Assessment Of Left Ventricular Volumes And Ejection Fraction Measured By Gated SPECT: Comparison With LV Angiography And Echocardiography

Objectives: The aim of this study was to validate the accuracy of gated ^99mTc-MIBI SPECT in assessing left ventricular (LV) volume and ejection fraction (EF) by comparison with monoplane LV angiography and M-mode echocardiography. Furthermore, the small hearts error and effection was analyzed in comparison with LV angiography and M-mode echocardiography.Methods: Thirty [18M,12F,mean age56.97 ±10.78(31-76)] in-patients with suspected or known coronary artery disease were examined using rest gated ^99mTc-MIBI SPECT(8 gates/cardiac cycle).EDV, ESV and LVEF were calculated using QGS.Within one week, LV angiography and two-dimensional echocardiography were performed in all patients. EDV, ESV, and LVEF were calculated using Simpson's rule algorithm for monoplane LV angiography, using M-mode method for two-dimensional echocardiography. All values of each method were detected for twice. The patients were divided into 2 groups: 9 patients with small hearts(ESV≤25ml)and 21 patients with large hearts(ESV>25ml).Results: There is a good correlation between results of gated ^99mTc-MIBI SPECT and LV angiography: EDV(r=0.811), ESV(r=0.968), and LVEF(r=0.863). P<0.001. Gated SPECT underestimated EDV, LVEF significantly compared with LV angiography (EDVspect=94.2ml, EDVlvag=137.2ml; LVEFspect=57.73%, LVEFlvag=71.40%, P<0.05). Whereas similar in ESV (ESVspect =44.7ml, ESVlvag=45.4ml). Correlation between results of gated ^99mTc-MIBI SPECT and echocardiography was high for EDV(r=0.871), ESV(r=0.920),and LVEF(r=0.694), P<0.001.Only EDV detected with SPECT were lower than with echocardiography (EDVspect vs. echo=94.2ml vs. 120.0ml,P<0.05). ESV and LVEF differ slightly(ESVspect vs. echo=44.7ml vs. 46.2ml, LVEFspect vs.echo=57.73% vs.64.60%).Best reproducibility was seen in SPECT(r-EDV=0.9996 , r-ESV=0.9996 , r-LVEF=0.9997, P<0.0001). Agreement between methods were acceptable but Bland-Altman limits of agreement ranged widely.Of the 9 patients with small hearts, there was no statistically significant correlation between G-SPECT and others(either LV-angiographic or ultrasound).the EDV and LVEF were overestimated by LV angiography method compared with the results obtained with G-SPECT(EDVlvag vs. spect=103.56ml vs.53ml;LVEFlvag vs.spect =87% vs.70%).Conclusion: EDV, ESV and LVEF determined by Gated ^99mTc-MIBI SPECT have good reproducibility, excellent correlation and an fair limit agreement with LV angiography and echocardiography, but there is more or less underestimation in the value of EDV and LVEF...