score matching for age and BMI, 37 men and 37 women were matched. The results were consistent before and after propensity score matching.ConclusionThis study determined the clinical reference values for left ventricular function and synchronicity parameters evaluated by GMPI using quantitative software. Compared to the women, EDV, ESV, EDVI, and ESVI in the men were higher, while EF and the prevalence of having a small heart were lower. There were no differences in left ventricular synchronicity parameters between the men and women.