Usefulness of Right Ventricular Ejection Fraction by First Pass Radionuclide Angiography and Gated SPECT Myocardial Perfusion Imaging in Patients with Heart Failure: One Center Experience

Purpose: Right ventricular ejection fraction (RVEF) is a strong predictor of adverse outcomes in patients with heart failure and LV dysfunction. RVEF calculated by first pass radionuclide ventriculography (FPRNA) has been almost neglected and replaced by other modalities. This study aimed to renovate the use of FPRNA as part of gated SPECT MPI, in order to assess perfusion, dyssynchrony and function of right and left ventricles. The prognostic value of RVEF was assessed.

Methods: In a prospective study, patients with systolic LV dysfunction referred for gated SPECT, underwent FPRNA by Tc 99m sestamibi prior to gated SPECT MPI. FPRNA was done by a dedicated cardiac system with a general purpose collimator while gated SPECT was done with high resolution collimator. Patients with LVEF < 40%, were studied. RVEF was correlated to LV variables, scar size, location of scar and LV dyssynchrony parameters .The patients were followed for all cause mortality.

Results: There were 214 patients with mean age 66 ± 10, 91% men. Mean LVEF was 26%±8, RVEF 49 %±12, infarct size (score 0-4) 3.1±1.8, NYHA class 2.4±0.7 and LV dyssynchrony by phase SD was 59±21. RV dysfunction (RVEF<40%) was demonstrated in 44 (20.6%) patients. RVEF demonstrated significant correlation with NYHA class, LVEF, LV EDV and ESV but there was no correlation with infarct size, septum scar, and LV dyssynchrony. During 464±256 days of follow up, there were 27 (12.6%) deaths. In Cox regression analysis, NYHA class and RVEF were the only independent predictors of all cause death (2.306 14, CI 95% 1.120-4.746; p=0.023) and RVEF 0.968, CI 0.938-1.000, p=0.048).

Conclusion: RVEF by FPRNA with gated SPECT in patients with LV dysfunction is useful and can be done as one stop shop. In addition to NYHA, RVEF was the only independent predictor of death in patients with LV systolic failure.