Clinical validation of the gated blood pool SPECT QBSS® processing software in congestive heart failure patients:: correlation with MUGA, first-pass RNV and 2D-echocardiography

Introduction: Left (LVEF) and right ventricular ejection fraction (RVEF) as well as LV regional wall motion at rest are valuable tools to monitor and tailor treatment of congestive heart failure (CHF) patients. Gated blood pool SPECT (GBPS) is under evaluation as an "all-in-one" technique, providing information on LVEF, RVEF, and wall motion derived from a single examination. Aim of the study was to evaluate a commercially available automated GBPS processing software for EF measurements and wall motion analysis in heart failure patients. Methods: Thirty-two patients (12 female; mean age +/- SD: 53 +/- 13 years), suffering from dilated (63%), ischemic (25%) or hypertrophic (13%) cardiomyopathy, were studied. First-pass radionuclide ventriculography (FP-RNV), planar multigated radionuclide angiography (MUGA), and GBPS were performed at rest after in vivo labeling of red blood cells, and LVEF and RVEF was calculated with each method. Later on the same day LVEF was calculated by echocardiography. LV wall motion (summed motion score and wall motion index) was derived from GBPS and echocardiography using the standard 16-segment model. Results: Mean LVEF measured by GBPS, echocardiography, MUGA and FP-RNV was 33 +/- 13%, 37 +/- 15%, 41 +/- 14% and 45 +/- 13%, respectively. LVEF values calculated from GBPS showed moderate to good correlation with FP-RNV (r=0.61), MUGA (r=0.65) and ECHO (r=0.74; all p < 0.01). Mean RVEF calculated by GBPS, FP-RNV and MUGA was 45 +/- 14%, 46 +/- 9% and 38 +/- 9%, respectively. RVEF values calculated from GBPS showed weak correlation with FP-RNV (r=0.33) and MUGA (r=0.26; all p=n.s.). Assessment of GBPS wall motion was qualitatively possible in all patients. The agreement between GBPS and ECHO was 82% (kappa=0.73). The wall motion index showed good correlation between both methods (r=0.88; p < 0.001). Conclusion: An automated algorithm for LVEF calculation and wall motion analysis using GBPS is feasible for clinical routine diagnostic in CHF patients. The RVEF calculation method needs to be improved before routine clinical application can be recommended.