Comparison of Emory, Cedar Sinai, 4D-MSPECT & Myometrix cardiac softwares for the assessment of left ventricular ejection fraction using Tc99mtetrofosmin gated SPECT with equilibrium radionuclide angiocardiography. Results in Indian patient population

Objectives We compared Emory cardiac toolbox (ECT), Cedar Sinai (CS), 4D-MSPECT (4DM) & Myometrix cardiac softwares for the assessment of Left Ventricular Ejection fraction (LVEF) using Tc99mTetrofosmin Gated SPECT (MPS) and validated the LVEF derived from these four softwares with Equilibrium radionuclide angiocardiography (ERNA) in patients with known/suspected CAD.

Methods A total of 109 patients (80M: 29F; mean age-54.5yrs; median - 54 range: 32-77yrs) were included in the study. 55 patients had known CAD and 54 patients were referred for suspected CAD All the patients underwent ERNA and MPS as per the standard protocol. ERNA was processed using the vendor provided ‘EF analysis’ and gated MPS processed using individual softwares.

Results The mean LVEF on ERNA was 47.9 ± 15.5 % [median-51 range: 13 - 77 %]. The mean LVEF values for ECT, CS, 4D-M and Myometrix were 51.5 ± 19.6 %, 51.0 ± 18.6 %, 57.1 ± 19.3 % and 49.7 ± 19% respectively. On correlation analysis significant positive correlation was observed between LVEF on ERNA and ECT (r-0.842; p<0.0001), CS (r-0.835; p<0.0001), 4D-M (r-0.830; p<0.0001) and Myometrix (r-0.875; p<0.0001). Significant correlation was also seen for LVEFs among the 4 softwares. On ROC analysis using 50% cut-off on ERNA as normal, the normal cut off values of ECT, CS, 4D-M and Myometrix were 56%, 52%, 54% and 51% respectively. McNemar analysis showed that each of the software had its own significance and could less likely be replaced by the other.

Conclusions Good correlation was observed between ECT, CS, 4D-M and Myometrix softwares when compared with ERNA & also among them for assessment of LVEF. However, there are differences in the values generated by the each software which may be taken into account for clinical studies