Assessment of myocardial adrenergic innervation with a solid-state dedicated cardiac cadmium-zinc-telluride camera: First clinical experience

Abstract

AimsTo investigate the relationships between regional adrenergic innervation heterogeneity, myocardial perfusion, and contractile function obtained by means of a low-dose imaging protocol with a cadmium-zinc-telluride (CZT) dedicated camera.MethodsTwenty-eight patients with or without ischaemic heart disease underwent 123I-metaiodobenzylguanidine (MIBG) planar scintigraphic and CZT early and delayed evaluations followed by 99mTc-tetrofosmin rest gated CZT with a single-day protocol. The heart-to-mediastinum ratio and the washout rate were computed from planar 123I-MIBG images. The summed 123I-MIBG defect scores (SS-MIBG) were semi-quantitatively assessed from CZT images. The summed rest score (SRS), summed motion score (SMS), and summed thickening score (STS) were quantitated from 99mTc-tetrofosmin images.ResultsSixteen patients showed a depressed left ventricular systolic function [ejection fraction (EF)<50%]. They presented higher SRS (P = 0.007), SMS (P < 0.001), STS (P < 0.001), and early SS-MIBG (P = 0.007) values than those with normal contractile function. Interestingly, higher early SS-MIBG values, index of regional sympathetic innervation heterogeneity, clustered with more elevated SRS (P = 0.023), and more impaired measures of regional and global left ventricle systolic function, i.e. SMS (P = 0.046), STS (P = 0.014), and EF (P = 0.027). At multivariate analysis, a higher SRS (P = 0.039) remained the only independent predictor of more elevated early SS-MIBG values. In the 20 of 28 ischaemic patients, the correlations between early SS-MIBG and SMS (P = 0.017) and also STS (P = 0.036) were further confirmed. The effective dose of the investigation was 4.2 ± 0.72 mSv.ConclusionsAn altered early SS-MIBG, assessed with a low-dose imaging protocol and a CZT cardiac camera, identifies patients with more impaired myocardial perfusion and contractile function. © 2014 Published on behalf of the European Society of Cardiology. All rights reserved.