Comparison of CZT SPECT and conventional SPECT for assessment of contractile function, mechanical synchrony and myocardial scar in patients with heart failure

Aim The aim of this study was to compare CZT-SPECT (CZT SPECT) to conventional SPECT (C-SPECT) in the assessment of left ventricular myocardial scar, contractile function, and mechanical synchrony in patients with heart failure (HF). Methods Fifty-nine patients with HF who were referred for myocardial perfusion/metabolism imaging were enrolled. All patients underwent resting 99m Tc-MIBI gated myocardial perfusion imaging using a CZT SPECT camera and a C-SPECT camera, respectively, and 18 F-FDG PET myocardial metabolism imaging within three days. Summed rest score (SRS) and total perfusion defect (TPD) (as indices of perfusion abnormality), left ventricular (LV), end diastolic volume (EDV), end systolic volume (ESV), and ejection fraction (EF) (as indices of LV systolic function), and histogram band width (BW) and standard deviation (SD) (as indices of mechanical synchrony) were analyzed by automated software while the perfusion/metabolism patterns were analyzed visually. Results There was a good correlation between CZT SPECT and C-SPECT for SRS and TPD. CZT SPECT tended to underestimate SRS and TPD compared to C-SPECT. CZT-SPECT and C-SPECT showed excellent agreement in assessing the perfusion/metabolism pattern though a small proportion of normal segments (6.6%) identified by CZT/PET exhibited mismatch pattern on C-SPECT/PET. CZT SPECT also showed excellent correlation with C-SPECT in measuring EDV, ESV, and EF. Finally, BW and SD measured by CZT SPECT correlated well with C-SPECT but CZT SPECT tended to overestimate BW and SD compared to C-SPECT. Conclusion CZT SPECT provided comparable data to C-SPECT for measuring LV scar, function and synchrony at a considerable reduction in imaging time. CZT SPECT holds a promise for comprehensive evaluation of myocardial performance in patients with HF.