Elsevier

Journal of Nuclear Cardiology

Volume 29, Issue 6, December 2022, Pages 3341-3351
Journal of Nuclear Cardiology

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

https://doi.org/10.1007/s12350-022-02951-4Get rights and content

Abstract

Background

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 123I/99mTc-acquisition protocol using a cadmium-zinc-telluride (CZT) single-photon emission computed tomography (SPECT) camera.

Methods and results

Thirty-six patients with HF underwent simultaneous low-dose 123I-metaiodobenzylguanidine (MIBG)/99mTc-sestamibi gated CZT-SPECT cardiac imaging. Perfusion and innervation total defect sizes and perfusion/innervation mismatch size (defined by 123I-MIBG defect size minus 99mTc-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) 123I-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, 123I-MIBG washout rate (WR) correlated with perfusion/innervation mismatch (P < .05).

Conclusions

In patients with HF, a simultaneous low-dose dual-isotope 123I/99mTc-acquisition protocol is feasible and could have important clinical implications.

Introduction

Cardiac 123I-metaiodobenzilguanidine (MIBG) imaging has a central role in the evaluation of cardiac sympathetic activity, and impairment of innervation status has been correlated to a poor prognosis in patients with heart failure (HF).1 Semiquantitative parameters of 123I-MIBG uptake, such as the heart-to-mediastinum (H/M) ratio and washout rate (WR), indicators of autonomic dysfunction, demonstrated prognostic value in patients with HF.2 Prior studies evaluating myocardial perfusion and adrenergic innervation with two separate single-photon emission computed tomography (SPECT) acquisition procedures demonstrated that quantification of perfusion/innervation mismatch provides information about the trigger zone as a prognostic factor of ventricular arrhythmia.3

The introduction of novel dedicated SPECT cameras with semiconductor cadmium–zinc–telluride (CZT) detectors has enabled significant improvements in spatial, temporal and energy resolution in the acquisition protocols by comparison to conventional Anger cameras.4,5 Phantom and clinical studies have shown good correlation between 123I-MIBG H/M ratio and WR obtained by CZT-SPECT and Anger cameras for single tracer studies.6, 7, 8 The increased energy resolution of CZT-SPECT allows a simultaneous assessment of myocardial perfusion and sympathetic innervation in a single-session, thereby reducing imaging time. Thus, when using a low-dose of 123I-MIBG and 99mTc-labeled tracers, it is possible to considerably reduce radiation exposure.

Recently Blaire et al9 in a phantom study assessing perfusion (99mTc) and innervation (123I) using two commercially available CZT-SPECT cameras demonstrated that a simultaneous dual-isotope (SDI) acquisition is feasible and provides perfectly registered functional images with a reduced imaging time. Prior studies have demonstrated correlation between the impairment of innervation, rest perfusion and mechanical dyssynchrony or diastolic function using sequential perfusion and innervation imaging.10,11 However, no studies are available on the quantitative evaluation of perfusion and adrenergic innervation in patients with HF using a simultaneous acquisition protocol by CZT-SPECT. The aim of our study was firstly to evaluate the feasibility of a simultaneous low-dose dual-isotope 123I/99mTc-acquisition protocol using a CZT-SPECT camera. We also assessed the relationship between myocardial perfusion, adrenergic innervation and left ventricular (LV) function in patients with HF undergoing this protocol.

Section snippets

Patients

Thirty-six consecutive patients with HF referred to 123I-MIBG imaging to evaluate cardiac adrenergic innervation, underwent low-dose SDI imaging acquisition. Heart failure was defined as the presence of typical symptoms (e.g., breathlessness, ankle swelling, and fatigue) and/or evidence of structural and/or functional cardiac abnormality, with preserved (≥ 50%), mid-range (40%-49%) or reduced (< 40%) LV ejection fraction (EF).12 The exclusion criteria were atrial fibrillation, implanted

Patient characteristics

Mean regional 123I-MIBG uptake in controls and patients is reported in Table 1. In controls, tracer uptake was reduced in the inferior region compared to the other regions (P < .05). In patients, both apex and inferior walls showed a lower 123I-MIBG uptake compared to the other regions (P < .01). To rule out that the 123I-MIBG uptake reduction in the inferior region in patients may reflect normal physiology more than pathological patterns, we compared individual uptake and found that in 26

Discussion

To our knowledge this is the first study assessing the feasibility of a low-dose SDI 123I/99mTc single imaging session protocol in patients with HF using CZT-SPECT. It is already known that cardiac CZT-SPECT systems have a twofold improvement in energy resolution, allowing simultaneous dual-isotope acquisition with lower down-scatter of the two isotope photo-peaks as compared to conventional SPECT.15,16 When used in combination, the close photo-peaks of 99mTc- and 123I-isotopes require careful

New knowledge gained

Low-dose CZT-SPECT cardiac imaging may enable rapid assessment of differences in LV perfusion and innervation patterns, possibly better characterizing cardiac functional status with reduced radiation exposure and shorter examination time and an associated quality improvement over single isotope studies.

Conclusions

The extent of both myocardial innervation and perfusion defects are related to a reduction of LV systolic function, and late H/M ratio result was an independent predictor of reduced LVEF. Among parameters of cardiac innervation, WR results significantly correlated to extent of perfusion/innervation mismatch area and this could have important clinical implications.

Funding

Open access funding provided by Università degli Studi di Napoli Federico II within the CRUI–CARE Agreement.

Disclosures

Roberta Assante, Adriana D’Antonio, Carmela Nappi, Teresa Mannarino, Valeria Gaudieri, Emilia Zampella, Valeria Cantoni, Roberta Green, Emanuele Criscuolo, Roberto Bologna, Nicola Frega, Hein J. Verberne, Mario Petretta and Alberto Cuocolo declare that they have no financial conflicts of interest. Wanda Acampa is consultant of D-Spectrum.

References (31)

  • PetrettaM et al.

    Combined assessment of left ventricular function and rest-redistribution regional myocardial thallium-201 activity for prognostic evaluation of patients with chronic coronary artery disease and left ventricular dysfunction

    J Nucl Cardiol

    (1998)
  • AgostiniD et al.

    I-123-mIBG myocardial imaging for assessment of risk for a major cardiac event in heart failure patients: Insights from a retrospective European multicenter study

    Eur J Nucl Med Mol Imaging

    (2008)
  • BellevreD et al.

    First determination of the heart-to-mediastinum ratio using cardiac dual isotope (123I-MIBG/99mTc-tetrofosmin) CZT imaging in patients with heart failure: The ADRECARD study

    Eur J Nucl Med Mol Imaging

    (2015)
  • NakajimaK et al.

    Cross calibration of 123I-meta-iodobenzylguanidine heart-to-mediastinum ratio with D-SPECT planogram and Anger camera

    Ann Nucl Med

    (2017)
  • Ben-HaimS et al.

    Simultaneous dual-radionuclide myocardial perfusion imaging with a solid-state dedicated cardiac camera

    Eur J Nucl Med Mol Imaging

    (2010)
  • Cited by (6)

    The authors of this article have provided a PowerPoint file, available for download at SpringerLink, which summarises the contents of the paper and is free for re-use at meetings and presentations. Search for the article DOI on SpringerLink.com.

    The authors have also provided an audio summary of the article, which is available to download as ESM, or to listen to via the JNC/ASNC Podcast.

    Copyright comment corrected publication 2022

    View full text