Simultaneous assessment of myocardial perfusion and adrenergic innervation in patients with heart failure by low-dose dual-isotope CZT SPECT imaging

In patients with heart failure (HF) sequential imaging studies have demonstrated a relationship between myocardial perfusion and adrenergic innervation. We evaluated the feasibility of a simultaneous low-dose dual-isotope 123 I/ 99m Tc-acquisition protocol using a cadmium-zinc-telluride (CZT) single-photon emission computed tomography (SPECT) camera. Thirty-six patients with HF underwent simultaneous low-dose 123 I-metaiodobenzylguanidine (MIBG)/ 99m Tc-sestamibi gated CZT-SPECT cardiac imaging. Perfusion and innervation total defect sizes and perfusion/innervation mismatch size (defined by 123 I-MIBG defect size minus 99m Tc-sestamibi defect size) were expressed as percentages of the total left ventricular (LV) surface area. LV ejection fraction (EF) significantly correlated with perfusion defect size ( P < .005), innervation defect size ( P < .005), and early ( P < .05) and late ( P < .01) 123 I-MIBG heart-to-mediastinum (H/M) ratio. In addition, late H/M ratio was independently associated with reduced LVEF ( P < .05). Although there was a significant relationship ( P < .001) between perfusion and innervation defect size, innervation defect size was larger than perfusion defect size ( P < .001). At multivariable linear regression analysis, 123 I-MIBG washout rate (WR) correlated with perfusion/innervation mismatch ( P < .05). In patients with HF, a simultaneous low-dose dual-isotope 123 I/ 99m Tc-acquisition protocol is feasible and could have important clinical implications.