Influence of gender, age and weight on the cardiac functional parameters determined by gated myocardial SPECT imaging in patients with low-likelihood coronary heart disease

Abstract

Objective To derive reference limits of cardiac functional parameters (CFP) determined by gated myocardial SPECT imaging, and to analyze the influence of gender, age and weight on CFP. Methods One hundred and seventy-five consecutive outpatients (89 males with age of (48.3±10.7) years and 86 females with age of (49.8±10.4) years) were defined as patients with low-likelihood coronary heart disease (LCHD). All patients underwent adenosine or exercise stress 99Tcm-MIBI G-MPI from February 2008 to April 2011. The EF, EDV and ESV of the left ventricle were measured by quantitative gated SPECT (QGS) software. The reference limits were derived by means of Gaussian distribution or percentiles. The influence of gender, age and weight on CFP was analyzed by multiple regressions for linear models. Two-sample t test was used to analyze data of 2 groups. Parameters between different age groups were compared by one-way analysis of variance. Results The lower reference limit of EF for males was 50%, the upper limit of EDV and ESV was 112 ml and 49 ml respectively. For females, the corresponding reference limits were 54%, 77 ml and 30 ml. Men had higher EDV, ESV (EDV: (75.8±18.3) ml vs (53.3±11.7) ml, t=9.35, P 0.05). For females, EDV was not different (F=2.408, P>0.05), while ESV and EF were significantly different among 3 groups (F values: 5.010, 6.229, both P<0.05). Conclusions The CFP determined by G-MPI in LCHD patients are significantly affected by gender and age. The age-related changes of CFP in males are different from those in females. Key words: Coronary disease; Ventricular function; Myocardial perfusion imaging; Tomography, emission-computed, single-photon; Technetium Tc 99m sestamibi