Simultaneous assessment of myocardial perfusion and adrenergic innervation in patients with heart failure by low-dose dual-isotope CZT SPECT imaging
Roberta Assante, Adriana D’Antonio, Teresa Mannarino, Carmela Nappi, Valeria Gaudieri, Emilia Zampella, Pietro Buongiorno, Valeria Cantoni, Roberta Green, Nicola Frega, Hein J. Verberne, Mario Petretta, Alberto Cuocolo, Wanda Acampa
Abstract
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.